diff --git a/VideoMMMU_ASR_large/Art/new_Art_1.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..950a38b8c918c13587cdf5b6168d5aa03ba6e15f --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_1.mp4.txt @@ -0,0 +1,20 @@ +[4.21s -> 16.50s] There are seven elements of art and they could be considered the building blocks of art everything That is created starts from these seven things +[16.85s -> 27.20s] These seven words and their definitions and understanding them are the vocabulary we will use when we describe works of art and talk about things together. +[27.20s -> 32.66s] All of you must be able to define and identify these seven things. +[38.64s -> 52.85s] Line is the first building block or element of art. Line is a path created by a moving point, mark, or object. Line can be straight, swirly, wavy, jagged. +[52.85s -> 66.05s] dotted dashed broken you get the point it can be squiggly or straight it can be diagonal vertical horizontal parallel perpendicular thick thin +[66.05s -> 71.34s] There are many things that can be done with line, as you can see here in these examples. +[88.24s -> 97.33s] Shape is a two-dimensional flat enclosed area. When a line crosses over itself it closes to create a shape. +[97.71s -> 111.63s] There are geometric shapes, like squares, triangles, circles, rectangles, and ovals, and organic shapes, which would be everything else, like a leaf or a butterfly. +[124.75s -> 137.68s] Form is a three-dimensional shape. It has height, width, and depth. It would be something you could walk around. Forms are things like cubes, cylinders, and spheres. +[137.68s -> 146.03s] On a flat surface you can use shading and perspective to make a flat shape turn into a form. +[167.22s -> 177.46s] Value is the lightness or darkness of an object. A black and white object can have value and so can a colored object. +[178.26s -> 191.07s] It is the effect of light and shade in a picture. Some of the words we would use to just to talk about value would be tint and that's when you add white to something or make it lighter and shade. +[191.07s -> 194.61s] which is when you add black to something or make it darker. +[213.33s -> 226.26s] Color, also known as hue, can add interest and mood to pieces of art. The primary colors are red, blue, yellow. There are also secondary colors and tertiary colors. +[226.26s -> 239.54s] You can have warm colors or cool colors, tints, lighter colors or shades, darker colors. And you can use color to add emphasis and interest to your work. +[254.22s -> 267.68s] Texture is how something feels or looks like it would feel if you could touch it. There are two kinds of texture. There's real texture, so that would be like a sculpture you could actually touch. +[267.68s -> 276.82s] implied texture which is when an artist makes something look like it has texture even though you can't feel it +[292.59s -> 304.13s] Space is the element of art that refers to the emptiness or area around or within objects. Positive space refers to the part of the artwork that takes up the space. +[304.13s -> 307.82s] Negative space is the area around that object. +[308.24s -> 321.74s] This element of art also refers to the parts of a picture, so you can have the foreground, middle ground, and background. Perspective is another way to show that there is space and dimension in an artwork. diff --git a/VideoMMMU_ASR_large/Art/new_Art_2.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..950a38b8c918c13587cdf5b6168d5aa03ba6e15f --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_2.mp4.txt @@ -0,0 +1,20 @@ +[4.21s -> 16.50s] There are seven elements of art and they could be considered the building blocks of art everything That is created starts from these seven things +[16.85s -> 27.20s] These seven words and their definitions and understanding them are the vocabulary we will use when we describe works of art and talk about things together. +[27.20s -> 32.66s] All of you must be able to define and identify these seven things. +[38.64s -> 52.85s] Line is the first building block or element of art. Line is a path created by a moving point, mark, or object. Line can be straight, swirly, wavy, jagged. +[52.85s -> 66.05s] dotted dashed broken you get the point it can be squiggly or straight it can be diagonal vertical horizontal parallel perpendicular thick thin +[66.05s -> 71.34s] There are many things that can be done with line, as you can see here in these examples. +[88.24s -> 97.33s] Shape is a two-dimensional flat enclosed area. When a line crosses over itself it closes to create a shape. +[97.71s -> 111.63s] There are geometric shapes, like squares, triangles, circles, rectangles, and ovals, and organic shapes, which would be everything else, like a leaf or a butterfly. +[124.75s -> 137.68s] Form is a three-dimensional shape. It has height, width, and depth. It would be something you could walk around. Forms are things like cubes, cylinders, and spheres. +[137.68s -> 146.03s] On a flat surface you can use shading and perspective to make a flat shape turn into a form. +[167.22s -> 177.46s] Value is the lightness or darkness of an object. A black and white object can have value and so can a colored object. +[178.26s -> 191.07s] It is the effect of light and shade in a picture. Some of the words we would use to just to talk about value would be tint and that's when you add white to something or make it lighter and shade. +[191.07s -> 194.61s] which is when you add black to something or make it darker. +[213.33s -> 226.26s] Color, also known as hue, can add interest and mood to pieces of art. The primary colors are red, blue, yellow. There are also secondary colors and tertiary colors. +[226.26s -> 239.54s] You can have warm colors or cool colors, tints, lighter colors or shades, darker colors. And you can use color to add emphasis and interest to your work. +[254.22s -> 267.68s] Texture is how something feels or looks like it would feel if you could touch it. There are two kinds of texture. There's real texture, so that would be like a sculpture you could actually touch. +[267.68s -> 276.82s] implied texture which is when an artist makes something look like it has texture even though you can't feel it +[292.59s -> 304.13s] Space is the element of art that refers to the emptiness or area around or within objects. Positive space refers to the part of the artwork that takes up the space. +[304.13s -> 307.82s] Negative space is the area around that object. +[308.24s -> 321.74s] This element of art also refers to the parts of a picture, so you can have the foreground, middle ground, and background. Perspective is another way to show that there is space and dimension in an artwork. diff --git a/VideoMMMU_ASR_large/Art/new_Art_4.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..950a38b8c918c13587cdf5b6168d5aa03ba6e15f --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_4.mp4.txt @@ -0,0 +1,20 @@ +[4.21s -> 16.50s] There are seven elements of art and they could be considered the building blocks of art everything That is created starts from these seven things +[16.85s -> 27.20s] These seven words and their definitions and understanding them are the vocabulary we will use when we describe works of art and talk about things together. +[27.20s -> 32.66s] All of you must be able to define and identify these seven things. +[38.64s -> 52.85s] Line is the first building block or element of art. Line is a path created by a moving point, mark, or object. Line can be straight, swirly, wavy, jagged. +[52.85s -> 66.05s] dotted dashed broken you get the point it can be squiggly or straight it can be diagonal vertical horizontal parallel perpendicular thick thin +[66.05s -> 71.34s] There are many things that can be done with line, as you can see here in these examples. +[88.24s -> 97.33s] Shape is a two-dimensional flat enclosed area. When a line crosses over itself it closes to create a shape. +[97.71s -> 111.63s] There are geometric shapes, like squares, triangles, circles, rectangles, and ovals, and organic shapes, which would be everything else, like a leaf or a butterfly. +[124.75s -> 137.68s] Form is a three-dimensional shape. It has height, width, and depth. It would be something you could walk around. Forms are things like cubes, cylinders, and spheres. +[137.68s -> 146.03s] On a flat surface you can use shading and perspective to make a flat shape turn into a form. +[167.22s -> 177.46s] Value is the lightness or darkness of an object. A black and white object can have value and so can a colored object. +[178.26s -> 191.07s] It is the effect of light and shade in a picture. Some of the words we would use to just to talk about value would be tint and that's when you add white to something or make it lighter and shade. +[191.07s -> 194.61s] which is when you add black to something or make it darker. +[213.33s -> 226.26s] Color, also known as hue, can add interest and mood to pieces of art. The primary colors are red, blue, yellow. There are also secondary colors and tertiary colors. +[226.26s -> 239.54s] You can have warm colors or cool colors, tints, lighter colors or shades, darker colors. And you can use color to add emphasis and interest to your work. +[254.22s -> 267.68s] Texture is how something feels or looks like it would feel if you could touch it. There are two kinds of texture. There's real texture, so that would be like a sculpture you could actually touch. +[267.68s -> 276.82s] implied texture which is when an artist makes something look like it has texture even though you can't feel it +[292.59s -> 304.13s] Space is the element of art that refers to the emptiness or area around or within objects. Positive space refers to the part of the artwork that takes up the space. +[304.13s -> 307.82s] Negative space is the area around that object. +[308.24s -> 321.74s] This element of art also refers to the parts of a picture, so you can have the foreground, middle ground, and background. Perspective is another way to show that there is space and dimension in an artwork. diff --git a/VideoMMMU_ASR_large/Art/new_Art_Theory_1.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_Theory_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1a51398ee6e7f380402bbad1b13a84186df6e8e --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_Theory_1.mp4.txt @@ -0,0 +1,54 @@ +[0.00s -> 10.75s] Surrealism. The surrealism was an artistic and literary movement that emerged in the early 20th century aiming to explore the unconscious mind and unleash creativity beyond rationality. +[10.75s -> 25.12s] Led by figures like Andre Breton and Salvador Dali, Surrealists sought to depict dreamlike imagery, juxtaposing unrelated elements in surprising ways to provoke thought and evoke strong emotions. Surrealist artworks often feature fantastical landscapes, +[25.12s -> 32.08s] bizarre creatures and symbolic motifs, inviting viewers to interpret their meanings freely. Romanticism +[32.08s -> 43.01s] The Romanticism art emerged in the late 18th and early 19th centuries as a reaction against the rationalism of the Enlightenment and the strictures of Neoclassicism. It emphasized emotion, +[43.01s -> 52.77s] imagination and individualism, celebrating nature, the sublime and the exotic. Romantic artists often depicted dramatic landscapes, turbulent skies, +[52.77s -> 64.30s] and awe-inspiring natural phenomena to evoke a sense of the sublime and the ineffable. They also explored themes of nationalism, folklore, and mythology celebrating the spirit of freedom and revolution. +[64.59s -> 74.40s] Realism Realism is an artistic movement that emerged in the 19th century primarily in Europe as a reaction against the idealized and romanticized portrayals of life. +[74.40s -> 88.91s] It aimed to depict everyday subjects and situations truthfully, without embellishment or idealization. Realist artists often focused on the lives of ordinary people, depicting their struggles, joys, and environments with meticulous detail and accuracy. +[89.26s -> 101.46s] Minimalism. The minimalism is an art movement that emerged in the 1960s, characterized by extreme simplicity and a focus on fundamental elements like geometric shapes, basic colors, and clean lines. +[101.46s -> 107.47s] artists sought to strip away excess and decoration, creating works that emphasize pure form and presence. +[107.47s -> 117.54s] Minimalist art often invites viewers to engage directly with the physical qualities of the artwork and the surrounding space, encouraging contemplation and reflection. +[117.54s -> 130.19s] The Renaissance art was characterized by a revival of interest in classical Greek and Roman art, leading to a focus on realism, perspective, and humanism. Renaissance artists such as Leonardo da Vinci, Michelangelo, and Raphael +[130.19s -> 144.19s] created works that emphasized accurate depiction of the human form, lifelike expressions, and spatial depth. Their masterpieces, including paintings, sculptures, and architecture, reflected a renewed appreciation for the individual, nature, +[144.19s -> 158.06s] and the pursuit of knowledge. Baroque The Baroque art characterized by dramatic use of light and shadow, intense emotion, and rich, detailed compositions. Baroque artists aim to evoke powerful emotional responses in viewers. +[158.06s -> 169.23s] often employing dynamic compositions and theatrical effects. Religious themes were prevalent, with artists seeking to convey spiritual messages with heightened drama and intensity. +[169.23s -> 179.39s] The Expressionism was an art movement that emerged in the early 20th century, primarily in Germany. It aimed to convey emotional and psychological experiences rather than physical reality. +[179.39s -> 192.11s] Often through distorted or exaggerated forms and vivid colors, expressionist artists such as Edvard Munch and Ernst Ludwig Kirchner sought to evoke intense feelings and explore themes of angst, alienation, and inner turmoil. +[192.11s -> 201.94s] Abstract Expressionism The Abstract Expressionism was a post-World War II art movement that originated in New York City in the 1940s and 1950s. +[201.94s -> 213.33s] It emphasized spontaneous intuitive and emotional expression through abstract forms and gestural brushwork. Artists such as Jackson Pollock, Willem de Kooning, and Mark Rothko were central figures in this movement. +[213.33s -> 226.50s] Abstract expressionists often explored themes of individuality, the subconscious, and the act of painting itself, rejecting traditional representation in favor of conveying raw emotion and inner experience on canvas. Fauvism +[226.50s -> 240.40s] Favism was an early 20th century art movement characterized by bold colors, spontaneous brushwork, and simplified forms. Artists like Henri Matisse and Andre Duran were key figures, emphasizing emotional expression over realistic representation. +[240.56s -> 248.34s] Cubism. The Cubism was an influential art movement pioneered by Pablo Picasso and Georges Braque in the early 20th century. +[248.34s -> 256.62s] It revolutionized traditional artistic representation by breaking down subjects into geometric shapes and depicting multiple viewpoints simultaneously. +[256.62s -> 266.74s] Cubist artworks often feature fragmented forms, abstract shapes, and a flattened perspective, challenging viewers to rethink how they perceive space and form. Classicism +[266.74s -> 276.70s] The classicism refers to a movement in art and literature that draws inspiration from ancient Greek and Roman cultures, particularly their emphasis on harmony, balance, and order. +[276.70s -> 290.85s] It emerged during the Renaissance and experienced revivals in various periods, including the 17th and 18th centuries. Classicism prioritizes clarity, simplicity, and idealized forms rejecting the extravagant ornamentation of preceding styles. +[290.85s -> 301.46s] Artists like Jacques-Louis David and Nicolas Poussin are renowned for their classical works which often depict heroic or mythological themes with a sense of timeless grandeur and dignity. +[301.97s -> 308.82s] Symbolism The symbolism was an artistic and literary movement that emerged in the late 19th century, primarily in France. +[308.82s -> 317.81s] It emphasized the use of symbols and metaphors to evoke emotions, dreams, and spiritual experiences. Symbolist artists such as Gustav Klimt and Odilon Radon +[317.81s -> 332.30s] sought to convey abstract ideas and inner visions rather than represent objective reality. Symbolism often featured dreamlike imagery, mythological motifs, and richly symbolic content exploring themes of mysticism, spirituality, and the subconscious mind. +[332.30s -> 343.71s] Op art. The op art, short for optical art, is a style of visual art that uses optical illusions and geometric patterns to create the impression of a movement, depth, or distortion. +[343.71s -> 354.46s] It often employs contrasting colors and precise, repetitive shapes to stimulate the eye and mind, creating a dynamic and sometimes disorienting visual experience. Futurism +[354.46s -> 368.69s] The Futurism was an avant-garde movement that emerged in Italy in the early 20th century. It celebrated modern technology, speed, and the dynamism of urban life, advocating for the rejection of traditional artistic forms in favor of embracing the future. +[368.69s -> 382.05s] Artists like Umberto Boccioni and Giacomo Balla depicted motion and energy through fragmented forms, dynamic compositions, and vibrant colors. Dada Dada was an avant-garde movement that emerged during World War I. +[382.05s -> 394.53s] originating in Zurich, Switzerland. It rejected traditional artistic conventions and embraced absurdity, chaos, and anti-establishment sentiments. Dadaists like Marcel Duchamp and Tristan Tzara used collage. +[394.53s -> 407.86s] found objects and performance art to challenge the rationality of society and the art world. Dada's legacy lies in its subversion of artistic norms and its influence on later movements such as surrealism and conceptual art. +[408.14s -> 418.53s] Art Nouveau, a late 19th and early 20th century art movement embraced organic forms, flowing lines, and intricate patterns. It emerged as a reaction against the academic art of the time. +[418.53s -> 430.46s] seeking to integrate art into everyday life through architecture, interior design, and decorative arts. Inspired by nature and exotic cultures, Art Nouveau artists like Alphonse Mucha and Hector Guimard +[430.46s -> 436.69s] aimed to create a total aesthetic experience characterized by its sinuous curves and ornamental motifs. +[437.20s -> 448.29s] Impressionism The Impressionism was an art movement in the late 19th century characterized by capturing the fleeting effects of light and atmosphere through loose brushwork and vivid colors. +[448.29s -> 461.60s] It focused on depicting everyday scenes, often outdoors, with an emphasis on conveying the artist's impression rather than precise details. Key artists include Claude Monet, Edgar Degas, and Pierre-Auguste Renoir. Post-Impressionism +[461.60s -> 472.90s] The Post-Impressionism was an art movement that emerged in the late 19th century as a reaction to Impressionism. Artists associated with Post-Impressionism, such as Paul Cézanne, Vincent Van Gogh, and Georges Seurat, +[472.90s -> 483.57s] built upon Impressionist techniques while pushing the boundaries of color, form, and expression. They focused on subjective interpretations of reality using bold colors, distinctive brushwork, +[483.57s -> 495.47s] and innovative compositions to convey emotions and ideas. Rococo The Rococo was an artistic movement that flourished in Europe during the 18th century, particularly in France. +[495.47s -> 509.68s] It is characterized by its ornate and playful style, featuring delicate pastel colors, asymmetrical compositions, and lavish decorations. Rococo art often depicted scenes of leisure, love, and frivolity reflecting the aristocratic culture of the time. +[510.06s -> 520.48s] Neoclassicism The Neoclassicism was an artistic and architectural movement that emerged in the 18th century as a reaction against the excesses of the Rococo style. +[520.48s -> 529.34s] Inspired by the ideals of ancient Greek and Roman art, neoclassical artists sought to revive the classical aesthetic of harmony, proportion, and clarity. +[529.34s -> 542.35s] Rejecting the ornate decoration of the rococo, neoclassical works emphasized clean lines, symmetry, and a return to classical subject matter, such as historical events and mythological themes. Mannerism +[542.35s -> 554.75s] The Mannerism was an art movement that emerged in the late Renaissance period, primarily in Italy during the 16th century. It is characterized by a departure from the balance, harmony, and naturalism of high Renaissance art. +[554.75s -> 567.50s] Mannerist artists deliberately distorted proportions, exaggerated poses, and employed intricate compositions to create a sense of elegance, sophistication, and intellectual complexity in their works. +[567.50s -> 581.02s] The modern art encompasses a wide range of artistic styles and movements that emerged in the late 19th and early 20th centuries, breaking away from traditional forms and techniques. It includes movements like cubism, surrealism, +[581.02s -> 591.82s] abstract expressionism, and pop art among others. Modern art often explores new concepts, materials, and techniques and can be highly experimental and diverse in its expressions. +[592.53s -> 604.45s] Precisionism. Precisionism was an American art movement in the early 20th century known for its precise, detailed portrayal of urban and industrial landscapes. Artists depicted scenes with sharp lines, geometric shapes, and smooth surfaces. +[604.45s -> 613.94s] Capturing the modernization and industrialization of America, this style often emphasized the beauty and order found in architecture, machinery, and infrastructure. diff --git a/VideoMMMU_ASR_large/Art/new_Art_Theory_2.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_Theory_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1a51398ee6e7f380402bbad1b13a84186df6e8e --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_Theory_2.mp4.txt @@ -0,0 +1,54 @@ +[0.00s -> 10.75s] Surrealism. The surrealism was an artistic and literary movement that emerged in the early 20th century aiming to explore the unconscious mind and unleash creativity beyond rationality. +[10.75s -> 25.12s] Led by figures like Andre Breton and Salvador Dali, Surrealists sought to depict dreamlike imagery, juxtaposing unrelated elements in surprising ways to provoke thought and evoke strong emotions. Surrealist artworks often feature fantastical landscapes, +[25.12s -> 32.08s] bizarre creatures and symbolic motifs, inviting viewers to interpret their meanings freely. Romanticism +[32.08s -> 43.01s] The Romanticism art emerged in the late 18th and early 19th centuries as a reaction against the rationalism of the Enlightenment and the strictures of Neoclassicism. It emphasized emotion, +[43.01s -> 52.77s] imagination and individualism, celebrating nature, the sublime and the exotic. Romantic artists often depicted dramatic landscapes, turbulent skies, +[52.77s -> 64.30s] and awe-inspiring natural phenomena to evoke a sense of the sublime and the ineffable. They also explored themes of nationalism, folklore, and mythology celebrating the spirit of freedom and revolution. +[64.59s -> 74.40s] Realism Realism is an artistic movement that emerged in the 19th century primarily in Europe as a reaction against the idealized and romanticized portrayals of life. +[74.40s -> 88.91s] It aimed to depict everyday subjects and situations truthfully, without embellishment or idealization. Realist artists often focused on the lives of ordinary people, depicting their struggles, joys, and environments with meticulous detail and accuracy. +[89.26s -> 101.46s] Minimalism. The minimalism is an art movement that emerged in the 1960s, characterized by extreme simplicity and a focus on fundamental elements like geometric shapes, basic colors, and clean lines. +[101.46s -> 107.47s] artists sought to strip away excess and decoration, creating works that emphasize pure form and presence. +[107.47s -> 117.54s] Minimalist art often invites viewers to engage directly with the physical qualities of the artwork and the surrounding space, encouraging contemplation and reflection. +[117.54s -> 130.19s] The Renaissance art was characterized by a revival of interest in classical Greek and Roman art, leading to a focus on realism, perspective, and humanism. Renaissance artists such as Leonardo da Vinci, Michelangelo, and Raphael +[130.19s -> 144.19s] created works that emphasized accurate depiction of the human form, lifelike expressions, and spatial depth. Their masterpieces, including paintings, sculptures, and architecture, reflected a renewed appreciation for the individual, nature, +[144.19s -> 158.06s] and the pursuit of knowledge. Baroque The Baroque art characterized by dramatic use of light and shadow, intense emotion, and rich, detailed compositions. Baroque artists aim to evoke powerful emotional responses in viewers. +[158.06s -> 169.23s] often employing dynamic compositions and theatrical effects. Religious themes were prevalent, with artists seeking to convey spiritual messages with heightened drama and intensity. +[169.23s -> 179.39s] The Expressionism was an art movement that emerged in the early 20th century, primarily in Germany. It aimed to convey emotional and psychological experiences rather than physical reality. +[179.39s -> 192.11s] Often through distorted or exaggerated forms and vivid colors, expressionist artists such as Edvard Munch and Ernst Ludwig Kirchner sought to evoke intense feelings and explore themes of angst, alienation, and inner turmoil. +[192.11s -> 201.94s] Abstract Expressionism The Abstract Expressionism was a post-World War II art movement that originated in New York City in the 1940s and 1950s. +[201.94s -> 213.33s] It emphasized spontaneous intuitive and emotional expression through abstract forms and gestural brushwork. Artists such as Jackson Pollock, Willem de Kooning, and Mark Rothko were central figures in this movement. +[213.33s -> 226.50s] Abstract expressionists often explored themes of individuality, the subconscious, and the act of painting itself, rejecting traditional representation in favor of conveying raw emotion and inner experience on canvas. Fauvism +[226.50s -> 240.40s] Favism was an early 20th century art movement characterized by bold colors, spontaneous brushwork, and simplified forms. Artists like Henri Matisse and Andre Duran were key figures, emphasizing emotional expression over realistic representation. +[240.56s -> 248.34s] Cubism. The Cubism was an influential art movement pioneered by Pablo Picasso and Georges Braque in the early 20th century. +[248.34s -> 256.62s] It revolutionized traditional artistic representation by breaking down subjects into geometric shapes and depicting multiple viewpoints simultaneously. +[256.62s -> 266.74s] Cubist artworks often feature fragmented forms, abstract shapes, and a flattened perspective, challenging viewers to rethink how they perceive space and form. Classicism +[266.74s -> 276.70s] The classicism refers to a movement in art and literature that draws inspiration from ancient Greek and Roman cultures, particularly their emphasis on harmony, balance, and order. +[276.70s -> 290.85s] It emerged during the Renaissance and experienced revivals in various periods, including the 17th and 18th centuries. Classicism prioritizes clarity, simplicity, and idealized forms rejecting the extravagant ornamentation of preceding styles. +[290.85s -> 301.46s] Artists like Jacques-Louis David and Nicolas Poussin are renowned for their classical works which often depict heroic or mythological themes with a sense of timeless grandeur and dignity. +[301.97s -> 308.82s] Symbolism The symbolism was an artistic and literary movement that emerged in the late 19th century, primarily in France. +[308.82s -> 317.81s] It emphasized the use of symbols and metaphors to evoke emotions, dreams, and spiritual experiences. Symbolist artists such as Gustav Klimt and Odilon Radon +[317.81s -> 332.30s] sought to convey abstract ideas and inner visions rather than represent objective reality. Symbolism often featured dreamlike imagery, mythological motifs, and richly symbolic content exploring themes of mysticism, spirituality, and the subconscious mind. +[332.30s -> 343.71s] Op art. The op art, short for optical art, is a style of visual art that uses optical illusions and geometric patterns to create the impression of a movement, depth, or distortion. +[343.71s -> 354.46s] It often employs contrasting colors and precise, repetitive shapes to stimulate the eye and mind, creating a dynamic and sometimes disorienting visual experience. Futurism +[354.46s -> 368.69s] The Futurism was an avant-garde movement that emerged in Italy in the early 20th century. It celebrated modern technology, speed, and the dynamism of urban life, advocating for the rejection of traditional artistic forms in favor of embracing the future. +[368.69s -> 382.05s] Artists like Umberto Boccioni and Giacomo Balla depicted motion and energy through fragmented forms, dynamic compositions, and vibrant colors. Dada Dada was an avant-garde movement that emerged during World War I. +[382.05s -> 394.53s] originating in Zurich, Switzerland. It rejected traditional artistic conventions and embraced absurdity, chaos, and anti-establishment sentiments. Dadaists like Marcel Duchamp and Tristan Tzara used collage. +[394.53s -> 407.86s] found objects and performance art to challenge the rationality of society and the art world. Dada's legacy lies in its subversion of artistic norms and its influence on later movements such as surrealism and conceptual art. +[408.14s -> 418.53s] Art Nouveau, a late 19th and early 20th century art movement embraced organic forms, flowing lines, and intricate patterns. It emerged as a reaction against the academic art of the time. +[418.53s -> 430.46s] seeking to integrate art into everyday life through architecture, interior design, and decorative arts. Inspired by nature and exotic cultures, Art Nouveau artists like Alphonse Mucha and Hector Guimard +[430.46s -> 436.69s] aimed to create a total aesthetic experience characterized by its sinuous curves and ornamental motifs. +[437.20s -> 448.29s] Impressionism The Impressionism was an art movement in the late 19th century characterized by capturing the fleeting effects of light and atmosphere through loose brushwork and vivid colors. +[448.29s -> 461.60s] It focused on depicting everyday scenes, often outdoors, with an emphasis on conveying the artist's impression rather than precise details. Key artists include Claude Monet, Edgar Degas, and Pierre-Auguste Renoir. Post-Impressionism +[461.60s -> 472.90s] The Post-Impressionism was an art movement that emerged in the late 19th century as a reaction to Impressionism. Artists associated with Post-Impressionism, such as Paul Cézanne, Vincent Van Gogh, and Georges Seurat, +[472.90s -> 483.57s] built upon Impressionist techniques while pushing the boundaries of color, form, and expression. They focused on subjective interpretations of reality using bold colors, distinctive brushwork, +[483.57s -> 495.47s] and innovative compositions to convey emotions and ideas. Rococo The Rococo was an artistic movement that flourished in Europe during the 18th century, particularly in France. +[495.47s -> 509.68s] It is characterized by its ornate and playful style, featuring delicate pastel colors, asymmetrical compositions, and lavish decorations. Rococo art often depicted scenes of leisure, love, and frivolity reflecting the aristocratic culture of the time. +[510.06s -> 520.48s] Neoclassicism The Neoclassicism was an artistic and architectural movement that emerged in the 18th century as a reaction against the excesses of the Rococo style. +[520.48s -> 529.34s] Inspired by the ideals of ancient Greek and Roman art, neoclassical artists sought to revive the classical aesthetic of harmony, proportion, and clarity. +[529.34s -> 542.35s] Rejecting the ornate decoration of the rococo, neoclassical works emphasized clean lines, symmetry, and a return to classical subject matter, such as historical events and mythological themes. Mannerism +[542.35s -> 554.75s] The Mannerism was an art movement that emerged in the late Renaissance period, primarily in Italy during the 16th century. It is characterized by a departure from the balance, harmony, and naturalism of high Renaissance art. +[554.75s -> 567.50s] Mannerist artists deliberately distorted proportions, exaggerated poses, and employed intricate compositions to create a sense of elegance, sophistication, and intellectual complexity in their works. +[567.50s -> 581.02s] The modern art encompasses a wide range of artistic styles and movements that emerged in the late 19th and early 20th centuries, breaking away from traditional forms and techniques. It includes movements like cubism, surrealism, +[581.02s -> 591.82s] abstract expressionism, and pop art among others. Modern art often explores new concepts, materials, and techniques and can be highly experimental and diverse in its expressions. +[592.53s -> 604.45s] Precisionism. Precisionism was an American art movement in the early 20th century known for its precise, detailed portrayal of urban and industrial landscapes. Artists depicted scenes with sharp lines, geometric shapes, and smooth surfaces. +[604.45s -> 613.94s] Capturing the modernization and industrialization of America, this style often emphasized the beauty and order found in architecture, machinery, and infrastructure. diff --git a/VideoMMMU_ASR_large/Art/new_Art_Theory_3.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_Theory_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1a51398ee6e7f380402bbad1b13a84186df6e8e --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_Theory_3.mp4.txt @@ -0,0 +1,54 @@ +[0.00s -> 10.75s] Surrealism. The surrealism was an artistic and literary movement that emerged in the early 20th century aiming to explore the unconscious mind and unleash creativity beyond rationality. +[10.75s -> 25.12s] Led by figures like Andre Breton and Salvador Dali, Surrealists sought to depict dreamlike imagery, juxtaposing unrelated elements in surprising ways to provoke thought and evoke strong emotions. Surrealist artworks often feature fantastical landscapes, +[25.12s -> 32.08s] bizarre creatures and symbolic motifs, inviting viewers to interpret their meanings freely. Romanticism +[32.08s -> 43.01s] The Romanticism art emerged in the late 18th and early 19th centuries as a reaction against the rationalism of the Enlightenment and the strictures of Neoclassicism. It emphasized emotion, +[43.01s -> 52.77s] imagination and individualism, celebrating nature, the sublime and the exotic. Romantic artists often depicted dramatic landscapes, turbulent skies, +[52.77s -> 64.30s] and awe-inspiring natural phenomena to evoke a sense of the sublime and the ineffable. They also explored themes of nationalism, folklore, and mythology celebrating the spirit of freedom and revolution. +[64.59s -> 74.40s] Realism Realism is an artistic movement that emerged in the 19th century primarily in Europe as a reaction against the idealized and romanticized portrayals of life. +[74.40s -> 88.91s] It aimed to depict everyday subjects and situations truthfully, without embellishment or idealization. Realist artists often focused on the lives of ordinary people, depicting their struggles, joys, and environments with meticulous detail and accuracy. +[89.26s -> 101.46s] Minimalism. The minimalism is an art movement that emerged in the 1960s, characterized by extreme simplicity and a focus on fundamental elements like geometric shapes, basic colors, and clean lines. +[101.46s -> 107.47s] artists sought to strip away excess and decoration, creating works that emphasize pure form and presence. +[107.47s -> 117.54s] Minimalist art often invites viewers to engage directly with the physical qualities of the artwork and the surrounding space, encouraging contemplation and reflection. +[117.54s -> 130.19s] The Renaissance art was characterized by a revival of interest in classical Greek and Roman art, leading to a focus on realism, perspective, and humanism. Renaissance artists such as Leonardo da Vinci, Michelangelo, and Raphael +[130.19s -> 144.19s] created works that emphasized accurate depiction of the human form, lifelike expressions, and spatial depth. Their masterpieces, including paintings, sculptures, and architecture, reflected a renewed appreciation for the individual, nature, +[144.19s -> 158.06s] and the pursuit of knowledge. Baroque The Baroque art characterized by dramatic use of light and shadow, intense emotion, and rich, detailed compositions. Baroque artists aim to evoke powerful emotional responses in viewers. +[158.06s -> 169.23s] often employing dynamic compositions and theatrical effects. Religious themes were prevalent, with artists seeking to convey spiritual messages with heightened drama and intensity. +[169.23s -> 179.39s] The Expressionism was an art movement that emerged in the early 20th century, primarily in Germany. It aimed to convey emotional and psychological experiences rather than physical reality. +[179.39s -> 192.11s] Often through distorted or exaggerated forms and vivid colors, expressionist artists such as Edvard Munch and Ernst Ludwig Kirchner sought to evoke intense feelings and explore themes of angst, alienation, and inner turmoil. +[192.11s -> 201.94s] Abstract Expressionism The Abstract Expressionism was a post-World War II art movement that originated in New York City in the 1940s and 1950s. +[201.94s -> 213.33s] It emphasized spontaneous intuitive and emotional expression through abstract forms and gestural brushwork. Artists such as Jackson Pollock, Willem de Kooning, and Mark Rothko were central figures in this movement. +[213.33s -> 226.50s] Abstract expressionists often explored themes of individuality, the subconscious, and the act of painting itself, rejecting traditional representation in favor of conveying raw emotion and inner experience on canvas. Fauvism +[226.50s -> 240.40s] Favism was an early 20th century art movement characterized by bold colors, spontaneous brushwork, and simplified forms. Artists like Henri Matisse and Andre Duran were key figures, emphasizing emotional expression over realistic representation. +[240.56s -> 248.34s] Cubism. The Cubism was an influential art movement pioneered by Pablo Picasso and Georges Braque in the early 20th century. +[248.34s -> 256.62s] It revolutionized traditional artistic representation by breaking down subjects into geometric shapes and depicting multiple viewpoints simultaneously. +[256.62s -> 266.74s] Cubist artworks often feature fragmented forms, abstract shapes, and a flattened perspective, challenging viewers to rethink how they perceive space and form. Classicism +[266.74s -> 276.70s] The classicism refers to a movement in art and literature that draws inspiration from ancient Greek and Roman cultures, particularly their emphasis on harmony, balance, and order. +[276.70s -> 290.85s] It emerged during the Renaissance and experienced revivals in various periods, including the 17th and 18th centuries. Classicism prioritizes clarity, simplicity, and idealized forms rejecting the extravagant ornamentation of preceding styles. +[290.85s -> 301.46s] Artists like Jacques-Louis David and Nicolas Poussin are renowned for their classical works which often depict heroic or mythological themes with a sense of timeless grandeur and dignity. +[301.97s -> 308.82s] Symbolism The symbolism was an artistic and literary movement that emerged in the late 19th century, primarily in France. +[308.82s -> 317.81s] It emphasized the use of symbols and metaphors to evoke emotions, dreams, and spiritual experiences. Symbolist artists such as Gustav Klimt and Odilon Radon +[317.81s -> 332.30s] sought to convey abstract ideas and inner visions rather than represent objective reality. Symbolism often featured dreamlike imagery, mythological motifs, and richly symbolic content exploring themes of mysticism, spirituality, and the subconscious mind. +[332.30s -> 343.71s] Op art. The op art, short for optical art, is a style of visual art that uses optical illusions and geometric patterns to create the impression of a movement, depth, or distortion. +[343.71s -> 354.46s] It often employs contrasting colors and precise, repetitive shapes to stimulate the eye and mind, creating a dynamic and sometimes disorienting visual experience. Futurism +[354.46s -> 368.69s] The Futurism was an avant-garde movement that emerged in Italy in the early 20th century. It celebrated modern technology, speed, and the dynamism of urban life, advocating for the rejection of traditional artistic forms in favor of embracing the future. +[368.69s -> 382.05s] Artists like Umberto Boccioni and Giacomo Balla depicted motion and energy through fragmented forms, dynamic compositions, and vibrant colors. Dada Dada was an avant-garde movement that emerged during World War I. +[382.05s -> 394.53s] originating in Zurich, Switzerland. It rejected traditional artistic conventions and embraced absurdity, chaos, and anti-establishment sentiments. Dadaists like Marcel Duchamp and Tristan Tzara used collage. +[394.53s -> 407.86s] found objects and performance art to challenge the rationality of society and the art world. Dada's legacy lies in its subversion of artistic norms and its influence on later movements such as surrealism and conceptual art. +[408.14s -> 418.53s] Art Nouveau, a late 19th and early 20th century art movement embraced organic forms, flowing lines, and intricate patterns. It emerged as a reaction against the academic art of the time. +[418.53s -> 430.46s] seeking to integrate art into everyday life through architecture, interior design, and decorative arts. Inspired by nature and exotic cultures, Art Nouveau artists like Alphonse Mucha and Hector Guimard +[430.46s -> 436.69s] aimed to create a total aesthetic experience characterized by its sinuous curves and ornamental motifs. +[437.20s -> 448.29s] Impressionism The Impressionism was an art movement in the late 19th century characterized by capturing the fleeting effects of light and atmosphere through loose brushwork and vivid colors. +[448.29s -> 461.60s] It focused on depicting everyday scenes, often outdoors, with an emphasis on conveying the artist's impression rather than precise details. Key artists include Claude Monet, Edgar Degas, and Pierre-Auguste Renoir. Post-Impressionism +[461.60s -> 472.90s] The Post-Impressionism was an art movement that emerged in the late 19th century as a reaction to Impressionism. Artists associated with Post-Impressionism, such as Paul Cézanne, Vincent Van Gogh, and Georges Seurat, +[472.90s -> 483.57s] built upon Impressionist techniques while pushing the boundaries of color, form, and expression. They focused on subjective interpretations of reality using bold colors, distinctive brushwork, +[483.57s -> 495.47s] and innovative compositions to convey emotions and ideas. Rococo The Rococo was an artistic movement that flourished in Europe during the 18th century, particularly in France. +[495.47s -> 509.68s] It is characterized by its ornate and playful style, featuring delicate pastel colors, asymmetrical compositions, and lavish decorations. Rococo art often depicted scenes of leisure, love, and frivolity reflecting the aristocratic culture of the time. +[510.06s -> 520.48s] Neoclassicism The Neoclassicism was an artistic and architectural movement that emerged in the 18th century as a reaction against the excesses of the Rococo style. +[520.48s -> 529.34s] Inspired by the ideals of ancient Greek and Roman art, neoclassical artists sought to revive the classical aesthetic of harmony, proportion, and clarity. +[529.34s -> 542.35s] Rejecting the ornate decoration of the rococo, neoclassical works emphasized clean lines, symmetry, and a return to classical subject matter, such as historical events and mythological themes. Mannerism +[542.35s -> 554.75s] The Mannerism was an art movement that emerged in the late Renaissance period, primarily in Italy during the 16th century. It is characterized by a departure from the balance, harmony, and naturalism of high Renaissance art. +[554.75s -> 567.50s] Mannerist artists deliberately distorted proportions, exaggerated poses, and employed intricate compositions to create a sense of elegance, sophistication, and intellectual complexity in their works. +[567.50s -> 581.02s] The modern art encompasses a wide range of artistic styles and movements that emerged in the late 19th and early 20th centuries, breaking away from traditional forms and techniques. It includes movements like cubism, surrealism, +[581.02s -> 591.82s] abstract expressionism, and pop art among others. Modern art often explores new concepts, materials, and techniques and can be highly experimental and diverse in its expressions. +[592.53s -> 604.45s] Precisionism. Precisionism was an American art movement in the early 20th century known for its precise, detailed portrayal of urban and industrial landscapes. Artists depicted scenes with sharp lines, geometric shapes, and smooth surfaces. +[604.45s -> 613.94s] Capturing the modernization and industrialization of America, this style often emphasized the beauty and order found in architecture, machinery, and infrastructure. diff --git a/VideoMMMU_ASR_large/Art/new_Art_Theory_4.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_Theory_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ea8a1098c0b0e95404c48d8adbec8518ae507fec --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_Theory_4.mp4.txt @@ -0,0 +1,42 @@ +[0.24s -> 10.45s] Hi, my name is Taya and I'm here to teach you a little bit about art history. In today's lecture, I'm going to be going through one of my favourite art periods, the Baroque. +[10.48s -> 23.98s] This period is known for its painting, architecture, music and poetry as they flourished through 17th century Europe. Encouraged by the Catholic Church, this art style has a rich story that I can't wait to tell you. +[25.78s -> 37.58s] The Baroque is a famous style of painting, sculpture, architecture, music, dance, poetry and other arts that was popular from the early 17th century to mid-18th century. +[37.58s -> 49.10s] Following the Renaissance and Mannerism, the Baroque was highly encouraged by the Catholic Church as a means to counter the Counter-Reformation and the austerity of Protestant art, music and architecture. +[49.10s -> 60.11s] though you can see Lutheran Baroque throughout Europe. The Baroque is primarily known for artists' use of strong contrast, grandeur, exuberant detail, deep colour, +[60.11s -> 65.26s] movement and surprise all intended to achieve a sense of awe from their viewers. +[65.26s -> 76.86s] The style began in Rome in the early 17th century before it moved rapidly throughout Italy, France, Portugal and Spain. Later it would spread to Poland, southern Germany and Austria. +[76.86s -> 86.74s] By the 1730s, the style would transform to a more flamboyant style known as the Rococo, which was common in France and Central Europe till the late 18th century. +[88.56s -> 101.74s] The English word baroque is originally French, and some scholars believe the French word originated from the Portuguese term barroco, which means a flawed pearl. Some others suggest it came from the Latin term barroco. +[101.74s -> 112.26s] typically used in logic but eventually was utilised to describe anything that was absurdly complex. Some even associate the Latin word with excess, magic and confusion. +[112.26s -> 124.80s] By the 18th century the word Baroque was associated with misshapen pearls and therefore often associated with jewellery. From the 18th century it began being used to describe music and not in a nice way either. +[124.80s -> 135.94s] By 1788 the term was defined by the Methodical Encyclopedia by Order of Subject Matter as a term used to describe an architectural style that is highly adorned and tormented. +[135.94s -> 148.62s] It wasn't until 1888 that a serious work was published on the style by Heinrich Wolflin, titled Renaissance and Baroque, and it described the differences between the styles in relation to painting, sculpture and architecture. +[149.97s -> 156.19s] The Baroque architecture style derived from the Catholic Church's reaction to the Protestant Reformation at the Council of Trent. +[156.19s -> 170.51s] The Counter-Reformation's first phase imposed a strict academic style of religious architecture that only appealed to intellectuals, not the majority of churchgoers. At the Council of Trent, it was decided that they should appeal to a wider audience, and they made a declaration. +[170.51s -> 182.11s] declaration that the arts should communicate religious themes simply, directly and emotionally. Baroque churches were designed to hold a large central space, a dome and paintings on their ceilings. +[182.11s -> 194.51s] These were different from the painted ceilings of Michelangelo. The Baroque ceiling paintings were created in a way that allowed viewers on the floor to see the entire ceiling in the correct perspective, leaving the impression that the figures were real. +[194.51s -> 204.99s] The interiors of these churches became increasingly ornate, with a focus on the altar. The most celebrated decorative works of the High Baroque include the Baldaccino of St. Peter, +[204.99s -> 211.31s] and the chair of Saint Peter both by Gian Lorenzo Bernini in Saint Peter's Basilica in Rome. +[211.31s -> 223.82s] In order to create illusions, of which many Baroque buildings are known for, Baroque artists would use forced perspective, which involved making objects appear further away, closer, larger or smaller than it typically is. +[223.82s -> 238.58s] Through the use of scaled objects and their correlation with specific vantage points, these architects would manipulate the human visual perception. A statue at the end of the Palazzo Sparta in Rome appears to be life-size, but it's actually 60cm high. +[239.89s -> 252.46s] Baroque painters deliberately worked to set themselves apart from the Renaissance and Mannerism. They utilised intense warm colours with particular focus on utilising the primary colours within close proximity. +[252.46s -> 262.61s] They avoided the even lighting of Renaissance works, instead choosing strong contrasts of light and dark that would illuminate certain parts of the composition or draw attention to specific figures. +[262.61s -> 274.43s] Artists avoided the tranquil sense that was seen through the Renaissance, instead choosing to focus on movement, drama and emotion. They utilized asymmetry within their compositions in order to create a sense of instability. +[274.43s -> 287.60s] Their movement was enhanced by depicting costumes being blown by wind or moved by the figure's gestures. The focus of everything was movement, emotion and drama. The final essential element of Baroque painting was the use of allegory. +[287.60s -> 295.50s] This basically means that every painting told a story and had a message that could be deduced through symbols and allegorical characters. +[295.50s -> 309.74s] In Italy, Baroque artists would collaborate with Baroque architects on decorating interiors. A major painter for this was Pietro da Cortona, who painted for the palace of the Barberini family and worked on the largest frescoes at the Sistine Chapel. +[310.45s -> 323.95s] The most important figure for Baroque sculpture was Gian Lorenzo Benigni, who under the patronage of Pope Urban VIII created remarkable and monumental statues depicting saints and figures of immense emotion and realism. +[323.95s -> 333.62s] He would also produce rounds with groups of monumental sculptures that decorated the major squares in Rome. Roman statues were the main inspiration behind Baroque sculpture. +[335.89s -> 347.30s] There are a few main characteristics that differentiate Rococo and Baroque. Unlike the Baroque, the Rococo style involves an abandonment of asymmetry, though only partial. +[347.30s -> 361.14s] The works of the Rococo embraced graceful lines and curves similar to those seen in Art Nouveau, the use of flowers in ornamentation, the use of Chinese and Japanese motifs, and the use of warm pastel colours. +[362.38s -> 376.98s] The decline of the Baroque was contributed to by Madame de Pompadour, a mistress of Louis XV, when she sent her nephew on a journey to study Italy's archaeological and artistic developments. Accompanied by several other artists, they returned +[376.98s -> 379.73s] with her new passion for classical art. +[379.73s -> 394.03s] When he later became the Royal Director of Buildings, he turned official French architecture towards the neoclassical. His contemporary, Nicolas Cochin, became a popular art critic, where he denounced the style of Boucher and called for neoclassical. +[394.03s -> 395.02s] works. +[396.56s -> 411.15s] An influential figure of the Baroque era is none other than Caravaggio. This artist is highly praised through history for his realistic approach to the human figure, the way he painted directly from real life and his mastery of chiaroscuro. The work Caravaggio created +[411.15s -> 417.33s] not only shocked his artistic peers but completely changed the path of art history and the history of painting. +[418.80s -> 427.18s] Artemisia Gentileschi is known for being one of the most accomplished painters of the 17th century, producing professional work by the age of 15. +[427.18s -> 439.70s] Gentileschi became the first woman to be admitted to the Academy of Arts and Drawing in Florence. Her paintings predominantly featured women from the Bible, allegories and myths, and included warriors, suicides and victims. +[441.23s -> 452.02s] Elisabetta Sorani was an Italian Baroque painter and printmaker who was one of the first women artists in early modern Bologna and established an academy for other women artists of her time. +[453.52s -> 468.11s] Peter Paul Rubens was the most important painter of the Flemish Baroque style for his highly charged compositions, references to classical and Christian history, and his unique Baroque style that emphasised movement, sensuality and colour. The artist specialised in +[468.11s -> 480.68s] portraits, landscapes, history paintings and altarpieces. And that's it for the Baroque. Thank you so much for watching today's video. Don't forget to like and subscribe for more videos just like this. diff --git a/VideoMMMU_ASR_large/Art/new_Art_Theory_5.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_Theory_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ea8a1098c0b0e95404c48d8adbec8518ae507fec --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_Theory_5.mp4.txt @@ -0,0 +1,42 @@ +[0.24s -> 10.45s] Hi, my name is Taya and I'm here to teach you a little bit about art history. In today's lecture, I'm going to be going through one of my favourite art periods, the Baroque. +[10.48s -> 23.98s] This period is known for its painting, architecture, music and poetry as they flourished through 17th century Europe. Encouraged by the Catholic Church, this art style has a rich story that I can't wait to tell you. +[25.78s -> 37.58s] The Baroque is a famous style of painting, sculpture, architecture, music, dance, poetry and other arts that was popular from the early 17th century to mid-18th century. +[37.58s -> 49.10s] Following the Renaissance and Mannerism, the Baroque was highly encouraged by the Catholic Church as a means to counter the Counter-Reformation and the austerity of Protestant art, music and architecture. +[49.10s -> 60.11s] though you can see Lutheran Baroque throughout Europe. The Baroque is primarily known for artists' use of strong contrast, grandeur, exuberant detail, deep colour, +[60.11s -> 65.26s] movement and surprise all intended to achieve a sense of awe from their viewers. +[65.26s -> 76.86s] The style began in Rome in the early 17th century before it moved rapidly throughout Italy, France, Portugal and Spain. Later it would spread to Poland, southern Germany and Austria. +[76.86s -> 86.74s] By the 1730s, the style would transform to a more flamboyant style known as the Rococo, which was common in France and Central Europe till the late 18th century. +[88.56s -> 101.74s] The English word baroque is originally French, and some scholars believe the French word originated from the Portuguese term barroco, which means a flawed pearl. Some others suggest it came from the Latin term barroco. +[101.74s -> 112.26s] typically used in logic but eventually was utilised to describe anything that was absurdly complex. Some even associate the Latin word with excess, magic and confusion. +[112.26s -> 124.80s] By the 18th century the word Baroque was associated with misshapen pearls and therefore often associated with jewellery. From the 18th century it began being used to describe music and not in a nice way either. +[124.80s -> 135.94s] By 1788 the term was defined by the Methodical Encyclopedia by Order of Subject Matter as a term used to describe an architectural style that is highly adorned and tormented. +[135.94s -> 148.62s] It wasn't until 1888 that a serious work was published on the style by Heinrich Wolflin, titled Renaissance and Baroque, and it described the differences between the styles in relation to painting, sculpture and architecture. +[149.97s -> 156.19s] The Baroque architecture style derived from the Catholic Church's reaction to the Protestant Reformation at the Council of Trent. +[156.19s -> 170.51s] The Counter-Reformation's first phase imposed a strict academic style of religious architecture that only appealed to intellectuals, not the majority of churchgoers. At the Council of Trent, it was decided that they should appeal to a wider audience, and they made a declaration. +[170.51s -> 182.11s] declaration that the arts should communicate religious themes simply, directly and emotionally. Baroque churches were designed to hold a large central space, a dome and paintings on their ceilings. +[182.11s -> 194.51s] These were different from the painted ceilings of Michelangelo. The Baroque ceiling paintings were created in a way that allowed viewers on the floor to see the entire ceiling in the correct perspective, leaving the impression that the figures were real. +[194.51s -> 204.99s] The interiors of these churches became increasingly ornate, with a focus on the altar. The most celebrated decorative works of the High Baroque include the Baldaccino of St. Peter, +[204.99s -> 211.31s] and the chair of Saint Peter both by Gian Lorenzo Bernini in Saint Peter's Basilica in Rome. +[211.31s -> 223.82s] In order to create illusions, of which many Baroque buildings are known for, Baroque artists would use forced perspective, which involved making objects appear further away, closer, larger or smaller than it typically is. +[223.82s -> 238.58s] Through the use of scaled objects and their correlation with specific vantage points, these architects would manipulate the human visual perception. A statue at the end of the Palazzo Sparta in Rome appears to be life-size, but it's actually 60cm high. +[239.89s -> 252.46s] Baroque painters deliberately worked to set themselves apart from the Renaissance and Mannerism. They utilised intense warm colours with particular focus on utilising the primary colours within close proximity. +[252.46s -> 262.61s] They avoided the even lighting of Renaissance works, instead choosing strong contrasts of light and dark that would illuminate certain parts of the composition or draw attention to specific figures. +[262.61s -> 274.43s] Artists avoided the tranquil sense that was seen through the Renaissance, instead choosing to focus on movement, drama and emotion. They utilized asymmetry within their compositions in order to create a sense of instability. +[274.43s -> 287.60s] Their movement was enhanced by depicting costumes being blown by wind or moved by the figure's gestures. The focus of everything was movement, emotion and drama. The final essential element of Baroque painting was the use of allegory. +[287.60s -> 295.50s] This basically means that every painting told a story and had a message that could be deduced through symbols and allegorical characters. +[295.50s -> 309.74s] In Italy, Baroque artists would collaborate with Baroque architects on decorating interiors. A major painter for this was Pietro da Cortona, who painted for the palace of the Barberini family and worked on the largest frescoes at the Sistine Chapel. +[310.45s -> 323.95s] The most important figure for Baroque sculpture was Gian Lorenzo Benigni, who under the patronage of Pope Urban VIII created remarkable and monumental statues depicting saints and figures of immense emotion and realism. +[323.95s -> 333.62s] He would also produce rounds with groups of monumental sculptures that decorated the major squares in Rome. Roman statues were the main inspiration behind Baroque sculpture. +[335.89s -> 347.30s] There are a few main characteristics that differentiate Rococo and Baroque. Unlike the Baroque, the Rococo style involves an abandonment of asymmetry, though only partial. +[347.30s -> 361.14s] The works of the Rococo embraced graceful lines and curves similar to those seen in Art Nouveau, the use of flowers in ornamentation, the use of Chinese and Japanese motifs, and the use of warm pastel colours. +[362.38s -> 376.98s] The decline of the Baroque was contributed to by Madame de Pompadour, a mistress of Louis XV, when she sent her nephew on a journey to study Italy's archaeological and artistic developments. Accompanied by several other artists, they returned +[376.98s -> 379.73s] with her new passion for classical art. +[379.73s -> 394.03s] When he later became the Royal Director of Buildings, he turned official French architecture towards the neoclassical. His contemporary, Nicolas Cochin, became a popular art critic, where he denounced the style of Boucher and called for neoclassical. +[394.03s -> 395.02s] works. +[396.56s -> 411.15s] An influential figure of the Baroque era is none other than Caravaggio. This artist is highly praised through history for his realistic approach to the human figure, the way he painted directly from real life and his mastery of chiaroscuro. The work Caravaggio created +[411.15s -> 417.33s] not only shocked his artistic peers but completely changed the path of art history and the history of painting. +[418.80s -> 427.18s] Artemisia Gentileschi is known for being one of the most accomplished painters of the 17th century, producing professional work by the age of 15. +[427.18s -> 439.70s] Gentileschi became the first woman to be admitted to the Academy of Arts and Drawing in Florence. Her paintings predominantly featured women from the Bible, allegories and myths, and included warriors, suicides and victims. +[441.23s -> 452.02s] Elisabetta Sorani was an Italian Baroque painter and printmaker who was one of the first women artists in early modern Bologna and established an academy for other women artists of her time. +[453.52s -> 468.11s] Peter Paul Rubens was the most important painter of the Flemish Baroque style for his highly charged compositions, references to classical and Christian history, and his unique Baroque style that emphasised movement, sensuality and colour. The artist specialised in +[468.11s -> 480.68s] portraits, landscapes, history paintings and altarpieces. And that's it for the Baroque. Thank you so much for watching today's video. Don't forget to like and subscribe for more videos just like this. diff --git a/VideoMMMU_ASR_large/Art/new_Art_Theory_6.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_Theory_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ea8a1098c0b0e95404c48d8adbec8518ae507fec --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_Theory_6.mp4.txt @@ -0,0 +1,42 @@ +[0.24s -> 10.45s] Hi, my name is Taya and I'm here to teach you a little bit about art history. In today's lecture, I'm going to be going through one of my favourite art periods, the Baroque. +[10.48s -> 23.98s] This period is known for its painting, architecture, music and poetry as they flourished through 17th century Europe. Encouraged by the Catholic Church, this art style has a rich story that I can't wait to tell you. +[25.78s -> 37.58s] The Baroque is a famous style of painting, sculpture, architecture, music, dance, poetry and other arts that was popular from the early 17th century to mid-18th century. +[37.58s -> 49.10s] Following the Renaissance and Mannerism, the Baroque was highly encouraged by the Catholic Church as a means to counter the Counter-Reformation and the austerity of Protestant art, music and architecture. +[49.10s -> 60.11s] though you can see Lutheran Baroque throughout Europe. The Baroque is primarily known for artists' use of strong contrast, grandeur, exuberant detail, deep colour, +[60.11s -> 65.26s] movement and surprise all intended to achieve a sense of awe from their viewers. +[65.26s -> 76.86s] The style began in Rome in the early 17th century before it moved rapidly throughout Italy, France, Portugal and Spain. Later it would spread to Poland, southern Germany and Austria. +[76.86s -> 86.74s] By the 1730s, the style would transform to a more flamboyant style known as the Rococo, which was common in France and Central Europe till the late 18th century. +[88.56s -> 101.74s] The English word baroque is originally French, and some scholars believe the French word originated from the Portuguese term barroco, which means a flawed pearl. Some others suggest it came from the Latin term barroco. +[101.74s -> 112.26s] typically used in logic but eventually was utilised to describe anything that was absurdly complex. Some even associate the Latin word with excess, magic and confusion. +[112.26s -> 124.80s] By the 18th century the word Baroque was associated with misshapen pearls and therefore often associated with jewellery. From the 18th century it began being used to describe music and not in a nice way either. +[124.80s -> 135.94s] By 1788 the term was defined by the Methodical Encyclopedia by Order of Subject Matter as a term used to describe an architectural style that is highly adorned and tormented. +[135.94s -> 148.62s] It wasn't until 1888 that a serious work was published on the style by Heinrich Wolflin, titled Renaissance and Baroque, and it described the differences between the styles in relation to painting, sculpture and architecture. +[149.97s -> 156.19s] The Baroque architecture style derived from the Catholic Church's reaction to the Protestant Reformation at the Council of Trent. +[156.19s -> 170.51s] The Counter-Reformation's first phase imposed a strict academic style of religious architecture that only appealed to intellectuals, not the majority of churchgoers. At the Council of Trent, it was decided that they should appeal to a wider audience, and they made a declaration. +[170.51s -> 182.11s] declaration that the arts should communicate religious themes simply, directly and emotionally. Baroque churches were designed to hold a large central space, a dome and paintings on their ceilings. +[182.11s -> 194.51s] These were different from the painted ceilings of Michelangelo. The Baroque ceiling paintings were created in a way that allowed viewers on the floor to see the entire ceiling in the correct perspective, leaving the impression that the figures were real. +[194.51s -> 204.99s] The interiors of these churches became increasingly ornate, with a focus on the altar. The most celebrated decorative works of the High Baroque include the Baldaccino of St. Peter, +[204.99s -> 211.31s] and the chair of Saint Peter both by Gian Lorenzo Bernini in Saint Peter's Basilica in Rome. +[211.31s -> 223.82s] In order to create illusions, of which many Baroque buildings are known for, Baroque artists would use forced perspective, which involved making objects appear further away, closer, larger or smaller than it typically is. +[223.82s -> 238.58s] Through the use of scaled objects and their correlation with specific vantage points, these architects would manipulate the human visual perception. A statue at the end of the Palazzo Sparta in Rome appears to be life-size, but it's actually 60cm high. +[239.89s -> 252.46s] Baroque painters deliberately worked to set themselves apart from the Renaissance and Mannerism. They utilised intense warm colours with particular focus on utilising the primary colours within close proximity. +[252.46s -> 262.61s] They avoided the even lighting of Renaissance works, instead choosing strong contrasts of light and dark that would illuminate certain parts of the composition or draw attention to specific figures. +[262.61s -> 274.43s] Artists avoided the tranquil sense that was seen through the Renaissance, instead choosing to focus on movement, drama and emotion. They utilized asymmetry within their compositions in order to create a sense of instability. +[274.43s -> 287.60s] Their movement was enhanced by depicting costumes being blown by wind or moved by the figure's gestures. The focus of everything was movement, emotion and drama. The final essential element of Baroque painting was the use of allegory. +[287.60s -> 295.50s] This basically means that every painting told a story and had a message that could be deduced through symbols and allegorical characters. +[295.50s -> 309.74s] In Italy, Baroque artists would collaborate with Baroque architects on decorating interiors. A major painter for this was Pietro da Cortona, who painted for the palace of the Barberini family and worked on the largest frescoes at the Sistine Chapel. +[310.45s -> 323.95s] The most important figure for Baroque sculpture was Gian Lorenzo Benigni, who under the patronage of Pope Urban VIII created remarkable and monumental statues depicting saints and figures of immense emotion and realism. +[323.95s -> 333.62s] He would also produce rounds with groups of monumental sculptures that decorated the major squares in Rome. Roman statues were the main inspiration behind Baroque sculpture. +[335.89s -> 347.30s] There are a few main characteristics that differentiate Rococo and Baroque. Unlike the Baroque, the Rococo style involves an abandonment of asymmetry, though only partial. +[347.30s -> 361.14s] The works of the Rococo embraced graceful lines and curves similar to those seen in Art Nouveau, the use of flowers in ornamentation, the use of Chinese and Japanese motifs, and the use of warm pastel colours. +[362.38s -> 376.98s] The decline of the Baroque was contributed to by Madame de Pompadour, a mistress of Louis XV, when she sent her nephew on a journey to study Italy's archaeological and artistic developments. Accompanied by several other artists, they returned +[376.98s -> 379.73s] with her new passion for classical art. +[379.73s -> 394.03s] When he later became the Royal Director of Buildings, he turned official French architecture towards the neoclassical. His contemporary, Nicolas Cochin, became a popular art critic, where he denounced the style of Boucher and called for neoclassical. +[394.03s -> 395.02s] works. +[396.56s -> 411.15s] An influential figure of the Baroque era is none other than Caravaggio. This artist is highly praised through history for his realistic approach to the human figure, the way he painted directly from real life and his mastery of chiaroscuro. The work Caravaggio created +[411.15s -> 417.33s] not only shocked his artistic peers but completely changed the path of art history and the history of painting. +[418.80s -> 427.18s] Artemisia Gentileschi is known for being one of the most accomplished painters of the 17th century, producing professional work by the age of 15. +[427.18s -> 439.70s] Gentileschi became the first woman to be admitted to the Academy of Arts and Drawing in Florence. Her paintings predominantly featured women from the Bible, allegories and myths, and included warriors, suicides and victims. +[441.23s -> 452.02s] Elisabetta Sorani was an Italian Baroque painter and printmaker who was one of the first women artists in early modern Bologna and established an academy for other women artists of her time. +[453.52s -> 468.11s] Peter Paul Rubens was the most important painter of the Flemish Baroque style for his highly charged compositions, references to classical and Christian history, and his unique Baroque style that emphasised movement, sensuality and colour. The artist specialised in +[468.11s -> 480.68s] portraits, landscapes, history paintings and altarpieces. And that's it for the Baroque. Thank you so much for watching today's video. Don't forget to like and subscribe for more videos just like this. diff --git a/VideoMMMU_ASR_large/Art/new_Art_Theory_7.mp4.txt b/VideoMMMU_ASR_large/Art/new_Art_Theory_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ea8a1098c0b0e95404c48d8adbec8518ae507fec --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Art_Theory_7.mp4.txt @@ -0,0 +1,42 @@ +[0.24s -> 10.45s] Hi, my name is Taya and I'm here to teach you a little bit about art history. In today's lecture, I'm going to be going through one of my favourite art periods, the Baroque. +[10.48s -> 23.98s] This period is known for its painting, architecture, music and poetry as they flourished through 17th century Europe. Encouraged by the Catholic Church, this art style has a rich story that I can't wait to tell you. +[25.78s -> 37.58s] The Baroque is a famous style of painting, sculpture, architecture, music, dance, poetry and other arts that was popular from the early 17th century to mid-18th century. +[37.58s -> 49.10s] Following the Renaissance and Mannerism, the Baroque was highly encouraged by the Catholic Church as a means to counter the Counter-Reformation and the austerity of Protestant art, music and architecture. +[49.10s -> 60.11s] though you can see Lutheran Baroque throughout Europe. The Baroque is primarily known for artists' use of strong contrast, grandeur, exuberant detail, deep colour, +[60.11s -> 65.26s] movement and surprise all intended to achieve a sense of awe from their viewers. +[65.26s -> 76.86s] The style began in Rome in the early 17th century before it moved rapidly throughout Italy, France, Portugal and Spain. Later it would spread to Poland, southern Germany and Austria. +[76.86s -> 86.74s] By the 1730s, the style would transform to a more flamboyant style known as the Rococo, which was common in France and Central Europe till the late 18th century. +[88.56s -> 101.74s] The English word baroque is originally French, and some scholars believe the French word originated from the Portuguese term barroco, which means a flawed pearl. Some others suggest it came from the Latin term barroco. +[101.74s -> 112.26s] typically used in logic but eventually was utilised to describe anything that was absurdly complex. Some even associate the Latin word with excess, magic and confusion. +[112.26s -> 124.80s] By the 18th century the word Baroque was associated with misshapen pearls and therefore often associated with jewellery. From the 18th century it began being used to describe music and not in a nice way either. +[124.80s -> 135.94s] By 1788 the term was defined by the Methodical Encyclopedia by Order of Subject Matter as a term used to describe an architectural style that is highly adorned and tormented. +[135.94s -> 148.62s] It wasn't until 1888 that a serious work was published on the style by Heinrich Wolflin, titled Renaissance and Baroque, and it described the differences between the styles in relation to painting, sculpture and architecture. +[149.97s -> 156.19s] The Baroque architecture style derived from the Catholic Church's reaction to the Protestant Reformation at the Council of Trent. +[156.19s -> 170.51s] The Counter-Reformation's first phase imposed a strict academic style of religious architecture that only appealed to intellectuals, not the majority of churchgoers. At the Council of Trent, it was decided that they should appeal to a wider audience, and they made a declaration. +[170.51s -> 182.11s] declaration that the arts should communicate religious themes simply, directly and emotionally. Baroque churches were designed to hold a large central space, a dome and paintings on their ceilings. +[182.11s -> 194.51s] These were different from the painted ceilings of Michelangelo. The Baroque ceiling paintings were created in a way that allowed viewers on the floor to see the entire ceiling in the correct perspective, leaving the impression that the figures were real. +[194.51s -> 204.99s] The interiors of these churches became increasingly ornate, with a focus on the altar. The most celebrated decorative works of the High Baroque include the Baldaccino of St. Peter, +[204.99s -> 211.31s] and the chair of Saint Peter both by Gian Lorenzo Bernini in Saint Peter's Basilica in Rome. +[211.31s -> 223.82s] In order to create illusions, of which many Baroque buildings are known for, Baroque artists would use forced perspective, which involved making objects appear further away, closer, larger or smaller than it typically is. +[223.82s -> 238.58s] Through the use of scaled objects and their correlation with specific vantage points, these architects would manipulate the human visual perception. A statue at the end of the Palazzo Sparta in Rome appears to be life-size, but it's actually 60cm high. +[239.89s -> 252.46s] Baroque painters deliberately worked to set themselves apart from the Renaissance and Mannerism. They utilised intense warm colours with particular focus on utilising the primary colours within close proximity. +[252.46s -> 262.61s] They avoided the even lighting of Renaissance works, instead choosing strong contrasts of light and dark that would illuminate certain parts of the composition or draw attention to specific figures. +[262.61s -> 274.43s] Artists avoided the tranquil sense that was seen through the Renaissance, instead choosing to focus on movement, drama and emotion. They utilized asymmetry within their compositions in order to create a sense of instability. +[274.43s -> 287.60s] Their movement was enhanced by depicting costumes being blown by wind or moved by the figure's gestures. The focus of everything was movement, emotion and drama. The final essential element of Baroque painting was the use of allegory. +[287.60s -> 295.50s] This basically means that every painting told a story and had a message that could be deduced through symbols and allegorical characters. +[295.50s -> 309.74s] In Italy, Baroque artists would collaborate with Baroque architects on decorating interiors. A major painter for this was Pietro da Cortona, who painted for the palace of the Barberini family and worked on the largest frescoes at the Sistine Chapel. +[310.45s -> 323.95s] The most important figure for Baroque sculpture was Gian Lorenzo Benigni, who under the patronage of Pope Urban VIII created remarkable and monumental statues depicting saints and figures of immense emotion and realism. +[323.95s -> 333.62s] He would also produce rounds with groups of monumental sculptures that decorated the major squares in Rome. Roman statues were the main inspiration behind Baroque sculpture. +[335.89s -> 347.30s] There are a few main characteristics that differentiate Rococo and Baroque. Unlike the Baroque, the Rococo style involves an abandonment of asymmetry, though only partial. +[347.30s -> 361.14s] The works of the Rococo embraced graceful lines and curves similar to those seen in Art Nouveau, the use of flowers in ornamentation, the use of Chinese and Japanese motifs, and the use of warm pastel colours. +[362.38s -> 376.98s] The decline of the Baroque was contributed to by Madame de Pompadour, a mistress of Louis XV, when she sent her nephew on a journey to study Italy's archaeological and artistic developments. Accompanied by several other artists, they returned +[376.98s -> 379.73s] with her new passion for classical art. +[379.73s -> 394.03s] When he later became the Royal Director of Buildings, he turned official French architecture towards the neoclassical. His contemporary, Nicolas Cochin, became a popular art critic, where he denounced the style of Boucher and called for neoclassical. +[394.03s -> 395.02s] works. +[396.56s -> 411.15s] An influential figure of the Baroque era is none other than Caravaggio. This artist is highly praised through history for his realistic approach to the human figure, the way he painted directly from real life and his mastery of chiaroscuro. The work Caravaggio created +[411.15s -> 417.33s] not only shocked his artistic peers but completely changed the path of art history and the history of painting. +[418.80s -> 427.18s] Artemisia Gentileschi is known for being one of the most accomplished painters of the 17th century, producing professional work by the age of 15. +[427.18s -> 439.70s] Gentileschi became the first woman to be admitted to the Academy of Arts and Drawing in Florence. Her paintings predominantly featured women from the Bible, allegories and myths, and included warriors, suicides and victims. +[441.23s -> 452.02s] Elisabetta Sorani was an Italian Baroque painter and printmaker who was one of the first women artists in early modern Bologna and established an academy for other women artists of her time. +[453.52s -> 468.11s] Peter Paul Rubens was the most important painter of the Flemish Baroque style for his highly charged compositions, references to classical and Christian history, and his unique Baroque style that emphasised movement, sensuality and colour. The artist specialised in +[468.11s -> 480.68s] portraits, landscapes, history paintings and altarpieces. And that's it for the Baroque. Thank you so much for watching today's video. Don't forget to like and subscribe for more videos just like this. diff --git a/VideoMMMU_ASR_large/Art/new_Design_1.mp4.txt b/VideoMMMU_ASR_large/Art/new_Design_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..8205aa13e2df1123083eab1f6afc3f4073549cd6 --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Design_1.mp4.txt @@ -0,0 +1,26 @@ +[0.66s -> 14.90s] If the elements of art we just learned about, line, shape, form, value, color, texture, space, are the building blocks of art, then the principles of design explain how the artists used those blocks. +[14.90s -> 22.26s] how they chose to build in this short video i'm going to focus on 10 of those principles of design +[32.02s -> 38.14s] Let's start with pattern. Pattern is an orderly repetition of an object. +[38.14s -> 50.37s] You can see here that these artists found something that they liked an element of some sort and they repeated it over and over in their artwork Sometimes it's everything's not exactly +[50.37s -> 58.83s] the same but there's definitely a pattern going on and you'll even see in this portrait that there is a pattern within the shapes +[62.93s -> 70.42s] The principle of contrast is a juxtaposition that accentuates differences. +[70.77s -> 84.43s] This can be done often with color, but also with types of things. Here you see a pepper with apples. And here you have a natural object against man-made objects. It can be size. +[84.56s -> 98.10s] difference in texture a difference in darks and lights color and even the types of lines that are used as you see here and with this flower +[102.99s -> 115.81s] Balance is a distribution of equal visual weight and what's important to note is that it doesn't mean it has to be a mirrored image. These first examples are symmetrical. +[115.81s -> 126.64s] balanced images where you could almost fold your paper and have the same thing on each side it's symmetrical mirrored even +[130.99s -> 145.33s] These next images are asymmetrically balanced. They are weighted evenly in different ways, whether it's the quantity one big versus several little, or even though this cake is smaller, it is brighter and makes the white. +[145.33s -> 146.42s] even. +[151.50s -> 164.78s] Repetition sets up a feeling of rhythm by repeating the same shapes, texture, color, stroke, etc. So you'll see in these examples that there is something about each +[164.78s -> 166.64s] picture that is repeated. +[166.96s -> 181.36s] oftentimes the style and use of line or color or shading is repeated as well so it's not necessarily just the object but also the way the artist put the object on the page +[184.82s -> 199.36s] Emphasis is an accentuation of importance. It's the part of the artwork our eye is drawn to first. An artist uses color very often when trying to employ this principle of design. Color, shape, +[199.36s -> 205.01s] Size and placement are just some ways to emphasize part of an art piece. +[215.44s -> 229.07s] Movement is a directed path of optical motion. Movement is the direction our eyes wander through a scene. It can be directed by lines or by a change in color or even scale. +[248.46s -> 254.54s] Harmony refers to a way of combining elements to accent their similarities. +[256.43s -> 266.54s] A picture seems to be bound together as a whole when the elements are harmonious and it tends to have a visually satisfying effect. +[278.42s -> 293.17s] proximity is the placement of objects whether near or far from each other elements near each other are perceived as being related while elements spaced apart are perceived as belonging to separate groups +[310.22s -> 322.74s] Rhythm is a repetitive, organized movement or visual flow within an image. As you'll see in these examples, there is something similar that gets repeated over and over but it forms a +[322.74s -> 328.88s] type of rhythm. You know what to expect next, just like when you clap your hands to a beat. +[337.30s -> 347.84s] proportion is a scaling of objects in relation to each other proportion appeals to our sense of depth and scaling using relative size +[347.84s -> 361.26s] And elements feel right when they appear to be as they should be. But as you can see, proportion can be tweaked and we can make things as they're not supposed to be. It depends on what the artist is trying to get to. +[364.37s -> 371.25s] To create an effective composition an artist will always employ one or more of the principles of design. diff --git a/VideoMMMU_ASR_large/Art/new_Design_2.mp4.txt b/VideoMMMU_ASR_large/Art/new_Design_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..8205aa13e2df1123083eab1f6afc3f4073549cd6 --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Design_2.mp4.txt @@ -0,0 +1,26 @@ +[0.66s -> 14.90s] If the elements of art we just learned about, line, shape, form, value, color, texture, space, are the building blocks of art, then the principles of design explain how the artists used those blocks. +[14.90s -> 22.26s] how they chose to build in this short video i'm going to focus on 10 of those principles of design +[32.02s -> 38.14s] Let's start with pattern. Pattern is an orderly repetition of an object. +[38.14s -> 50.37s] You can see here that these artists found something that they liked an element of some sort and they repeated it over and over in their artwork Sometimes it's everything's not exactly +[50.37s -> 58.83s] the same but there's definitely a pattern going on and you'll even see in this portrait that there is a pattern within the shapes +[62.93s -> 70.42s] The principle of contrast is a juxtaposition that accentuates differences. +[70.77s -> 84.43s] This can be done often with color, but also with types of things. Here you see a pepper with apples. And here you have a natural object against man-made objects. It can be size. +[84.56s -> 98.10s] difference in texture a difference in darks and lights color and even the types of lines that are used as you see here and with this flower +[102.99s -> 115.81s] Balance is a distribution of equal visual weight and what's important to note is that it doesn't mean it has to be a mirrored image. These first examples are symmetrical. +[115.81s -> 126.64s] balanced images where you could almost fold your paper and have the same thing on each side it's symmetrical mirrored even +[130.99s -> 145.33s] These next images are asymmetrically balanced. They are weighted evenly in different ways, whether it's the quantity one big versus several little, or even though this cake is smaller, it is brighter and makes the white. +[145.33s -> 146.42s] even. +[151.50s -> 164.78s] Repetition sets up a feeling of rhythm by repeating the same shapes, texture, color, stroke, etc. So you'll see in these examples that there is something about each +[164.78s -> 166.64s] picture that is repeated. +[166.96s -> 181.36s] oftentimes the style and use of line or color or shading is repeated as well so it's not necessarily just the object but also the way the artist put the object on the page +[184.82s -> 199.36s] Emphasis is an accentuation of importance. It's the part of the artwork our eye is drawn to first. An artist uses color very often when trying to employ this principle of design. Color, shape, +[199.36s -> 205.01s] Size and placement are just some ways to emphasize part of an art piece. +[215.44s -> 229.07s] Movement is a directed path of optical motion. Movement is the direction our eyes wander through a scene. It can be directed by lines or by a change in color or even scale. +[248.46s -> 254.54s] Harmony refers to a way of combining elements to accent their similarities. +[256.43s -> 266.54s] A picture seems to be bound together as a whole when the elements are harmonious and it tends to have a visually satisfying effect. +[278.42s -> 293.17s] proximity is the placement of objects whether near or far from each other elements near each other are perceived as being related while elements spaced apart are perceived as belonging to separate groups +[310.22s -> 322.74s] Rhythm is a repetitive, organized movement or visual flow within an image. As you'll see in these examples, there is something similar that gets repeated over and over but it forms a +[322.74s -> 328.88s] type of rhythm. You know what to expect next, just like when you clap your hands to a beat. +[337.30s -> 347.84s] proportion is a scaling of objects in relation to each other proportion appeals to our sense of depth and scaling using relative size +[347.84s -> 361.26s] And elements feel right when they appear to be as they should be. But as you can see, proportion can be tweaked and we can make things as they're not supposed to be. It depends on what the artist is trying to get to. +[364.37s -> 371.25s] To create an effective composition an artist will always employ one or more of the principles of design. diff --git a/VideoMMMU_ASR_large/Art/new_Design_6.mp4.txt b/VideoMMMU_ASR_large/Art/new_Design_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..faa625e4e1d62a3c1d63a029c44a6dc97f976eb6 --- /dev/null +++ b/VideoMMMU_ASR_large/Art/new_Design_6.mp4.txt @@ -0,0 +1,30 @@ +[1.33s -> 13.01s] Color. It plays a vital role in design and everyday life. It can draw your eye to an image, evoke a certain mood or emotion, +[14.03s -> 27.70s] even communicate something important without using words at all. So how do we know which colors look good together and which ones don't? The answer is simple. Color theory. +[28.98s -> 43.70s] Artists and designers have followed color theory for centuries, but anyone can learn more about it. It can help you feel confident in many different situations, whether it's choosing colors for a design or putting together the perfect outfit. +[45.26s -> 56.02s] All it takes is a little insight, and you'll be looking at color in a whole new way. Let's start at the beginning, the very beginning, with a refresher on the basics. +[56.85s -> 71.06s] Remember learning about primary and secondary colors in school? Then you already have some knowledge of color theory. Red and yellow make orange, yellow and blue make green, and blue and red make purple. +[71.86s -> 84.88s] If we mix these colors together, we get even more in-between shades, like red-orange and yellow-green. All together, they form what's called a color wheel. You can probably see where it gets its name. +[85.65s -> 99.89s] Now, let's take it one step further with hue, saturation, and value. These are terms you might never see in daily life, but they're the key to understanding more nuanced colors, like all those little paint chips at the home improvement store. +[101.71s -> 114.80s] Hue is the easiest one. It's basically just another word for color. Saturation refers to intensity. In other words, whether the color appears more subtle or more vibrant. +[115.86s -> 128.88s] Value has to do with how dark or light the color is, ranging from black to white. As you can see, this gives us many different shades, from a deep reddish brown to light pastel pink. +[130.16s -> 142.67s] So how do we put this all together to create professional-looking color schemes? There are actually tried-and-true formulas based on something called color harmony that can help. All you need is the color wheel. +[143.92s -> 156.88s] The easiest formula for harmony is monochromatic because it only uses one color or hue. Just pick a spot on the color wheel and use your knowledge of saturation and value to create variations. +[157.01s -> 169.90s] The best thing about monochromatic color schemes is that they're guaranteed to match. An analogous color scheme uses colors that are next to each other on the wheel, like reds and oranges, +[170.29s -> 184.18s] or cooler colors like blues and greens. Don't be afraid to play with the palette and create your own unique interpretation. That's what these formulas really are, merely starting points to help guide and inspire you. +[185.97s -> 194.48s] Complementary colors are opposite each other on the wheel. For instance, blue and orange, or the classic red and green. +[195.02s -> 203.60s] To avoid complementary color schemes that are too simplistic, add some variety by introducing lighter, darker, or desaturated tones. +[205.14s -> 217.14s] A split complementary color scheme uses the colors on either side of the complement. This gives you the same level of contrast, but more colors to work with, and potentially more interesting results. +[218.83s -> 225.49s] A triadic color scheme uses three colors that are evenly spaced, forming a perfect triangle on the wheel. +[225.78s -> 233.94s] These combinations tend to be pretty striking, especially with primary or secondary colors So be mindful when using them in your work +[235.70s -> 247.76s] Tetradic color schemes form a rectangle on the wheel, using not one but two complementary color pairs. This formula works best if you let one color dominate while the others serve as an accent. +[250.51s -> 259.73s] There are a few classic do's and don'ts when it comes to color. For instance, have you ever seen colors that seem to vibrate when they're placed next to each other? +[260.24s -> 275.02s] The solution is to tone it down, literally, and there's a simple way to do it. Start with one color, and try adjusting its lightness, darkness, or saturation. Sometimes, a little contrast is all your color palette needs. +[276.50s -> 289.30s] Readability is an important factor in any design. Your color should be legible, engaging, and easy on the eyes. Sometimes that means not using color, at least not in every little detail. +[289.46s -> 297.10s] Neutral colors like black, white, and gray can help you balance your design. So when you do use color, it really stands out. +[299.18s -> 310.70s] Every color sends a message. It's important to consider the tone of your project and choose a color palette that fits. For example, bright colors tend to have a fun or modern vibe. +[311.15s -> 321.46s] Desaturated colors often appear more businesslike. Sometimes it just depends on the context. You'd be surprised how flexible color can be. +[322.83s -> 337.49s] You can find ideas for color schemes in all kinds of interesting places, from advertising and branding to famous works of art. You can even use a web resource to browse color palettes or generate your own. +[338.06s -> 347.06s] Even experienced designers take inspiration from the world around them. There's nothing wrong with finding something you like and making it your own. +[348.50s -> 356.94s] Everywhere you look there's color, color, and more color. It can be intimidating to use it in your work, but it doesn't have to be. +[358.22s -> 367.02s] Just keep experimenting, and remember what you've learned about color theory. Soon, choosing great-looking colors will feel like second nature. +[370.00s -> 379.82s] We hope you enjoyed learning the basics of color. Check out the rest of our design topics including typography, images, and composition. diff --git a/VideoMMMU_ASR_large/Art/validation_Art_Theory_15.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Art_Theory_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f1a51398ee6e7f380402bbad1b13a84186df6e8e --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Art_Theory_15.mp4.txt @@ -0,0 +1,54 @@ +[0.00s -> 10.75s] Surrealism. The surrealism was an artistic and literary movement that emerged in the early 20th century aiming to explore the unconscious mind and unleash creativity beyond rationality. +[10.75s -> 25.12s] Led by figures like Andre Breton and Salvador Dali, Surrealists sought to depict dreamlike imagery, juxtaposing unrelated elements in surprising ways to provoke thought and evoke strong emotions. Surrealist artworks often feature fantastical landscapes, +[25.12s -> 32.08s] bizarre creatures and symbolic motifs, inviting viewers to interpret their meanings freely. Romanticism +[32.08s -> 43.01s] The Romanticism art emerged in the late 18th and early 19th centuries as a reaction against the rationalism of the Enlightenment and the strictures of Neoclassicism. It emphasized emotion, +[43.01s -> 52.77s] imagination and individualism, celebrating nature, the sublime and the exotic. Romantic artists often depicted dramatic landscapes, turbulent skies, +[52.77s -> 64.30s] and awe-inspiring natural phenomena to evoke a sense of the sublime and the ineffable. They also explored themes of nationalism, folklore, and mythology celebrating the spirit of freedom and revolution. +[64.59s -> 74.40s] Realism Realism is an artistic movement that emerged in the 19th century primarily in Europe as a reaction against the idealized and romanticized portrayals of life. +[74.40s -> 88.91s] It aimed to depict everyday subjects and situations truthfully, without embellishment or idealization. Realist artists often focused on the lives of ordinary people, depicting their struggles, joys, and environments with meticulous detail and accuracy. +[89.26s -> 101.46s] Minimalism. The minimalism is an art movement that emerged in the 1960s, characterized by extreme simplicity and a focus on fundamental elements like geometric shapes, basic colors, and clean lines. +[101.46s -> 107.47s] artists sought to strip away excess and decoration, creating works that emphasize pure form and presence. +[107.47s -> 117.54s] Minimalist art often invites viewers to engage directly with the physical qualities of the artwork and the surrounding space, encouraging contemplation and reflection. +[117.54s -> 130.19s] The Renaissance art was characterized by a revival of interest in classical Greek and Roman art, leading to a focus on realism, perspective, and humanism. Renaissance artists such as Leonardo da Vinci, Michelangelo, and Raphael +[130.19s -> 144.19s] created works that emphasized accurate depiction of the human form, lifelike expressions, and spatial depth. Their masterpieces, including paintings, sculptures, and architecture, reflected a renewed appreciation for the individual, nature, +[144.19s -> 158.06s] and the pursuit of knowledge. Baroque The Baroque art characterized by dramatic use of light and shadow, intense emotion, and rich, detailed compositions. Baroque artists aim to evoke powerful emotional responses in viewers. +[158.06s -> 169.23s] often employing dynamic compositions and theatrical effects. Religious themes were prevalent, with artists seeking to convey spiritual messages with heightened drama and intensity. +[169.23s -> 179.39s] The Expressionism was an art movement that emerged in the early 20th century, primarily in Germany. It aimed to convey emotional and psychological experiences rather than physical reality. +[179.39s -> 192.11s] Often through distorted or exaggerated forms and vivid colors, expressionist artists such as Edvard Munch and Ernst Ludwig Kirchner sought to evoke intense feelings and explore themes of angst, alienation, and inner turmoil. +[192.11s -> 201.94s] Abstract Expressionism The Abstract Expressionism was a post-World War II art movement that originated in New York City in the 1940s and 1950s. +[201.94s -> 213.33s] It emphasized spontaneous intuitive and emotional expression through abstract forms and gestural brushwork. Artists such as Jackson Pollock, Willem de Kooning, and Mark Rothko were central figures in this movement. +[213.33s -> 226.50s] Abstract expressionists often explored themes of individuality, the subconscious, and the act of painting itself, rejecting traditional representation in favor of conveying raw emotion and inner experience on canvas. Fauvism +[226.50s -> 240.40s] Favism was an early 20th century art movement characterized by bold colors, spontaneous brushwork, and simplified forms. Artists like Henri Matisse and Andre Duran were key figures, emphasizing emotional expression over realistic representation. +[240.56s -> 248.34s] Cubism. The Cubism was an influential art movement pioneered by Pablo Picasso and Georges Braque in the early 20th century. +[248.34s -> 256.62s] It revolutionized traditional artistic representation by breaking down subjects into geometric shapes and depicting multiple viewpoints simultaneously. +[256.62s -> 266.74s] Cubist artworks often feature fragmented forms, abstract shapes, and a flattened perspective, challenging viewers to rethink how they perceive space and form. Classicism +[266.74s -> 276.70s] The classicism refers to a movement in art and literature that draws inspiration from ancient Greek and Roman cultures, particularly their emphasis on harmony, balance, and order. +[276.70s -> 290.85s] It emerged during the Renaissance and experienced revivals in various periods, including the 17th and 18th centuries. Classicism prioritizes clarity, simplicity, and idealized forms rejecting the extravagant ornamentation of preceding styles. +[290.85s -> 301.46s] Artists like Jacques-Louis David and Nicolas Poussin are renowned for their classical works which often depict heroic or mythological themes with a sense of timeless grandeur and dignity. +[301.97s -> 308.82s] Symbolism The symbolism was an artistic and literary movement that emerged in the late 19th century, primarily in France. +[308.82s -> 317.81s] It emphasized the use of symbols and metaphors to evoke emotions, dreams, and spiritual experiences. Symbolist artists such as Gustav Klimt and Odilon Radon +[317.81s -> 332.30s] sought to convey abstract ideas and inner visions rather than represent objective reality. Symbolism often featured dreamlike imagery, mythological motifs, and richly symbolic content exploring themes of mysticism, spirituality, and the subconscious mind. +[332.30s -> 343.71s] Op art. The op art, short for optical art, is a style of visual art that uses optical illusions and geometric patterns to create the impression of a movement, depth, or distortion. +[343.71s -> 354.46s] It often employs contrasting colors and precise, repetitive shapes to stimulate the eye and mind, creating a dynamic and sometimes disorienting visual experience. Futurism +[354.46s -> 368.69s] The Futurism was an avant-garde movement that emerged in Italy in the early 20th century. It celebrated modern technology, speed, and the dynamism of urban life, advocating for the rejection of traditional artistic forms in favor of embracing the future. +[368.69s -> 382.05s] Artists like Umberto Boccioni and Giacomo Balla depicted motion and energy through fragmented forms, dynamic compositions, and vibrant colors. Dada Dada was an avant-garde movement that emerged during World War I. +[382.05s -> 394.53s] originating in Zurich, Switzerland. It rejected traditional artistic conventions and embraced absurdity, chaos, and anti-establishment sentiments. Dadaists like Marcel Duchamp and Tristan Tzara used collage. +[394.53s -> 407.86s] found objects and performance art to challenge the rationality of society and the art world. Dada's legacy lies in its subversion of artistic norms and its influence on later movements such as surrealism and conceptual art. +[408.14s -> 418.53s] Art Nouveau, a late 19th and early 20th century art movement embraced organic forms, flowing lines, and intricate patterns. It emerged as a reaction against the academic art of the time. +[418.53s -> 430.46s] seeking to integrate art into everyday life through architecture, interior design, and decorative arts. Inspired by nature and exotic cultures, Art Nouveau artists like Alphonse Mucha and Hector Guimard +[430.46s -> 436.69s] aimed to create a total aesthetic experience characterized by its sinuous curves and ornamental motifs. +[437.20s -> 448.29s] Impressionism The Impressionism was an art movement in the late 19th century characterized by capturing the fleeting effects of light and atmosphere through loose brushwork and vivid colors. +[448.29s -> 461.60s] It focused on depicting everyday scenes, often outdoors, with an emphasis on conveying the artist's impression rather than precise details. Key artists include Claude Monet, Edgar Degas, and Pierre-Auguste Renoir. Post-Impressionism +[461.60s -> 472.90s] The Post-Impressionism was an art movement that emerged in the late 19th century as a reaction to Impressionism. Artists associated with Post-Impressionism, such as Paul Cézanne, Vincent Van Gogh, and Georges Seurat, +[472.90s -> 483.57s] built upon Impressionist techniques while pushing the boundaries of color, form, and expression. They focused on subjective interpretations of reality using bold colors, distinctive brushwork, +[483.57s -> 495.47s] and innovative compositions to convey emotions and ideas. Rococo The Rococo was an artistic movement that flourished in Europe during the 18th century, particularly in France. +[495.47s -> 509.68s] It is characterized by its ornate and playful style, featuring delicate pastel colors, asymmetrical compositions, and lavish decorations. Rococo art often depicted scenes of leisure, love, and frivolity reflecting the aristocratic culture of the time. +[510.06s -> 520.48s] Neoclassicism The Neoclassicism was an artistic and architectural movement that emerged in the 18th century as a reaction against the excesses of the Rococo style. +[520.48s -> 529.34s] Inspired by the ideals of ancient Greek and Roman art, neoclassical artists sought to revive the classical aesthetic of harmony, proportion, and clarity. +[529.34s -> 542.35s] Rejecting the ornate decoration of the rococo, neoclassical works emphasized clean lines, symmetry, and a return to classical subject matter, such as historical events and mythological themes. Mannerism +[542.35s -> 554.75s] The Mannerism was an art movement that emerged in the late Renaissance period, primarily in Italy during the 16th century. It is characterized by a departure from the balance, harmony, and naturalism of high Renaissance art. +[554.75s -> 567.50s] Mannerist artists deliberately distorted proportions, exaggerated poses, and employed intricate compositions to create a sense of elegance, sophistication, and intellectual complexity in their works. +[567.50s -> 581.02s] The modern art encompasses a wide range of artistic styles and movements that emerged in the late 19th and early 20th centuries, breaking away from traditional forms and techniques. It includes movements like cubism, surrealism, +[581.02s -> 591.82s] abstract expressionism, and pop art among others. Modern art often explores new concepts, materials, and techniques and can be highly experimental and diverse in its expressions. +[592.53s -> 604.45s] Precisionism. Precisionism was an American art movement in the early 20th century known for its precise, detailed portrayal of urban and industrial landscapes. Artists depicted scenes with sharp lines, geometric shapes, and smooth surfaces. +[604.45s -> 613.94s] Capturing the modernization and industrialization of America, this style often emphasized the beauty and order found in architecture, machinery, and infrastructure. diff --git a/VideoMMMU_ASR_large/Art/validation_Design_12.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Design_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..63d88661c6703117277622980bb861eaf421a69d --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Design_12.mp4.txt @@ -0,0 +1,20 @@ +[1.20s -> 14.08s] hello everyone today we will learn the type of sleeves or the construction of sleeves well a sleeves can be classified on the basis of its length on the basis of fitting +[14.08s -> 23.44s] and on the basis of sleeve lines or construction besides that when it comes to styling a sleeve can be of numerous types +[23.44s -> 32.03s] but here we will focus on the types or the classification of sleeves on the basis of length fitting and its construction pattern +[32.03s -> 41.70s] Well, on the basis of length, sleeve can be of seven types. The first is sleeveless, where there is no sleeves or which is also known as tank. +[41.70s -> 50.59s] Then comes the cap sleeves which ends at the height of your cap. A sleeve that covers the cap height of your hand. +[50.59s -> 64.90s] then comes short sleeves which is also known as t-shirt sleeves that ends in between your shoulder point and the elbow then comes the above elbow sleeves or sleeves that ends right above your +[64.90s -> 75.73s] elbow and then comes the mid length sleeves or below elbow sleeves as the name suggests it ends below your elbow then comes the three quarter sleeves +[75.73s -> 90.00s] or three-fourth sleeve or quarter sleeves that ends somewhere at the mid of your elbow to wrist point that usually covers the three-fourth section of your hand and lastly comes the long sleeves which ends +[90.00s -> 91.46s] at your wrist +[91.46s -> 105.79s] besides that when it comes to fashion styling and creativity a sleeve can be long enough to touch the floor or it can be sleeveless right now come to the next section which is sleeves +[105.79s -> 118.80s] classification of sleeves according to the fitting when it comes to fitting it can be too fitted or too loose as we all know so here is a skin fitted sleeves which lies next to your skin +[118.80s -> 130.88s] Then comes fitted sleeves which is slightly loose as compared to the skin fitted sleeves. Then comes loose sleeves or basic sleeves which is a straight sleeves. +[130.88s -> 140.77s] then comes bell sleeves that has a slightly bell kind of shape and lastly comes the flare sleeves now the third classification is based +[140.77s -> 149.74s] on the construction of this which is also known as sleeve lines or the way we join sleeve to the top or the upper garment +[149.74s -> 164.56s] So it can also be divided into two parts which is separate construction and continuous construction. There are four types in separate construction. These are satin sleeves, raglan sleeves, +[165.14s -> 167.38s] Saddle sleeves or +[168.21s -> 182.80s] Drop sleeves and the second part is continuous construction where there is no cutting between the top and the sleeves. It is a single fabric or the single pattern that covers the upper body as well as the sleeve part. +[182.80s -> 186.74s] is round yoke and dormancy. There are only two types. +[186.74s -> 201.04s] so this is your classification of sleeves on the basis of length fitting and construction or sleeve lengths or on the basis of construction the way it is being joined to the top or the upper gown that's it i hope you understand +[201.04s -> 203.76s] Thank you. diff --git a/VideoMMMU_ASR_large/Art/validation_Music_3.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Music_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..4bb5ed643aaefe8de725d668512a0ee4ad22cd33 --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Music_3.mp4.txt @@ -0,0 +1,35 @@ +[0.00s -> 5.98s] Intervals, part one. Half of everything you need to know so you don't fail music class in seven minutes. +[5.98s -> 20.43s] Intervals are a measurement of the distance between two notes. They're an important part of the vocabulary of music and are useful in discussing the qualities, structure, and functions of scales, chords, and melodies. They are also useful for increasing your prowess at sight reading, sight singing, composition, and +[20.43s -> 34.64s] and improvisation. As with most things in music theory, familiarity with major scales and key signatures is fundamental to understanding intervals. If you're not confident on those concepts, you're going to have a bad time. Check the links in the description if you need to brush up on those concepts. Intervals are defined by a +[34.64s -> 47.68s] They have names like major third, minor third, diminished third, or augmented third, or perfect fifth, diminished fifth, or augmented fifth. The quality of an interval is determined by comparing the top note to the major scale of the bottom note. +[47.68s -> 62.03s] The number is much simpler, so we'll start there. The number in an interval is a measure of the relative position of two notes on the staff. It's defined by how many letter names are between the two notes, including the notes themselves. For instance, this is a fifth, because from A to E, there are five +[62.03s -> 76.26s] letter names you might imagine there are notes on every line in space and count each one one two three four five a to e is a fifth it's important to note that the number of the interval is independent of any accidentals that might be on the notes so +[76.26s -> 89.26s] This is still a fifth, as is this and this and even this. They're all five letter names away on the staff, so they're all fifths. Let's look at a few more. This is a second, a third, and a fourth. Here's a sixth and a seventh. +[89.84s -> 103.82s] And here's a 9th and an 11th. Intervals of 1 or 8 have special names because they involve two notes of the same name, like C to C or C to C. They're still notated with a number, but are commonly referred to as unison and octave. +[103.82s -> 117.28s] A 15th is two octaves, like C to C, but for some reason it doesn't have a special name. Personally, I like to call it Duboctia, the Destroyer. To review, this is a unison, second, third, fourth, fifth, sixth... +[117.28s -> 126.27s] 7th, and 8th, as well as 9th, 10th, 11th, 12th, 13th, 14th, and Dabhaktia, the Destroyer. +[126.27s -> 138.85s] As we said before, intervals also have a quality, such as major, minor, perfect, augmented, or diminished. There are a number of different symbols and abbreviations that are used for these qualities, but I'll be using these because I think they're the least ambiguous. +[138.85s -> 151.60s] In any major scale, the interval from the first note of that scale to the first, fourth, fifth, or eighth notes of the scale are referred to as perfect. Perfect unison, perfect fourth, perfect fifth, and perfect octave. +[151.60s -> 162.32s] The distance from the first note of the scale to the second, third, sixth, and seventh note are all referred to as major. Major second, major third, major sixth, and major seventh. +[162.32s -> 172.86s] Of course, these interval qualities are the same for any major scale. For instance, in D major, from the first note of the scale, the interval of unison, fourth, fifth, or octave are all called perfect. +[172.86s -> 181.54s] and a second, third, sixth, and seventh are all called major. You may be wondering, why are some intervals called perfect and some intervals are called major? +[181.54s -> 194.06s] Look, I know it seemed arbitrary. There's a reason. I promise. It just won't make any sense until we cover a little bit more. For now, just go with it. So far, we've only been looking at intervals from the first note of a major scale to any other note in that scale. +[194.06s -> 207.62s] But what happens if the upper note doesn't appear in the major scale of the bottom note? That's when you get into those other qualities, minor, diminished, and augmented. The quality of an interval is determined by comparing it to the major or perfect interval that normally occurs in a major scale. +[207.62s -> 219.42s] For instance, these are all thirds. C to E is a major third because E is natural in C major. All the other thirds have been altered from the major third in some way. C to E flat is one semitone smaller. +[219.42s -> 233.71s] it's referred to as a minor third. Any major interval that's been made smaller by a semitone is referred to as minor. Any interval that's been made two semitones smaller, like C to E double flat, is known as diminished. Finally, any major interval that's been made a semitone larger is +[233.71s -> 236.24s] augmented, like C to E sharp. +[236.66s -> 250.21s] This applies to all the major intervals. These are all sixths. The first one is major because A is natural in the key of C. The next is a minor sixth because the interval is one semitone smaller than the major. Next is diminished because it's two semitones smaller than the major. +[250.21s -> 264.11s] and the last one is augmented because it's one semitone larger than the major. These are all seconds and sevenths. As you can see, the major intervals are just as they appear in the major scale. The minor intervals are one semitone smaller. The diminished intervals are two semitones smaller. +[264.11s -> 272.27s] and the augmented intervals are one semitone larger. Let's try another key. D to F sharp is a major third, because F is sharp in D major. +[272.27s -> 285.17s] D to F natural is one semitone smaller than the major third, so it's a minor third. D to F flat is two semitones smaller than the major third, so it's diminished. D to F double sharp is one semitone larger than the major third, so it's an augmented third. +[285.17s -> 292.69s] And here are the different possible seconds, sixths, and sevenths in D major. Pause the video if you'd like to inspect and compare the intervals. +[293.87s -> 307.22s] So far, we've only been talking about alterations for major intervals. The perfect intervals are similar with one important difference. While the major intervals have four forms, major, minor, augmented, and diminished, the perfect intervals only have three. +[307.22s -> 320.34s] Augmented is the same, one semitone larger. But one semitone smaller is called diminished. There is no minor version of the perfect intervals. I know you're still wondering why some intervals are perfect and others are major. I haven't forgotten. We're getting there. +[320.34s -> 332.26s] So, this first interval is a perfect fifth, because G is natural in C major. But, if it's made a semitone larger, it's an augmented fifth. And, if it's a semitone smaller, it's a diminished fifth. Same thing for fourth. +[332.26s -> 346.13s] This is a perfect fourth. One semitone larger is augmented and one semitone smaller is diminished. Also, the perfect octave can be made augmented or diminished by making it a semitone larger or smaller. A perfect unison can be augmented +[346.13s -> 360.43s] But a diminished unison isn't really a thing. Remember, an interval is always evaluated by the key of the lower note. If you had a perfect unison and made the upper note lower, then you've actually made it lower than the first note, and now nothing makes sense. It's kind of like dividing a number by zero. +[360.43s -> 370.16s] It makes things complicated. So, to review, a major interval is any second, third, sixth, or seventh where the upper note appears in the major scale of the lower note. +[370.16s -> 377.73s] A major interval that's been made a semitone smaller is known as minor, two semitones smaller is diminished, and a semitone larger is augmented. +[377.73s -> 390.38s] A perfect interval is any unison, fourth, fifth, or octave where the upper note appears in the major scale of the lower note. A perfect interval that's been made a semitone smaller is known as diminished. If it's been made a semitone larger, it's augmented. +[390.38s -> 402.91s] And that's half of what you need to know about intervals. In part two, we'll cover intervals larger than an octave, what to do if the bottom note isn't in a major scale, and inversions, which will finally explain why some intervals are perfect and some are major. +[402.91s -> 407.73s] Be sure to like, comment, share, and subscribe for more videos. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Art/validation_Music_4.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Music_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..faa625e4e1d62a3c1d63a029c44a6dc97f976eb6 --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Music_4.mp4.txt @@ -0,0 +1,30 @@ +[1.33s -> 13.01s] Color. It plays a vital role in design and everyday life. It can draw your eye to an image, evoke a certain mood or emotion, +[14.03s -> 27.70s] even communicate something important without using words at all. So how do we know which colors look good together and which ones don't? The answer is simple. Color theory. +[28.98s -> 43.70s] Artists and designers have followed color theory for centuries, but anyone can learn more about it. It can help you feel confident in many different situations, whether it's choosing colors for a design or putting together the perfect outfit. +[45.26s -> 56.02s] All it takes is a little insight, and you'll be looking at color in a whole new way. Let's start at the beginning, the very beginning, with a refresher on the basics. +[56.85s -> 71.06s] Remember learning about primary and secondary colors in school? Then you already have some knowledge of color theory. Red and yellow make orange, yellow and blue make green, and blue and red make purple. +[71.86s -> 84.88s] If we mix these colors together, we get even more in-between shades, like red-orange and yellow-green. All together, they form what's called a color wheel. You can probably see where it gets its name. +[85.65s -> 99.89s] Now, let's take it one step further with hue, saturation, and value. These are terms you might never see in daily life, but they're the key to understanding more nuanced colors, like all those little paint chips at the home improvement store. +[101.71s -> 114.80s] Hue is the easiest one. It's basically just another word for color. Saturation refers to intensity. In other words, whether the color appears more subtle or more vibrant. +[115.86s -> 128.88s] Value has to do with how dark or light the color is, ranging from black to white. As you can see, this gives us many different shades, from a deep reddish brown to light pastel pink. +[130.16s -> 142.67s] So how do we put this all together to create professional-looking color schemes? There are actually tried-and-true formulas based on something called color harmony that can help. All you need is the color wheel. +[143.92s -> 156.88s] The easiest formula for harmony is monochromatic because it only uses one color or hue. Just pick a spot on the color wheel and use your knowledge of saturation and value to create variations. +[157.01s -> 169.90s] The best thing about monochromatic color schemes is that they're guaranteed to match. An analogous color scheme uses colors that are next to each other on the wheel, like reds and oranges, +[170.29s -> 184.18s] or cooler colors like blues and greens. Don't be afraid to play with the palette and create your own unique interpretation. That's what these formulas really are, merely starting points to help guide and inspire you. +[185.97s -> 194.48s] Complementary colors are opposite each other on the wheel. For instance, blue and orange, or the classic red and green. +[195.02s -> 203.60s] To avoid complementary color schemes that are too simplistic, add some variety by introducing lighter, darker, or desaturated tones. +[205.14s -> 217.14s] A split complementary color scheme uses the colors on either side of the complement. This gives you the same level of contrast, but more colors to work with, and potentially more interesting results. +[218.83s -> 225.49s] A triadic color scheme uses three colors that are evenly spaced, forming a perfect triangle on the wheel. +[225.78s -> 233.94s] These combinations tend to be pretty striking, especially with primary or secondary colors So be mindful when using them in your work +[235.70s -> 247.76s] Tetradic color schemes form a rectangle on the wheel, using not one but two complementary color pairs. This formula works best if you let one color dominate while the others serve as an accent. +[250.51s -> 259.73s] There are a few classic do's and don'ts when it comes to color. For instance, have you ever seen colors that seem to vibrate when they're placed next to each other? +[260.24s -> 275.02s] The solution is to tone it down, literally, and there's a simple way to do it. Start with one color, and try adjusting its lightness, darkness, or saturation. Sometimes, a little contrast is all your color palette needs. +[276.50s -> 289.30s] Readability is an important factor in any design. Your color should be legible, engaging, and easy on the eyes. Sometimes that means not using color, at least not in every little detail. +[289.46s -> 297.10s] Neutral colors like black, white, and gray can help you balance your design. So when you do use color, it really stands out. +[299.18s -> 310.70s] Every color sends a message. It's important to consider the tone of your project and choose a color palette that fits. For example, bright colors tend to have a fun or modern vibe. +[311.15s -> 321.46s] Desaturated colors often appear more businesslike. Sometimes it just depends on the context. You'd be surprised how flexible color can be. +[322.83s -> 337.49s] You can find ideas for color schemes in all kinds of interesting places, from advertising and branding to famous works of art. You can even use a web resource to browse color palettes or generate your own. +[338.06s -> 347.06s] Even experienced designers take inspiration from the world around them. There's nothing wrong with finding something you like and making it your own. +[348.50s -> 356.94s] Everywhere you look there's color, color, and more color. It can be intimidating to use it in your work, but it doesn't have to be. +[358.22s -> 367.02s] Just keep experimenting, and remember what you've learned about color theory. Soon, choosing great-looking colors will feel like second nature. +[370.00s -> 379.82s] We hope you enjoyed learning the basics of color. Check out the rest of our design topics including typography, images, and composition. diff --git a/VideoMMMU_ASR_large/Art/validation_Music_5.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Music_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f98b5e5fb7f676ddbacb0c998c72dc864244017e --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Music_5.mp4.txt @@ -0,0 +1,14 @@ +[1.01s -> 6.06s] In this video you will learn the names of the scale degrees. +[24.59s -> 38.00s] A scale degree is the position of a particular note on a scale relative to the first note of the scale. In other words, each note in a major and minor scale has a name that matches its function. +[39.41s -> 53.26s] Each note of a major and minor scale also has a name. Tonic, supertonic, mediant, subdominant, dominant, submediant, leaning tone, and then tonic again. +[54.29s -> 58.26s] The tonic is the name of the first note of a scale. +[59.66s -> 70.40s] This is the tonal center or pitch center of a piece or a song. Where do these names come from? The word dominant is inherited from medieval music theory. +[70.40s -> 84.88s] and refers to the importance of the fifth above the tonic in music. The word mediant means middle and refers to the fact that the mediant is in the middle of the tonic and dominant pitches. +[87.50s -> 96.40s] The Latin prefix super means above, so the supertonic is the second above the tonic. This is the only super interval. +[97.87s -> 111.73s] The Latin prefix sub means below. The subtonic, submediant, and subdominant are the inverted versions, meaning below the tonic, of the supertonic, median, and dominant. +[112.50s -> 127.25s] When the subtonic is only a half step below the tonic, it is called a leading tone. Let us show this a different way. Here is the tonic. The dominant is a fifth above the tonic. +[127.57s -> 141.62s] The subdominant is a fifth below the tonic. Between the tonic and the dominant is the mediant. Between the subdominant and the tonic is the submediant. +[142.32s -> 151.25s] A step up from the tonic is the supertonic. The step below is the subtonic or leading tone. +[151.89s -> 165.70s] So when you put these names in a scale, they are in this order. Tonic, supertonic, mediant, subdominant, dominant, submediant, subtonic, or leading tone. +[165.70s -> 172.46s] And here is what you have learned today. Keep practicing, and I will see you in the next video. +[172.88s -> 184.58s] If you liked the video, please hit like. If you would like to see more videos, please subscribe to my channel. You can also leave a comment or a question in the comment section below. diff --git a/VideoMMMU_ASR_large/Art/validation_Music_7.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Music_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7953666406be523b48188c728bd9f75963892977 --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Music_7.mp4.txt @@ -0,0 +1,35 @@ +[0.40s -> 14.08s] Functional harmony is a set of rules you can use to create logical chord progressions that sound quote-unquote right. It may sound complicated at first, but it's actually pretty easy. So let's go ahead and jump in. First, let's take a look at this diagram. +[14.08s -> 23.01s] Here we see all the chords within the key of C and then we have numbers underneath them sort of to represent them with Roman numerals. If it's an uppercase +[23.01s -> 31.50s] Roman numeral, then it's a major chord. If it's lowercase, it's minor. And if it's lowercase with the little diminished symbol, then it's, you know, a diminished chord. +[31.50s -> 43.74s] And by the way, I'll have a larger graphic at the end of this video. I'll put a timestamp up there for you, and it will show multiple keys so that you can use it as like a reference point along with this diagram using Roman numerals. +[43.74s -> 56.03s] So we have all the chords in the key of C, and we've numbered them and such, but the real question is, what order do we play them in, in such a way that, you know, it sounds like it should? To start off, we need to name a few different types of chords. +[56.03s -> 70.35s] The one chord and the three chord are called tonic chords. They're like the home base. They're kind of what everything revolves around. Ultimately, you're going to end with your one chord, right? That's the big chord you hear at the end of your composition or your chord progression. +[70.35s -> 79.62s] or whatever. So keep that in mind. Those are kind of the home base that we're trying to get to. Then we have the dominant chords. So that's going to be the 5 and the 7 chord. +[79.62s -> 93.07s] And then the last group of chords we have are the subdominant chords, which is everything else. It's going to be the 2, the 4, and the 6. Here's how things flow. Tonic is our home, or our root, like we said before. +[93.07s -> 104.11s] So we start from the tonic, and then from tonic chords we can go anywhere we want. We can go to a subdominant or a dominant, whatever. Once we get to a dominant, the dominant chord always wants to go back to the one. +[104.11s -> 116.46s] If we go to a subdominant, subdominant chords want to go to dominant. So your progression would either be a tonic chord to a dominant chord and then a tonic, or it could be like a tonic to a subdominant, then dominant. +[116.46s -> 125.39s] and then tonic, so that's sort of the way it works. Now let's go back to our first diagram. I'm going to put a T for tonic chords underneath the 1 and the 3. +[125.39s -> 139.60s] and then I'm going to put just a quick abbreviation for subdominance under the subdominance, and an abbreviation for dominance under the dominant, so that you can kind of, just looking at this graph, see how things are functioning. +[139.60s -> 147.57s] So let's actually go ahead and make up a chord progression. We'll start with our I chord, that's kind of a given, and let's go to a subdominant chord. So we'll go to the IV chord. +[147.57s -> 157.76s] And then from there, we're going to go to a dominant chord, which will be our V chord. Usually you want to go to the V chord for your dominant chord. It sounds a lot better than the VII in a major key, especially. +[157.76s -> 167.73s] But then we'll go from our 5 chord back to our 1. So we're just going 1, 4, 5, and then 1. So tonic, subdominant, dominant, tonic. Alright, listen to how this sounds. +[176.50s -> 188.98s] Alright, now let's do a different progression. We'll start with the tonic chord, and then we'll go to the IV chord again, a subdominant. But now we can go to any other subdominant we want to before we go to the dominant. So we're going to go to our IV, and now let's go to the II. +[188.98s -> 196.88s] And then from the 2, a subdominant, we'll go to the 5, our dominant, and then back to 1. So now we have a slightly longer chord progression. Check out how this sounds. +[206.42s -> 218.19s] Now here's another example where we play two tonic chords, and we go through three subdominant chords, then our dominant chord and our 1, right? So we're going to go 1, 3, 6, 4, 2. +[218.19s -> 223.76s] five one right so you see the kind of the flow here um check this out it sounds really cool +[239.34s -> 251.41s] Now, you may have noticed how a lot of times we're ending our chord progressions with a 5-1. And that's actually very normal in Western music. It has a name. It's called a cadence. There are a few exceptions to this rule, though. +[251.41s -> 261.49s] And there's some other, like, cadences that we have. They're very specific, though, and they're not used all the time. The first one that you see a lot is the 5 going to the 6. +[261.49s -> 271.71s] So instead of going to the 1 at the end, the 5 goes to the 6, which is weird because that's a dominant going to a subdominant, but it's one of those exceptions that you can use at the end of your chord progression. +[271.71s -> 283.70s] This makes a really cool sound. Just for the sake of comparison, let's do a 1-4-5-1, and then let's do a 1-4-5-6, so that you can kind of hear the juxtaposition of the two. +[302.70s -> 313.12s] So that's called a deceptive cadence when you go from the 5 to the 6. We call it deceptive because your ear kind of expects the 5 to go to 1 because that's what you hear all the time. +[313.12s -> 324.35s] but because it goes to the 6th, it's deceptive, quote-unquote. So, that's one cadence. There's another cadence that we should also take a look at called the plagal cadence. Sometimes it's called the amen cadence because you hear it often in hymns. +[324.35s -> 336.62s] So in this cadence, you're going to go from the 4 to the 1. So that's super crazy. Now we're going from a subdominant to a tonic, right? So that's kind of breaking the rules again, but it actually has a very pretty sound. +[336.62s -> 350.38s] So let's do an example real quick. We'll go 1, 2, 4, 1. So we're going tonic to two subdominants and then back to tonic. A little bit weird, but it actually has a very pretty sound to it. Check it out. +[358.42s -> 372.19s] Alright, that's pretty much all you need to know, but let's go ahead and take a look at minor keys. Everything here is actually the same. As you can see from this first diagram, everything looks a little bit different, the chords, but everything still functions the same. +[372.19s -> 384.29s] The 1 and the 3 are still tonic chords. The 2, the 4, and the 6 are still subdominant. And the 5 and the 7 are dominant. So all the same rules apply here. +[384.29s -> 394.83s] Let's make a quick progression here. We'll go from the 1 to the 3, both tonic chords, and then let's do a subdominant. So we'll do the 4, and then we'll go to the 5 here, and then back to the 1. So give this a quick listen. +[408.40s -> 422.18s] All right, that's pretty much it. Here's that larger graphic I was telling you about earlier. Hopefully you find this helpful. I have not all the keys, but a good number of the keys that you would normally be seeing along with the Roman numerals. +[422.18s -> 433.12s] So check this out, start kind of experimenting with playing these progressions in different orders following these rules, and let me know if you have any questions. And also as an added note here at the end... +[433.12s -> 446.56s] don't be afraid to kind of do whatever you want you don't have to follow these rules you don't have to go in this order um this is it's good to kind of know these rules as a guideline but it's not the end of the world if you like if you play some +[446.56s -> 460.06s] random chord progression and you think it sounds cool, that's fine. You can go with it. There's nothing wrong with that. I, for a long time, thought you had to do only functional harmony progressions, but you really don't. You can kind of do whatever you want. +[460.06s -> 466.38s] So that being said, knock yourselves out and best of luck to you guys. I'll talk to you next week. diff --git a/VideoMMMU_ASR_large/Art/validation_Music_8.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Music_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..71aa0483de55c407a4e6d03cc973c228083297ec --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Music_8.mp4.txt @@ -0,0 +1,15 @@ +[0.85s -> 5.65s] In this video you will learn how to read this. +[29.84s -> 40.45s] A major seventh chord is formed by adding another third above the fifth of the chord. There are five different seventh chords. Major, dominant, minor, half diminished, and full diminished. +[40.45s -> 53.01s] A major seventh chord has a major triad and an interval of a major seventh above the root. To make it a dominant seventh chord, lower the seventh a half step. To make it a minor seventh chord, lower the third and the seventh a half step. +[53.01s -> 65.58s] To make it a half diminished 7th chord, lower the 3rd, 5th, and 7th a half step. To make it a full diminished 7th chord, lower the 3rd and the 5th a half step, and the 7th a whole step. Let us start with the C major 7th chord. +[65.58s -> 78.90s] The notes C, E, and G make a C major triad and the note B is a major 7th above the note C. To make it a C dominant 7th chord, lower the 7th from the note B natural to the note B flat. To make it a C minor 7th, +[78.90s -> 92.51s] Lower the third from the note E natural to the note E flat. To make it a C half diminished seventh, lower the fifth from the note G natural to the note G flat. To make it a C full diminished seventh, lower the note B flat to the note B double flat. +[92.51s -> 106.40s] Let us make a G full diminished chord. Start with a major triad using note G, B, and D, and a major seventh above the root, which is the note F sharp. Lowering the seventh a half step from the note F sharp to F natural would make this a G dominant seventh chord. +[106.40s -> 117.36s] Lowering a third a half step from the note B natural to B flat would make this a G minor seventh chord. Lowering the fifth on the note D natural to the note D flat would make this a G half diminished seventh chord. +[117.36s -> 126.21s] Lowering the 7th from the note F natural to the note F flat would make this a G full diminished 7th chord. Let us make an E full diminished 7th chord. +[126.21s -> 137.60s] Make an E major triad with the notes E, G sharp, and B, and a major 7th above the root with the note D sharp. To make it a dominant 7th chord, lower the 7th with the note D sharp to D natural. +[137.60s -> 149.95s] To make it a minor 7th chord, lower the 3rd from the note G sharp to G natural. To make it a half diminished 7th chord, lower the 5th from the note B natural to B flat. To make it a full diminished 7th chord, +[149.95s -> 163.22s] Lower the 7th from the note D natural to D flat. Let us do one more. A F full diminished 7th chord. Make an F major triad with the notes F, A, and C, and a major 7th above the root with the note E. +[163.22s -> 176.88s] To make it a dominant 7th chord, lower the 7th from the note E natural to E flat. To make it a minor 7th chord, lower the 3rd from the note A natural to A flat. To make it a half diminished 7th chord, lower the 5th from the note C natural +[176.88s -> 190.90s] to C flat. To make it a full diminished chord, lower the seventh with the note E flat to E double flat. And here is what you have learned today. Keep practicing, and I will see you in the next video. +[195.95s -> 207.89s] If you liked the video, please hit like. If you would like to see more videos, please subscribe to my channel. You can also leave a comment or a question in the comment section below. diff --git a/VideoMMMU_ASR_large/Art/validation_Music_9.mp4.txt b/VideoMMMU_ASR_large/Art/validation_Music_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6507cbac541d80888ba86e7ff4d1b0bca9a0f88e --- /dev/null +++ b/VideoMMMU_ASR_large/Art/validation_Music_9.mp4.txt @@ -0,0 +1,17 @@ +[0.85s -> 5.65s] In this video you will learn how to read this. +[32.27s -> 36.85s] Inverting a chord is not simply rearranging the notes of the chord. +[37.42s -> 49.66s] This chord is still in root position because the root of the chord is the lowest note. In an inverted chord, the root is not the lowest note. To make this chord into a first inversion, +[49.66s -> 63.82s] move the root up an octave making the third of the chord the lowest note. This chord will still be in first inversion as long as the third of the chord is the lowest note, even when we move or double the notes in the chord. +[64.91s -> 72.53s] To make this chord into a second inversion, move the third of the chord up an octave, making the fifth of the chord the lowest note. +[74.42s -> 88.37s] Inversions are notated using numbers called fingered bass. The numbers indicate the number of scale steps above the bass note of the chord. In the first inversion of the chord, the intervals above the bass are a sixth and a third. +[88.37s -> 103.18s] The first inversion is notated by just using the number 6. In the second inversion, the intervals above the bass note are a 6th and a 4th. The second inversion is notated by using the number 6 and a 4. +[103.66s -> 112.91s] An often used notation for chord inversions in jazz, pop, and rock is to write the name of the chord followed by a forward slash and then the name of the bass note. +[113.58s -> 121.20s] The chord symbol F slash A would be a first inversion F major chord, with the note A being the lowest note. +[122.32s -> 134.99s] For seventh chords, there are three inversions. Let us start with a C dominant seventh chord in root position. To make this chord into a first inversion, move the root up an octave making the third of the chord the lowest note. +[135.25s -> 145.62s] The intervals above the bass are a 6th, a 5th, and a 3rd. The first inversion of the 7th chord is notated by just using the numbers 6 and 5. +[146.32s -> 153.01s] To make this chord into a second inversion, move the third up an octave, making the fifth of the chord the lowest note. +[154.06s -> 166.78s] The intervals above the bass are a 6th, a 4th, and a 3rd. The second inversion of a 7th chord is notated by just using the numbers 4 and 3. To make this chord into a 3rd inversion, +[166.78s -> 171.12s] Move the fifth up an octave, making the seventh of the chord the lowest note. +[172.18s -> 186.48s] The intervals above the bass are a sixth, a fourth, and a second. The third inversion of a seventh chord is just notated by using the number two. And here is what you have learned today. +[186.93s -> 190.90s] Keep practicing, and I will see you in the next video. +[196.02s -> 207.89s] If you liked the video, please hit like. If you would like to see more videos, please subscribe to my channel. You can also leave a comment or a question in the comment section below. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_1.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a2db352ca3c2590df69c4a2194b8baf0430c564b --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_1.mp4.txt @@ -0,0 +1,80 @@ +[0.00s -> 13.07s] Hello and welcome to the session in which we will discuss cost behavior. This topic is important whether you are taking managerial accounting, the CPA exam, cost accounting, or the CMA exam. +[13.07s -> 24.50s] We have to understand how costs behave because when we make costing decision, it's important to know whether the cost is a variable cost, a fixed cost, or a mixed cost. +[24.50s -> 37.02s] Before we start, I would like to remind you whether you are an accounting student or a CPA candidate, I strongly suggest you take a look at my website, farhatlectures.com. No, I don't replace your CPA review course. +[37.02s -> 44.02s] I can be a useful addition to your CPA review course. I can be supplemental material to your CPA review course. +[44.02s -> 54.53s] My course is designed to mirror image your CPA review course. The risk of trying me is one month of subscription. The potential gain is passing the actual CPA. +[54.53s -> 61.97s] And if not for anything, take a look at my website to find out how well or not well your university doing on the CPA. +[61.97s -> 75.86s] I also have accounting lectures for intermediate accounting, auditing, managerial accounting, cost taxation. Also, I have the AICPA previously released questions and my courses are there. +[75.86s -> 82.02s] to mirror image your CPA review course. So if you're taking an audit course with Roger or a reg course with Glymph. +[82.02s -> 95.79s] my course are designed to help you with these courses hand in hand or if you're taking a course with backer if you haven't connected with me on linkedin please do so take a look at my linkedin recommendation like this recording share it with other connect with me on instagram facebook +[95.79s -> 99.97s] Twitter, and Reddit. So let's talk about how costs behave. +[99.97s -> 114.26s] so how costs behave we have three three types of cost behaviors and i have to let you know up front that in the real world those like for example you may not have a 100 variable cost or 100 fixed mostly they are variable within a +[114.26s -> 127.41s] range, fixed within a range, mostly mixed. But for educational purposes, for knowledge purposes, we're going to assume that certain cost is a variable cost. What is a variable cost? From the word variables, it means it varies. +[127.41s -> 138.16s] And how does it varies? It varies in total and direct proportion to changes in the level of activity. The best example I can give you to illustrate this concept. +[138.45s -> 152.61s] the old cell phones cell phone plans when the cell phone was was becoming a more popular a common household item here's what would happen you would +[152.61s -> 165.89s] pay for the phone and you will pay based on the usage so if you did not use the phone if you use the phone zero minutes okay so this is let's assume this is the minutes +[165.89s -> 179.76s] and this is the dollar and i'm gonna say i'm gonna say one minute per dollar to make it easy so if you use it one minute you'll pay one dollar okay if you use it two minutes you'll pay two dollars +[179.76s -> 192.99s] If you used it three minutes, so this is one, two, three minutes. And this is how it used to be, actually. Believe it or not, maybe some of you don't remember this. Three minutes, you would pay $3. This is the dollar. Now we can draw a graph. +[192.99s -> 206.14s] and it would look something like this so as your usage goes up as your usage goes up your total this is your total goes up in proportion to the level of activity +[206.14s -> 216.67s] So this is an example of total variable cost changing in proportion to the level of activity. Okay, hopefully this make sense. +[216.67s -> 227.34s] In the real world, you might have cost drivers such as unit produced. For example, for each unit produced, you spend, you know, $4. If you produce two units, you will spend... +[227.34s -> 241.78s] eight dollars so on and so forth it could be based on machine hours what's driving your cost again the cell phone is the cell phone usage for example if you have a vehicle that's delivering it's miles and miles driven if you're using a vehicle to produce +[241.78s -> 246.96s] or it could be labor hours. So those are all cost drivers. +[247.38s -> 260.18s] The variable cost per unit, you have to understand now what we are discussing. The variable cost per unit is constant. And if we go back to this example to my cell phone, I said for each one minute. +[260.78s -> 273.65s] You pay a dollar. So the cost per unit, the variable cost per unit is variable. Why is it variable? Well because for every unit +[273.65s -> 285.36s] The cost is always a dollar. The cost is always the same. Therefore, it would look something like this. Per unit. Per one single unit. Per one single unit. +[285.36s -> 299.44s] So per one single unit, you'll have a flat line. But in total, it varies in total. It increases in total. But per unit, it's $1 per unit. So this is the variable cost. +[299.44s -> 308.18s] Let's talk about the fixed cost. And if we always when we say the fixed cost, we say the fixed cost within the relevant range. And I'll explain what do I mean by the relevant range. +[308.18s -> 319.44s] in a moment. But what is a fixed cost? Well, as the terminology implies, it's fixed, fixed regardless of the activity, again, within a relevant range. A cost cannot be fixed forever. +[319.44s -> 325.07s] For example, if you are renting a building, let's assume you are operating a building and you are renting that building. +[325.42s -> 339.04s] And let's assume you are paying $10,000 rent per month. And that $10,000 is for 1,000 square feet. Okay, so $10,000. +[339.04s -> 348.16s] to rent 1000 square feet. So simply put, as long as you are within 1000 square feet, you only have to pay $10,000. +[348.16s -> 359.55s] Okay, as long as you are that. But let's assume you are expanding your operation and now you need more space, more than 1,000 feet. The next thing is you cannot rent, for example, five square feet. +[359.55s -> 372.75s] feet you have to rent it goes from 1000 to 2000 so what we say is now the the fixed cost jumped so since you need an additional 1000 now you have to pay we're going to say it's +[372.75s -> 386.27s] proportional we have to pay twenty thousand so what's happening here the relevant range of the activity is flat within a relevant range so this is this is flat up to one thousand square feet +[386.27s -> 395.58s] Then if you're going to go up to 2000, then it's going to jump and it's going to stay flat to a certain degree. So the fixed cost always fixed within. +[395.58s -> 409.34s] range so the cost remain constant regardless of the level of activities again within a relevant range within a relevant range it cannot be fixed forever so in total the cost is fixed +[409.34s -> 422.74s] So in total, let's assume in total, so if we look at the graph for the total fixed cost, let's assume we are paying $10,000. So the $10,000 is the same regardless of the +[422.93s -> 435.09s] activity assuming we're not jumping activity with as long as we are we are within the relevant range the fixed cost is the same what happened to fixed cost per unit well the fixed cost per unit +[435.09s -> 440.53s] is inversely related what does that mean let's assume we are paying ten thousand dollar +[441.58s -> 453.81s] as fixed cost fixed cost and we are producing for the sake of simplicity 10 000 unit of xyz if i ask you what is your fixed cost per unit you would say 10 000 divided by +[453.81s -> 463.70s] a thousand your fixed cost per unit is a dollar let's assume we were very productive and we produced twenty thousand units for that month +[464.05s -> 477.97s] And we're still paying, remember, the fixed cost is 10,000. If we produce 20,000 units, now our fixed cost per unit is only half, 50 pennies. So what happens to our fixed cost per unit? As we produce more... +[477.97s -> 489.23s] our fixed cost per unit goes down our fixed cost per unit so per unit it's inversely related however in total in total again we are dealing within the relevant range in total +[489.23s -> 503.36s] it stays the same ten thousand so you need to understand how variable costs behave in terms of in total it varies in total it stays constant per unit fixed cost +[503.36s -> 511.25s] it stays total in fixed cost and total it's fixed per unit it's inversely related and we'll see an example to illustrate this +[511.25s -> 518.91s] these concepts now who wants to guess what a mixed cost would be well a mixed cost will have both the component of a fixed will have a both +[518.91s -> 532.80s] a fixed component and a variable component that's why it's called mixed and most costs in the real world they will take the form of a mixed cost there's nothing 100 variable there's not nothing 100 fixed so simply put +[532.80s -> 546.38s] If we want to express this algebraically, we can say that the total cost Y, the total cost, the total mixed cost Y equal to the fixed component. So A representing the fixed cost. +[546.38s -> 559.82s] or we're going to see this with or the y intercept or you know fixed cost we're going to see it on the graph a is fixed cost plus b is the variable cost b is the variable cost and x is the +[560.59s -> 569.46s] activity. So the total cost equal to the fixed cost plus the variable cost. So your cost consists of a fixed component and a variable component. +[569.46s -> 583.22s] And this is what it looks like on a graph. For example, here, and this is this is illustration of your utility bill. Notice here, even if you did not consume any kilowatt hours, zero kilowatt hours, you're still paying. +[583.22s -> 595.50s] let me change the color here you're still paying a certain amount and we're going to assume you pay 40 for your utility bill even if you don't do anything if you don't consume you were away everything was shut off +[595.60s -> 609.26s] As long as you have your utility active at the house, you pay $40, regardless, even if you consume zero kilowatt. Then what happened is this. For each kilowatt you consume, we're going to charge you. +[609.30s -> 623.55s] three pennies per kilowatt okay now this is the variable component why because it's varying per the activity here is the consumption of the kilowatts so let's assume you for a particular month +[623.55s -> 635.79s] you consumed two thousand kilowatts two thousand kilowatts for a particular month how do you find your total cost well you have to pay forty dollars that's a that's your fixed cost plus +[635.79s -> 648.54s] plus B, your variable cost is 0.03, three pennies. And for that particular month, we said you consumed 2000 kilowatt. +[648.54s -> 661.82s] Now we can find, so this is A is the fixed cost, and this part here is the variable cost. If we solve this, we find out that your total cost, which is Y, total cost is Y, is... +[661.82s -> 671.66s] Now what we can do, we can start to estimate your cost for any level of activity. For example, if we say your activity goes up to $3,000. +[671.66s -> 685.02s] we can predict your total cost if your activity goes down to 500 kilowatt we can predict your total cost so this is the cost formula which is your total cost equal to your fixed component +[685.02s -> 691.92s] plus your variable component. Your fixed component is the y-intercept. This point here is the y-intercept. +[692.69s -> 707.14s] Now let's take a look at an example to see if we can solve this problem. Ronald Company recorded sales volume of 50,000 units. Its total fixed costs are 50,000. If I ask you right now, what is the fixed cost per unit? That's easy. +[707.14s -> 720.21s] Fixed cost is $50,000 of fixed cost and we produce 50,000 units. We would say the fixed cost per unit is $1. The variable cost per unit is $70,000. This is the variable cost. +[720.21s -> 731.06s] And the relevant range is 40 to 60. So we are within the relevant range. Now, if I ask you, what is the variable cost per unit? Well, you could compute variable cost per unit. You can take 70,000. +[731.92s -> 744.10s] divided by 50,000 unit and let's see how much would that be and we can find if I take $70,000 divided by 50,000 unit +[744.10s -> 748.69s] We know this is equal to $40. This is $40. +[748.94s -> 760.96s] and i can tell you if i ask you right now what is the total cost per unit you would see the total cost per unit is 2.40 okay what would be the total expected cost per unit if ronald were to sell +[760.96s -> 775.38s] rather than 50, sell 60,000 unit. My first question to you is this, would cost per unit goes up or would cost per unit goes down? I hope you can answer this question immediately. The cost per unit should go down. +[775.38s -> 787.84s] Why? Because you are within the relevant range. And now you are selling or you are producing or selling 60,000 units versus 50. So as you produce more, this $1. +[787.84s -> 800.05s] This $1 should go down. This fixed cost per unit should go down. For example, if I know it's $2.40, I can immediately eliminate. +[800.05s -> 807.54s] 240 i can eliminate 244 and i'm down to two options either it must be c or d now i'm going to have to use my formula +[807.60s -> 821.86s] to compute my total cost per unit well my fixed component is fixed it's not going to change so that's going to be fifty thousand dollars that's a in the formula the fixed cost plus b of b of x well the the +[821.86s -> 833.90s] Variable cost per unit. Remember the variable cost per unit is constant. So this $1.40 is constant. So 1.4 times 60. +[833.90s -> 842.82s] So that's going to give me my total cost. Let's do the computation and see how much do we get as total cost. So if we take $1.40. +[842.82s -> 856.50s] which is the variable cost per unit which is we computed earlier times 60 000 unit that's going to give us 84 000 plus the fixed cost of 50 000 that's going to give us total of 134 000 +[856.69s -> 864.16s] Now 134,000 and we're going to split it or allocate it over 60,000 unit. +[864.16s -> 875.71s] And now, again, as I said, we are ready to do the computation. If we take 134 divided by 60,000, and it's $2.23. $2.23. +[875.71s -> 885.26s] $22.23. As I told you, it's going to be less than 240, which we predicted this. Therefore, the answer is 223. +[885.26s -> 895.44s] Now, if you're looking to practice additional exercises in addition to viewing these lectures, you can go to my website, forhatlectures.com. I don't replace your CPA review course. +[895.44s -> 907.47s] I provide alternative resources. I can help you understand the material better. I can provide you with supplemental resources. This is what I can do. Invest in your career. Invest in yourself. +[907.47s -> 917.94s] Don't shortchange yourself. The CPA is a lifetime investment. Good luck. Study hard. And of course, stay safe and take a look at my course catalog. Good luck. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_13.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6fcc9790d63debe929575315b9ee697cf39d1828 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_13.mp4.txt @@ -0,0 +1,25 @@ +[2.03s -> 12.75s] We're going to be discussing the prime cost and the conversion cost for a manufactured product. So let's think back to the product cost that we've talked about earlier. +[12.75s -> 24.48s] for manufactured products so we have direct material direct labor and overhead as the three components of a manufactured product so now we want to take those three +[24.48s -> 33.30s] categories and classify those as prime cost or conversion cost. So when you look at the little outline I have here, we have +[33.30s -> 44.45s] The direct material and direct labor would be categorized as the prime cost. These are the main components of the product. The direct labor and the overhead +[44.45s -> 58.94s] would be the conversion cost we're going to take the labor we're going to use some overhead and we're going to take those materials and convert them into a product so this is how we classify so prime cost equals direct material plus direct labor +[58.94s -> 62.53s] Conversion cost equals direct labor +[62.53s -> 76.85s] plus overhead so now let's use what we've learned as our formulas here and let's fill in for an example that we're given so lucre company manufactures tennis shoes and last week the total direct materials used in production +[76.85s -> 81.52s] were $63,000. Total direct labor for the week +[81.52s -> 93.74s] was $44,800 and they've given us the breakout of how it was calculated. So it's $14 per hour times 80 employees times 40 hours in the week. +[93.78s -> 101.07s] So the total overhead incurred for Luker Company was $95,000 and they produced 27,000 +[101.07s -> 115.34s] pairs of tennis shoes. The first thing we want to do is we want to calculate the total prime cost for the week and the per unit prime cost. So here's the formula again for total prime cost. +[115.34s -> 128.83s] plus direct labor so let's look at the problem and let's determine the number so direct materials would be sixty three thousand dollars and direct labor forty four thousand eight hundred +[128.83s -> 138.99s] So now we just add the two together and so our total prime cost for this week was $107,800. So that's the total. +[139.73s -> 152.29s] Now they've also asked for the per unit prime cost. So for the per unit prime cost, this is the formula. Total prime cost divided by the number of units produced. +[152.29s -> 166.06s] So in Part A of Part 1, we calculated the total prime cost. So that's $107,800. The number of units produced was given here as 27,000 pairs. +[166.06s -> 178.51s] tennis shoes and so we will take 107 800 divide that by the 27 000 pairs and that gives us a per unit prime cost +[178.51s -> 193.20s] of $3.99 per pair so the direct material and direct labor per pair of tennis shoes is $3.99 if you calculate it you're going to have to round it slightly 107 800 divided by 27 000. +[193.90s -> 207.28s] So we'll round that to $3.99 per pair. So that's the total prime cost and per unit prime cost. Now part two asks, what is the total conversion cost for the week? +[207.28s -> 220.50s] and the per unit conversion cost. So the total conversion cost would be direct labor plus the overhead. So direct labor is $44,800. Overhead was given +[220.50s -> 233.70s] 95,000 so we're just going to add those two together so our total conversion cost for this week was 44,800 plus 95,000 that equals 100 +[233.70s -> 244.75s] thirty nine thousand eight hundred dollars and then to calculate the per unit conversion cost we're going to take the total conversion cost that we just calculated +[244.75s -> 255.55s] And then we will divide that by the number of units produced. And we know that was 27,000 pairs of tennis shoes. So 139,800. +[255.55s -> 261.97s] divided by 27 000 pairs so let's check our numbers as we work through +[264.05s -> 274.67s] And we will again round. This time we're going to round up. $5.18 per pair is the conversion cost. +[274.83s -> 279.18s] total conversion cost, and per unit conversion cost. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_14.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..27456b6a321af70e73adecb13ff258b4795b7f80 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_14.mp4.txt @@ -0,0 +1,42 @@ +[0.75s -> 13.01s] All right, let's look at some questions about job order cost sheets and brief job order cost sheets, perhaps, I think is what we're going to be talking about right here. +[13.01s -> 25.74s] so we've got a couple of multiple choice questions to start us off with that are that are objective no calculations involved which of the following is true about the job order cost sheet +[25.74s -> 39.63s] It is going to be prepared for every job. This is true in a job order costing system. So that sounds good. It is a subsidiary of the work in process account. That is also true. +[40.66s -> 55.25s] it is the primary document for accumulating all costs related to a particular job that is true and in fact it does contain all information pertinent to that job so make sure that you understand that +[55.25s -> 69.26s] A job order cost sheet can do all four of these things. So we're going to go ahead and circle E. The more important thing is to know that the job order cost sheet can actually serve all of these purposes. +[69.58s -> 83.66s] all right let's see what we have here it says which of the following is the order in which cost elements flow through accounts until they are recognized as an expense +[83.66s -> 97.52s] Okay, so raw materials is where we would actually start at the very beginning and look at choice B, raw materials, to work in process. That's good, but uh-oh, we have a problem. +[97.52s -> 103.17s] purchase returns is not part of that process so what that tells us since that's the only +[103.17s -> 115.47s] choice that starts with materials is that we're not actually starting at the very beginning here and if we look at choice a it says work in process that's the number two step then to finished goods +[115.47s -> 127.31s] and then to cost a good soul so the only way this answer could be any better was if we inserted materials right here in front of work in process but this is the correct sequence +[127.31s -> 141.84s] you know, after materials are requisitioned, okay? So we're going to go ahead and circle that because A is the correct answer given the choices that we have. +[142.90s -> 152.00s] Looks like we may have some calculations here. It says plant-wide overhead is 150% of direct labor costs. +[152.00s -> 163.78s] Okay, so we've got direct labor cost as our activity level. That sometimes happens whenever we have highly skilled employees. We use cost rather than +[163.78s -> 177.66s] hours because there's so much variance in how much they make per hour. Job cost sheets had the following balances, and so basically we have jobs one through four, and these are the balances. It says +[177.66s -> 188.78s] Jobs Z3 and Z4 were not completed at the end of December. And they want to know what is the balance in work in process at the end of December. +[188.78s -> 194.19s] Well, if jobs Z3 and Z4 were not completed, +[194.99s -> 207.89s] We probably need to count those. So I'm assuming that these two here are completed. So we don't want to count those. Bring our trusty calculator over here. 35,000. +[209.07s -> 222.80s] uh for job z3 plus 18 750 53 750 and look at that my pencil's already pointing to the right answer +[223.60s -> 237.14s] And there it is. So this looks, you know, if you just took a glance at this initially, you'd think, well, this is kind of a hard question or might be. But then you actually look at what they want to know. And, oh, it's not so difficult after all. +[237.14s -> 248.06s] Might be able to handle that. All right, so this one is going to be a little bit more involved, but nothing that we can't handle if we work together. Says, let's just see what they want to know first. +[248.06s -> 260.34s] what is the cost of goods sold for the month of march okay so i highly suggest that you if you really want to understand how to do all of this because we could ask a whole lot of questions +[260.34s -> 269.39s] from this scenario. I do have a fairly long video on brief job order cost sheets that you might find helpful and you might not. +[270.58s -> 283.50s] So they design and build basketball gymnasiums. These are all custom built, as is the case with anything in a job order costing system, to customer specifications. +[283.50s -> 295.34s] uh sunlight uses job order costing to keep track of its cost that's good because that's what chapter we're in in march it worked on three jobs and we have the information here +[296.46s -> 310.94s] says that overhead is applied at a rate of $20 per machine hour. And of course, it looks like it's going to give us the machine hours for each job. That comes in handy. By March 31st, +[310.94s -> 315.34s] Job 178 is the only one unfinished. +[315.70s -> 329.60s] so job seventy eight is a part of work in process notice the question is what is cost of goods sold so if it were me i would just immediately cross this job off +[329.60s -> 338.48s] Because it's not completed. And they want a no cost of goods sold. I can't sell it if it's not completed. Additional information. +[339.31s -> 349.62s] The balance of finished jobs on March the 1st is $60,000, consisting of job number 177, okay? +[350.13s -> 359.28s] jobs one seventy seven and one seventy nine are sold during march sunlight sells its product at a cost of thirty per cent +[360.78s -> 369.84s] So what? I'm not asking you to calculate gross margin or revenue or anything like that, so that doesn't matter. +[370.29s -> 382.80s] So let's see here. 177 and 179 are sold. Well, that means that 175 is complete but has not sold. So this is strictly finished goods. +[382.80s -> 395.54s] And they didn't ask for finished goods. They asked for cost of goods sold. I'm going to put an x through it just like so. All right. So we know a couple things. Job. +[396.02s -> 403.89s] 177 equals $60,000 in cost. Where'd I get that number? Well, they told me right here. +[406.22s -> 416.10s] 177. There it is. And we sold that one, so we're going to need that number. And then 179. So it looks like we've got 32,600. +[416.10s -> 428.40s] $42,000. And then we've got to account for our machine hours. We have 3,000 machine hours times $20 per machine hour. +[429.20s -> 442.06s] equals 60,000. So times $20 per machine hour equals 60,000. Okay. +[443.09s -> 454.58s] So we can just take these costs. We've already got, actually this $60,000 right here on the calculator is for this $60,000 in overhead. I'm going to add +[454.58s -> 463.54s] I'm going to go kind of backwards here. Direct labor cost of 42,000 plus direct materials of 32,600. +[464.02s -> 471.60s] plus this 60,000 here from job 177. So that's a different 60,000. +[471.95s -> 481.84s] equals 194. So 134.6 was our total for job 179. +[487.28s -> 498.45s] We add those together. We come up with 194,600, and that happens to match choice B. And that is all there is to it. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_15.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..399b46d28692f15ebda14bab489948b8c7320f83 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_15.mp4.txt @@ -0,0 +1,31 @@ +[0.43s -> 12.27s] Welcome to helpyourmath.com. This video is a continuation of the correlation coefficient in which we'll be finding the regression equation of the correlation chart. +[12.27s -> 26.86s] Last time we had all these data values with the sum of x being 30, the sum of y being 48, the sum of x times y being 295, the sum of x squared 186, and the sum of y squared at 474, while our n equals 5. +[26.86s -> 41.55s] Now to get the regression equation, the predictive value equation, we have y hat equals b1, which is the slope, times x, plus b0, which is the y-intercept. So here I'll just notarize that. b1 is the slope of the equation. +[41.55s -> 44.24s] While the b0 is the y-intercept. +[48.21s -> 61.71s] Now to calculate these two values, there are two equations we can use that contain these sums to assist us so we can get the b1, the slope, and also the b0, the y-intercept. Now the equation for the slope... +[61.71s -> 75.44s] is similar to the correlation equation with minor differences, right? The numerator is the same as the correlation coefficient, n times the sum of xy minus the sum of x times the sum of y divided by... +[75.44s -> 89.15s] just part of the correlation coefficient, which is going to be just the n times the sum of x squared minus the sum of x bn squared. I'll be careful when you're inserting this, as this is the sum of the value. +[89.15s -> 102.11s] x squared, while the second term here is just the sum of x, bn squared. All right, let's calculate this. So now here we go for the slope, and that b1 is equivalent to 5 times +[102.11s -> 112.02s] Now, the sum of xy is 295. We'll just write this in. And the sum of x is just 30, while the sum of y is just 48. +[112.62s -> 124.93s] All of this is going to be divided by the n, which is 5, the sum of x squared, which is 186, subtracted by the sum of x again, which is right on top, which is 30 bn squared. +[124.93s -> 139.31s] So let's calculate what we get on top now, right? 5 times 295 is 1475. While 30 times 48 would give us 1440. +[141.14s -> 153.65s] In the denominator here, we have 5 times 186. That's going to give us 930. And 30 squared is 900. +[155.76s -> 165.86s] So be sure to use a calculator while you're calculating these to calculate them with accuracy. And also don't forget that when you're doing this on a calculator, you want to calculate everything on top. +[165.86s -> 176.86s] and everything on bottom and resolve them one at a time before you actually divide as some calculators may take a mistake while you're dividing them all right so here our b1 is going to give us +[176.86s -> 186.42s] 1475 minus 1440, that's going to be 35. And on the bottom hand of the denominator we have 930 minus 900, which is just 30. +[186.42s -> 193.52s] When we divide these two, we see they have common factors, and this can be reduced if you want to make this easier for yourself. 7 over 5. +[194.58s -> 208.61s] Actually, 7 over 6, not 5. And dividing this, we're going to get a repeating decimal. So this will become 1.1666. Continue. This we're going to round up to the fourth place. +[208.61s -> 222.29s] as this continually goes to 666 this last six will become a seven because as this continues forever to get a four digit number we need this to be 1.1667 so there we have our slope +[222.32s -> 236.02s] The only thing missing, so we can complete this equation, is our value of b0. There's a really short formula to do this for the y-intercept. So the b0 value is just the sum of y minus... +[236.50s -> 241.68s] The b1 value times the sum of x all divided by n. +[242.61s -> 257.07s] This is actually just a very short formula, really easy to calculate as well. We'll take into account the sum of x, the sum of y, the value of m, and these are the only three we need in combination with the b1. So here we're going to have just 48. +[257.39s -> 267.38s] Take away the slope value once it's rounded up 1.1667 and this is going to be multiplied by 30 +[267.86s -> 279.41s] And everything here is going to be divided by 5. So this takes a bit of calculation, but just be patient. You should be just fine while doing this. And here we're going to have the value of B0. It's 48. +[279.82s -> 290.93s] minus the product of 1.1667 and 30 which is exactly 35.001 +[291.47s -> 305.23s] And then we also have the 5 in the denominator still. If you're still using that calculator, all you have to do is subtract these two top numbers. And here we're going to get the value of 12.9999. +[307.57s -> 317.55s] this number is very close to 13. had this not been there the difference between 48 and 35 is just 13 but with this little decimal here we're going to get this result +[317.68s -> 325.39s] Now for the final division, once we divide 12.999 by 5, what we're going to get here is 2.5. +[333.30s -> 346.74s] And there we have our y-intercept. Now to complete the equation of the line, it's pretty straightforward. All we're going to do is we're going to take this equation. We're going to substitute our b1, which is 1.667. +[347.02s -> 358.45s] And we're going to insert our p0. So here we'll have y hat equals 1.1667x. +[358.93s -> 366.67s] Plus, since the y-intercept is positive, we keep this positive. 2.5998. +[367.73s -> 375.95s] So that's our final value for our equation of the predicted value equation. All right, there's our regression equation line. Thank you. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_2.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c7c7465fb8bd7e82b1fa6ff3a44ef9b6b7421c3e --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_2.mp4.txt @@ -0,0 +1,11 @@ +[13.55s -> 25.52s] Do you have a savings account? I sure hope so. It's good money management practice. Well, corporations have savings accounts too, only it is called retained earnings. +[26.03s -> 31.22s] Let's analyze these two words, retained plus earnings. +[31.86s -> 45.65s] Retained means to keep. Corporations retain their earnings from year to year to be used for different purposes. What is retained earnings used for? 1. To pay out dividends. +[45.65s -> 55.73s] 2. Reinvest earnings into other business ventures. 3. Finance other areas of their operations. +[57.52s -> 65.10s] Earnings is the amount of money earned through the regular course of business after all expenses are deducted. +[67.86s -> 76.05s] Where is retained earnings reported? Retained earnings is reported in the stockholders equity section on the balance sheet. +[77.78s -> 92.40s] So how do we calculate retained earnings? Here is the equation. Beginning retained earnings plus net income minus dividends equals ending retained earnings. +[92.82s -> 98.58s] The ending retained earnings is the value that is reported on the balance sheet. +[98.96s -> 111.79s] Now, let's review. What is retained earnings? It is the amount of income earned through regular course of business that is retained from year to year. +[111.79s -> 124.18s] Here is the equation revisited. Beginning retained earnings plus net income minus dividends equals ending retained earnings. +[127.98s -> 142.96s] For more free videos, online courses, and accounting training, visit accountinguniv.com. And remember to subscribe and like. More videos coming your way soon. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_20.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0d44814a6b4434d4e1733dbb43951a6c720d99f2 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_20.mp4.txt @@ -0,0 +1,18 @@ +[0.00s -> 4.18s] In this video, we're going to discuss multi-factor models in investing. +[4.18s -> 18.58s] So the most widely known model for estimating the expected return of a security is the capital asset pricing model, where it's modeling the expected return as a function of a single factor, which is capturing systematic returns. +[18.58s -> 32.78s] risk this is beta so we talk about the beta of a security we're saying how many units of risk are in this security with respect to changes in the overall market so the systematic risk remember that's risk that cannot be +[32.78s -> 41.20s] diversified away. It's saying how much does this securities return a function of changes in the overall market? +[41.20s -> 55.50s] Okay, so the market goes up. Let's say we've got a beta 1.5. We say, okay, the market goes up by 1%. Then this security goes up by 1.5%. Now, the single factor model is nice for its simplicity. +[55.50s -> 69.71s] we might think about this systematic risk it includes so many different things it includes expectations about the overall economy and what the GDP is going to be it includes expectations about what the inflation rate is going to be what interest +[69.71s -> 83.92s] rates are going to be. All these different macroeconomic factors are part of this systematic risk. And so you might consider and say, hey, maybe different types of securities react in different ways. +[83.92s -> 98.13s] to changes in interest rates, to changes in inflation. For example, might a bank respond differently to changes in interest rates than a grocery store? Sure, that's reasonable to think that. And so when we just use a single... +[98.13s -> 112.34s] factor that measures systematic risk that's a great start but some people have said well look we can actually think about breaking this systematic risk into its component parts so that we might more accurately predict the expected +[112.34s -> 126.54s] return of the security and when we do that when we have multiple factors here so we have we could have this factor we have another factor we have another factor for interest rates and so forth we have different factors we call that a multi-factor model +[126.54s -> 134.50s] So I want to give you just an easy example. So let's say that we are going to estimate a two-factor model for a fictional company called Happy Bank. +[134.50s -> 147.84s] And our two factors, we're going to make this really simple. We're just going to have inflation and interest rates. Those will be the only two factors in the model. And so we go and we estimate the model with regression analysis and we get the following result. +[147.84s -> 162.13s] And so we've got this 0.11 here. That's going to be the expected excess return for Happy Bank. So that's 11%. That's the expected excess return. But now we've got to think about our two factors. We've got a factor here and we've got a factor here. +[162.13s -> 176.43s] And each of these factors, so it's a coefficient estimate is what we call this in a regression. So this 0.2 is telling us that if we have a one percentage point increase in inflation. +[176.43s -> 190.74s] Okay, so we have an unexpected 1 percentage point increase in inflation. Then that would lead to a 0.2 percentage point increase in the expected return. Okay, now conversely, now we have an... +[190.74s -> 204.94s] negative sign with our other factor so that means that if we were to have an unexpected 1% increase one percentage point increase in interest rates then that would predict that we would have a decrease of +[204.94s -> 219.15s] 0.4 percentage points in the expected return. Okay, so we don't have to have just two factors here. We could have a third factor that measures GDP. We could have a fourth factor. We could have a fifth factor. +[219.15s -> 229.84s] most famous of the multi-factor models is the Fama French model. And then also we've got Fama French Carhartt and so forth. And we'll talk about all of those in the videos to come. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_24.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_24.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fcff92f8e4504310d0f50b0693770b423c263bb3 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_24.mp4.txt @@ -0,0 +1,32 @@ +[0.00s -> 14.42s] In this video, I want to walk you through a CFA level one exam style question on Jensen's alpha or simply alpha, which is a topic very much related to the capital asset pricing model. So if this is something you +[14.42s -> 21.90s] want to get right in the exam, do keep watching and let's get solving. So this is the question which I want us to have a go at. +[21.90s -> 35.79s] if you watch the previous two videos you will recall these figures for portfolio x y and z we've got some performance information including return standard deviation and beta we also have the return on the market portfolio 2.3 percent +[35.79s -> 50.06s] its standard deviation and a risk-free rate of return equal to 0.5 and we're asked about which portfolio offers the best performance as measured by jensen's alpha now jensen's alpha is +[50.06s -> 64.48s] basically something that we probably had already exposure to. I've definitely recorded previous videos on this, although I didn't call it alpha as such. It was all about whether a stock is generating returns. +[64.48s -> 75.39s] in excess or below the rate of return required under the CAPM model, given its level of systematic risk. So basically... +[75.39s -> 88.88s] this thing called alpha, which we also call Jensen's alpha, is equal to the return on the portfolio, either expected or, you know, historically experienced minus +[88.88s -> 101.52s] what the CAPM model would predict is the required rate of return. And that's obviously a function of the risk-free rate plus the beta of that specific portfolio times RM. +[101.52s -> 107.92s] minus rf where rm is the rate return on the market portfolio and rf is once again +[107.92s -> 122.03s] the risk-free rate of return and obviously if this relationship is positive if a portfolio is generating more than what's required by uh under the cap and model let me +[122.03s -> 134.50s] perhaps just finish this off with a nice square bracket at the end to close this off and make the formula complete well if this relationship is positive then a stock would be described as lying above +[134.50s -> 147.86s] the sml the security market line if the relationship is negative it's yielding less than what's required and that would respectively lead us to conclude that the stock is either +[147.86s -> 161.42s] undervalued if it's above or the sml or undervalued if it's below the sml and we've had previous questions on that comparison and whether stocks are under or overvalued okay so +[161.46s -> 172.53s] Let's compute this for portfolio X to start with. Its return is 2%. What would be predicted by the CAPM model? +[172.53s -> 186.42s] The RF is 0.5% plus the beta on this specific portfolio being 0.8 times the rate of return on the market, which is 2.3. +[186.93s -> 199.62s] minus 0.5 percent close the bracket okay i'm going to take my phone with the calculator and quickly do this not really sharing my phone screen with you as there is nothing um +[199.62s -> 205.26s] terribly exciting happening in terms of the computations so let me start with +[205.55s -> 218.93s] this 2.3 minus 0.5 that's obviously 1.8 times the beta of 0.8 okay plus 0.5 okay and i see +[219.86s -> 233.04s] A result equal to, let me write this down over here, it's going to be 0.06% and it's positive. So this suggests a little bit of alpha, very small. +[233.04s -> 243.31s] but a little bit of excess performance on a sort of risk-adjusted basis where we, as risk, we take into account systematic risk only. +[243.31s -> 255.02s] Good. So better than the required rate of return from the CAPM model. How about Y? Well, over here we're going to have... +[255.02s -> 269.01s] the return of four and a half percent minus the same thing as before 0.5 plus and the only thing that changes here is the beta which is going to be specific to the teach portfolio 1.6 other than that +[269.20s -> 276.58s] We've got 2.3 minus 0.5, just like before. So I know the term here in the... +[276.58s -> 290.86s] in the bracket is 1.8 so that's 1.8 times the new beta of 1.6 let's add 0.5 to that 3.38 okay and this is definitely going to yield something +[290.86s -> 299.02s] positive i see a positive difference of 1.12 percent so this stock definitely +[299.02s -> 312.29s] yields more than what would be required under the CAPM model given its level of systematic risk as measured by beta. So we would say that this stock is lying above the SML, the security market line. +[312.29s -> 324.40s] And we would also conclude that it is undervalued. Now, what about Z? For portfolio Z, we've got 6.2%. Once again, minus... +[324.40s -> 338.64s] square bracket 0.5 percent plus a beta of 2.5 and uh same thing as before in the bracket 2.3 minus 0.5 close both brackets +[339.41s -> 353.04s] So, this is 1.8 multiplied by a beta of 2.5 plus 0.5, okay, minus... +[354.51s -> 359.55s] And for this one, I see a result which is even higher. +[359.55s -> 371.22s] it's positive and it's 1.2 percent so that's a measure of the excess return above what's required and that will lead me to conclude that portfolio z is +[371.50s -> 380.46s] The one which performs best. It's got the best performances measured by Jensen's alpha. So, answer C. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_25.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_25.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..9a2e5e22e4cee9ae59e31d02307331766c3d7c11 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_25.mp4.txt @@ -0,0 +1,33 @@ +[0.43s -> 12.67s] Helo, selamat hari. Dalam video sebelum ini, saya telah membincangkan beberapa teori portfolio dan harga aset utama dari teori portfolio moden pada tahun 1952 +[12.67s -> 26.86s] ke Kepem pada tahun 60-an. Hari ini saya akan bergerak ke tahun 1970 dengan menunjukkan kepada anda teori yang mempengaruhi aset, teori harga arbitraj. +[26.86s -> 36.02s] Mari kita mengetahui bersama-sama apa itu APT dan bagaimana APT boleh digunakan dalam peningkatan aset. +[37.30s -> 49.17s] Pada tahun 1976, Stephen Ross mengembangkan Teori Pricing Arbitrasi. Dia mempunyai pendekatan multifaktor untuk menjelaskan harga aset. +[50.38s -> 61.33s] Sebelum kita bergerak ke kisah tentang APT, mari kita ambil masa untuk memahami konsep arbitrage. Kemudian anda akan dapat menghargai +[61.33s -> 75.10s] mengapa model yang dikembangkan oleh Stephen Ross dipanggil APT. Menurut definisi Valdi, Kane dan Marcus pada tahun 2011, arbitrage adalah penggunaan. +[75.10s -> 87.10s] peningkatan keselamatan dengan cara sebegitu bahawa keuntungan tanpa risiko boleh diperoleh. Menurut Herschel dan Nozinger dalam 2010, arbitrage +[87.10s -> 96.94s] hanyalah pembelian dan penjualan aset yang sama pada harga yang berbeza untuk menangkap peningkatan yang salah +[100.08s -> 113.78s] Peraturan Satu Harga mengatakan bahawa dua aset yang sama sepatutnya mempunyai harga pasaran yang sama. Peluang pembayaran akan muncul jika aset yang sama dihantar untuk harga yang berbeza. +[113.78s -> 124.35s] di dua lokasi yang berbeza. Perbelanjaan satu harga dilaksanakan oleh pembayar RBI yang akan mengambil kesempatan harga dalam kawasan ini. +[124.35s -> 136.21s] Penjual akan membeli aset di tempat yang murah dan menjual di tempat yang tinggi. Melalui mekanisme penjualan ini, harga akan berpindah kembali ke kawasan. +[136.30s -> 149.22s] Peluang arbitrage berlaku apabila pelabur dapat memperoleh keuntungan tanpa membuat pelaburan net. +[149.22s -> 160.19s] pelabur boleh menggunakan proses daripada jualan pendek untuk membeli long dan oleh itu transaksi boleh dibuat tanpa pelaburan +[160.19s -> 165.65s] Ini menjadikan transaksi transaksi yang tidak berguna +[168.46s -> 180.88s] APT adalah teori untuk menjelaskan keuntungan stok berdasarkan sensitiviti kepada banyak faktor risiko. Ia mengandung model linier. +[180.88s -> 192.13s] keuntungan dalam pelaburan boleh dijelaskan dengan lebih daripada satu faktor. Menurut APT, pasar adalah sempurna efisien jika +[192.13s -> 200.85s] tidak mungkin untuk menghasilkan keuntungan arbitrage tanpa risiko dengan membeli dan menjual aset yang sama +[202.42s -> 213.36s] APT mengatakan bahawa terdapat banyak faktor yang menyebabkan kembali, berbeza dengan KPM di mana risiko yang terkait sahaja adalah beta. +[213.68s -> 227.79s] APT tidak mengatakan apa faktornya. Contohnya, keuntungan stok perniagaan syarikat mungkin terpaksa oleh perubahan dalam harga minyak. Kebanyakan syarikat transport, seperti pesawat, +[227.79s -> 240.72s] akan mempunyai sensitiviti negatif kepada perubahan harga minyak. Beberapa syarikat akan lebih sensitif kepada faktor tertentu daripada syarikat lain. Contohnya, syarikat minyak +[240.72s -> 246.16s] boleh menjadi lebih sensitif kepada faktor minyak daripada industri pengguna +[249.04s -> 260.46s] APT adalah model yang lebih jeneralisasi daripada CAPM dan kurang restriktif dalam pengiraannya. Ada lima pengiraan yang ditandakan di sini. +[263.12s -> 274.16s] Ini menunjukkan model APT. Dalam formula ini, keuntungan sebenar pada aset dikalkulasi. ER bermakna keuntungan yang diharapkan +[274.16s -> 287.73s] F adalah setan faktor umum yang mempengaruhi keuntungan pada aset Beta adalah sensitiviti faktor pada keuntungan aset E adalah terma kesilapan +[287.89s -> 301.20s] Di sini, formula menunjukkan bahawa APT adalah proses stokastik yang menghasilkan keuntungan aset yang boleh dikatakan sebagai fungsi linear setiap faktor risiko +[302.77s -> 313.58s] The APT can also be expressed in terms of expected risk premium. Expected risk premium is the actual return minus risk free rate. +[313.58s -> 327.22s] APT mengatakan bahawa premium risiko yang diharapkan pada stok harus bergantung pada premium risiko yang diharapkan terkait dengan setiap faktor dan sensitiviti stok kepada setiap faktor +[328.62s -> 334.06s] Mari kita gunakan formula APT dalam contoh ini +[342.80s -> 350.48s] Apa jawapan anda? Jawapan adalah C +[354.93s -> 362.80s] Mari kita cuba contoh lain. Di sini kita mempunyai portfolio A dan B. Apa yang akan anda lakukan? +[372.94s -> 385.28s] Jika anda mahu mengambil kesempatan arbitrage, anda harus mengambil posisi pendek dalam portfolio B dan posisi panjang dalam A. Mengapa begitu? +[385.28s -> 394.35s] kerana A di bawah nilai dan B di atas nilai apabila mereka terhadap risiko yang sama F +[398.86s -> 403.50s] Saya harap anda dapat memahami sesi ini. Jumpa lagi dan selamat tinggal. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_26.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_26.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..df68585ed66294016a5c791898bf065df597f5f4 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_26.mp4.txt @@ -0,0 +1,21 @@ +[0.00s -> 9.76s] In this video we are going to discuss cost-based pricing strategy and one very important concept associated with cost-based pricing strategy. +[9.76s -> 21.60s] now in another video we talked about different types of cost based pricing strategy like the cost plus pricing and markup pricing but in this video we are going to talk about break even pricing +[21.60s -> 34.51s] break-even pricing is a very important concept in pricing strategy because break-even pricing is the price at which you are able to recoup all your cost right so your profit is zero +[34.51s -> 47.12s] the revenue that you are going to get is equal to the cost that you are incurring so if you can find out your break-even price then you know that a price higher than the break-even price would lead to profit +[47.12s -> 60.42s] and a price lower than the breakeven price would lead to a loss. Now let's do some calculations to understand this concept a little bit more. Now we know that profit equals to +[60.42s -> 72.54s] total revenue minus total cost now we know that total revenue is a multiplication of your price times quantity which we will turn p times q here +[72.54s -> 84.46s] We also know that your total cost consists of fixed cost and variable cost where the variable cost is the unit variable cost multiplied by the quantity. +[84.94s -> 98.06s] Whereas the fixed cost is represented just by the fixed cost Now since we have profit equals total revenue minus total cost Our equation comes out like this +[109.07s -> 118.08s] From this equation we can see that for different quantities the breakeven prices will be different So let's figure this out with an example +[118.08s -> 132.29s] Let's consider that the unit variable cost to produce this toasty toast is $5 So if you produce one unit of this it will cost you $5 if you produce a hundred unit of it It will cost you $500 +[132.29s -> 140.53s] here the price is dependent upon how many you produce now let's consider the fixed cost to produce this product and think that it is +[140.53s -> 148.69s] for example say ten thousand dollars now that cost is fixed it means that it does not matter whether you produce one or you produce a million +[148.69s -> 159.39s] the cost is still going to be $10,000. For example, the factory, the machines, the real estate, the company uses for production is $10,000. Even if you shut down the factory, +[159.39s -> 172.24s] you still have to incur that cost of 10,000. So it's a fixed cost. Now, for example, let's say that we want to produce 5000 of these Tostitos. Therefore, the quantity Q is 5000. +[172.34s -> 186.74s] Now we have our previous equation which can be represented as this. Now doing some math. Yada yada yada. Yada yada yada. Yada yada yada. We get the price equals to seven dollars. +[186.74s -> 199.04s] now based upon this analysis you should price your product at at least seven dollars to break even if you're planning on selling five thousand units now one thing we need to know +[199.04s -> 210.11s] is that the price is dependent on the quantity produced so this price of seven dollars is is if you produce five thousand units now if you produce lower +[210.11s -> 219.70s] quantity then the break-even price will go higher but if you produce a higher quantity then the break-even price would go down now let's check this by +[219.70s -> 233.31s] imagining that we want to sell 8,000 Tostitos instead of 5,000. Now using the same formula. +[233.31s -> 247.02s] Yetta what? We get a price of $6.25. So in this case, your break even price went down from $7 to $6.25 if you want to produce 8,000 units. +[247.02s -> 250.46s] Thank you very much for watching. Have a good day. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_27.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_27.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c876b49c1f8dd1d31570a0aaba207b95f5fb4e55 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_27.mp4.txt @@ -0,0 +1,23 @@ +[0.00s -> 4.66s] In this video, I'm going to teach you how you can calculate the debt to equity ratio for a company. +[4.66s -> 18.40s] using a balance sheet so let's start by looking at the basic formula so debt to equity ratio is simply the ratio of the total liabilities divided by the total stockholders equity or in other words we're basically doing all of the money the company owes +[18.40s -> 27.36s] divided by all of the money that's been put in by the owners of the company. And this is going to give us a measure of how reliant the business is on debt. +[27.36s -> 41.65s] and can also tell whether there's too much equity and perhaps they have capacity to take on more debt. And it's also a risk measure to some extent. So let's look at a balance sheet. So we've got the balance sheet from a company called Realty Income, very popular real estate investment. +[41.65s -> 52.13s] trust and it files a form 10k the good thing about form 10k is it's set out in a really clear way that's quite easy to pick out our value so you have to have some care and caution here +[52.13s -> 62.42s] So you've got the debt to equity ratio formula there. We can immediately see that the total liabilities is given there. So you've got the dividends that haven't been paid out yet. Things like accounts payable. +[62.42s -> 74.27s] That's money that they are going to be paying to other people at some point. It's not their money. It's money they need to pay out. And then you've got various categories of loans and liabilities. And they're all added up for you. +[74.27s -> 84.13s] So we take that number and then we have to get the total stockholders equity. And this is where it gets a little bit confusing. There is a line that says total stockholders equity, but that's not the one that we're going to use. +[84.13s -> 92.21s] we're going to use the total equity so the sec and their definition of debt to equity and generally the accepted definition of of +[92.21s -> 99.55s] debt to equity includes non controlling interest because they are equity capital in the company. So we're going to include that. +[99.55s -> 110.90s] And so you do the division. So you substitute in your total liabilities on the top. You take your total equity and you put it on the bottom. You calculate that and it gives you a debt to equity of 0.89. +[110.90s -> 125.04s] So this means that there is 0.89 cents or 89 cents of debt for every dollar of equity. Sometimes it's helpful to present it in a percentage. So this is saying that +[125.04s -> 137.73s] there is a debt to equity percentage of 89%. And we now need to think about how you actually interpret this number and we'll look at it in terms of the decimal value. So this is a general rule of thumb and you have to +[137.73s -> 151.39s] analyze the company individually different companies are perfectly safe perfectly well not safe they're perfectly reasonable at much higher debt to equity ratios than some other companies +[151.39s -> 162.34s] so as a rule of thumb something that's lower than 0.5 is generally low risk you're not going to be worried just because of the debt to equity if something's going to worry you is going to be somewhere else +[162.34s -> 175.44s] A debt to equity of less than 0.5, suggesting that perhaps the company is overfinancing their business with equity and are overly cautious and their returns are going to be lower because the cost of debt is so much lower than the cost of equity. +[175.44s -> 188.74s] Less than one is fairly reasonable. You're not going to be setting off alarm bells. One to two is typical for a lot of businesses. Once it starts to go more than two, you want to proceed with a little bit of caution. You ought to be considering the trend. +[188.74s -> 199.12s] Is it getting worse? Are they leveraging up? If a company is loss making with a debt to equity of over two, you're going to start to get really worried. If it's more than five, you want to proceed with great caution. +[199.12s -> 211.98s] So you'll be looking for special cases, for example, banks, by the way that they operate, just have higher debt to equity ratios because banks are financed by borrowing money from one set of people and lending it out at a higher rate. +[211.98s -> 222.42s] and utility companies that have very sustainable cash flows things like electricity generation companies that have got monopoly positions power distribution and +[222.42s -> 234.86s] water companies they can survive with very high debt to equity because they have very guaranteed very stable cash flows and so that's not going to worry you so much whereas a cyclical business +[234.86s -> 249.14s] Like an airline with a debt to equity of more than five would really be a no-go. So there's some general rules of thumb, but it is very company specific and you have to do your analysis and use this as one of many tools in understanding the financial position of a business. +[249.14s -> 255.09s] So hopefully this video has been very helpful to you. And finally, thank you very much for watching. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_3.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a310c12f97224180625b95dc91ed98b3f1df8193 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_3.mp4.txt @@ -0,0 +1,27 @@ +[0.66s -> 12.40s] hello everybody so today i want to talk about finance the topic today is about discounted +[13.20s -> 16.02s] operating cash flow +[16.56s -> 30.19s] and next present value. So we have initial investment and we have 3 selections of projects from A to C. +[30.19s -> 43.87s] Now we need to select which one should be the highest NVV. So now I want to show you how to answer. The formula of this one +[43.87s -> 52.75s] we have NBV equals to negative initial investment. +[60.02s -> 63.60s] Then we need to add about +[66.13s -> 75.76s] operation cat flow number one represent about the Z number one over one plus R +[76.72s -> 87.86s] and the second one we have OCF number 2 over 1 plus R to the power of 2 +[90.13s -> 103.76s] and so on until we have OCFN over 1 plus R to the power of n. +[104.78s -> 117.30s] So in this situation, I just select only 3 years from year number 1 to year number 3. Now we can apply this formula in here. +[118.26s -> 124.78s] So we calculate about next present value of project 8. +[130.54s -> 138.93s] So we have negative 10,000 initial investment in here. +[141.78s -> 153.97s] so because we need to use about discounted operating cash flow so we have 5,000 we divide by 1 plus r +[155.28s -> 168.91s] And the interest rate, that is about 5%. And the next one, we have 5,000. That is about year number 2. +[173.07s -> 184.14s] and we have 1 plus 5 to the power of 2 and the last one we have 5,000 +[185.46s -> 198.10s] over 1 plus 5% to the power of 3 so we calculate this one +[198.90s -> 207.98s] and we have 3616.24 +[210.51s -> 217.58s] This is about the next present value of the project 8. Now let's go to B. +[221.90s -> 228.85s] So we have negative 10,000 that is about initial investment +[229.52s -> 237.97s] so if we look carefully that's only year number two and we have 15,000 we put in here +[239.25s -> 251.82s] because this is about yi number 2 so we have 1 plus r to the power of 2 and that is about 5% in here +[252.43s -> 265.65s] So we calculate this one and we have 3,605.44 +[266.29s -> 276.27s] and the last one we have negative 10,000 +[278.22s -> 282.83s] So in this situation we just have this one and this one. +[313.20s -> 324.75s] We have 3389.48. +[325.55s -> 337.97s] Now after we calculate and we can see that this one that is about the highest NPV So we need to select about this project 8 +[339.06s -> 343.15s] That is the end. Thank you for watching. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_5.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..03079f4be1411c1260b5b2c6f6f7f6e475b84f34 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_5.mp4.txt @@ -0,0 +1,28 @@ +[1.17s -> 7.86s] Hi, in this video I explain how to calculate equivalent units under the weighted average method. +[8.43s -> 19.38s] Now, equivalent units of production represent the number of physical units that could have been completed during the period when we consider the amount of material and conversion costs that were used. +[20.14s -> 32.00s] Think of soda bottles being filled at a manufacturing plant. Not all bottles will be completed at the end of the month. Using the method of equivalent units, we can take these partially completed units, +[32.00s -> 44.34s] and combine them into the number of equivalent units for our calculation purposes. For example, if we have four physical units that are 25% complete, those would equate to one equivalent unit. +[45.04s -> 58.29s] There are two common methods for calculating equivalent units, FIFO and weighted average. Now in this video, I only cover the weighted average method. I have a separate video where I show how to do the calculations under the FIFO method. +[58.93s -> 72.85s] Now the weighted average method is not concerned with our units at the beginning of the period, but instead we look at the end of the period and how much resources were used to date in creating those units. +[73.20s -> 76.11s] So let's look at our weighted average unit example. +[76.50s -> 89.30s] Here we have some data on some physical units, and we have a formula that tells us that beginning units in work in process plus units started equals our ending work in process plus units completed. +[89.30s -> 103.02s] What this formula is basically showing us is that when we consider all of the units that were worked on during the period, those units are either completed or not completed, meaning they're in our ending work in process. +[103.02s -> 114.16s] So we can take this formula and plug in the amounts given from the table and then solve the formula to determine that our unit's ending work in process is 1,100. +[114.70s -> 126.86s] Now we have the complete information we need on our physical units, so now we can start calculating our equivalent units. So again, we're going to look at our table and fill in the physical unit information that we need. +[127.38s -> 141.42s] Now, as I said, weighted average method is not concerned with our beginning inventory, so we do not need any of this information when doing our weighted average calculations. What we do need to know is our units completed. +[142.22s -> 153.39s] and our units in ending work in process. So we can add those to our tables, and now we see that our total units to be accounted for is 48,400. +[153.78s -> 157.39s] Next we need to look at how much was completed. +[158.54s -> 171.57s] So notice our degree of completion is different between our direct materials and our conversion costs. For this reason, we have to calculate separate equivalent units for direct materials and for conversion. +[171.92s -> 186.70s] So let's start with direct materials. When we look at our table, again we have our units completed. Those units are 100% done because they're complete. So therefore in our table we can put 100%. +[188.11s -> 201.78s] Now for our units and ending work in process, we need to look at the data that was given and that data tells us that they are 0% complete with regards to materials. No materials have been added to these units in process so far. +[202.35s -> 214.77s] We're going to go ahead and put 0 in our table. And now to calculate the equivalent units, we're going to take the physical units times that percent added, and that gives us the equivalent units. +[216.53s -> 228.27s] When we multiply that out, we see that our equivalent units for direct materials is 47,300. Now we have to repeat this process for the conversion costs. +[228.82s -> 239.95s] So again, our degree of completion is different between the two. And so we are doing a separate set of equivalent units for our conversion costs. +[242.58s -> 250.10s] Again, our units completed are completed, so they're done with regards to conversion costs as well, so we put a 100% in our table. +[250.64s -> 263.02s] And then we look to our data to determine the status of our units and ending work in process. And here our table tells us that they are 30% complete. And so we're going to put the 30% into our table. +[264.46s -> 278.06s] Next, we calculate our equivalent units by taking the physical units times the percent added during the period. We multiply it out and we see that our equivalent units for conversion costs are 47,630. +[279.57s -> 292.59s] Now I want to point out just one more time that because these percentages of completion are different between direct materials and conversion, we end up with two different sets of equivalent units for our calculations. +[293.52s -> 305.55s] Next, we can look at our costs. Here we have our costs to be accounted for. We're going to take our beginning work in process costs plus the cost added this period to get us our total cost to account for. +[305.90s -> 320.46s] Now we can calculate our cost per equivalent unit. To calculate cost per equivalent unit, we need total cost and the equivalent units. So here we're going to take the total cost, plug it into our table. +[320.46s -> 332.66s] Our equivalent units, which came from step two, and we divide to determine our cost per equivalent unit. And so here we have our cost per equivalent unit when we use the weighted average method. +[333.30s -> 341.11s] Now again, I have a separate video where I describe how to calculate equivalent units and unit costs under the FIFO method. diff --git a/VideoMMMU_ASR_large/Business/validation_Accounting_9.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Accounting_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..09c57de097f45000aa0074ffb4bc6a1328f0aecd --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Accounting_9.mp4.txt @@ -0,0 +1,17 @@ +[0.08s -> 4.42s] Hi guys, so let's now take a look at cash flow and +[4.42s -> 18.77s] cash inflows and cash outflows okay so a nice little analogy to help you understand this is uh thinking of this sort of bathtub excuse my really crude drawing here but hopefully uh it gets the perspective +[18.77s -> 32.98s] here okay so we've got inflows coming into the bar through the tap and then we've got the outflows going down the plug hole here okay so let's have a look at these inflows inflows also know +[32.98s -> 47.18s] as receipts of course so it could be that you make cash sales and you actually get paid up front or when those goods are actually taken by the consumer of course then you've got credit sales that's where the consumer buys now but +[47.18s -> 61.39s] a little bit later okay so you may offer 28 days credit perhaps okay and that means that they've got four weeks to actually pay that invoice it could be of course that you get a loan and that loan will actually boost your cash +[61.39s -> 75.60s] flow and help actually ensure that you have cash in the bank or water in the tub so to speak okay it could also be that you have capital introduced through owners capital or that you have a share +[75.60s -> 79.70s] sale and that you sell share capital. +[79.70s -> 94.22s] alternatively you might choose to actually sell any unwanted assets or do a sale and lease back on a vehicle or something like that and that sale of that asset would bring cash into your bank account of course and then +[94.22s -> 108.43s] bank interest received all right so any savings that you've got may well get interest on them uh any savings the business has that is okay may well receive interest on them and as a direct consequence of that then again that's +[108.43s -> 122.64s] going to make money entering your bathtub okay but of course you've got money going down your plug hole as well and that is outflows or payments okay so the outflows or payments well cash purchases where you've had +[122.64s -> 136.85s] buy raw materials of stock credit purchases where you've bought things on buy now pay latest basis okay and perhaps again you have 28 days to pay those back you got rent okay uh you've got rates uh rates +[136.85s -> 141.74s] Very similar to council tax, but applied to business. Wages. +[141.74s -> 156.02s] a variable cost of course production more you produce the greater the wages will be salaries well they're going to be a fixed cost of course uh monthly uh payments to your workers okay so if you take salary at 24 +[156.02s -> 167.46s] thousand pounds divide that by twelve it's two thousand pounds every month okay um then you've got utilities so heating lighting water phone +[167.46s -> 181.74s] broadband etc uh purchase of assets so if you buy any new assets okay of course that's going to be a cash outflow then there's value added tax okay to pay and bank interest all right so if you've got to pay +[181.74s -> 191.26s] any interest back on any loans or mortgages perhaps that you've actually got then you've got to pay those back so overall you get your net cash flow +[191.26s -> 204.10s] uh position your net cash flow position is simply your inflows minus your outflows or alternatively your receipts minus your payments okay guys i hope that was useful thanks a lot diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_1.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2d1a7761d771a549f8ef8773ec8d2abe1029fae7 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_1.mp4.txt @@ -0,0 +1,36 @@ +[3.54s -> 4.34s] Thank you. +[4.34s -> 18.90s] Hey guys, in this video, I'm going to try to quickly explain the difference between the reserve ratio and the required reserve ratio. These are two terms that we might come across in our textbooks, and sometimes kids get a little bit confused between the reserve ratio and the required reserve ratio. +[18.90s -> 21.79s] In a nutshell, guys, the reserve ratio is focused on what's +[21.79s -> 36.08s] actually going on inside of the banking system it is saying hey what is the ratio between reserves and demand deposits that we're actually seeing out there okay the required reserve ratio is focused on the potential relationship +[36.08s -> 40.37s] the maximum potential relationship between reserves. +[40.37s -> 54.64s] and demand deposits, okay? So again, the required reserve ratio is focused on potential or maybe better, maximum. The reserve ratio is actual. Now, if you didn't get that, let's get through the rest of the video, okay? So I want to say that what's actually happening in banks +[54.64s -> 57.73s] Banks are choosing to hold... +[57.73s -> 72.05s] $1 in reserve for every $5 in demand deposits. Let me say that again. $1 in reserves for every $5 in demand deposits. So that means their reserve ratio, if that's what they're actually doing, is 20%, right? +[72.05s -> 73.95s] 20%. They're holding. +[73.95s -> 88.27s] 20% of their demand deposits as reserves. Let me say that again. They're holding 20% of their demand deposits as reserves. Now, we then might find out in the problem that the required reserve ratio is 10%, and then the problem may go on to... +[88.27s -> 100.27s] ask how many excess reserves are banks choosing to hold which the correct answer would then be 10% right because if you add 10% and 10% you get +[100.27s -> 114.58s] 20% what's actually going on. Okay. Now, another problem that you might get might not actually show the actual ratio of one to five. All right. It might just simply start off with, Hey, required reserve ratio is. +[114.58s -> 119.38s] 10% excess reserves are 5% +[119.38s -> 133.74s] and then it might say hey what is the reserve ratio to which again you would in this situation say it is 15 okay that's what's actually going on again banks have to hold this but they're also choosing to hold an additional +[133.74s -> 143.98s] 5% of reserves for every demand deposit that they have, giving us a reserve ratio of 15%. Now, the money multiplier. Do we do... +[143.98s -> 151.98s] one over the rr right do we do one over the reserve ratio for our money multiplier you can if a problem +[151.98s -> 166.35s] basically said hey here's the amount of demand deposits that we see here's the amount of reserves that we see what must be the money multiplier so hey they say five hundred thousand they say one hundred thousand what must be the money multiplier well it must be five +[166.35s -> 177.57s] But you are rarely going to see that, okay? Most of the time when they start talking about the money multiplier, they want the money multiplier that gives the maximum. +[177.57s -> 191.95s] the maximum expansion of demand deposits that we can get from reserves okay let me say that again most of the time when we're talking about the money multiplier when i say most i'm saying almost all the time we're talking about the money multiplier we're going to be focused on what's the maximum +[191.95s -> 202.61s] expansion and demand deposits that we can get from reserves. So let's get to the required reserve ratio. First thing, definition. It is the percent. +[202.61s -> 210.54s] of demand deposit a bank must or is required to hold in reserves that's what the required reserve ratio is +[210.54s -> 218.10s] Where do kids mess that up? Occasionally, when I ask a student, they may say it is the percent of reserves that they must hold in reserves. +[218.10s -> 232.46s] guys that's a problem right that doesn't even make sense okay that's a nonsensical statement right there again the required reserve ratio is the percent of demand deposits a liability to banks they must hold in reserves reserves being an asset okay so +[232.46s -> 242.62s] in this particular case guys yeah maybe they're choosing to only have five times more demand deposits than reserves but it's saying the maximum +[242.62s -> 256.91s] okay, amount of demand deposits they could have to their reserves is a tenfold increase. For every one reserve, it can support $10 in demand deposits, which means the required reserve ratio is 10. +[256.91s -> 271.12s] percent and then if you get asked the money multiplier you would then say oh the money multiplier is one over the rrr especially if they are asking me a question about the maximum change in say bank +[271.12s -> 280.16s] lending, demand deposits, or the money supply. I'm going to use 1 over the RRR, which in this particular case is 1 over 0.1, which is +[280.16s -> 291.04s] So if we see reserves go into the system of a certain amount, let's just say $100,000, +[291.04s -> 303.58s] The required reserve ratio is 10%. So banks get $100,000 in reserves. And it says, what's the maximum demand deposits could expand to? Our answer is going to be $1 million, right? $100,000. +[303.58s -> 310.32s] times 10 demand deposits could expand to a maximum of 1 million dollars again if banks +[310.32s -> 323.33s] don't hold any excess reserves. But again, when you are focused on the required reserve ratio, you're focused on maximums, and you are assuming they're not holding any excess reserves. Because remember, when banks choose to hold, +[323.33s -> 336.85s] excess reserves. We're not going to get near the money expansion as we could be or as we could get if banks didn't hold any excess reserves and only held the reserves that they were required to do so. +[336.85s -> 339.22s] Again, the reserve ratio, it's about what's actually +[339.22s -> 353.52s] happening in banks. It looks at not just the required reserves, but also the excess reserves banks are choosing to hold on to. The required reserve ratio is all about the potential money expansion, bank lending expansion, demand deposit expansion. +[353.52s -> 365.87s] maximum, and it only looks at the reserves that a bank is required to hold on to. When you do 1 over the required reserve ratio, you'll almost always get a number bigger than 1 over the reserve ratio. +[365.87s -> 374.67s] at least if banks are choosing to hold any excess reserves. I hope that made sense to you, and I hope it wasn't too long of a video. We'll see you in the next video. diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_11.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e0369ae6ac01fa23c927af9e451518742dcb17cf --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_11.mp4.txt @@ -0,0 +1,35 @@ +[0.00s -> 13.09s] In this video, we're going to think about the economic profit of a monopoly, of a monopoly firm. And to do that, we're gonna draw our standard price and quantity axes. +[13.09s -> 22.43s] So that's quantity. And this is price. And this is going to, of course, be in dollars. +[22.43s -> 36.72s] we can first think about the demand for this monopoly firm's product. And the demand curve would look similar to other demand curves that we've seen multiple times, that at a high price, people wouldn't want a lot, wouldn't be demanding a lot, and then at a lower price, or as price goes lower, +[36.72s -> 44.40s] people are going to demand a higher and higher quantity, or the market will demand a higher and higher quantity. So that might be the demand curve. Now what's interesting about +[44.40s -> 53.41s] Any imperfectly competitive firm, in the extreme case is a monopoly, is what the marginal revenue curve looks like given this demand curve. In a +[53.41s -> 61.50s] perfectly competitive firm, the marginal revenue curve is equal to the demand curve, and in that situation, it's actually a horizontal line. +[61.50s -> 75.95s] But here, because when the monopoly firm reduces price, it doesn't just reduce it on that incremental unit. It would be typical that it would have to reduce its price on all of the units, and we've studied this in other videos. You have a marginal revenue curve that would go +[75.95s -> 84.78s] go down faster than the demand curve. It would look something like this. And if this is unfamiliar to you, I encourage you to watch some of those videos that go into depth why this is happening. +[84.78s -> 99.71s] So it's a monopoly, or actually any imperfectly competitive firm, its marginal revenue curve will go down faster than the demand curve. So what would be a rational quantity for this firm to produce? Well, to think about that, we have to think about its marginal cost curve. +[99.71s -> 114.16s] So it's marginal cost curve, the typical way we often think about it is, at first you get some economies of scale, but then you start having coordination costs and maybe some diseconomies of scale, your inputs start getting more expensive, and so your marginal cost curve might look something like this. +[114.16s -> 117.87s] Something like that. And the rational quantity produces. +[117.87s -> 131.36s] As long as your incremental revenue for every unit is higher than your incremental cost for every unit, you would want to produce more and more and more and more until the point that your marginal cost is equal to your marginal revenue. +[131.36s -> 134.34s] And so the rational quantity to produce right over here, +[134.34s -> 148.24s] would be right over there. I'll do that Q. I could call that Q for the firm. I could also call that Q sub M because we're dealing a situation where the firm is, at least from the producer side, it is the market. It is the only producer. It's a monopoly. +[148.24s -> 161.58s] But what's the price here? Well, to know that, we just have to look at the demand curve. At this quantity, the price is right over here. So the price is right over here. Once again, we could call that the market price. +[161.58s -> 165.42s] And so something interesting has happened here for the Monopoly firm. +[165.42s -> 176.61s] In a perfectly competitive firm, where the marginal cost and demand curves intersect, that's what dictated the demand, because the demand curve and the marginal revenue curve were the same. +[176.61s -> 184.02s] But here, we are now producing a quantity less than that. We're producing a quantity where price +[184.02s -> 198.32s] is greater than marginal cost. You can see it right over there. At this quantity, price is greater than marginal cost. And so you can view this difference right over here as kind of a markup that is possible for a monopoly firm to do. +[198.32s -> 206.54s] that would not be possible with a perfectly competitive firm. And this also introduces an idea of deadweight loss. Because at least in theory, +[206.54s -> 220.82s] at a higher quantity, people were willing to pay more than the marginal cost. So you would think that there is some type of a benefit that the market as a whole could gain from that incremental unit, or those incremental units, and then even some more incremental units. +[220.82s -> 233.04s] like theirs to gain, but because of the, what is rational for this monopoly firm, and there's insurmountable barriers for entry for other people to enter, this is not going to be captured until you have this dead weight loss. +[233.10s -> 247.70s] Now, an interesting question, and this is where I started off is, is well, what would be the economic profit for this monopoly firm? And to think about that, we have to think about the average total cost curve. And so the average total cost, I'll draw a typical average total cost. +[247.70s -> 259.38s] it might look something like this. While marginal cost is below the average total cost, the average total cost will +[259.38s -> 271.46s] trend downwards. And as soon as marginal cost is higher than average total cost, well now, of course, average total cost is going to start trending upwards. So marginal cost intersects the average total cost curve. +[271.46s -> 284.00s] at the minimum point right over there. And so, based on this average total cost curve, it looks like this monopoly firm is earning an economic profit, because at that quantity, this is the price per unit it's getting. +[284.00s -> 292.34s] This is the average cost per unit. So on average per unit, it's getting this height. It's getting, it's getting. +[292.34s -> 306.80s] it's getting this difference right over here. And then if you were to multiply it times the number of units, well that's going to give you its economic profit. So you could view the economic profit in this situation as being this shaded area of this rectangle. +[306.80s -> 310.82s] rectangle. So I'll leave you there. The big thing to appreciate is when we're dealing with +[310.82s -> 323.63s] in an extreme form of a monopoly, your marginal revenue curve is no longer your demand curve, and your marginal revenue curve is downward sloping like this. It's not the flat curve that we saw with the perfect competition. +[323.63s -> 330.10s] And because of that, your marginal cost is going to intersect marginal revenue at a +[330.10s -> 344.34s] where price is greater than marginal cost, which introduces deadweight loss in the market, and the way to think about the economic profit is to compare what that price in the market is of that quantity to the average total cost. +[344.34s -> 345.90s] at that quantity. +[345.90s -> 360.27s] And what's also interesting about this monopoly firm is because of the barriers to entry, we talked about in the long run with perfect competition, if there's economic profit going on, more entrants would enter into the market. But that's not going to happen in a monopoly because the barriers to entry +[360.27s -> 372.12s] are so high. So this monopoly is sitting pretty. It's going to be able to keep earning this type of economic profit unless something dramatically changes in the market somehow. diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_14.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..83735932bcee5dd1e258917557fe466d2a40eef1 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_14.mp4.txt @@ -0,0 +1,33 @@ +[2.06s -> 15.09s] What we're going to do in this video is think about all of the different ways that a supply curve or a demand curve can shift. And that's why we actually have eight versions of the exact same diagram. +[15.09s -> 29.36s] Each of them is showing where we are right now, let's say in a given region, in the ice cream market. It's important to title your graphs, especially if you were taking some type of a standardized exam like an AP exam. And in the vertical axis, +[29.36s -> 43.57s] we have P representing price, and then the horizontal axis, Q, representing quantity. We have our upward sloping supply curve. I'm calling this S1, just as kind of our starting point. And then we have our downward sloping demand curve, D1. +[43.57s -> 47.86s] and where they intersect, that gives us our equilibrium price. +[47.86s -> 62.16s] P1, and our equilibrium quantity, Q1. And once again, if you were taking some type of a standardized test, it's important that you label all of these things, including P1 and Q1, and show this dotted line where it intersects the horizontal axis is Q1, and where it +[62.16s -> 76.77s] intersects the vertical axis is P1. Now with that out of the way, let's think about what happens to the equilibrium price and the equilibrium quantity given different shifts in the supply or the demand curve or both of them. +[76.77s -> 83.87s] So in this first scenario, let's imagine that all of a sudden a major ice cream +[83.87s -> 98.27s] producer enters into the market. So here we're going to, this first one, we're gonna think about a situation where the supply goes up. So one way to think about it is, at any given price, people are willing to supply +[98.27s -> 109.44s] more quantity. So here we would have our supply curve shift to the right. I'll call this S2 right over here. +[109.44s -> 116.21s] It's shifting to the right and down. And so given this, what happens to our equilibrium price and our equilibrium quantity? +[116.91s -> 131.36s] Well, you see it right over here. If I draw a dotted line, we see our equilibrium price P2 is lower and our equilibrium quantity Q2, Q2 is. +[131.36s -> 144.10s] Once again, assuming that we have a downward sloping demand curve like this, which is what you would typically see. And so in this case, let me just write it here, we have our quantity. +[144.10s -> 157.10s] or actually let me write it this way. We have our price goes down and our quantity goes up. Alright, now let's do this example and let's imagine the other way. +[157.10s -> 169.71s] Let's imagine in this scenario our supply goes down. What is going to happen to this graph? In particular, what's going to happen to our equilibrium price and our equilibrium quantity? +[170.38s -> 181.62s] Well, in this situation, for a given price, people are willing to supply less. That's how I like to think about it. So we would have a shift to the left and +[181.62s -> 194.19s] And so we could call this supply curve two right over here. And then what is our equilibrium point? It's right over there. It is right over there. And so... +[194.19s -> 205.01s] This would be our new price. It has gone up. And this would be our new quantity. It has gone down. So price has gone up and quantity has gone down. +[205.01s -> 213.17s] And once again, in either of these scenarios, hopefully this feels a little bit like common sense. If you have a supplier enter into the market +[213.17s -> 221.86s] there's gonna be quantity might go up and there's more competition amongst the suppliers and so the price would go down. Here, +[221.86s -> 236.14s] where the supply goes down, maybe some of the ice cream stores close down. Well now, the quantity will go down, there's just less people supplying, but the price goes up. For the ice cream that's there, the equilibrium price is going to be higher. +[236.14s -> 246.91s] Now let's do the same thing with the demand curve. Let's think about a situation where, first, let's think about a scenario where demand goes up. +[246.91s -> 253.09s] Demand goes up. What is going to happen in this world? +[253.09s -> 267.34s] Well, demand might go up because maybe there's some type of report that ice cream is much healthier for you than expected, and so at a given price, people are willing to demand a higher quantity. +[267.34s -> 280.24s] So for example, at that price, people would demand a higher quantity, and so we would have a shift to the right and up. Let's call this D2 right over here. And this is our new equilibrium point. And then notice. +[280.24s -> 290.70s] Notice what has just happened here. At our new equilibrium point, this is Q2, and then this right over here is +[290.70s -> 301.41s] This right over here is P2, our new price, our new equilibrium price and our new equilibrium quantity. In this situation where demand goes up, both price and... +[301.41s -> 309.42s] both price and quantity are going to go up, assuming we have this upward sloping supply curve again. +[309.42s -> 323.33s] And once again, that makes sense. More people just wanna buy ice cream. The total, the supply curve dynamics have not changed, so we're gonna move along that supply curve to the right and up. So both price and quantity go up. +[323.33s -> 332.11s] Well, if demand goes down, you could imagine the opposite is going to happen. So here, if we have +[332.11s -> 345.84s] demand goes down, let's say a big study comes out that ice cream is even unhealthier than we originally thought, well then at a given price people are going to want, they're going to demand less ice cream. +[345.84s -> 359.26s] And so our demand curve would shift to the left and down. So we'll call this D2 right over here. And then we can see our equilibrium price and quantity. So let's show that new equilibrium price. +[359.26s -> 372.45s] is P2 right over here, and then our new equilibrium quantity is Q2. And notice, both price and quantity go down. People just don't wanna buy ice cream as much because they think it's unhealthy now, so price. +[372.45s -> 375.09s] goes down and quantity goes down. diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_2.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e54ceef1ca0f44f2105b7d9f42c6ec055719c6b8 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_2.mp4.txt @@ -0,0 +1,41 @@ +[0.53s -> 14.72s] Hi guys, in this video let's consider and discuss price controls to solve market failure. We're looking at minimum prices, i.e. price floors, and maximum prices, i.e. price ceilings here. Let's focus on a minimum price first, or a price floor. +[14.72s -> 22.16s] This will be used to discourage the consumption of demerit goods, i.e. whether there are negative externalities in consumption. +[22.16s -> 33.66s] So I'll take a context here of alcoholic drinks. Scotland have imposed a minimum price on alcohol. We see one in Canada as well. So good context to apply here. And the idea is in the free market of P1 and Q1. +[33.66s -> 46.46s] There'll be an overconsumption and an overproduction of alcoholic drinks here. So if I'm posting a minimum price above equilibrium, a floor price, which the price can't go below, we will contract demand. You can see that along here. +[46.46s -> 57.78s] consumption will be discouraged, quantity in the market will fall from Q1 to Q star, the socially optimum level of output. That's the idea. By doing so, the X-anity will be internalized here. +[57.78s -> 72.08s] we will solve the overconsumption, overproduction issues, we'll get to allocative efficiency, and thus welfare will be maximized in the market. That's the intention. That's what the idea of the minimum price is. But there are many issues with imposing this minimum price, especially on alcohol. +[72.08s -> 84.64s] We can argue that there is price inelastic demand here. So when the price goes up, we're not questioning that demand will fall, we're questioning how much will it fall. If there is price inelastic demand, the fall in QD, +[84.64s -> 94.99s] will be proportionally less than the increase in price and therefore we might not see a fall in quantity enough to fully solve the market failure. We'll stop here maybe instead of getting the Q star. +[94.99s -> 108.50s] Minimum prices are aggressive. We often use that phrase only for indirect taxation but we can use it here as well even though it's not a tax. It certainly will burden the poor and therefore could widen income inequality in society where the government lose a key. +[108.50s -> 120.02s] macro objective. That's not the idea of this policy, but it's very, very likely to happen given that it's regressive. It will take a greater proportion of the income of the poor than it will of the rich here, burning the poor. +[120.37s -> 123.74s] Individuals always will find alternative supplies if they are +[123.74s -> 135.47s] suffering because of a higher price and they really want to buy alcoholic drinks still, they could well find alternative supplies in the black market. That is dangerous for them. Who knows about the quality of the good that they're buying in the black market. +[135.47s -> 149.87s] More, they might find alternative supplies in the form of much cheaper, worse for them alcoholic drinks. Again, not really solving the market failure, potentially making the market failure worse. They may smuggle from abroad. I mean, if it's Scotland here, it's not really smuggling, but it's going to England and buying booze from England. +[149.87s -> 158.74s] England instead of bringing it back. That's not the intention of the policy but very likely to happen. That could certainly lead to government failure. The other problem with black market activity +[158.74s -> 166.54s] that tax revenue could well be lost here. They're buying it from illegal sources here and the government loses out there as well. So very much... +[166.54s -> 180.91s] likely to see black market in terms of supply and potential source of government failure there. We can also see unintended consequences maybe on producers. So if the minimum price is set really high, we'll get to that now, it's set really high and it's not internalizing the XRT, it's going... +[180.91s -> 181.78s] than that. +[181.78s -> 196.14s] There could be an impact on firms here who may suffer. They may leave the country. They may shut down. There might be unemployment caused here. Again, unintended consequences linking to government failure. But good evaluation. If demand is price and elastic, producers will actually see an increase in their... +[196.14s -> 203.52s] revenue here they will not be punished they will not suffer they'll actually gain here so that's eva but if the minimum price is set too high +[203.52s -> 215.70s] is set above the level whereby quantity needs to reduce to solve the market failure, then these two issues in particular become very severe guaranteed government failure. If it's set too low, then +[215.70s -> 222.62s] quantity in the market may not reduce to the socially optimum level. We may not be internalizing the externality perfectly at all. +[222.62s -> 237.04s] Just bear in mind guys, one thing we can't really talk about here is the notion of an excess supply. That's normally something we talk about for a minimum price. We can't talk about it here because producers won't produce extra thinking the government is going to buy up the excess. They know that that's not going to happen. +[237.04s -> 251.34s] So they're going to try and produce at the level of demand in the market, which is Q-star here. Let's now talk about maximum prices. Maximum prices or price ceilings are used in markets where the price in the market is deemed too high by the government. +[251.34s -> 262.32s] So by imposing a minimum price or a price ceiling below that equilibrium price, we are promoting equity, we're encouraging more consumption of essential goods or services, like rented accommodation. +[262.32s -> 276.59s] Cities like New York and in Berlin, the most common examples of rent control, we see a maximum price to encourage more consumption, to promote more equity when it comes to the market for rented accommodation. Of course, people need to have accommodation, right? That's the idea. +[276.59s -> 284.86s] So you can see on the diagram a reduction in price here. So prices are lower, there is an extension of demand. The idea is obviously more consumption, more equity as a result. +[284.86s -> 292.40s] and thus we solve that income inequality kind of prevalent market failure where price exclusion really shouldn't exist in the government's eyes. +[292.40s -> 301.94s] But there are many issues with imposing maximum prices like this. It's not just rented accommodation, guys. We also see this on basic food items in Venezuela for the same ideas. +[301.94s -> 315.34s] The biggest problem is that a shortage will be created. You can see that on the diagram. Yes, there is an extension of demand, but there is a contraction of supply here. The government creates this excess demand, this shortage, this inefficiency in the market. +[315.38s -> 323.95s] So those who are able to find accommodation at the lower price of PMAX, great for them, no problems for them at all. But what about this chunk of people? +[323.95s -> 336.03s] The people who are willing and able to buy rented accommodation at that lower price but are not getting the supply. The people within the excess demand. What happens to them? They don't get the accommodation. That, you can argue, is a pure government failure. +[336.03s -> 348.86s] Where are they likely to go, therefore? Well, the black market. Of course, landlords are going to be willing to offer rented accommodation at a slightly higher price, of course, than PMAX. And there are going to be many of those within the excess demand who are going to be happy to pay that. +[348.86s -> 362.03s] We create a black market and that has a very natural consequence here of the shortage created by the government. That's dangerous for consumers here because they're going to be exploited probably by landlords in the black market. Who knows the prices they can offer? Who knows the quality? +[362.03s -> 373.95s] of the accommodation that they can offer here. That is a government creative problem, the black market. Furthermore, the contraction of supply is bad news because we are likely to see more producers building +[373.95s -> 386.82s] sky-rise luxury apartments instead of the cheaper rented accommodation knowing that the price is too low that's not very good that's only going to drive out more and more and more the lower income households in a given city furthermore if the prices are lower +[386.82s -> 399.50s] The quality offered by landlords here is going to be low as well. So all of these issues are as a result of having a price below the equilibrium price ceiling here. Black market activity, pure government failure right here. +[399.50s -> 412.08s] Furthermore, there needs to be enforcement of this. Who is going out and checking that landlords aren't charging a price beyond PMAX? In Berlin, that's a big issue. So you can always question the enforcement. But you can question whether the maximum price is going to be set at the right level. +[412.08s -> 423.15s] If it's going to be set too low, there's going to be a massive excess demand here. If it's going to be set too high, so too close to equilibrium, then we're not going to see the promotion of equity and greater consumption that is desired. +[423.38s -> 437.97s] And we can also say there is cost involved. If governments are not happy with the shortage, they want to try and increase supply to get it to equal QD here, well that could be very costly. They might subsidize private animals, big cost involved. They might produce their own housing instead. +[437.97s -> 452.18s] their own housing very costly as well big opportunity cost a cost that's dealing with their own problems the inefficiency that they've caused you can argue large government failure here at the end as well so not as simple the intention is simple but many issues here with both minimum prices and +[452.18s -> 456.33s] prices thank you so much for watching guys I'll see you all in the next video diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_3.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..67957a473f1d256df763938a90e8ab22f8f2532d --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_3.mp4.txt @@ -0,0 +1,79 @@ +[0.78s -> 11.02s] Principles of Macroeconomics Chapter 10 The International Trade and Capital Flows Professor Wagner +[13.04s -> 26.50s] What's going to be covered in this chapter are some rather interesting things considering what's going on with tariffs and trade relations across the globe, in particular U.S. and China. They're going to talk about +[26.50s -> 36.03s] Trade balances, also in a historical and international context. Trade balances the flows of financial capital. +[36.03s -> 46.45s] national saving, investment identity, pros and cons of trade deficits and surpluses and the difference between level of trade and trade balance. +[49.30s -> 56.24s] You know money is the the currency of exchange although +[56.24s -> 70.21s] it may come in many different currencies it's all backed by governments it's all created by fiat which means it's created and printed on the basis that the government will always be able to back their debt now that's +[70.21s -> 77.87s] true for more for some than let's say others uh that's a discussion we'll ensue on a little bit later +[78.54s -> 90.35s] A trade balance is simply the difference between a nation's exports and imports. So you can say there's a trade imbalance, you know, if you feel like the +[90.35s -> 101.10s] the pretty quote quote aspect of it is the trade isn't yeah the trade is not really equal you're importing much more than you're exporting or vice versa +[101.10s -> 111.50s] In high-income economies, U.S. goods comprise less than half the country's total production, while services comprise more than half. +[113.23s -> 126.85s] Merchandise trade balance versus current account balance. And so these are three definitions. So the merchandise trade balance, balance of trade looking only at the exchange of goods. +[126.85s -> 140.48s] current account balance a broad measure of balance of trade that includes trade goods and services and international flows of income foreign aid and then there's unilateral transfers +[140.48s -> 148.66s] payments you know like government private charities individuals will send abroad without any expectation of a return +[151.47s -> 165.31s] Here we have a couple of graphs. The first graph A shows the current trade account balance versus the total merchandise trade balance from 1960 to 2013. +[165.31s -> 176.38s] and if the lines are above zero dollars the us was running a positive trade balance and current balance if it fell below zero +[176.38s -> 186.94s] just the opposite we were running a deficit and a deficit in the current account balance whereupon graph b shows the same items +[186.94s -> 194.70s] trade balance and current account balance in the relationship to the size of the U.S. economy or GDP. So there's a comparative advantage. +[196.66s -> 206.37s] a measure of economies, globalization, so it's a function of the exports of goods and services as a percentage of GDP. +[206.37s -> 214.06s] uh the dollar value of exports divided by the dollar value of a country's gdp so this is a ratio +[214.90s -> 225.36s] Trade balances in the flow of financial capital. So we can get a definition of financial capital being the international flows of money to facilitate trade and investment. +[225.36s -> 238.40s] uh the connection between the trade balances international flows of capital uh is so that economists sometimes describe the balance of trade as the balance of payments +[238.40s -> 247.92s] Each category of the current account balance involves a corresponding flow of payments between a given country and the rest of the world economy. +[249.23s -> 262.51s] Here we have a kind of a cyclical graph where you have exports, investments, imports, and investment income paid. You have the home country. You have +[262.51s -> 273.15s] the rest of the world so this is you know your country in relationship to global trade and so each element of the current account balance involves a flow of payment +[273.15s -> 284.32s] between countries top line shows exports of goods and services you know leaving the home country second line shows money receives for those exports third lines +[284.32s -> 294.48s] it shows the imports that that home country receives from others and then the last line shows the payments that the home country sent abroad for an exchange +[296.05s -> 309.71s] The balance of trade is the balance of payments. A current account deficit means the country is a net borrower. Conversely, a positive current balance means they are a lender. +[309.71s -> 321.55s] Inflow, it is possible to be both. An inflow or outflow of foreign capital does not necessarily refer to it. +[321.55s -> 326.96s] the debt the governments owe to other governments, although government debt may be part of the picture. +[327.06s -> 341.65s] These international flows of capital refer to the other ways in which private investors in one country may invest in another country. And this can happen in terms of buying real estate companies or financial investments like stocks or bonds. +[341.65s -> 346.72s] Point of note, this is not always a healthy. +[346.72s -> 357.02s] exchange depending on what type of relationships people have with the other countries so right now there's a phenomenon on the west coast +[357.02s -> 361.98s] in particular where china's buying up real estate up and down the west coast +[361.98s -> 376.27s] uh Vancouver Canada and British Columbia is a really great example I was there a couple of years ago lots of really beautiful tall buildings very modern very clean and only to learn that most of those buildings were +[376.27s -> 385.30s] empty and that was so that the Chinese could drive up the cost of the rental market in that area so +[385.30s -> 395.82s] it's not always a benign exchange and that's something you need to bear in mind sometimes tariffs or even embargoes may have to take place to get things back into shape +[395.82s -> 408.06s] Here we have a little formula, probably we'll see it on the test, about national savings, investment identity, total private savings, and public savings, or, and this, that. +[408.06s -> 420.38s] instance a government budget surplus that happens every now and then and so you have the supply financial capital equal demand for financial capital so those two things are +[420.38s -> 433.95s] Meaning an equilibrium and then you have your formula where you have this the savings by individuals added by either imports or by exports +[433.95s -> 445.36s] You also have the individual private sector investment, government spending minus taxes collected. Probably we'll see this on a test once again. +[445.68s -> 456.21s] National savings and investment identity continued. We'll go back to our formula. I think a couple notes on the bottom with government is +[456.21s -> 468.27s] spending more than it's pulling in the way of taxes they'll demand financial capital so this is what happens with quantitative easing or let's just say simply a shortage of +[468.27s -> 482.40s] cash for the government to conduct its business they'll either print more money or do a stimulus package and we've seen a lot of that in recent years so that's something that you should become familiar with +[482.40s -> 494.85s] where the opposite if we're collecting more taxes and the government's actually spending uh we could be a supplier of financial capital which means we can use the money for +[494.85s -> 501.71s] other means, perhaps leveraging other countries to do our bidding or to give us favorable trade. +[503.50s -> 514.64s] And domestic saving and investment determine the trade balance. So they're talking about really the retail investor to a larger extent. +[514.64s -> 527.65s] Economists view the balance of trade as a fundamentally macroeconomic phenomenon in the case of a trade deficit, which is something that's constantly spoken of. +[527.65s -> 532.62s] with respect to trade with other nations and the trade balance. +[532.62s -> 544.98s] uh the national savings and investments can be written as such so you have this formula it's a variant on what we were talking about earlier so the only way that +[545.10s -> 552.43s] Domestic investment can exceed domestic savings as capital flowing into a country from abroad. +[555.92s -> 570.40s] domestic saving and investment okay that's determining the trade balance in continuation so in case of a surplus uh you have the formula down there domestic savings both private and public is higher than the +[570.40s -> 581.49s] domestic investment, meaning that money's basically just sitting in the bank. Extra financial capital would be invested abroad. +[584.27s -> 593.06s] National savings and investment identity also provides a framework for thinking about what will cause trade deficits to rise or fall. +[593.06s -> 607.10s] this is a little bit predictive based on the behavior of several factors once again we have our equation and so this is a case where you have a table where you have if domestic investment goes up +[607.10s -> 619.25s] And the savings doesn't change. The difference between taxes and government spending does not change. +[619.25s -> 630.99s] Minus X must drive. So this is a ceteris paribus situation where they freeze certain vegetables. I mean variables and +[630.99s -> 635.98s] Anyways, you'll see what yeah, you probably need to see this on the test. I'd refer this +[639.34s -> 652.82s] In the short run, when an economy is in a recession around the upswing, these things influence balances. Recession tends to make trade deficits smaller or a trade +[652.82s -> 664.50s] surplus larger while a period of strong growth tends to make the deficits larger and those trade surplus smaller so they kind of behave inversely of each other +[668.78s -> 679.71s] Okay, to the pros and cons of deficits and surpluses, really there's no economic merit or advantage of just being on the sidelines. +[679.71s -> 687.81s] It does make sense for a national economy to borrow from abroad as long as it puts money to good use. +[687.81s -> 694.93s] and tends to raise the nation's economic growth over time a couple of examples and +[694.93s -> 705.66s] you know, the mid-1800s industrial revolution in the United States and South Korea in the 70s who have greatly benefited from this. +[705.66s -> 717.17s] whereas not everybody necessarily does this with the right goals in mind or they say they're going to do something or want to do something different so they get the you know results +[717.17s -> 730.82s] mexico brazil and a lot of africa had seen in the 70s and 80s most of these countries are pretty dilapidated from an economic standpoint they have high inflation they have +[730.82s -> 741.14s] you know income inequality that's not even on par with what we're doing so they have they have issues because they're not making prudent choices +[741.46s -> 751.47s] So the difference between the level of trade and the trade balance, the level of trade tells how much production it exports. Okay, so the separate term and the... +[751.47s -> 765.07s] Balance of trade and that's measured as a matter of exports out of the GDP. So it's a it's a ratio Three factors that influence the nation's level of trade is the size of its economy its geography +[765.07s -> 779.41s] and its history so what would you think about the following countries having a low or high level of trade let's talk about you can talk about sweden and sweden amazingly has +[779.41s -> 791.68s] Quite a high level of trade. You think of Volvo or you think of Ikea and a number of other things that, you know, really are global brands. +[791.68s -> 802.48s] do have quite a bit of participation in spite of their their size and really anonymity because not everybody thinks of sweden as a as a +[802.48s -> 815.34s] economic powerhouse of any kind, but they are a developed nation, United States. We have a very high level of trade and Japan most definitely does too. +[816.62s -> 829.30s] So some final takeaways about trade imbalances. Trade deficits could be good or a bad sign for our economy and surpluses could be a good or bad sign. So there's no... +[829.30s -> 843.33s] uh imperative as to whether it's going to be one direction or another there are other influencing factors that may impact its benefits or or negatives on any given economy +[843.33s -> 850.16s] uh trade balance is zero which means we're hit a point of equilibrium where we're neither a borrower or a lender +[850.16s -> 859.73s] it could also be a good or bad sign so there's really a lot of ambiguity about this stuff that's the thing you need to keep in mind um +[859.73s -> 871.14s] You know, whether a particular country is borrowing or lending in the particular economic conditions of that country makes sense. So basically, you know. +[871.14s -> 883.06s] a prudent government or a prudent central bank would take a look at the current economic policy, the productivity of the country. +[883.06s -> 896.59s] and try to adjust their policy to either promote growth or any number of factors and these will be spoken of later this concludes chapter 10. diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_5.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b0b160bd8201b23cec0e6e304c2f5976e520bbeb --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_5.mp4.txt @@ -0,0 +1,16 @@ +[3.06s -> 16.34s] How you doing AP Econ students? It's Mr. Clifford. It's time to learn the most important graph in all of macroeconomics. Aggregate demand and aggregate supply. You already learned about demand and supply in regular markets. Now it's time to look at the entire economy working at aggregates. +[16.34s -> 30.77s] Okay, first one is aggregate demand. Aggregate demand, just like regular demand, is downward sloping. Why? Because when the price level is high, the quantity demanded in our entire economy is not going to be very high, right? Price level is the general prices of things. +[30.77s -> 44.61s] level was lower, then more people would want to buy stuff. Now, aggregate demand is actually made up of the GDP, the four components of GDP, C plus I plus G plus XN. The next step is aggregate supply. +[44.61s -> 57.82s] Agri-supply, as you can expect, is going to be upward sloping. But, pay attention, this is the short-run agri-supply. When price levels go up, more firms will produce more. Done. You've seen that before. But, pay attention. +[57.82s -> 69.23s] In the short run, the prices go up, the wages of workers and the price of resources don't go up in the short run. And so when the price goes up, firms will produce more because they're making more profit. +[69.23s -> 81.39s] But in the long run, when price goes up by a certain amount, let's say it doubles, the wages of the workers will also increase in the long run. And so that leads to another graph, something called the long run aggregate supply. +[81.39s -> 95.14s] I'll put it right here. The reason why it's vertical, the long run agri-supply is when the price level goes up, the actual amount produced is not going to increase because wages go up by the same amount. That's the concept. The long run agri-supply is perfectly vertical. +[95.14s -> 102.69s] Okay, now the way I drew this, I drew this at quantity, full, and plent. What does that mean? Well, it means that the long-winded average supply is right here. +[102.69s -> 114.08s] And the aggregate demand supply in the short run is right here, and so we're at full employment output. Our economy is running at full employment. Let's show you visually why the long-run aggregate supply curve is vertical. +[114.08s -> 125.74s] Let's assume right now we're here at point A where supply and aggregate demand meet. And now there's an increase in consumer spending. Consumers want more stuff. Aggregate demand shifts to the right. +[125.74s -> 138.32s] Right over here, now we have a higher price level and a higher quantity. Well, now we have something called inflationary gap. Our current GDP is beyond the full employment GDP. And now that's going to put upward pressure on prices. +[138.32s -> 152.27s] If there's more people who want stuff, we get demand pull inflation, and that's going to lead to upper pressure on prices and wages. And in the long run, those wages will go up by the same amount that prices went up. When that happens, that causes aggregate supply. +[152.27s -> 166.37s] to shift to the left. Agri-supply now would shift to the left because wages went up and prices for resources went up, leading to a new equilibrium, which is at B, right back in the long run. Now, it also goes the other direction. +[166.37s -> 179.17s] Let's say, for example, we're in a recessionary gap. Aggregate demand falls. That puts pressure on, downward pressure on prices, decreasing price level and decreasing the quantity. Now that puts us here. Now, in theory... +[179.17s -> 191.26s] when the price level falls and wages are flexible, so wages eventually fall, and if wages fall and resource prices fall, that would actually increase aggregate supply, shifting aggregate supply to the right. +[191.26s -> 202.99s] leading to a new equilibrium, right? We started at A, we ended at B. Where is it? It's the long run. That's why the long run X supply is vertical. Make sure you know that. Aggregate demand, X supply, long run X supply. Until next time. diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_6.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2df2b1cef81040758b83e157ec75cf8de006415a --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_6.mp4.txt @@ -0,0 +1,46 @@ +[0.00s -> 1.87s] We are now going to discuss +[1.87s -> 16.21s] price elasticity of demand, which sounds like a very fancy concept, but really it's a way for economists to sense how sensitive is quantity to change in prices. And in this video, we're gonna denote it as a +[16.21s -> 25.87s] a capital E, so price elasticity of demand. And the easy way to think about it is it is your percent. +[25.87s -> 36.03s] change in, I'll use the Greek letter delta shorthand for change in your percent, change in quantity over your percent change in price. +[36.03s -> 48.67s] And so you might say, wait, how does this relate to the everyday idea of elasticity? Well, imagine two bands. So let's imagine an inelastic band, inelastic. +[48.67s -> 61.55s] right over here, and let's imagine an elastic band right over here. So in an inelastic band, if we apply some amount of force, you're not going to be able to stretch it much. It might stretch a little bit. +[61.55s -> 75.15s] While an elastic band, if you apply that same amount of force, you might be able to stretch it a lot more. And so the analogy here is we're not using force, but we're saying how much does quantity stretch for a given amount of +[75.15s -> 87.02s] And so something where the quantity changes a lot for a given price change would be very elastic. So this, the magnitude of this will be larger. And if the +[87.02s -> 95.34s] If percent change in quantity doesn't change a lot for a given percent change in price, well then we're dealing with an inelastic price elasticity of demand. +[95.34s -> 108.42s] And we'll be able to internalize these more as we work through the numbers. And actually let's do that for this demand schedule that we have right over here and it's visualized as our demand curve. In the vertical axis we have price of +[108.42s -> 121.09s] burgers, and then in our horizontal axis we have quantity in terms of burgers per hour. And so let's just use this definition of price elasticity of demand to calculate it across different +[121.09s -> 129.60s] points on our demand curve. So let me make a new column here. So price elasticity of demand. +[129.60s -> 137.63s] And the way I'm gonna do it is really the simplest method for calculating this. In other videos, we can go into more in-depth methods like the +[137.63s -> 148.54s] midpoint method, and I'll show you the weakness in what we're doing right here, but for the sake of, say, an AP economics, microeconomics course, this would be sufficient. So, +[148.54s -> 162.38s] Let's think about our price elasticity of demand as we go from point A to point B. Well remember, that's just going to be our percent change in quantity over our percent change in price. +[162.38s -> 175.06s] So what is our percent change in quantity? Well, we're starting at a quantity of two, so put that in our denominator, and we're going from two to four. +[175.06s -> 187.87s] So we are adding two. So we have two over two. We could multiply that times 100% if we like. So this would give us, we have 100% change in quantity over. +[187.87s -> 198.48s] Now what was the corresponding change in price, percent change in price? So our corresponding percent change in price, our initial price is nine. +[199.38s -> 212.69s] and we go from nine to eight, so we're going down by one, and then we multiply that times 100%. So this is going to be about a negative 11% change in price. +[212.69s -> 226.11s] And this math is reasonably straightforward because the hundred percents cancel out. This is just a one. One over negative 1 9th is just going to be equal to negative nine. +[226.11s -> 231.62s] So you have a negative nine price elasticity of demand. +[231.62s -> 245.10s] So before I interpret that more, let's look at the price elasticity of demand at other points, or starting from other points to other points on this curve. So let's think about it going from, actually let's think about it going from E to F. +[245.10s -> 257.47s] So as we go from E to F, we're going to do the same exact exercise. What is our percent change in quantity? Well, our initial quantity is 16, and we're going from 16 to 18. +[257.47s -> 270.96s] So we have a change of two, so two over 16 times 100%. That is our percent change in quantity. And what is our percent change in price? Well, our initial price is two. +[271.50s -> 280.82s] And we're going from two to one. So we have a price change of negative one times 100%. +[280.82s -> 294.77s] And so what you see here is this is 1 eighth times 100%. This would be 12.5% up here. So this is 12.5% up there. And then this over here is going to be negative 50%. +[294.96s -> 304.69s] So when price went down by 50%, you had a 12.5% increase in quantity. +[304.69s -> 316.88s] 12.5% is 1 4th of 50%, so this is going to give us a price elasticity of demand of negative 0.25. +[316.88s -> 322.51s] So there's a couple of interesting things that you might already be realizing. One is +[322.51s -> 336.82s] Even though our demand curve right over here is a line, it actually has a constant slope, you see that the price elasticity of demand changes depending on different parts of the curve. Now the reason why this is, is really +[336.82s -> 348.27s] it just boils down to math. When we were going from A to B, our initial prices were relatively high. So even though you had a price decrease of one, it was from an initial price of nine. +[348.27s -> 360.19s] so your percentage change in price looked fairly low, while your percentage change in quantity was high, because you're going from a low quantity of two, and you're adding two to it, so you had 100% change in quantity. +[360.19s -> 370.70s] When you go to the other end of our curve, and you go from E to F, it's the other way around. Your price starting point is low, so your percent change in price when you +[370.70s -> 383.62s] decrease price by one, it looks like a fairly large magnitude, while your percent change in quantity when you go from E to F, because you are already at a quantity of 16, adding two to that is not that large of a percentage. +[383.62s -> 395.31s] Now another thing you might be appreciating is if we tried to calculate the price elasticity of demand up here on the curve, and instead of going from A to B, if we went from B to A, we would have gotten a different value. +[395.31s -> 405.95s] because our initial prices and quantities would have been different. Our initial price we would have put an eight right over here, and our initial quantity we would have put a four over here, and we would have gotten a different value. +[405.95s -> 419.60s] And that's one of the negatives of the technique, which is arguably the simplest technique that I just used. There's other techniques like the midpoint technique that can give you a more consistent result whether you're going from A to B or B to A, but I won't cover it just yet. +[419.60s -> 428.72s] But let's think now about how to interpret this. And the best way to interpret it is to think about the absolute value of the price elasticity of demand. +[428.72s -> 442.16s] So over here, the absolute value of our price elasticity of demand is equal to nine, and then over here, the absolute value of our price elasticity of demand +[442.16s -> 446.06s] is equal to 0.25. +[446.06s -> 459.34s] And a general rule of thumb is if your absolute value of your price elasticity of demand is less than one, you are dealing with an inelastic, inelastic +[459.76s -> 471.06s] and if your price elasticity of demand, the absolute value of it, is greater than one, you're dealing with an elastic situation. +[471.06s -> 485.28s] Why does that make sense? Well, in this first scenario, it's saying for a given percentage change in price, you have a smaller percent change in quantity, while here, for a given percent in price, +[485.28s -> 492.80s] you're gonna have a larger than that percentage change in your quantity. So once again, it goes back to these rubber band analogies. +[492.80s -> 506.14s] So when we're going from A to B, the absolute value of our price elasticity of demand is definitely larger than one. So economists would consider this to be an elastic situation. +[506.14s -> 519.84s] While when we go from point E to point F, our price elasticity of demand, or the absolute value of it, is definitely less than one, so this is going to be an inelastic situation. diff --git a/VideoMMMU_ASR_large/Business/validation_Economics_8.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Economics_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ca5ac8e2cc622583b99527a9e29850139450e504 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Economics_8.mp4.txt @@ -0,0 +1,38 @@ +[10.83s -> 24.90s] Hope you are well. Another interesting topic to work on today. In the last class, we looked at how nominal GDP and real GDP are calculated. We used a simplified model and assumed only four products in the economy. +[24.90s -> 37.30s] We're thinking about how hard the calculation would be with large number of products and services that the US produces. It is complicated work and economists working with the US government manage this data and update it frequently. +[37.55s -> 45.26s] In today's class, we will talk about another way to calculate GDP. The approach we will introduce today is called the expenditure model. +[46.58s -> 60.34s] The expenditure model relies on the assumption that what is produced generates income and therefore spending, or expenditure must have taken place. So instead of calculating the products, calculate the spending. +[60.78s -> 72.72s] The expenditure model breaks the economy to four sections and can be presented in this equation. Y equals C plus I plus G plus NX. +[73.52s -> 83.92s] This states that the economic output represented by Y is the sum of C, I, G, and an X. +[84.11s -> 92.59s] Our goal today is to discuss what these expenditure components are and how they contribute to the GDP. Let's start with C. +[92.85s -> 101.49s] C stands for consumption and it reflects all the spending by consumers. In the US, it is normally their largest component of GDP. +[102.00s -> 116.50s] In the US, consumption by private individuals accounts for roughly 68% of GDP. This graph shows the share of GDP for personal consumption from 2001 to 2019. +[116.88s -> 126.32s] Roughly two-thirds of the US economy is based on consumer spending. This is why we often refer to the US as a consumer economy. +[127.89s -> 138.58s] consumer spending can be broken down to three types. Spending on durable goods, spending on non-durable goods, and spending on services. +[139.34s -> 148.66s] Durable goods are goods that last long periods of time. Goods like cars, electronics, furniture, appliances are examples of durable goods. +[148.91s -> 159.44s] Whereas non-durable goods are goods that need to be replaced in a short period of time usually within three years. Examples are food, clothing, or cosmetics. +[159.89s -> 173.26s] services is consumer spending where physical goods are not exchanged usually to pay for someone's advice or assistance this lesson is a good example of a service you are paying for the opportunity to learn from me +[174.00s -> 188.27s] Economists interested in the health of the economy will follow overall consumer expenditure, but also will look into consumer spending on durable, non-durable, and services. They are usually interested in spending on durable goods specifically. +[188.50s -> 196.27s] Changes in durable goods spending are considered leading indicators of what will happen to the US economy in the future. +[196.56s -> 204.27s] When consumers reduce their spending on durable goods, it is a signal that the U.S. economy is heading towards trouble in the future. +[204.69s -> 212.21s] This is a graph of quarterly U.S. personal consumption on durable goods from 2006 to 2020. +[213.10s -> 222.29s] Spending on durable goods started to fall before the US officially went into recession. We can see a fall in spending on durable goods in the first quarter of 2020. +[225.84s -> 240.02s] The next component of GDP in Y equals C plus I plus G plus NX is I or investment. Investment relates to spending by businesses to increase their business activity. +[240.02s -> 250.85s] It includes purchases of building, also referred to as capital, or spending on building inventory, or other spending by businesses. In investment, +[250.85s -> 259.98s] we also include spending by consumers on new residential housing. That spending does not fall under personal consumption. It is included in investment. +[261.01s -> 272.85s] One note to make here in macroeconomics when we say investment, we do not mean purchasing of stocks and bonds. It refers to purchasing of goods for production purposes. +[273.97s -> 286.42s] This is private domestic investment expenditure from 2001 to 2020 reported quarterly. You can see that since 2009, there has been an increase in investment spending in the US. +[286.64s -> 301.26s] Also, investment fell during the 2008 recession. The next component of GDP is government spending. This is spending by state, local, and federal government on goods and services. +[301.55s -> 314.22s] When calculating this number, we exclude transfer payments. Transfer payments are payments to people like Social Security, Medicare, unemployment insurance, welfare programs, and subsidies. +[314.61s -> 322.19s] These are examples of transfer payments. They are not included in GDP because they are not payments for goods or services +[323.12s -> 333.49s] Government spending as a fraction of GDP in the US in 2020 is about 17%. For an international comparison, let's compare the government share of GDP in Oman. +[333.84s -> 346.96s] On a personal note, I am from Oman. I highly recommend a visit to Oman one day. It is a beautiful country and welcoming. If you are into outdoor adventure, Oman should be top on your list. +[347.44s -> 361.65s] In Oman, government expenditure accounts for 25% of GDP. The final component of GDP has to do with trade. NX stands for net exports. It is calculated as the difference between exports +[361.65s -> 376.43s] and imports exports labeled x are the goods and services that the domestic economy sells internationally and imports labeled m are goods we buy from other countries +[376.72s -> 390.27s] We add the spending on exports and subtract out the spending on imports. The reason we subtract imports is because they are already counted in spending by C, I and G. +[390.27s -> 404.66s] So we do not want to double count them This calculation has actually caused confusion in markets Seeing that imports have a negative sign in front of it. Some have argued that we can increase GDP by eliminating imports +[404.66s -> 415.86s] Mathematically, that looks correct. However, we need to be clear that when we eliminate imports, we are also reducing spending by consumers, businesses and governments. +[416.59s -> 422.38s] Being aware of why there is a negative sign in front of imports is important for policies towards trade. +[423.18s -> 436.54s] To recap, the GDP in the US economy can be calculated by following the spending in the economy. In this class, we learned that GDP can be calculated by Y equals C plus +[436.54s -> 451.28s] I plus G plus X minus M. And we call this the expenditure model. We also have a better idea of what the trends are for each of these components and how they look like in the United States. +[451.73s -> 461.81s] we are starting to get a good understanding of GDP and its impact on the health of the economy. Make sure to reach out if you have any questions. See you next class. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_11.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0cd9c2d54b647561d15de76a8ae821ec843b48b2 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_11.mp4.txt @@ -0,0 +1,21 @@ +[0.00s -> 13.46s] In this video, I'll show you how to calculate the real rate of return. The first thing that I'll do is explain what real rate of return is and why it's important for an investor. And then we'll look at a real-life example where we put this into practice. +[13.46s -> 22.05s] So suppose we can invest our money at 10% into an account for one year, but we expect the rate of inflation to be 5%. +[22.05s -> 33.14s] At the end of the year, we'll have $110 saved up as a result of our investment, but $100 worth of goods before now cost $105 a year later. +[33.14s -> 41.82s] In other words, what you could have purchased for $100 at the beginning of the year, now will be worth $105 at the end of the year. +[41.82s -> 54.21s] Therefore, by investing and deferring our purchasing decisions, we really only have 5 extra dollars and not 10. This leads us to ask, in one year, what is the actual purchasing power? +[54.21s -> 65.78s] that is the real rate of return for this investment considering inflation. To answer this question, we must calculate the real rate of interest using this formula shown right here. +[66.06s -> 74.80s] The value we get for I sub real, which is a percentage, tells us the actual purchasing power after the impact of inflation. +[74.80s -> 88.30s] And this is not to be confused as a nominal interest rate used to calculate some future value of a current saving. It's completely different. If you're curious as to how this formula is derived, +[88.30s -> 98.82s] A link to a write-up of its derivation is found in the description below. So here's our question. Mark invests at 5.39% annual interest. +[98.82s -> 113.04s] However, Mark expects inflation to be 3.1%. What is the real rate of return? Now, these values, if you live in Canada, are true. Some banks do offer 5.39% as of... +[113.04s -> 126.24s] 2024, and the inflation rate for 2023 was around 3.1%. Using this formula, we'll write down I sub real is equal to +[126.24s -> 139.63s] i represents the interest that you earn for your investment, and in this case, it's 5.39. Making that into a non-percentage, it is equal to 0.0539. +[139.70s -> 149.52s] R represents the rate of inflation. 3.1% is the same as saying 0.031. +[151.41s -> 160.14s] over, again, we have 1 plus 0.031. Let's go ahead and use our calculator for this. +[161.36s -> 171.47s] We have in parentheses the expression at the top, which is 0.0539, take away 0.031. +[171.89s -> 183.73s] That gets divided by the bottom expression, which is 1 plus 0.031. We end up with the real rate of interest being +[184.21s -> 190.13s] 0.0222 +[190.42s -> 204.37s] which, when rounded, is roughly 2.22%. To help you interpret what 2.22% means, it means that Mark is able to purchase 2.22% +[204.37s -> 209.18s] more goods at the end of the year than he could at the beginning of the year. +[209.18s -> 223.20s] The fact that the nominal rate was greater than the rate of inflation ensures that Mark's investment outpaced the general rise in prices, safeguarding the value of his funds. This is why it's wise to invest your money +[223.20s -> 234.22s] earning interest rather than keeping it saved in some stagnant account. If you have any questions regarding this topic, feel free to use the comment section below. Thank you for watching. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_12.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..8316e41701b14bdf03e198feebec99b7068cd572 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_12.mp4.txt @@ -0,0 +1,14 @@ +[0.00s -> 13.62s] In order to calculate the total return on a stock, let's first walk through an example of a no dividend stock. So we're going to assume that PepsiCo has not paid any dividends over the last five years on their stock. +[13.62s -> 25.66s] Our return for this situation is total return equals price at time 1, so time 1 will be when we actually sell the stock, divided by price at time 0, and time 0 is when we purchase the stock. +[25.66s -> 39.95s] minus one that'll make it into a percentage form now to just keep this as simple as possible for the first example let's say we purchased the stock here in 2018 when the price was 100 so that will be t equals zero so time equals +[39.95s -> 48.93s] zero and then let's say we sold the stock right here in 2021 when the price was $150 so that is +[48.93s -> 59.47s] t equals one so our total return over that investment would have been uh 150 divided by 100 +[59.95s -> 64.91s] minus one, which is just a 50% total return. +[64.91s -> 79.22s] Now let's make it a little bit more complicated and realistic and assume that this stock actually pays dividends. So we can use the same, you know, time equals zero. So t equals zero, we purchase the stock when its price is equal to... +[79.22s -> 87.41s] 100 right there and now let's say that we actually sold it right here so time equals 1 is going to be this +[87.86s -> 102.10s] and we'll assume that at that time it may not be exact but we'll say the price was 125 when we actually sold that stock but let's say also that at the end of 2019 right here +[102.48s -> 114.40s] This stock paid a dividend of $10 right so at the end of every year PepsiCo pays a $10 dividend. I'm not saying that actually happens, but we'll just roll with it +[114.40s -> 126.48s] So then our total return is going to be what we looked at earlier. So it's going to be the price at time 1 divided by the price at time 0. +[127.22s -> 140.66s] And that's going to give us what we would actually call the capital gains yield. But now there's another component with the dividend. So with the dividend, we're actually going to have a whole other yield included, which is... +[140.66s -> 152.45s] the dividend divided by the initial purchase price of 100 and then we're going to take this entire thing and we will subtract by one so our cap our uh +[152.45s -> 166.70s] capital gains yield would actually have been 25% and our dividend yield is going to have been 10% making a total return of 35%. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_15.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..31225fdfaff83dacf5d0bc9fdd0542bcefe251c0 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_15.mp4.txt @@ -0,0 +1,30 @@ +[0.00s -> 14.48s] In this video, I want to show you how to calculate the IRR using trial and error. So the IRR, which stands for Internal Rate of Return, is the rate of return that would result in an NPV of zero for a project when it's used as a +[14.48s -> 28.69s] discount rate for that project so let me show you what i mean by that with an example let's say we have a project with the following cash flows in year zero which is today there's a cash outflow of fifty thousand dollars so to take on this project we have to +[28.69s -> 42.90s] pay out $50,000 today but then one year from today we're going to have a cash inflow of $33,000 and then two years from today we're going to have another cash inflow of $24,200. +[42.90s -> 57.10s] Okay, so we've got one cash outflow today and then two cash inflows over the next two years. So how would we set this up to figure out the IRR? Well, remember, it's the rate of return that's going to give us an NPV of zero. +[57.10s -> 61.26s] we set it up where we say, okay, here's our MPV of zero. +[61.26s -> 75.60s] we'll put that on the right hand side so this is zero what would we have to do if we had a negative fifty thousand dollar cash outflow today this doesn't need to be discounted and then the thirty three thousand dollar cash inflow that needs to be discounted by one period so +[75.60s -> 82.70s] We divide it by one plus R. Okay, so this is basically, we're just taking the cash flows and we're discounting them. +[82.70s -> 96.98s] Okay, obviously not the first one because it occurs today. And then the second cash flow occurs two periods from now. So it would be $24,200 divided by 1 plus R raised to the second power because it's two periods from now. +[96.98s -> 111.18s] a third year then we would have the third cash flow and it'd be divided by 1 plus R to the third power okay and so these cash flows the discounted cash flow the net the net discounted cash flows when we take the net +[111.18s -> 120.13s] negative one and then we've got the two positive ones, then we net it all together, should equal zero. The question is, what is the r? +[120.13s -> 134.45s] What is the R that would make this equal to zero? How do we get the left-hand side here equal to zero? And so we can use trial and error. What we do is basically plug in different numbers for our R. So we can try. +[134.45s -> 143.66s] for example nine percent so if we try nine percent we say okay let's just take the same thing here and let's just plug in 0.09 for our r +[143.66s -> 150.08s] okay so we got negative 50 000 plus 33 000 divided by 1.09 +[150.08s -> 164.37s] Okay, and then 24,200 divided by 1.09 to the second power. Again, that's because that's two periods in the future. So we're just using the time value of money to discount these cash flows. And it gives us an MPV. So if we calculate... +[164.37s -> 175.68s] this these out you get an MPV of six hundred and forty four dollars now remember we said the IRR is supposed to get is that when we plug in the M4R it's supposed to give us an MPV of zero +[175.68s -> 188.02s] But we don't have an MPV of zero. We have $644. So obviously, 9% is not correct. So that's not our IRR. So let's try another one. Let's try 9.5%. +[188.02s -> 197.90s] and we'll just iteratively go and try different values. So again, we just plug in, this is the same formula as here, but now for the r, we have 0.095. +[197.90s -> 212.24s] see that so now it's 1.095 is what we're dividing the 33 000 by and then the 24 200 we divide by 1.095 to the second power or to the second power and then what we get here here's the +[212.24s -> 226.45s] I've divided all this out for you. So, but it's just basically just doing division here. This equals this and so forth. So that gives us an MPV of $320. Okay, so here we had an MPV of $644. +[226.45s -> 239.74s] we tried nine percent and then we went up to nine point five percent and got an MPV that is still not zero this this is obviously not zero but it's closer to zero okay we went from 644 +[239.74s -> 252.67s] to 320. So by going up from 9 to 9.5, we got closer to zero. So even though 9.5 is not correct, it's not the RRR, we're going in the right direction. So let's keep going up. +[252.67s -> 261.20s] Let's keep going up. Let's try now 10% Okay, so now we're just gonna plug in for this R. It's gonna be we're gonna plug in a 0.1 +[261.20s -> 275.12s] And so if we do that, now we've got negative 50,000 plus 33,000 divided by 1.1, and then plus 24,200 divided by 1.1 squared, okay, to the second power. What does that equal? +[275.12s -> 284.30s] And that equals zero. So now that we've actually found a rate here that equals zero, now we know what our IRR is. +[284.30s -> 296.67s] Our IRR is 10% because when we discount these cash flows and net them together using a discount rate of 10%, that was where we got this 0.1. +[296.67s -> 309.74s] When we do that, we end up with an NPV for the project of zero. So 10% is this project's internal rate of return. Now, what do we do with that? Well, we're going to look at the company's hurdle rate. +[309.74s -> 317.15s] Okay, so let's say the company has a hurdle rate where they said, look, we have to achieve a return of at least 8%. +[317.15s -> 331.54s] on our projects and so we compare them and say okay well this project has a IRR 10% and our hurdle rate is 8% so we meet the required rate of return for this particular company so then we would accept the +[331.54s -> 345.74s] Okay, if the hurdle rate was 13%, then we would say, well, we get a 10% return here, but we don't meet the hurdle rate. We would reject the project. And again, we also, if we do exceed the hurdle rate, we want to make sure too that we don't. +[345.74s -> 360.34s] have any kind of capital constraints and I'll make another video where we talk about what to do. You might have an IRR that exceeds the hurdle rate but you have some kind of capital constraints where the company only has so much money to invest in certain projects and we'll talk about that in another video. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_16.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_16.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..45f983c5318f0907f4a1a267275f386d9862c0c8 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_16.mp4.txt @@ -0,0 +1,20 @@ +[0.00s -> 14.32s] Let's say that you agree to lend me some money. Say you agree to lend me $100. And I ask you, all right, do I just have to pay you back $100? And you say, no, no, you want some interest. And I say, how much interest? And you say. +[14.32s -> 27.04s] that you are going to charge me 5% per year interest. So one way to think about it is if I borrow $100 today, so $100 today. +[27.04s -> 31.46s] In a year, I'm going to have to pay you back $100. +[31.46s -> 45.81s] times, I'm gonna have to grow it by 5%, so that's the same thing as multiplying it by 1.05. This is how much I'm going to have to pay back. Let me write this down. This is borrow. This is what I'm going to have to pay back. +[45.81s -> 57.87s] And so this interest rate, the face value of how much more I'm gonna have to pay back, this is known as the nominal interest rate. Nominal interest rate. +[57.87s -> 66.29s] And we can compare this to the real interest rate. And you might say, why do we need some other type of interest rate? +[66.29s -> 79.12s] Well, even though on the face value I'm paying you back 5% more, that doesn't necessarily mean that you're going to be able to buy 5% more with the money that you get paid back, and you might guess why that is the case. +[79.12s -> 90.21s] because of inflation. $105 will not necessarily buy you in a year what it might buy you today. And so that's what the real interest rate is trying to get at. +[90.21s -> 98.96s] And to do that, to calculate our real interest rate, we are going to have to think about inflation. So let me put inflation right over here. +[99.76s -> 113.57s] And so let's say that we are in a world that has 2% inflation. So an indicative basket of goods that costs $100 today, if this is the inflation rate, would cost $102 in a year. +[113.57s -> 120.35s] So there's two ways that folks will calculate the real interest rate given the nominal interest rate and the inflation rate. +[120.35s -> 128.77s] The first way is an approximation, but it's very simple and you can do it in your head, and that's why it's often the first way that it's taught, but it's not exactly mathematically correct. +[128.77s -> 142.62s] So the first way, you'd say, well, this could approximately be equal to the nominal interest rate minus the inflation rate. So you could say this could be approximately equal to 5% minus, minus. +[142.62s -> 149.84s] which would be equal to 3%. And this is a decent approximation. +[149.84s -> 160.75s] But the actual way that you would want to calculate this, if you wanted to be more mathematically precise, is that your nominal interest rate multiplies things by 1.05. So 1.05. +[160.75s -> 173.68s] But then things are getting more expensive at a rate of 2% per year. Or another way to think about it, costs are being multiplied by 1.02 every year. So we divide by that amount, 1.02. +[173.68s -> 186.62s] and so this was going to give us 1.05 divided by 1.02 is equal to 1.0294. +[186.62s -> 195.98s] And another way to think about it, we just got a much better sense of what the real interest rate is. It's actually much closer to . +[195.98s -> 204.96s] And this is a very small difference, and so that's why people like this method. You can do it in your head, and it got pretty close. +[204.96s -> 213.47s] But keep in mind, even very small changes in interest can make a big deal when we compound over many years. And in other videos, we've talked about compounding. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_17.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_17.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3055ef3f06adde403de0431cefbfc907baa1798c --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_17.mp4.txt @@ -0,0 +1,8 @@ +[0.37s -> 10.30s] We know that the bond price is equal to present value of all future cash flows. So what is the future cash flows of a bond? We receive coupons and we receive +[10.30s -> 23.30s] the whole amount which is called face value therefore the bond price will be equal to the present value of coupon plus the present value of face time how many times do we get the coupon we get it periodically so we'll get it many times +[23.30s -> 36.24s] how many times we get the face value we get it only once at maturity therefore the bond price will be equal to for the coupon we need to get the present value for the annuity while for face value we need to get the present value of single cash flow +[36.24s -> 49.98s] which we studied before in time value of money therefore we could say that our bond price is equal to for bond price we'll give it symbol P capital P so the formula of present value of ordinary annuity is +[49.98s -> 63.31s] c multiplied by open bracket 1 minus open second bracket 1 plus i close bracket to the power negative n close bracket divided by i plus get the present value of single cash flow which is face value +[63.31s -> 75.17s] multiplied by 1 plus i to the power negative n. So, how do we calculate the coupon? We said that our coupon is equal to coupon rate times face value. Therefore, here we use the coupon rate only once. +[75.17s -> 87.74s] but what about this i this discount factor we have it here three times so what do you mean by this i this i refers to yield to maturity some textbook will give it abbreviation of ytm +[87.74s -> 93.91s] other textbook it will be little y other textbook it will be i and this will be our discount factor diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_18.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_18.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..88ac499e691bd8c8e9086c334d357bf1da335d57 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_18.mp4.txt @@ -0,0 +1,18 @@ +[0.85s -> 3.94s] Today, I wanted to briefly discuss the arbitrage. +[3.94s -> 16.08s] pricing theory or APT. Now, I really like this graphic here, but I don't know what Bob's market has to do with the APT. And I really don't know what these bananas have to do with the APT. But what I do know is that APT is related to the CAPM. +[16.08s -> 21.84s] or the capital asset pricing model but it isn't i highly recommend that you watch my videos on cap m +[21.84s -> 35.62s] prior to watching this video you can check out those videos if you follow these links right here so again it is related to CAPM let's refresh our memory in terms of CAPM now the important thing to remember here is that there's this beta and that represents +[35.62s -> 48.86s] and exposure to the market and that's kind of it that's the only thing that matters that is really it but i don't think that's particularly realistic i think you could think of a number of things that would impact uh asset +[48.86s -> 61.63s] prices so what the arbitrage pricing theory does is it attempts to improve the cap m now the cap m is really kind of a special case of the arbitrage pricing theory now +[61.63s -> 76.18s] In CAPM, there's only one beta, but APT says, well, maybe there are more beta. So we can look at this formula and say, well, instead of that being the exposure, it's just an exposure to something that impacts asset prices. And there probably are other things. We can add another. +[76.18s -> 86.93s] exposure and another one and we can just keep going until we have all the exposures that we think impact prices and this gives us a more realistic model to price assets +[86.96s -> 92.77s] Now, what are these factors? Well, they're going to be like microeconomic factors. +[92.77s -> 107.06s] They aren't specified in the theory book. Well, maybe there's three to seven of these things that really impact prices. Now, keep in mind, I have some issues with the way we calculate inflation. I have some issues with GDP. You can check out videos on those topics here. Inflation. +[107.06s -> 121.26s] and here GDP. I think you'll find those of interest. Let's just do a quick example. Let's say we have an asset and we have some exposures out there. We have some factors out there. So let's say we have GDP growth. We were saying it's expected return is 4% and our +[121.26s -> 122.38s] asset has a beta. +[122.38s -> 136.67s] uh versus it a 0.8 we've got inflation we expect that to be 2.3 our asset has a beta exposure 0.6 to that we think gold prices are going to go up by 3.5 and our asset has a negative 0.5 beta exposure to gold prices +[136.67s -> 150.90s] And we have the S&P 500. I think that's going to go up 7%. And our particular asset has a beta of 1.4 versus that asset. And of course, there's also that risk-free rate. So to calculate this, what we're going to do is say our expected return. So we're going to take that beta of. +[150.90s -> 165.10s] gdp growth we're going to take that risk premium so our expected return for gdp growth minus the risk-free rate we're going to get you know 2.4 we do the same kind of thing for inflation same kind of thing for gold prices same kind of thing for this 500 return and then we add those things up together +[165.10s -> 169.17s] say based on this model we expect our asset +[169.17s -> 183.44s] to return 10.33 that's basically it you need to stop it and go through math go ahead and do that but that's about it next time we'll talk about assumptions uh because there are some assumptions that are different than cap m that i think are important to highlight anyway +[183.44s -> 186.75s] I hope you enjoyed that. I'm Brian Kozlowski. Thank you so much. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_2.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b48f664db2a69353a65c5f050e12ef4246e0c07f --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_2.mp4.txt @@ -0,0 +1,12 @@ +[1.55s -> 8.74s] Okay, this example we're going to calculate the expected return using arbitrage pricing theory. +[8.74s -> 20.27s] We've got four variables, gross domestic product or GDP, inflation, gold prices, and S&P 500 index. We have betas for each of these. +[20.27s -> 34.62s] and risk premiums so if we if we were given expected returns we would just subtract the ex the expected return +[34.62s -> 45.78s] minus the risk-free rate and we would expect return on the market we would go go about it that way and but so anyway +[45.78s -> 52.62s] Our expected return here is simply going to be... +[55.79s -> 68.37s] call it erp for expected return on portfolio so it's our risk free rate plus the first beta 0.6 +[68.69s -> 82.86s] right here, multiplied by the market risk premium, plus the second beta, 0.8, multiplied by the market risk premium of 2, that's these two numbers, plus +[83.38s -> 92.88s] negative 0.7 5% +[93.20s -> 107.68s] down here oh and then what's the s p 500 beta of 1.3 times the risk premium multiply those out and we get +[107.68s -> 114.00s] and an expected return of 15.6 percent so the +[114.26s -> 127.30s] Example in your homework is slightly different, but it already gives you an expected return, and it gives you changes in variables. +[127.30s -> 138.99s] multiply the beta, use the expected return, and multiply the beta by the change in those variables to get the new expected return. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_20.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7171e98c19a455b44c2fb8e634cf7b4495981313 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_20.mp4.txt @@ -0,0 +1,33 @@ +[0.14s -> 11.54s] Let's say that I am a producer of wine. And in this axis, vertical axis, this is dollars per bottle. So 10, 20, 30. +[11.54s -> 21.81s] $40 per bottle. And on this axis right over here, I'll have quantity of bottles I produce per week. So let's say that this is 100, this is 200. +[21.81s -> 34.70s] 300 and then 400. So this is quantity of bottles. Bottles per week. And this is dollars per bottle. +[34.74s -> 48.29s] So let's think about the demand curve here. The demand curve for my type of wine. We're going to assume this is highly differentiated wine. The demand curve looks something like that. I'm doing it as a straight line for simplicity. +[48.29s -> 62.58s] The demand curve looks like that. And since I said differentiated, this is not going to be perfect competition. I have a monopoly in my type of wine. So this isn't the market for wine generally. This is a market for my wine. My wine has won some taste. +[62.58s -> 76.78s] taste test, it has this unique flavor and whatever else, and so you can view me as a monopolistic competitor. There's obviously competition from other wine labels, from other wine producers, but my wine is differentiated and I have a monopoly in my +[76.78s -> 86.03s] particular type of wine. And we've done this multiple times. If I have a monopoly in my type of wine, we're talking about the market in my wine, then my marginal revenue curve +[86.03s -> 99.10s] My marginal revenue curve will have twice the slope of this. So it will look something like that. And I'll actually keep going negative after that. So that is my marginal revenue curve. And then we can think about the cost side. +[99.10s -> 104.22s] The cost side of things, my marginal cost might look something like this. +[104.22s -> 117.12s] Marginal cost, or you could even view that as a supply curve for my wine. Then we can also do average total cost. The average total cost started off high. We have a fixed cost divided by a small quantity. +[117.12s -> 128.72s] But the marginal costs are lower than the average. So the average keeps going down and down and down and down. Then they're equal. Now each incremental unit is bringing up the average in cost. So then the average total cost might look something like that. +[128.72s -> 133.44s] average total cost. And we've seen this show multiple times. +[133.44s -> 147.86s] If in the near term, I do have a monopoly here, so I would just produce the quantity where my marginal revenue is equal to my marginal cost. Before that quantity, for every unit, I'm getting economic profit, economic profit, economic profit. If I produce more, +[147.86s -> 158.10s] Other than that, I'm not getting any economic profit anymore. So I'm going to produce this quantity, which looks like about 160 units. And I'm going to sell it. +[158.10s -> 172.40s] for the price I'm going to be able to sell it. So this is the quantity that I'm going to be able to sell. The price I'm going to sell it at, go up to the demand curve, that point of the demand curve. And it looks like I'll be able to sell it for about, I don't know, $33,000. +[172.40s -> 173.55s] $3 a bottle. +[173.55s -> 187.95s] So $33 a bottle. And if we want to think about economic profit, this is the average revenue per bottle. This is the average cost per bottle. So this is the average economic profit per bottle. And I multiply that times the total number of bottles. +[187.95s -> 190.98s] and I'm gonna get my economic profit. +[190.98s -> 205.36s] So this area right over here is my total economic profit. And we can think about how much are the consumers benefiting from it? How much benefit are they getting excess of what they're paying for it? And that would be this area right over here. +[205.36s -> 218.40s] consumer surplus. Now let's say I'm just not happy with this. I see that there's an opportunity here to get even more economic profit because after all, and we've been talking about this from the beginning, +[218.40s -> 232.06s] There are people here who are getting over $40 of benefit from my wine, but I'm selling it to them for only $33. Everything we've assumed so far is that all of the consumers are buying something at the exact same price. +[232.06s -> 237.82s] But I'm a crafty wine producer, and I say, well, let me call that into question. Why can't I? +[237.82s -> 250.75s] just put a different label on my exact same wine and sell it to these people for a different price. And so I do that exact thing. I still produce this exact same quantity. I produce this exact same quantity. But the first... +[250.75s -> 257.63s] The first 100 units of my quantity, I put a different label on it. This label says super fancy wine. +[257.63s -> 272.05s] Super fancy, premium, the best wine you ever drank. Super fancy, premium wine. It has all of the awards, all of the fancy people who like it. I put it in the best wine boutiques and the best restaurants with that label. All this exact same stuff in the... +[272.05s -> 286.26s] a bottle, and I sell that one at $40 a bottle. So the first 100 units, I sell at $40 a bottle. So now my economic profit on those units, remember, I'm producing 150, so my average total cost is down here. +[286.26s -> 300.46s] cost is this line right over here. So on those bottles, I'm getting this much economic profit per bottle times these 100 units. I've now increased my economic profit. I've eaten into the consumer surplus. I've taken some of that for myself and turned it into economic profit. +[300.46s -> 309.87s] And then the other, I don't know, this looks like about 60 or 70 bottles, I just have with the traditional label and I maybe sell at the supermarket. Traditional. +[310.10s -> 324.69s] traditional label, and I just sell it at the supermarket. I call it just, you know, pretty good wine, just so in case someone who bought it at the fancy place doesn't see that the pretty good wine is the exact same thing. And what I've just done here is I've discriminated +[324.69s -> 330.98s] amongst consumers. Depending on consumers' willingness to pay, I've essentially charged them different prices and also +[330.98s -> 344.14s] I guess to some degree based on where they shop and their gullibility, I am charging them two completely different prices. And this right over here is called price discrimination. +[344.14s -> 358.74s] And it's a way that a supplier can essentially take some of the consumer surplus for themselves, eat into some of that excess marginal benefit that they're essentially giving to the consumer and turning it into economic profit. +[358.74s -> 359.63s] profit. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_25.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_25.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..31be180b29129369918b38ee4142e9306655bb1b --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_25.mp4.txt @@ -0,0 +1,40 @@ +[0.00s -> 10.00s] This is an example about how to calculate free cash flow to equity using financial statements. We have different formulas for free cash flow to equity. +[10.00s -> 24.13s] one of these formulas is net income at back depreciation minus capital expenditure minus change in net operating working capital plus net debt or we can call it net borrowing so we will get net income and depreciation from our income statement +[24.13s -> 33.14s] So we have here net income of 4.9 in year 2019 plus depreciation of 10 in year 2019. +[33.46s -> 44.96s] When we calculate capex, a change in net operating capital and net debt, we need two balance sheets. Therefore, we need to get the year 2019 as well as the previous year, which is 2018. +[44.96s -> 59.12s] Therefore, in order to calculate CAPEX, we have two ways to calculate CAPEX expenditure. The first one is get BPE NAT, property, plant, and equipment. Don't use NAT, use GROSS. And the other formula is NAT. So this means that we will use... +[59.12s -> 71.28s] two formulas gross and net we'll start with gross so we'll get bbe gross at t minus bbe gross at the previous year so let's look at our balance sheet we have our bbe gross of year 2019 70 +[71.28s -> 78.30s] minus the previous year which is 2018 70. so we'll get here capex equals 70 minus 70 equals zero +[78.30s -> 91.41s] or we can calculate it from BBE net our formula will be BBE net at time t minus BBE net at the previous year plus annual depreciation from income statement so let's look at the balance sheet we have BBE net of 50 +[91.41s -> 103.18s] in year 2019 minus BBE net of 60 in the previous year 2018 so we get here 50 minus 60 plus annual depreciation from income statement in year 2019 which is 10. +[103.18s -> 117.52s] And this will give us exactly the same value, which is zero. Therefore, in our formula here, we'll say minus zero. Then we need to calculate a change in net operating working capital. So our formula for a change in net operating working capital is operating current asset. +[117.68s -> 130.22s] of this year minus the previous year minus open bracket the change in operating current liability which is operating current liability this year minus previous year therefore we need to check our balance sheet and we need to look at +[130.22s -> 134.51s] current assets and current liabilities and you choose operating +[134.96s -> 146.98s] current assets and operating current liabilities. So what do we mean by the word operating? It means that it's used directly in operation, which means that it doesn't incur an interest or return. Therefore, in this example, +[146.98s -> 161.38s] here under current assets account receivables and inventories are an examples of operating current asset under current liabilities accounts payable is an example of current operating current liabilities therefore i need to get here z +[161.38s -> 169.58s] a change in account receivables plus a change in inventory minus change in accounts payable so our formula will be +[169.58s -> 177.34s] Account receivables at time t minus the previous year plus inventory at time t minus the previous year minus accounts payable at time t minus the previous year. +[177.34s -> 191.28s] So we have here account receivables of 26 minus 15 plus inventory 28 minus the previous year 20 minus accounts payable 15 minus the previous year 5. This will give us a change in net operating working capital of 9. So in our formula. +[191.28s -> 205.39s] we will say here minus nine then we need to calculate net debt so from our balance sheet in order to calculate net debt we need to get our non-operating liabilities at time t minus +[205.39s -> 218.26s] the previous period non-operating liabilities so it's the opposite of what we did with non a change in non-operating working capital so here we need to choose what +[222.51s -> 234.10s] Okay, this is the opposite of what we did with a change in net operating working capital. So here we use operating items, but now we use non-operating items. So let's look at liability side. +[234.35s -> 247.65s] current liabilities and long-term liabilities and we need to choose the non-operating items. What do we mean by non-operating items? They are used indirectly in the operation, which means they incur an interest or a return. Therefore, notes table +[247.65s -> 260.83s] current portion of long-term debt long-term loans long-term bonds are examples of non-operating liabilities therefore we will get here our net debt as notes payable at time t minus notes payable of the previous year +[260.83s -> 270.91s] plus current portion of long term debt at time t minus current portion of long term debt of the previous year plus long term loans at time t minus long term loans of the previous year +[270.91s -> 284.88s] plus long-term bonds at time t minus long-term bonds of the previous period so this will give us net debt equal to nine point one minus four which is the change in notes payable plus six minus six which is the change in current portion of long-term debt +[284.88s -> 295.36s] plus 24 minus 30, which is the change in long-term loans, plus 25 minus 25, which is the change in long-term bonds. And this will give us net debt of negative 0.9. +[295.36s -> 308.22s] so in our formula we'll say here negative 0.9 and this will give us free cash flow to equity equal to 5. another formula to calculate free cash flow to equity is using operating cash flow +[308.22s -> 319.33s] so our free cash flow to equity is equal to operating cash flow minus capex plus net debt we get operating cash flow from statement of cash flows we know that in statement of cash flows we have three categories +[319.33s -> 331.55s] net cash flow from operations, net cash flow from investment, and net cash flow from financing, we will get net cash flow from operations, which is 5.9. Therefore, we will say here our free cash flow to equity is equal to +[331.55s -> 339.66s] 5.9 minus capex of 0 plus net debt which is negative 0.9 so this will give us 5. +[341.55s -> 355.89s] Another formula to calculate free cash flow to equity is based on a change in cash balance plus net payment to shareholders. We know that a change in cash balance we can get it from a statement of cash flows and this will be our net cash flow. +[355.89s -> 369.98s] which is the summation of net cash flow from operations plus net cash flow from investment plus net cash flow from financing so right here our free cash flow to equity is equal to one plus net payment to shareholders so what will be the formula +[369.98s -> 377.70s] of net payment to shareholders net payment to shareholders is what are the payments that will be received to +[377.70s -> 391.70s] shareholders so from shareholders perspective what you're going to receive so you will receive dividends when a company makes profits they will distribute cash dividends minus net equity so what do you mean by net equity this is share issuance +[391.70s -> 400.86s] minus share repurchase so minus minus will be positive so this means that it's dividends minus share issuance plus share repurchase so +[400.86s -> 415.41s] how we're going to calculate net equity from the balance sheet we need to get issued capital or contributed capital at time t minus contributed capital of the previous period so we will get here dividends from our income statement here we have four +[416.05s -> 428.34s] and then we need to look at the balance sheet we need to get contributed capital at year 2019 minus the previous year at 2018 so this will be here minus 29 minus 29 this will give us 4 +[428.78s -> 436.14s] Therefore our formula here will be 1 plus 4 this will give us 5 which is exactly same as what we did before. +[436.59s -> 450.75s] We calculated earlier free cash flow to firm as 7.79, so we can calculate free cash flow to equity based on free cash flow to firm. So our free cash flow to equity is equal to free cash flow to firm minus interest multiplied by 1 minus tax rate plus net debt. +[450.75s -> 465.04s] we have here free cash flow to firm of 7.79 minus interest from income statement is 2.7 multiplied by 1 minus tax rate of 30% plus net debt our net debt here is negative 0.9 so this will give us 5 +[465.04s -> 473.84s] So in this example, we had four formulas in order to calculate free cash flow to equity, and each formula gave us exactly the same number. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_29.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_29.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..38f43914924a998ae1957b935387b55501a9ec50 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_29.mp4.txt @@ -0,0 +1,17 @@ +[0.72s -> 14.90s] This video is about discounted payback period. I am assuming that you already know how to calculate payback period. If not, you may want to watch that video first. The link is also given in the description below. +[14.99s -> 25.87s] In this video, I will explain what discounted payback period is, how to calculate discounted payback period, and finally how to make decisions based on your calculation. +[26.13s -> 36.37s] Discounted payback period is the length of time required for an investment's cash flows, discounted at the investment's cost of capital, to cover its cost. +[36.72s -> 47.28s] Although this method is similar to payback period, it takes the time value of money problem into consideration, which payback period totally ignores. +[47.54s -> 61.46s] Thus, I think this method of finding breakeven point is superior to simple payback period technique. Here is an example. Your division is considering two projects with the following cash flows in millions. +[61.46s -> 75.28s] Weighted average cost of capital is 10%. What are the discounted payback periods for both projects and which project will you accept? I will show the calculation for project A and you can try project B on your own. +[75.73s -> 86.45s] Let's calculate present value of each cash flow and write them down. For example, negative 25 is already in the zero year, so we do nothing for it. +[86.77s -> 99.10s] To calculate present value of 5, we divide it by 1.01 to the power 1 which is 4.55. For rest of them, we find 8.26 +[99.10s -> 113.14s] and 12.77 respectively now we find cumulative cash flows by adding discounted cash flows subsequently we now use these two numbers to calculate +[113.14s -> 121.49s] discounted payback period for project A. 2 plus 12.19 over 12.17. +[121.94s -> 133.55s] Now, if you follow the same steps, you will get the discounted payback period for project B as 2.77 years. +[133.90s -> 147.76s] Decision Rules. If project A and B are independent, select project that has discounted payback period less than project's life. So, both project A and B should be accepted. +[148.08s -> 161.49s] When project A and B are mutually exclusive Since the discounted payback period of project B is shorter than project A project B should be accepted in other words if you invest in project B +[161.49s -> 164.37s] you will reach the breakeven point a lot quicker. +[164.62s -> 177.47s] Although discounted payback period method takes time-developed money into consideration, it still has a limitation such as it does not consider the cash flows beyond the discounted payback period. +[177.47s -> 191.36s] Net present value or NPV method could be a better technique for project selection. If you like to learn the NPV technique, you may consider watching the next video. The link of the video is also given in the description below. +[191.36s -> 195.28s] So, I am going to see you in the next video. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_4.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a13331ea2512b34ef6280d64774ef0f041e935e8 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_4.mp4.txt @@ -0,0 +1,5 @@ +[0.00s -> 10.38s] An example of another profitability ratio is the operating profit margin. Operating profit margin formula is operating profit divided by sales. +[11.15s -> 19.89s] We can get both operating profit and sales from the income statement. Let's calculate operating profit margin for the year 2018. +[20.27s -> 29.01s] We have EBIT that equals $8 million divided by sales of $50 million, which is equal to 16%. +[29.62s -> 41.14s] The unit of operating profit margin is a percentage. This means that for every dollar of sales, the company generates a profit of 16 cents after paying off all operating costs. +[41.30s -> 46.60s] For all profitability ratios generally the higher the better diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_6.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..39eaa698b46241480bae53c511b13e2640a801b7 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_6.mp4.txt @@ -0,0 +1,7 @@ +[0.00s -> 13.98s] Mark made two smart investments three years ago. One, he invested $400 in a rare coin and just sold it for $1,000. And two, he bought one share in company A for $100, collected $30 in dividends, and just sold that share for $250. +[13.98s -> 28.18s] For the sake of simplicity, we'll assume there were no commissions or other fees involved. To quantify his success, we could simply calculate the profit in each case. So, one, we subtract the $400 cost from the $1000 price he sold at, and realized he made a $600 profit on his coin. +[28.18s -> 40.91s] Two, we subtract the $100 cost from the $250 he got when selling plus $30 through dividends. After drawing the line, he made a $180 profit on his share. Was the coin a better investment because he made more money? +[40.91s -> 50.96s] well let's not forget that he also paid more for it to also account for that we calculate the so-called return on investment or roi by dividing the profit by the amount which was invested in other words +[50.96s -> 63.79s] 1. For the gold coin, his ROI was 600 divided by 400, or 150%. 2. For the share, his ROI was 180 divided by 100, so 180%, which is better than the gold coin ROI. +[63.79s -> 75.89s] Please understand that each method has its limitations, including ROI, because, for example, it doesn't factor in how long you held an investment. A 180% ROI might be great if you held for 3 years, but awful if you had to wait 30 years. +[75.89s -> 79.28s] always understand what and why you're measuring. diff --git a/VideoMMMU_ASR_large/Business/validation_Finance_8.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Finance_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..152d673a360885bcac37562a5f185076480a22a1 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Finance_8.mp4.txt @@ -0,0 +1,32 @@ +[2.26s -> 14.66s] Hi everyone, welcome back to my channel. For those who are new, please don't forget to like, subscribe, and comment below. In this video, we will discuss about additional funds needed. +[14.66s -> 28.88s] i will give you simple problems and step-by-step solutions enjoy the video here's the reference book use for this video some details about myself okay let's begin every business +[28.88s -> 42.08s] has three primary capital sources we will focus in the third type which is the afn or additional funds needed let's have a recap of the afn equation this is the amount of external capital +[42.08s -> 53.84s] or interest bearing debt and preferred and common stock that will be necessary to acquire the required assets. Let's start with problem number one. Please read the given. +[54.96s -> 69.23s] Here's a summary of the solutions to problem 17-1. On the left side, you will find an Excel template which I've created where all the information given was input and it automatically computed. +[69.23s -> 77.33s] the required additional fonts needed, which you will find below. The solutions can be found on the right side of the page. +[78.45s -> 84.56s] Let's start by computing the net income required and dividends for 2018. +[85.65s -> 99.46s] We were given profit margin of 3% which will now compute the net income. So 3% multiplied by the total sales for 2018 will give you $150,000. And for the retention rate, +[99.46s -> 112.86s] which was given a 30%, we will use this to get the payout or dividends payout ratio, which is equivalent to 1 less 30%, and will give you 70%, or 0.7000. +[112.86s -> 121.39s] to get the dividends multiply 0.70 to the net income of 150 000 it will give you 105 000. +[122.54s -> 130.05s] The target growth rate in sales for 2019 is given at 20% or 0.2000. +[130.05s -> 139.02s] We can easily solve for the rest of your requirements. Please check the right side of the page to get the solutions for the answers. Kindly note +[139.02s -> 153.33s] that in getting the spontaneously generated funds, we did not use the entire 1 million of total liabilities. We have excluded the notes payable because this is not part of the spontaneously generated funds. We can only include +[153.33s -> 161.55s] the accrued payable which is $250,000 plus the accounts payable of $250,000. +[162.45s -> 173.42s] After all those computations, we can now compute our additional funds needed. We can easily get this by deducting the spontaneous increase in liabilities +[173.42s -> 184.51s] the increase in retained earnings from the projected increase in assets. This is equivalent to 600,000 less 100,000 less 54,000 which will give you +[184.51s -> 193.87s] and AFN or additional funds needed of $446,000. Please note of the solutions on the right side of the page. +[194.77s -> 207.73s] Let's now proceed to problem number two. We refer to 17-1. However, the assets is now increased to $4 million from $3 million, while the rest of the information remains the same. +[207.86s -> 219.86s] We can easily compute for the requirement for problem number 2 by substituting 3 million with 4 million dollars and the Excel template will easily compute for the required AFN. +[220.66s -> 234.90s] The increase in assets from $3 million to $4 million also caused an increase in capital intensity ratio from 0.60 to 0.80%. With this, the projected increase in assets +[234.90s -> 245.28s] has also increased from six hundred thousand to eight hundred thousand dollars all of the changes are highlighted in red as you can see at the bottom +[245.28s -> 255.28s] that the AFN has increased from 446,000 in problem 17-1 to 646,000 in problem 17-2. +[255.28s -> 264.78s] There is a difference of $200,000. It is important to note that increase in assets is dependent on the growth of rate in sales. +[265.42s -> 275.70s] Let's now solve problem number 3. Let's refer to problem 17-1, and the only difference is that there will be zero dividends in this situation. +[276.43s -> 287.15s] In solving for problem 17-3, we use the Excel template that we used for 17-1 and only remove the dividends and mark it at 0. +[287.95s -> 299.60s] The changes are highlighted in red. Dividends is at 0, and with dividends at 0, the retention ratio is equivalent to 1, because the payout is 0. +[300.37s -> 314.38s] Since we did not give out any dividends to our stockholders, it means that the increase in retained earnings is higher. From $54,000, it is now $180,000. +[314.38s -> 328.61s] With this increase, the result for our AFN is equivalent to 600,000 plus 100,000, and the new increase in retained earnings, which is 180,000, the equivalent AFN is equals to +[328.61s -> 337.74s] 320,000. If we compare among the three problems in 17-1 where the assets is only at 3 million, +[337.90s -> 350.14s] The AFN required is $446,000. When we increase the assets, we also need to increase our additional funds needed. It is now at $646,000. +[350.14s -> 364.53s] However, when we retained our income and did not give any dividends to our stockholders, our additional funds needed has actually decreased and it is now only at $320,000. +[367.09s -> 375.56s] This is the end of the presentation. I hope you've learned something from my video. If you have other requests, please comment below. Have a great day! diff --git a/VideoMMMU_ASR_large/Business/validation_Manage_13.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Manage_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c5d1fb3f1a3a7efc9b3831baa1d760b09a4b66f7 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Manage_13.mp4.txt @@ -0,0 +1,15 @@ +[7.12s -> 17.62s] Doing great. In this video, I'm going to explain joint cost allocation, the estimated net realizable value method. +[21.81s -> 32.53s] the scenario is the same which i have used both in my physical unit method and sales value at splittiff method now here +[32.53s -> 46.48s] The joint cost, the product A, product B and the byproduct C is there. As I have told you before also, if the byproduct C is inventoriable, in that case, we will deduct the value of the +[46.48s -> 60.21s] byproduct c from the joint cost but if it is very immaterial and it is not inventoried then this value it will not be deducted from the joint cost now in this particular example we have +[60.21s -> 64.11s] not inventoried the byproduct C. +[80.24s -> 93.23s] Here in this slide, I'm explaining how to allocate the cost using the estimated net realizable value method. So, how do you find out the net realizable value? The formula for that is +[93.23s -> 104.75s] final selling price per unit please students make note of this it is not the selling price at the split of point that you have to use you have to use the selling price after the for the processing cost +[104.75s -> 116.67s] So final selling price per unit minus the further processing cost or the selling cost into number of units of the product will give you the net realizable value of the product. +[116.67s -> 130.42s] For product A, here it is 26,000 and for product B, here it is 51,000. Please observe carefully that the final prices have been taken, final selling price. 20 for product B and +[130.42s -> 144.19s] 17 for product A. So now we have got the estimated NRVs of both the products. Now with this ratio we are going to allocate the joint cost. Now product A is equal to +[144.19s -> 156.82s] 26,000 divided by the total of these two. So it is 77,000 into 42,000. And 51,000 divided by 77,000 into 42,000. +[156.82s -> 166.86s] So you get the answers. And if you see the total joint cost that is being allocated to each of them together is 42,000. +[166.86s -> 176.53s] So this is how you calculate the estimated net realizable value method joint cost allocation. Now in case you have any doubts please do +[176.59s -> 188.16s] mail me if you have any questions which need to be clarified you can definitely mail to me at the address given on the slide and not only that any doubts you have please comment +[188.16s -> 197.42s] below. I'll definitely get back to you with the explanation. So see you in my next video. Till then take care and bye-bye. diff --git a/VideoMMMU_ASR_large/Business/validation_Manage_14.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Manage_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c0e33098f5014e2a1e8a334d0a24fd24cdcf55df --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Manage_14.mp4.txt @@ -0,0 +1,23 @@ +[7.31s -> 19.74s] Today is the day you begin a new project and you've got a new team. But how can you turn this cast of characters into a well-oiled machine? How can you determine how they'll approach their work +[19.74s -> 23.18s] and how can you identify their strengths and weaknesses? +[25.68s -> 39.60s] To answer these questions, Meredith Belbin developed a model to assess how individuals behave in a team. The model describes how each role comes with various strengths and weaknesses which can affect the productivity of a team. +[39.95s -> 50.50s] Belbin says that an effective team requires all nine roles to be fulfilled. However, this does not mean that a team always requires nine people. +[50.50s -> 64.08s] Most people fulfill two or three roles that can either be preferred, manageable, or least preferred, all of which should be taken into consideration when forming a team. Let's dive deeper into the model. +[64.14s -> 75.06s] Melbourne's team roles can be grouped into three distinct orientations. They are action-oriented roles, thinking roles, and social-oriented roles. +[75.54s -> 88.37s] Action-oriented roles focus on team improvement, putting ideas into action and completing tasks. Shapers, implementers and completer-finishers fit into this orientation. +[89.04s -> 101.42s] Shapers are dynamic individuals who enjoy questioning norms, invigorating others, and problem solving. However, they may be easily provoked and abrasive when communicating with others. +[102.10s -> 114.00s] An implementer's strength is that they like to take their colleagues' ideas and put it into action. They are usually efficient, organized, reliable, and practical. +[114.10s -> 119.44s] However, they may be slightly inflexible and close-minded at times. +[119.73s -> 133.04s] The completer finisher likes to make sure that every detail in the project is just right. Their allowable weaknesses include being excessively worried and that they can be reluctant to delegate tasks. +[134.13s -> 146.00s] Thinking-oriented roles focus on providing technical expertise and analysis. Plants, monitor evaluators and specialists fit into this orientation. +[146.61s -> 159.28s] The plant provides creative solutions and innovative ideas. However, they may have the tendency to ignore incidentals and have a lack of motivation to carry out their brilliant ideas. +[159.34s -> 172.02s] Monitor evaluators add to the team by being logical observers. They are great at judging options fairly and accurately. But at times, they can be uninspiring and overly critical. +[173.49s -> 186.35s] The specialist contributes by being especially knowledgeable in a particular area. A downside to that might be that they can only contribute on a narrow front and that they may dwell on technicalities. +[186.74s -> 197.52s] Social-oriented roles bring ideas and people together. Coordinators, team workers, and resource investigators fit into this orientation. +[198.58s -> 209.52s] The coordinator is an asset as they have the ability to clearly visualize goals. They make great leaders and are excellent with task delegation. However, +[209.52s -> 224.02s] They may be seen as manipulative and work-shy because they may sometimes offload their share of the work. The team worker helps the team function smoothly as they are good at diffusing conflicts without confrontation. +[224.30s -> 237.36s] They are usually cooperative, attentive, perceptive, and diplomatic. However, they can sometimes be overly avoidant of confrontation and a little indecisive. +[238.77s -> 251.42s] Resource investigators contribute to the team by being explorative, outgoing and enthusiastic. They like to explore opportunities and develop context. However, +[251.42s -> 256.53s] They can sometimes be overly optimistic and can lose interest in projects quickly. +[257.10s -> 267.50s] In summary, Belbin's model can help to better understand your team's dynamic and utilize every individual's strengths while managing their weaknesses. +[267.70s -> 272.88s] This can bring your team a step closer to realizing their full potential. diff --git a/VideoMMMU_ASR_large/Business/validation_Manage_17.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Manage_17.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..9cdc68fb6d418f1d296ae2a88e71da4135082f6f --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Manage_17.mp4.txt @@ -0,0 +1,33 @@ +[0.00s -> 10.42s] what's up you freaking geniuses so in this video i'm going to teach you how to solve commission problems all right so basically commission is just the same thing as a bonus okay so whenever +[10.42s -> 24.00s] You sell something at your job, you know, you get paid, but you also get a bonus. And the formula for calculating commission is commission is equal to the commission rate times the total sale, okay? +[24.00s -> 33.76s] And the units for these, well for commission, it would normally be in dollars. Okay, so that's going to be equal to the commission rate, which would be a percentage. +[33.76s -> 44.45s] and then we would multiply that by the total sale which would again be in dollars okay so let's jump into this first example so you can see how we solve these problems +[44.45s -> 57.55s] So this first problem says a real estate agent gets a 3% commission when they sell a home. They sell a haunted mansion for $260,000. So what is the agent's commission? +[58.19s -> 71.10s] Well, our formula up here says that the commission, and I'll just abbreviate that as C, is equal to the commission rate. So what is the commission rate here? Well, it says 3%, right? It gets a 3% commission. +[71.10s -> 83.06s] So I'm going to put 3%. And then we're going to multiply that by the total sale, right? What was the total sale? It was 260,000, right? So times... +[83.60s -> 86.70s] $260,000 +[87.60s -> 101.34s] Alright, how am I going to solve this? Well, the first thing you have to do is turn this percent into a decimal, okay? You can never have a percent in one of your formulas. You always have to convert it to a decimal first. +[101.34s -> 115.52s] Okay, so your commission is going to be equal to, now let's write 3% as a decimal. How would you do that? Well, I'll do it up here. And the easy way of doing it is just drop your percent symbol. Okay, so what number do we have here? We have the number 3, right? +[115.52s -> 129.22s] Okay, where's the decimal on the number three? It would be right there, right? So all you have to do is grab your decimal and move it two times to the left. So we're going to go one, two. Okay, so that's where your decimal is now. +[129.22s -> 143.02s] And as you can see, we have an empty place value right here. So whenever you have an empty place value like that, in order to fill in the blank, you just put a zero right there, okay? So 3% as a decimal would be .03. +[143.02s -> 156.26s] Okay, so I'll write that right here, 0.03. Okay, and the more proper way of writing this decimal would just be putting a 0 right there as a placeholder, right? So 0.03. And then we're going to multiply that. +[156.26s -> 170.61s] by 260,000. 260,000. Okay, so now you just have to throw this into your calculator. 0.03 times 260,000 is equal to... +[170.61s -> 185.36s] seven thousand eight hundred so your Commission is equal to seven thousand eight hundred seven thousand eight hundred what well remember the units for Commission are dollars right so I'll put a dollar sign right there +[185.36s -> 193.84s] So the commission is equal to $7,800. Hopefully that wasn't too bad. Let's try one more example here. +[195.18s -> 205.98s] Okay, so this problem says a toilet salesman sells a fancy toilet that plays music and tells you funny puns about Winnie the Pooh. Nice. +[205.98s -> 219.66s] He gets a $69 commission for selling a $460 toilet. What was his commission rate? Okay, so this time we're not looking for the commission. We're looking for the commission rate. +[219.66s -> 234.16s] All right, so how would we solve for that? Well, let's just use our formula up here and just plug in what we know, okay? So we know he got a $69 commission, right? So his commission was $69. So I'll put that right here. +[234.96s -> 246.45s] And that's going to be equal to, right, equal to his commission rate. So that's the part we don't know. So I'll just put a variable there for now. I'll put R for rate. +[246.45s -> 259.18s] And then we're going to multiply that by the total sale, right? So we're going to multiply by however much he sold it for. So selling a $460 toilet. So he sold it for $460. +[260.18s -> 274.78s] Okay, so here we have $69 is equal to R times $460. So how do we solve for R right here? Well, we want to isolate this variable by itself on one side of this. +[274.78s -> 284.74s] Equal sign right here. Okay, so in order to do that, or in order to undo the multiplication, we're going to divide. Okay, divide by what? +[284.74s -> 290.96s] Well, whatever you're trying to get rid of. So if we want to get rid of the 460, we're going to divide by 460. +[291.76s -> 303.78s] Okay, but whatever you do to one side of the equation you have to do to the other right so we have to divide by 460 on this side also Okay, so now simplifying some things +[303.78s -> 318.29s] These 460s, so there's one on top, one on the bottom, so those cancel out. So we're just going to be left with R right here on this side of the equation. Okay, and then that's going to be equal to, right, equal to 69 over 460. +[318.80s -> 332.22s] 69 over 460. Okay, so now you just have to throw this into your calculator. So 69 divided by 460 is equal to 0.10. +[332.22s -> 342.77s] And remember that's equal to r, right? It's equal to r. So is this our answer right here, 0.15? Well, almost, but remember... +[342.77s -> 350.62s] The units for commission rate is a percentage, okay? So how do you turn this decimal into a percent? +[350.62s -> 364.53s] Well, a quick way of doing that is just grabbing your decimal and moving it two times to the right. Okay, so you'd go one, two. So right there. Okay, so instead of having .15, you would now have... +[364.53s -> 374.26s] 15. Okay, 15%. So that's equal to R. Okay, so what was his commission rate? +[374.54s -> 387.15s] 15%. Okay, so that'd be your answer. All right guys, so that is how you solve commission rate problems. So if you found the video helpful, definitely leave a thumbs up down below. +[387.15s -> 399.25s] And if you have any other questions or want to see any other examples, just let me know in the comment section below. Also, there's a couple playlists attached that I think you'll find helpful. So definitely check those out and I'll see you there. diff --git a/VideoMMMU_ASR_large/Business/validation_Manage_3.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Manage_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..06ae13389bbae8b8b0fdc50c8ba5975052bbf3da --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Manage_3.mp4.txt @@ -0,0 +1,19 @@ +[2.19s -> 17.17s] When calculating a cash budget you have to determine cash receipts cash payments So this is going to look at how do I budget for cash collections with my accounts receivable one of the largest areas of cash inflows +[19.12s -> 32.98s] So let's say you have a beginning accounts receivable of $36,400. Your July sales, August sales, and September sales from your sales budget, now these are estimated amounts, are given. +[33.62s -> 45.74s] And historically, 35% of total sales or cash sales, the remaining are credit. Of those credit sales, 40% are collected on average. +[45.74s -> 60.05s] in the month of the sale 60 percent the month after the sale so having this information you can fairly accurately estimate what your cash collections are going to be will it be exact of course not but it could +[60.05s -> 69.49s] be very close so total sales looking at your estimates and your beginning accounts receivable +[70.16s -> 82.77s] Cash sales, 35% of the total sales. Credit sales remain, or the remainder, and of that remainder, 40% are collected the month of the sale, 60% the second month. +[83.86s -> 95.97s] So just start plugging the numbers and calculate what your cash inflows are going to be budgeted for. So looking at the beginning numbers, 36,400. +[95.97s -> 110.16s] If that's your beginning accounts receivable, and it's the first of the month, and these are your averages, then you're looking at collecting that amount. That must represent 60% of... +[110.16s -> 114.90s] June sales that you're estimating you will collect in July +[115.38s -> 127.60s] Now 35% of the total sales is $56,000. That's $56,000 cash you're expecting to collect from cash sales. +[128.40s -> 141.17s] take your 160 subtract that of your sales that remaining 65% you believe will be credit sales of that +[141.17s -> 149.46s] 40% you expect to collect in July and 60% in August. +[150.48s -> 160.66s] So that would be your beginning accounts receivable as of August 1st, which you're then expecting to collect in August. +[161.65s -> 167.66s] of your August sales 35 percent will be cash sales +[167.98s -> 180.94s] What remains, 113,750. Of that, you believe 40% will be collected in August. The remaining 60% of your August sales. +[180.94s -> 194.38s] will be your beginning accounts receivable balance which you are expecting to receive and collect in September you can follow the flow of your September sales +[194.38s -> 205.90s] 35% on average have been cash sales the remaining accounts receivable of that $91,000 you expect to collect +[205.90s -> 213.20s] 40% in September and the remaining 60% in October so not only can you estimate +[213.20s -> 226.80s] fairly accurately your budgeted cash collections you can estimate fairly accurately for your budgeted balance sheet what will remain in accounts receivable as of October 1st diff --git a/VideoMMMU_ASR_large/Business/validation_Manage_4.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Manage_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..299facf3b3a847cdc3b3c13b561948295945ab99 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Manage_4.mp4.txt @@ -0,0 +1,80 @@ +[1.78s -> 14.61s] We've seen the mathematical definition of the cost function. Now let's build some intuition about what the cost function is really doing. In this video, we'll walk through one example to see how the cost function can be used +[14.61s -> 26.22s] to find the best parameters for your model. I know this video is a little bit longer than the others, but bear with me, I think it'll be worth it. To recap, here's what we've seen about the cost function so far. +[26.35s -> 39.38s] You want to fit a straight line to the training data, so you have this model fwb of x is w times x plus b. And here, the model's parameters are w and b. +[39.57s -> 53.68s] Now, depending on the values chosen for these parameters, you get different straight lines like this. And you want to find values for W and B so that the straight line fits the training data well. +[53.90s -> 65.44s] To measure how well a choice of W and B fits the training data, you have a cost function J. And what the cost function J does is +[65.44s -> 72.08s] It measures the difference between the model's predictions and the actual true values for y. +[72.94s -> 87.47s] What you see later is that linear regression will try to find values for w and b that make j of w be as small as possible. In math, we write it like this. We want to minimize +[87.47s -> 91.98s] j as a function of w and b. +[92.85s -> 107.18s] So now, in order for us to better visualize the cost function j, let's work with a simplified version of the linear regression model. We're going to use the model fw of x is w. +[107.18s -> 120.69s] times x. You can think of this as taking the original mod on the left and getting rid of the parameter b, or setting the parameter b equal to zero, so it just goes away from the equation. +[120.72s -> 132.62s] So f is now just w times x. So you now have just one parameter w, and your cost function j looks similar to what it was before. +[132.62s -> 144.88s] taking the difference and squaring it, except that now f is equal to w times xi, and j is now a function of just w. +[144.98s -> 159.17s] And the goal becomes a little bit different as well, because you have just one parameter w, not w and b. So with this simplified model, the goal is to find a value for w that minimizes +[159.17s -> 160.91s] j of w +[161.39s -> 175.79s] To see this visually, what this means is that if b is set to 0, then f defines a line that looks like this. And you see that the line passes through the origin here because when x is 0, well, +[175.79s -> 186.13s] f of x is 0, 2. Now using this simplified model, let's see how the cost function changes as you choose different values for the parameter w. +[186.77s -> 194.61s] In particular, let's look at graphs of the model f and the cost function j. +[194.93s -> 208.26s] I'm going to plot these side by side, and you'll be able to see how the two are related. First, notice that for f subscript w, when the parameter w is fixed, that is, +[208.26s -> 222.10s] is always a constant value, then fw is only a function of x, which means that the estimated value of y depends on the value of the input x. +[222.48s -> 234.77s] In contrast, looking to the right, the cos function j is a function of w, where w controls the slope of the line defined by fw. +[234.77s -> 242.90s] So the cost defined by j depends on the parameter, in this case, the parameter w. +[243.38s -> 254.45s] So let's go ahead and plot these functions fw of x and j of w side by side so you can see how they are related. +[255.28s -> 268.67s] We'll start to the model that is the function fw of x on the left. Here the input feature x is on the horizontal axis and the output value y +[268.67s -> 282.19s] is on the vertical axis. Here's a plot of three points representing the training set at positions 1-1, 2-2, and 3-3. Let's pick a value for w. +[282.19s -> 294.61s] say w is 1. So for this choice of w, the function f looks like this straight line with a slope of 1. +[294.90s -> 309.54s] Now, what you can do next is calculate the cost, j, when w equals 1. So you may recall that the cost function is defined as follows. It's the squared error cost function. +[309.54s -> 322.64s] So if you substitute fw of xi with w times xi, the cost function looks like this, where this expression is now w times xi. +[322.64s -> 333.63s] minus yi. So for this value of w, it turns out that the error term inside the cost function, this w times xi minus yi, +[333.63s -> 346.46s] is equal to 0 for each of the three data points. Because for this data set, when x is 1, then y is 1. When w is also 1, then f of x equals 1. +[346.46s -> 352.78s] So f of x equals y for this first training example, and the difference is 0. +[353.04s -> 364.59s] Plugging this into the cos function j, you get 0 squared. Similarly, when x is 2, then y is 2, and f of x is also 2. +[364.59s -> 374.96s] So again, f of x equals y for the second training example. In the cost function, the squared error for the second example is also zero squared. +[375.38s -> 386.99s] Finally, when x is 3, then y is 3, and f of 3 is also 3. In the cost function, the third squared error term is also 0 squared. +[386.99s -> 400.40s] So for all three examples in this training set, f of x i equals y i for each training example i. So f of x i minus y i +[400.40s -> 411.98s] is 0. So for this particular data set, when w is 1, then the cost j is equal to 0. +[412.24s -> 423.47s] Now, what you can do on the right is plot the cost function j. And notice that because the cost function is a function of the parameter w, +[423.47s -> 434.19s] The horizontal axis is now labeled W and not X, and the vertical axis is now J and not Y. +[434.86s -> 449.65s] So you have j of 1 equals to 0. In other words, when w equals 1, j of w is 0. So let me go ahead and plot that. +[450.32s -> 465.10s] Now let's look at how f and j change for different values of w. W can take on a range of values, right? So w can take on negative values, w can be 0, and it can take on positive values too. +[465.49s -> 472.62s] So what if w is equal to 0.5 instead of 1? What will these drops look like then? +[473.33s -> 487.95s] Let's go ahead and plot that. So let's set w to be equal to 0.5, and in this case, the function f of x now looks like this, is aligned with a slope equal to 0.5. +[488.78s -> 495.54s] And let's also compute the cost j when w is 0.5. +[496.05s -> 509.06s] Recall that the cost function is measuring the squared error or difference between the estimated value that is y hat i, which is f of xi, and the true value +[509.06s -> 511.22s] That is, yi. +[511.54s -> 524.38s] for each example i. So visually you can see that the error or difference is equal to the height of this vertical line here when x is equal to 1. +[524.38s -> 537.22s] because this little line is the gap between the actual value of y and the value that the function f predicted, which is a bit further down here. So for this first example, +[537.22s -> 550.32s] When x is 1, f of x is 0.5. So the squared error on the first example is 0.5 minus 1 squared. +[550.38s -> 565.14s] Remember, the cost function will sum over all the training examples in the training set. So let's go on to the second training example. When x is 2, the model is predicting f of x is 1. +[565.46s -> 576.50s] and the actual value of y is 2. So the error for the second example is equal to the height of this lower line segment here. +[577.10s -> 585.49s] And the squared error is the square of the length of this line segment. So you get 1 minus 2 squared. +[586.22s -> 599.06s] Let's do the third example. Repeating this process, the error here, also shown by this line segment, is 1.5 minus 3 squared. +[599.15s -> 605.10s] Next, we sum up all of these terms which turns out to be equal to 3.5. +[605.52s -> 619.18s] Then we multiply this term by 1 over 2m, where m is the number of training examples. Since there are three training examples, m equals 3. +[619.73s -> 634.16s] So this is equal to 1 over 2 times 3, where this m here is 3. If we work on the math, this turns out to be 3.5. +[634.16s -> 644.56s] divided by 6. So the cos j is about 0.58. Let's go ahead and plot that over there on the right, okay? +[644.85s -> 656.72s] Now let's try one more value for w. How about if w equals 0? What do the graphs for f and j look like when w is equal to 0? +[657.10s -> 671.34s] It turns out that if w is equal to 0, then f of x is just this horizontal line that is exactly on the x-axis. And so the error for each example is a line that goes from each point. +[671.34s -> 684.82s] down to the horizontal line that represents f of x equals 0. So the cost j when w equals 0 is 1 over 2m times the quantity +[684.82s -> 698.53s] 1 squared plus 2 squared plus 3 squared, and that's equal to 1 over 6 times 14, which is about 2.33. So let's plot this point where +[698.53s -> 704.43s] W zero and J of zero is 2.33 over here. +[704.75s -> 718.43s] And you can keep doing this for other values of w. Since w can be any number, it can also be a negative value. So if w is negative 0.5, then the line +[718.43s -> 731.31s] F is a downward sloping line like this. It turns out that when W is negative 0.5, then you end up with an even higher cost around 5.25. +[731.31s -> 746.18s] which is this point up here. And you can continue computing the cost function for different values of w and so on and plot these, right? So it turns out that by computing a range of values, you can slowly +[746.18s -> 760.18s] trace out what the cost function j looks like. And that's what j is. To recap, each value of parameter w corresponds to a different straight line fit. +[760.18s -> 773.71s] f of x on the graph to the left. And for the given training set, that choice for a value of w corresponds to a single point, a single point on the graph on the right. +[773.71s -> 787.55s] because for each value of w, you can calculate the cost J . For example, when w equals 1, this corresponds to this straight line fit through the data. +[787.55s -> 801.63s] And it also corresponds to this point on the graph of j, where w equals 1 and the cost j of 1 equals 0. Whereas when w equals 0.5, +[801.63s -> 813.28s] This gives you this line which has a smaller slope. And this line in combination with the training set corresponds to this point on the cost function graph. +[813.28s -> 824.45s] at w equals 0.5. So for each value of w, you wind up with a different line, and its corresponding cost J . +[824.45s -> 837.02s] and you can use these points to trace out this plot on the right. Given this, how can you choose the value of w that results in the function f fitting the data well? +[837.02s -> 851.04s] Well, as you can imagine, choosing a value of w that causes j of w to be as small as possible seems like a good bet. j is the cost function that measures how big the squared errors are. +[851.04s -> 864.43s] So choosing W that minimizes these squared errors, makes them as small as possible, would give us a good model. In this example, if you were to choose the value of W that results in the smallest possible value, +[864.43s -> 876.30s] of J , you'd end up picking W equals 1. And as you can see, that's actually a pretty good choice. This results in a line that fits the training data very well. +[876.40s -> 888.21s] So that's how, in linear regression, you use the cost function to find the value of w that minimizes j. Or in the more general case, +[888.21s -> 897.84s] when we had parameters w and b rather than just w, you find the values of w and b that minimize j. +[898.10s -> 908.58s] So to summarize, you solve plots of both f and j and work through how the two are related. As you vary w or vary w and b, +[908.58s -> 921.52s] you end up with different straight lines, and when that straight line passes close to data, the cost j is small. So the goal of linear regression is to find the parameters w or w and b +[921.52s -> 926.10s] that results in the smallest possible value for the cost function j. +[926.35s -> 939.62s] Now in this video, we work through our example with a simplified problem using only w. In the next video, let's visualize what the cost function looks like for the full version of linear regression. +[939.62s -> 946.06s] using both w and b and you see some cool 3d plots let's go to the next video diff --git a/VideoMMMU_ASR_large/Business/validation_Marketing_18.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Marketing_18.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b61fdb74c3e83c68cffd0cb2e25ae2c5ef69b85e --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Marketing_18.mp4.txt @@ -0,0 +1,34 @@ +[0.00s -> 14.02s] In this video, I will explain the p-value to you. In order to explain the p-value, let's have a look at this example. We want to investigate if there is a difference in the salary of men and women. +[14.02s -> 25.79s] In order to understand the p-value, we first need the null hypothesis. So we assume that there is no difference in the salary of men and women in the population. +[25.79s -> 39.06s] Okay, so on the one side we have the population, but it's certainly not possible to ask all women and men of the population, for example of a whole country, about their salary. +[39.06s -> 49.04s] So therefore we need to draw a sample and in this sample we have a group of women and men and we ask them about their salary. +[49.04s -> 62.32s] So although there is no difference in the salary of men and women in the population, which is our null hypothesis, we will for sure at least have a small salary difference in the sample. +[62.32s -> 75.62s] So in our example several different results are possible. The salary difference in a sample could be 50 euros, it could be 150 euros or it could be 250 euros. +[75.62s -> 84.48s] But remember, the assumption is that in the population there is no salary difference. Now we will come to the p-value. +[84.48s -> 97.90s] In the first case, the p-value tells us how likely it is to draw a sample in which the salary of men and women differs by more than 50 euros. In the second case, +[97.90s -> 111.97s] The p-value would tell us how likely it is to draw a sample in which the salary difference of men and women differs by more than 150 euros. Yes, and in the third case, the p-value indicates +[111.97s -> 120.70s] How likely it is to draw a sample in which the salary of men and women differs by more than 250 euros? +[120.70s -> 129.95s] Our assumption for the population still is that there is no salary difference between men and women. Okay, so what does that mean now? +[129.95s -> 143.89s] Let's say that you calculate the p-value for a salary difference of 250 euros and you get the result that the p-value is let's say 0.03. +[143.89s -> 156.48s] The fastest way to calculate the p-value is by using data tab and I will show you how to do it in the following minutes. So what does a p-value of 0.03 mean? +[156.48s -> 170.62s] The result means that it's only 3% likely to draw a sample with a salary difference of 250 euros or more. Assuming that we have no salary difference in the population. +[170.62s -> 181.31s] Or to say it the other way around, it is only 3% likely that this sample is drawn from a population where the null hypothesis is true. +[181.31s -> 191.94s] which means that there is really no difference between men and women. Okay, so now the question is, at what point can we reject the null hypothesis? +[191.94s -> 203.74s] In order to answer this question, we need to look at the alpha level, also called significance level. The significance level is always determined before the examination +[203.74s -> 211.14s] And it must not be changed afterwards, for example, in order to obtain the desired results. +[211.14s -> 225.87s] The significance level is usually set at 5% or it's set at 1%. This is in order to ensure a certain degree of comparability. So what does it mean now? Well, an alpha level of +[225.87s -> 236.34s] 1% or below is called highly significant. If we have an alpha level of 5% or below, the result is called significant. +[236.34s -> 247.73s] And if we have an alpha level of more than 5%, the result would be not significant. Finally, we take a look at the definition of the p-value. +[247.73s -> 257.65s] Generally, the p-value is the probability of the observed result plus even more extreme results if the null hypothesis is true. +[257.65s -> 264.11s] So this might sound a bit complicated now, so let's take a look at our example again. +[264.11s -> 274.42s] What does it mean that the null hypothesis is true? This means that we have no difference between men and women in the population regarding their salary. +[274.42s -> 288.02s] And the p-value now gives us the probability that we draw a sample where the salary of men and women differs by more than 250 euros, although there is no difference in the population. +[288.02s -> 299.87s] So let's say that the p-value is 0.03. This means that it is only 3% likely that we draw a sample where the salary of men and women +[299.87s -> 313.36s] differs by more than 250 euros if there is no difference in the sample. And now I'd like to show you how you can calculate the p-value with DataTap for this example. +[313.81s -> 327.25s] In order to do this, please visit datadep.net and go to the statistics calculator. In this table, you can copy your own data now and I will use the example data. +[327.34s -> 339.98s] Now you can see your variables here and then you have to open the tab t-test and we want to analyze if the variable gender has an influence on the salary. +[339.98s -> 351.22s] And so we simply click on gender and salary. And now DataTab will automatically calculate a t-test for independent samples. +[352.24s -> 359.95s] And in this table you can see the descriptive statistics and further below you will find the resulting p-value. +[361.23s -> 368.88s] If you like, you can simply click on summary in words and Datatab will give you the interpretation of your results. +[369.39s -> 380.93s] Okay, now you know everything about p-value and how you can easily calculate it online with Datatab. If you don't know Datatab yet, just visit datatab.net. +[380.93s -> 394.61s] There you will find great and helpful tutorials and you can easily analyze your data directly online. If you want to be informed about new videos, just subscribe this channel. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Business/validation_Marketing_19.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Marketing_19.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7fae71d47f3517ec8da18d64880210fe7bacf783 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Marketing_19.mp4.txt @@ -0,0 +1,22 @@ +[0.24s -> 10.66s] Another kind of chi-square test is the chi-square test for independence. Now the chi-square test for independence evaluates the relationship between two variables. +[10.66s -> 19.31s] It is a non-parametric test that is performed on categorical data, that is, data that is measured on a nominal or an ordinal scale. +[20.50s -> 33.65s] So take this example. 500 elementary school boys and girls are asked which is their favorite color? Blue, green, or pink? And below we have the results. Now using an alpha level of 0.05, +[33.65s -> 37.81s] would you conclude that there is a relationship between gender and favorite color? +[39.50s -> 51.01s] So here is our table. On the bottom, you can see that I have the column totals, 120, 180, and 200. And on the right, I have the row totals, 300 and 200. +[51.01s -> 57.74s] And we had a total sample of 500 people. So we can use this information to calculate our chi-square. +[58.16s -> 67.44s] We're going to do a hypothesis test using these same seven steps that we always do. So step one is for us to state our null and alternative hypotheses. +[67.44s -> 81.49s] Our null is that for the population of elementary school students, gender and favorite color are not related. Our alternative hypothesis is that for the population of elementary school students, gender and favorite color are related. +[81.68s -> 85.87s] Now alpha like I said is always 0.05 +[86.32s -> 100.21s] Now, calculating degrees of freedom, we're going to take rows minus 1 times columns minus 1. Now we have two rows and three columns, so it's 3 minus 1 times 2 minus 1, or 1 times 2. +[100.21s -> 113.12s] which is 2. This analysis will use 2 degrees of freedom. And that's how we'll find our decision rule. We're going to go to our chi-square table and using alpha 0.05 and 2 degrees of freedom, +[113.12s -> 127.34s] we find a critical value of 5.99147. So our decision rule is if the calculated chi squared is greater than 5.99 we are going to end up rejecting the null hypothesis. +[127.92s -> 139.54s] So let's calculate our chi-square now. Now we're going to use the same equation to calculate chi-square, except now it's going to be a little bit more complicated to find the expected frequencies. +[140.21s -> 153.07s] And this is how we're going to do it. We're going to multiply the frequencies for the columns times the frequency for the rows and then divide by the total number of subjects to get the expected frequency for each cell. +[153.65s -> 155.44s] So, for example... +[155.89s -> 169.70s] Let's say we wanted to find how many boys are expected to have chosen blue as their favorite color. We take the column total for blue which is 120 and multiply it by the row total for boys which is 300. +[169.70s -> 180.72s] and then we divide by the total number of subjects which is 72. And we find out that in this sample we would have expected 72 boys to choose blue as their favorite color. +[180.85s -> 193.25s] And then we can continue that to get the expected values for all six cells. So now I'm just going to move that up and we have the observed values and then next to them in parentheses we have the expected values. +[193.25s -> 207.47s] And now we're going to do chi-squared like we did it before. We're going to take all the observed values and subtract the expected values, then square that and divide by the expected values to get those six different fractions. When we add those all together, +[207.47s -> 212.78s] we find a chi-squared of 276.389. +[213.26s -> 225.17s] So our result is because our chi-square was greater than 5.99, it was 276.389, we will reject the null hypothesis. That is to say that in the population +[225.17s -> 233.12s] there is a relationship between gender and favorite color using the chi-square test for tests of independence. diff --git a/VideoMMMU_ASR_large/Business/validation_Marketing_2.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Marketing_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6a6c3e81a1823bf1aa1aef61e14234c753da2607 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Marketing_2.mp4.txt @@ -0,0 +1,12 @@ +[0.88s -> 4.27s] Okay, oops, I forgot to finish filling this out. +[5.33s -> 16.43s] If you're conducting an ANOVA test, you're going to calculate an F test statistic. You know, if you've done this stats course for a while, you've probably seen t, z, chi. +[16.43s -> 26.72s] So lots of different letters that we use. It's because not everything follows that normal distribution pattern. We have to have different test statistics for different situations because they often have different +[26.72s -> 37.14s] you know distribution patterns behind them so for anova gotta use an f test statistic and what it does is the f test statistic finds out the variance between the groups +[37.14s -> 51.50s] Like California is one group, Washington is a group, Maine is a group, Oklahoma is a group. The F-Test statistic compares the variance between each of these groups and then divides by the variance within the two groups. +[51.50s -> 59.98s] So that means there's two different degrees of freedom. You have degrees of freedom from the numerator, which is k minus 1, the number of groups. +[64.46s -> 71.73s] minus 1. And then you divide by capital N minus K. Capital N means +[78.64s -> 93.04s] Total sample size. And then K obviously is the group. So let's see the number of groups we have. We have 1, 2, 3, 4 groups. So the numerator degrees of freedom is 3. +[93.46s -> 104.51s] So we've got to do capital N minus K. Lowercase N usually means a sample for just one group. Capital N means the sample for the entire group. +[104.51s -> 117.65s] doesn't give us the number directly so we can use multiplication there's four in each row and there's one two three four five six seven eight there's eight columns sorry there's eight rows four columns +[118.26s -> 130.38s] 8 times 4 is 32. I had to check myself. And then there is 4 groups. So the denominator has a degrees of freedom of 28. +[136.24s -> 149.19s] I think that might be it. That's all I wanted for that question. Same type of thing for this one. Same type of thing for this one. Okay. diff --git a/VideoMMMU_ASR_large/Business/validation_Marketing_21.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Marketing_21.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..4050b8d0aefd490275f7cf7ed815c073296af2a5 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Marketing_21.mp4.txt @@ -0,0 +1,48 @@ +[0.00s -> 13.17s] Hello and welcome. In this video, I explain to you what an analysis of variance, a so-called ANOVA is, and how you can calculate it. There are different types of analyses of variance. +[13.17s -> 24.72s] This video is about the one-way or single factor analysis of variance without measurement repetitions. And that's where we start. The first question is +[24.72s -> 33.68s] Why do you need an analysis of variance at all? What does an analysis of variance do? An analysis of variance checks +[33.68s -> 40.37s] whether there are statistically significant differences between more than two groups. +[40.75s -> 53.46s] Therefore, the analysis of variance is the extension of the t-test for independent samples to more than two groups. When calculating an independent t-test +[53.46s -> 62.67s] We looked at whether there is a difference or more precisely a difference in means between two independent groups. For example, +[62.67s -> 71.84s] if there is a difference in the salary of men and women. In this case, we have two groups, the men's group and the women's group. +[71.84s -> 82.26s] If we want to compare more than two independent groups, we use the analysis of variance. In case of the t-test, we used an independent t-test +[82.26s -> 94.58s] if the two groups or samples were independent. This is the case if one person in the first group has nothing to do with a person from the second group. +[94.58s -> 104.88s] Exactly the same now applies to the analysis of variance without repeated measures. Except that here we have at least three independent samples. +[105.23s -> 115.44s] If we have more than two dependent samples, we would use an analysis of variance with repeated measures. Now let's look at an example. +[115.44s -> 127.55s] Let's say that as the founder of DataTap, I might be interested in whether there are differences in the age between people who use DataTap, SPSS, or R. +[127.55s -> 138.50s] In order to do this, I take a sample of people who use statistical software and ask them which statistical software they use and how old they are. +[138.50s -> 151.63s] I've only compared three groups in this example. Of course, there could also be more groups. In order to analyze this example, I would now use an ANOVA. So the next question is... +[151.63s -> 159.04s] What is the research question I can answer with using an ANOVA? The research question is +[159.04s -> 168.83s] Is there a difference in the population between the different groups of the independent variable in relation to the dependent variable? +[168.83s -> 183.18s] The independent variable is the variable with the different categories. In our example, it is the statistic software used. Here we have the three groups, StataDep, SPSS, and R. +[183.18s -> 195.66s] The dependent variable in our example is the age of the software users. We would like to know whether the groups of the independent variables have an influence on the dependent variable. +[195.66s -> 209.12s] Of course, the analysis of variance does not give us any information about the direction of the causal relationship. But why is our research question about the population? Don't we just have a sample? +[209.12s -> 221.23s] Actually, we want to make a statement about the population. Unfortunately, in most cases, it is not possible to survey the whole population and we can only draw a sample. +[221.23s -> 231.73s] The aim is to make a statement about the population based on our sample with the help of the analysis of variants. For our example, the question would be +[231.73s -> 244.46s] Is there a difference between the users of different statistical software solutions in terms of age? But what about the hypotheses? In the case of the analysis of variance, +[244.46s -> 257.10s] The null hypothesis is that there are no differences between the means of the individual groups. We have our individual groups of which we can calculate the mean in each case. +[257.10s -> 271.10s] And our null hypothesis is that there is no difference in the mean in the population. The alternative hypothesis H1 is that there is a difference between at least two group means. +[271.10s -> 280.37s] Therefore, our null hypothesis assumes that there is no difference and the alternative hypothesis says that there is a difference. +[280.37s -> 289.95s] All well and good, now we know what the null hypothesis is. But what does this mean graphically? How can one picture that vividly? +[289.95s -> 301.78s] Let's say we want to test whether there is a difference in salary between the three groups, group 1, group 2 and group 3. The salary has some dispersion. +[301.78s -> 308.08s] Some people earn 400 euros a month, some 2,600 and others. +[308.08s -> 320.96s] 6,000 euros a month. Thus, both in the population and in our sample, the salary is broadly distributed. Now the question is, where does this variation come from? +[320.96s -> 334.06s] And can we explain some of the variation by these three groups? So how much of the variation in salary can we explain by dividing the people into these three groups? +[334.06s -> 347.54s] In the extreme case, the result could be that the salary in group 1 has this distribution, in group 2 that distribution, and in group 3 the distribution would look like this. +[347.54s -> 357.98s] In this case, the division into groups could explain a lot of variance in a variable salary. The result would be different in this case. +[357.98s -> 370.34s] Here however, we could explain almost no variance by forming the three groups. Within the groups, the variance is almost the same as in the whole sample. +[370.34s -> 379.97s] Therefore, it does not matter whether we form the groups or not. The three groups have nearly no influence on the salary. +[379.97s -> 389.60s] If we now look at the variance within the groups, we can see that in this case we have very small variances within the groups. +[389.60s -> 399.15s] So within this group we have a very small variance, within that group we have a small variance and also in the last group. +[399.15s -> 409.70s] On the other hand, the variance between the groups is very large because the mean values of the individual groups are very far apart. +[409.70s -> 414.82s] In the other case we have a very large variance within the groups. +[414.82s -> 426.78s] However, the variance between the groups is very small because the mean values of the groups are very close together. How can we calculate an ANOVA? +[426.78s -> 437.54s] There are two possibilities for the calculation. Either you use a statistics software like DataZap or you calculate the analysis of variance by hand. +[437.54s -> 451.95s] Admittedly, no one will calculate the analysis of variance by hand, but the knowledge is very helpful to understand more precisely how an analysis of variance works. In this video, I show +[451.95s -> 463.65s] you how you can easily calculate an analysis of variance online with DataTap. To calculate an analysis of variance with DataTap, just visit datatap.net +[463.65s -> 470.74s] you can find the link in the video description below. Then you copy your own data into this table. +[473.78s -> 486.42s] and click on this tab. Under this tab you will find a variety of hypotheses tests. Here below you can see the variables you copied into the table. +[486.42s -> 496.86s] Depending on which variables you select, DataTap will calculate the appropriate hypothesis test. If you click on a metric variable, +[496.86s -> 505.46s] and a nominal variable with at least three characteristics, DataDap calculates an analysis of variance. +[505.71s -> 520.30s] Here you can read the p-value. If you don't know exactly how to interpret the p-value, just get the summary in words above. Furthermore, you can check the assumptions of the analysis of variance here. +[522.03s -> 525.42s] Thanks for watching and I hope you enjoyed the video. diff --git a/VideoMMMU_ASR_large/Business/validation_Marketing_22.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Marketing_22.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..86a928bc14bdadfdfde6f4ca3bdd06ca76c40854 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Marketing_22.mp4.txt @@ -0,0 +1,48 @@ +[3.66s -> 16.45s] The other day I went to the store and I bought a package of M&M's. Now I love M&M's but I in particular love the orange ones. I don't know why I just prefer that particular color. Now I started to think +[16.45s -> 24.85s] What is the probability that if I went into this package of M&Ms and I withdrew one that it would be an orange M&M? No. +[24.85s -> 35.34s] The problem is that I don't know what the distribution of colors in my package of M&Ms are, so I went on the internet and googled it. Now, it turns out that there are +[35.34s -> 47.70s] two different factories where the standard M&Ms are made in the United States. There's one in Cleveland and there's one in Hackettsville. And the distribution of colors that are produced at these two different plants is different. +[47.70s -> 59.66s] now if i get a package how do you know which of these two plants they are and therefore which distribution of colors well it turns out they tell you if you go and flip it over and look on the back then +[59.66s -> 73.31s] Right up here there's a code and if that code has HKP in it then you're going to say that it is indeed from the Hackettsville plant and it has a different code if it's from the Cleveland plant. +[73.31s -> 84.14s] So it's that HKP that tells me that this particular bag of M&Ms that I bought at the store came from that particular plant. And then I know the distribution, or at least Google is going to tell me what it is. +[84.14s -> 96.30s] So this creates the perfect conditional probability example I can ask all sorts of questions like what's the probability of an orange M&M given that it comes from the Hackettsville plant and so on. So let's go take a look at the math involved. +[96.30s -> 110.18s] So I went and put the data that I found online into a table. That I have one row for the Cleveland plant and one row for the Hackettstown plant. And the point of this table is that one cell of the table is a conditional probability. +[110.18s -> 123.63s] so for example let me look at this hackettstown orange plant one this is the probability that i get an orange eminem given the vertical line here means given given +[123.63s -> 135.33s] that I know it's from the Hackettstown plant. And that's what all the different probabilities in this table. They reference different conditional probabilities. Probability that it's a blue wimp because it comes from the Cleveland plant and so on. +[135.33s -> 150.06s] So that's what 0.25 means. But what about if I do it the other way around? What if I ask, for example, what is the probability that you get a M&M that came from the Hackettstown plant if you know that it's orange? +[150.06s -> 163.17s] Now, there isn't actually enough data on this table, or it appears anywhere on the internet, to be able to answer this question exactly. The issue is that while they told us the probability of the M&Ms coming from these two different plants, +[163.17s -> 172.62s] We don't know what the probability of coming from each of the plants are. Does one sell 10 times as many as the other? I don't know, and it's not publicly available. So... +[172.62s -> 185.39s] If you know that you've got an orange M&M, but you haven't looked at the package, there's no good way of doing the other conditional probability, the probability that it's coming from a particular plant, given that you've got an orange M&M. +[185.65s -> 199.81s] So because I want to carry on with this video and do a little bit more probability, but I don't have the numbers, I'm just going to, I don't know, make them up. Imagine that I go off, I buy a bunch of M&Ms from the one plant and a bunch of M&Ms from the other plant, and I create the following table. +[199.81s -> 210.18s] In this table, the cells don't represent conditional probabilities. They are the number of M&Ms that I have mixed together in some bool. And what you can see is that... +[210.18s -> 221.25s] along the Cleveland plant road that there's a hundred M&Ms that came from there and there's a hundred that came from that Hackettstown one. I've also added to my table one column that gives you the +[221.25s -> 234.91s] total number of M&M's in any given row and one row which gives you the total number of M&M's in any given column. So nonetheless I have these 200 M&M's with this different distribution of the colors and the plants. +[234.91s -> 242.56s] So let me ask the same question I asked before. What's the probability of it being orange given that it comes from the Hackettstown plant? Note that +[242.56s -> 257.06s] Now I am using this data in my made-up table, not the total availability for all M&Ms, so I actually am going to use my conditional probability formula. And the way the conditional probability formula works is you look at the probability of the intersection. +[257.06s -> 269.71s] the probability that it's both orange and from the Hackestown plant, and then you divide out by the probability that came from the Hackestown plant. That's my conditional probability formula. So, in this case... +[269.71s -> 283.31s] The probability that it's orange and that it's HKP from the Hackistown plant is, well, there's 25. It's this cell right up here. There's 25 of those M&Ms out of 200 in total. +[283.31s -> 294.03s] And then for the probability that it comes from the Hackettstown plant, the P of HKP, well, there's 100 M&Ms from that plant out of 200 total. So again, what we're going to get here is... +[294.03s -> 305.74s] 25 over 200 on the top, the 25 ones that are orange and from the Hackett's tan plant, divided out by the 100 divided by 200, the 100 M&Ms divided by 200 total. +[305.87s -> 320.24s] When you're doing this, the dividing by the total number, the 200, appears in the numerator and the denominator. We can cancel that. And so what are we left with? 25 over 100, just 0.25. Now, one way to think about this is that... +[320.24s -> 331.30s] when i tell you when i give you that it's coming from the hackettstown plan that that allows us to focus just on that particular row the hackettstown row and sort of ignore all the other information +[331.30s -> 344.45s] In which case, you could get to the answer a little bit faster than going through the full formula. You could say, well look, there's 25 orange out of 100 total in this row, 25 divided by 100, that's it. As in, when you have a table, the... +[344.45s -> 357.31s] Conditional probability is kind of like just saying which row or which column are you talking about? Let's say one that uses columns. Let's go the other way around, the one we couldn't previously do. That is, I want to now investigate. +[357.31s -> 370.21s] The probability that it comes from the Hackettstown plant, given that it's orange. So imagine I'm taking my 200 M&Ms, I'm mixing them all up together, I don't know what it is, I pull out one at random, and I tell you that the one you've pulled out is orange. Well... +[370.21s -> 381.31s] What's the probability it comes from one plant versus the other? In this case, we do the same thing. Our conditional probability formula tells us the probability of the intersection. That it comes from a Hackestan plant. +[381.31s -> 395.17s] and that it's orange, and then you divide out by the probability that it's orange. Well, the numerator is as it was before. There's 25 in that category that's both out of 200. And then if I look at the column for orange, well... +[395.17s -> 407.60s] There's a grand total of 45 out of the 200 that happened to be orange. So what do we have here? 25 divided by 200 on the top and 45 divided by 200 on the bottom. The 200s... +[407.60s -> 414.99s] Again, they just sort of cancel. We can get rid of them. It's 25 over 45. And that gives me a decimal 0.56 approximately. +[414.99s -> 423.47s] And then when I think about it this direction, it's a little bit like just choosing a specific column. If I just focus in on that orange column. +[423.47s -> 433.76s] Well, then I can just say it's 25 divided by 45. 25 that come from the HGP and are orange divided by the 45 orange in total. +[433.76s -> 444.85s] So when you do conditional probability from a table, it's just choose a particular row or choose a particular column, and then you can do a normal probability within that row or within that column. +[445.36s -> 454.69s] Let's just do one more example, one more with a little bit of a trick. Let's do the probability that it comes from the Hackestown plant, but that it is not orange. +[454.69s -> 463.73s] No, when I do it that way, when I say that it is not orange, this is like me just sort of throwing out that one particular column of the table and just saying this is not a possibility. +[463.89s -> 476.80s] Now my 200 M&Ms, I subtract off 45, I only have 155 remaining M&Ms. And if I want to think about what's the probability here, well, it's the same old conditional probability. +[476.80s -> 483.30s] Probability from the Hackestown plant and the probability of not being orange divided out by the probability of not being orange. +[483.30s -> 494.61s] But now I have to add up a whole bunch of things in the numerator and the denominator, because the way to not be orange is to be red or yellow or green or blue or brown, all of those different possibilities. So... +[494.61s -> 508.50s] Let's figure out how many there's going to be. Well, in the numerator, I add up all of the ones that are not orange and chyme from the Hackestown plant. So there was 12 that were red, and then there were 13 that were yellow, and so on. +[508.56s -> 518.42s] And then in the denominator, I'm going to put in just what's the total numbers of ones that are not orange. Well, there's 25 total reds and there's 27 total yellows and so on. +[518.80s -> 530.90s] If I want to, I could divide the top and the bottom by the 155, the number of total M&Ms, but it's going to cancel anyway, so I didn't write it down. Nonetheless, you add these numbers up and you get approximately 0.52. +[531.02s -> 545.02s] Okay, now all that's left is to eat some M&Ms. So, uh, let's see what we have here. Oh my goodness. They're going everywhere. Alright, so it looks like I have four orange ones over here. Those are the good ones. And then I've got four... +[545.02s -> 559.31s] eight, twelve, fourteen, and some scrambled up ones. I guess it was in the bottom of my backpack. Now this bag is not at all necessarily representative of all bags, but for this bag there was a four fourteenth chance of getting an orange one. +[559.31s -> 569.33s] All right, I hope you enjoyed that video. Give it a thumbs up if you did. If you have a question about the video, leave it down in the comments and I will see you for some more math in the next video. diff --git a/VideoMMMU_ASR_large/Business/validation_Marketing_25.mp4.txt b/VideoMMMU_ASR_large/Business/validation_Marketing_25.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..52dc2e2bf9c127e0b04c436c678fc61d89c9c505 --- /dev/null +++ b/VideoMMMU_ASR_large/Business/validation_Marketing_25.mp4.txt @@ -0,0 +1,18 @@ +[0.00s -> 12.86s] In this video I'll be going over how to do a paired t-test. I'll be using data from a classroom in which every student took two tests and in between the tests they did a change in study habits. +[12.86s -> 25.50s] And so the test is really about whether or not those study habits had an effect or didn't have an effect. Notice that for each student there are two inputs and then you have the calculated difference that you do. +[25.50s -> 38.94s] The null hypothesis is that there is no difference. The alternative hypothesis is that the difference is not zero. So whether it's positive or negative. So from that we know that this is a two-sided test. +[38.94s -> 47.02s] The first thing you want to do is calculate the mean of the difference. This gives us an average of 1.571. +[47.02s -> 58.34s] The next is to calculate the standard deviation of the difference and so just like how we calculate every other standard deviation you do the square root of the sum of each +[58.34s -> 69.30s] Difference minus the average of the differences and then that quantity squared Divided by n minus 1 and so when you do that you get 9.325 +[69.30s -> 79.38s] Now in either one of these cases, if you're having trouble, I have videos that go over in more detail if you need a brush up on how to do standard deviation or the mean. +[79.38s -> 89.63s] Given that in almost every instance the denominator of the standard deviation is what the degrees of freedom formula is, I thought I would add that here. +[89.63s -> 101.52s] And so in this case, we know it's n minus 1, and so it's 7 minus 1, which means we have 6 degrees of freedom. And so we'll note that for when we look up the t-table. +[101.87s -> 111.06s] Since I had to clean up I put all the information we just previously had right here So if I reference that it's it's right here for you +[111.41s -> 125.42s] The next thing we want to do is calculate the standard error. And the calculation for the standard error is the standard deviation over the square root of n. And so we have 9.325 over the square root of 7, which yields 3.525. +[125.62s -> 136.34s] The next thing is to calculate the t statistic itself. So we have t equals the average of the differences over the standard error of the differences. +[136.94s -> 145.04s] This gives us 1.571 over 3.525, which yields 0.446. +[145.04s -> 157.10s] The last things we have to do is look up the T-table with a critical value at our 95% confidence level and then come up with the conclusion based off that. +[157.17s -> 167.28s] So let's go look at the t-table given that we have a degrees of freedom of 6 at the 95% confidence interval for a two-tailed test. +[177.58s -> 190.03s] Now the conclusion is that given that the absolute value of RT, which is 0.446, is less than the critical value, we fail to reject the null hypothesis. +[190.03s -> 202.74s] That's it in terms of the tests. I will be going over rejection regions later. This is equivalent to a one sample t-test because you're only looking at the difference. +[202.74s -> 205.66s] Thank you for watching and stay nerdy my friends. diff --git a/VideoMMMU_ASR_large/Engineering/new_Computer_Science_1.mp4.txt b/VideoMMMU_ASR_large/Engineering/new_Computer_Science_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0fe2cdb8e5b30907b4a057767a0093bb0ac66dc6 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/new_Computer_Science_1.mp4.txt @@ -0,0 +1,42 @@ +[1.23s -> 14.74s] In the last video, you learned about the neural network layer and how that takes as input a vector of numbers and in turn outputs another vector of numbers. In this video, let's use that layer +[14.74s -> 26.08s] to build a more complex neural network. And through this, I hope that the notation that we're using for neural networks will become clearer and more concrete as well. Let's take a look. +[26.08s -> 40.14s] This is the running example that I'm going to use throughout this video as an example of a more complex neural network. This network has four layers, not counting the input layer, which is also called layer zero. +[40.14s -> 54.16s] where layers 1, 2, and 3 are hidden layers, and layer 4 is the output layer, and layer 0, as usual, is the input layer. By convention, when we say that a neural network has four +[54.16s -> 66.22s] That includes all the hidden layers in the output layer, but we don't count the input layer. So this is a neural network with four layers in the conventional way of counting layers in the network. +[67.22s -> 80.91s] Let's zoom in to layer 3, which is the third and final hidden layer, to look at the computations of that layer. Layer 3 inputs a vector A. +[80.91s -> 91.47s] superscript square bracket 2 that was computed by the previous layer, and it outputs A3, which is another vector. +[91.47s -> 102.03s] So what is the computation that layer 3 does in order to go from A2 to A3? If it has three +[102.42s -> 116.80s] neurons, or we call it three hidden units. Then it has parameters w1b1, w2b2, and w3b3, and it computes A1 equals sigmoid of w1 +[116.80s -> 122.06s] dot product with this input to the layer plus b1. +[122.70s -> 135.90s] and it computes A2 equals sigmoid of W2 dot product with, again, A2, the input to the layer, plus B2, and so on, to get A3. And then the output of this layer +[135.90s -> 146.00s] is a vector comprising a1, a2, and a3. And again, by convention, if we want to +[146.00s -> 156.11s] more explicitly denotes that all of these are quantities associated with layer 3, then we add in all of these superscript square brackets 3 here. +[156.11s -> 167.02s] to denote that these parameters w and b are the parameters associated with neurons in layer 3 and that these activations are activations with layer 3. +[167.73s -> 177.52s] Notice that this term here is w1 super script square bracket three, meaning the parameters associated with layer three dot product width. +[177.78s -> 192.24s] a superscript square bracket 2, which was the output of layer 2, which became the input to layer 3. So that's why there's a 3 here, because there's a parameter associated of layer 3 dot product with, and there's a 2 there because it's the output. +[192.24s -> 206.05s] of layer 2. Now let's just do a quick double check of our understanding of this. I'm gonna hide the superscripts and subscripts associated with the second neuron. +[206.05s -> 216.56s] And without rewinding this video, go ahead and rewind if you want, but I prefer you not. But without rewinding this video, are you able to think through? +[216.56s -> 230.67s] what are the missing superstrips and substrips in this equation and fill them in yourself. Why don't you take a look at the end video quiz and see if you can figure out what are the appropriate superstrips and substrips for this equation over here. +[231.25s -> 244.82s] If you chose the first option, then you got it right. The activation of the second neuron at layer 3 is denoted by A32. To apply the activation function G, +[244.82s -> 257.94s] Let's use the parameters of this same neuron. So W and B will have the same subscript 2 and superstript . The input features +[257.94s -> 263.15s] will be the output vector from the previous layer, which is layer 2. +[263.47s -> 277.71s] So that would be the vector A superscript 2. The second option is using vector A3, which is not the output vector from the previous layer. The input to this layer is A +[277.71s -> 291.87s] And the third option has A22 as input, which is just a single number rather than the vector. Because recall that the correct input is a vector. +[291.87s -> 296.72s] A2 with the little arrow on top and not just a single number. +[297.84s -> 310.13s] So to recap, A3 is activation associated with layer 3 for the second neuron, hence there's a 2. There's a parameter associated with the third layer. +[310.13s -> 318.61s] For the second neuron, this is a2, same as above, and then plus b32. So hopefully that makes sense. +[319.31s -> 332.96s] Here's the more general form of this equation for an arbitrary layer L and for an arbitrary unit J, which is that A, deactivation output of layer L is unit J. +[332.96s -> 337.65s] like a32, that's going to be the sigmoid function. +[338.16s -> 350.77s] applied to this term, which is the weight vector of layer L, such as layer 3, for the jth unit. So there's 2 again in the example above. And so there's dot product at width. +[350.83s -> 364.56s] A deactivation value of, and notice this is not L, this is L minus one, like the two above here, because you're dot prototyping with the output from the previous layer, and then plus B. +[364.56s -> 367.60s] the parameter for this layer for that unit j. +[368.98s -> 381.57s] And so this gives you the activation of layer L's unit J, where the superscript in square brackets, L, denotes layer L, and the substript J denotes unit J. +[381.57s -> 394.26s] And when building neural networks, unit J refers to the J-th neuron. So we use those terms a little bit interchangeably, where each unit is a single neuron in a layer. G here is the sigmoid function. +[394.26s -> 407.36s] In the context of a neural network, G has another name, which is also called the activation function, because G outputs this activation value. So when I say activation function, I mean +[407.36s -> 420.72s] this function g here. And so far the only activation function you've seen is the sigmoid function, but next week we'll look at when other functions than the sigmoid function can be plugged in in place of g as well. +[420.72s -> 426.70s] But so the activation function is just that function that outputs these activation values. +[427.28s -> 437.42s] and just one last piece of notation. In order to make all this notation consistent, I'm also doing to give +[437.42s -> 450.99s] the input vector x, and now the name, which is a0. So this way, this same equation also works for the first layer, where when l is equal to 1, deactivation is of the first layer, that is a1. +[450.99s -> 464.59s] will be a sigmoid times the weights dot product with a0, which is just this input feature vector x. So with this notation, you now know how to compute the activation values of +[464.59s -> 478.88s] any layer in a neural network as a function of the parameters as well as the activations of the previous layer. So you now know how to compute the activations of any layer given the activations of the previous layer. +[478.88s -> 489.09s] Let's put this into an inference algorithm for a neural network. In other words, how to get a neural network to make predictions. Let's go see that in the next video. diff --git a/VideoMMMU_ASR_large/Engineering/test_Architecture_and_Engineering_206.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Architecture_and_Engineering_206.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..4e4ead44683fdba5f838332e9591b777002b3e4a --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Architecture_and_Engineering_206.mp4.txt @@ -0,0 +1,44 @@ +[8.34s -> 20.98s] Hello everyone, in this video I am going to solve an example related to the case number 2 of Stereo method of tachymetric surveying in which the staff is being held vertical and line of sight is inclined. +[23.12s -> 33.68s] So looking at this example, we are being given with three different points. At one point, the instrument is being placed. At two other points, the staff readings are being taken. +[33.68s -> 46.03s] Tachometer constants are also being given to us and we are being asked to calculate the horizontal distance between point B and point C and it is also being required to calculate the reduced level of point C. +[46.03s -> 56.18s] So in order to solve any kind of example related to surveying, it's always advisable to draw the sketch first. So let's draw the sketch first. +[58.13s -> 72.77s] So let's say this is point A as it is being given to us that the instrument is being placed at point A and it is also being given to us that the instrument station is in between point B and point C. +[72.77s -> 84.05s] Therefore, I have drawn the sketch for point A at the mid. Now, the stereo readings that have been taken at point B and point C are also being +[84.05s -> 96.24s] shown here now looking at the stereo readings for point b which is also the benchmark we can see that this vertical angle is negative which means point b is +[96.24s -> 108.94s] at a lower altitude than that of point A because this angle is angle of depression so therefore we will draw this sketch for point B lower than that of point A +[111.50s -> 125.68s] this is also the benchmark similarly you can see point C has an angle as angle of elevation means angle is given as positive 6 degree and 11 minutes so therefore we will draw the sketch for point C +[125.68s -> 128.02s] higher than the top point A. +[130.26s -> 141.49s] and it is being asked to calculate this distance between point B and point C so as we know that instrument station is point A and we also know that this is the axis of instrument +[141.49s -> 154.19s] the staff reading is to be taken let's say for staff reading at point a or the one as shown in this table angle is also being given similarly the staff reading at point c is to be +[154.19s -> 167.76s] drawn angle is also being given so in order to calculate this horizontal distance this setup is to be divided into two parts the first part which is the distance between point a and point b +[167.76s -> 182.03s] as h1 and the second part as the distance between point a and point c as h2 now let's consider this first setup for the determination of the horizontal distance between point a and point b +[184.66s -> 198.46s] Now recalling the horizontal distance that we have learned from the case number two of stereo method So here you can see that in order to determine the horizontal distance. We should be knowing the constants vertical angle +[198.46s -> 205.17s] staff intercept so this horizontal distance formula can be rewritten for this case as +[206.86s -> 219.36s] So here theta1 is given to us. The staff intercept would be the difference of upper and lower stadia readings. And once you calculate it, it will come out to be 0.73. +[219.36s -> 225.28s] the multiplying and additive constants are also given to us so placing the value of theta1 +[225.28s -> 234.96s] s1 and multiplying another constant we will have then the horizontal distance as s1 is equal to 72.7 meter +[234.96s -> 247.63s] so once we have calculated this horizontal distance h1 which came out to be 72.7 meter now let's consider the second setup in order to determine the horizontal distance h2 +[251.06s -> 257.07s] Now the same horizontal distance formula can be rewritten for this setup as h2 +[257.07s -> 271.34s] is equal to the formula here the staff intercept would be the difference of the upper and lower and once you will calculate it it will come out to be 1.12 and as to the angle 6 degree and 11 minutes is also being given the same multiple +[271.34s -> 281.57s] constants would be used here so placing the value of s2 theta 2 and the constants we can solve for the h2 and once you will do the calculation +[281.57s -> 292.85s] will come out to be 110.85 meter so now we have h2 as well so once we have h1 and h2 adding them together we will have the total horizontal distance +[292.85s -> 300.75s] as 183.55 meter now the next thing that is being asked to us is the reduced level of point c +[300.75s -> 312.98s] so reduce level at the benchmark is given to us so we will be looking for the reduced level at point c so in order to determine the reduced level we would be using the vertical distance formula +[312.98s -> 327.38s] that we have learned from case number two of Stadia method. This V distance is actually the distance from the axis of instrument to the central Stadia reading. Like for the first setup the distance is being shown as V1. Similarly for the +[327.38s -> 341.58s] second setup as v2 the distance from the axis of instrument to the central stevia reading at point C so in order to calculate the reduced level we will also be utilizing the central stevia reading so central stevia reading for first +[341.58s -> 353.14s] is being represented with h1 and the central stadia reading for the second setup is being represented with h2 now the reduced level at point C would be +[353.14s -> 360.64s] so reduced level at point B is being given to us or you can say that a reduced level at the benchmark is given to us this +[360.64s -> 371.49s] dotted red line shows the level of the reduced level so reduced level at point c would be then equal to reduced level at the benchmark since this benchmark is +[371.49s -> 384.94s] lower than the point c so we need to move higher so once we are moving higher then we need to add the distances like once we will move by magnitude of h1 +[385.01s -> 396.75s] Then we will add H1 and again we are lower than point C. We need to move higher than that. So again we will be moving by V1 distance. +[397.04s -> 409.62s] so again V1 would be added and again here you can see we are lower than point C we need to move even higher so again we are moving by V2 distance +[409.62s -> 417.25s] so again v2 to be added and now here you can see that this dotted red line is higher than +[417.25s -> 431.54s] the point c so it means now we need to move down by magnitude of h2 so therefore this h2 is to be subtracted so then this will be the final equation for the reduced level at point c now putting the values +[431.54s -> 436.10s] Reduce Level at Benchmark is given to us which is 32.12 +[436.10s -> 448.48s] the central stereo reading for the first setup is 1.73 the v1 is to be calculated using the equation that is being given to us this same equation can be rewritten as +[448.48s -> 461.47s] so here we have s1 and theta1 that we have already calculated when we were doing the calculation for the horizontal distance so putting the value of s1 and theta1 and also the constants +[461.47s -> 467.84s] we can have then the v1 as 5.72 beta so putting the value of +[467.84s -> 477.63s] v1 here again we need to calculate v2 so again this particle distance formula can be rewritten as again we know theta2 s2 +[477.63s -> 490.72s] and constants putting those values we will have then v2 is equal to 12.016 so that will be inserted here and h2 is the central std reading for the second setup that is one point +[490.72s -> 505.10s] 22 and that will be subtracted so once you do the calculation you will get the reduced level at point c as 50.356 meter so this is how the calculation for the horizontal distance and the vertical distance are +[505.10s -> 514.06s] can say the reduce level is to be performed when this kind of example is to be given so this is all from this video thank you for watching this video diff --git a/VideoMMMU_ASR_large/Engineering/test_Architecture_and_Engineering_359.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Architecture_and_Engineering_359.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c2ee078808b83c4b287a0633990df748ebbb0b25 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Architecture_and_Engineering_359.mp4.txt @@ -0,0 +1,51 @@ +[5.42s -> 14.00s] The analysis of a three hinged arch. The loads applied to a beam cause stress in the member. +[15.22s -> 24.72s] For convenience, we often represent the state of internal stress in beams using shear force and bending moment. In the context of structural design, +[24.72s -> 30.77s] There is a direct relationship between the magnitude of these forces and the size and depth of the beam. +[31.70s -> 40.37s] The larger the force, especially the bending moment, the deeper the cross section of the beam needs to be in order to safely carry the load. +[45.01s -> 58.59s] For beams with a relatively long span, bending moment could become excessively large, requiring the use of even a deeper cross-section. In such a situation, it may be desirable to curve the beam forming an arch. +[58.59s -> 66.38s] This configuration results in a significant reduction in bending moment but at the expense of putting the member in compression. +[69.26s -> 80.91s] We can classify arches based on their boundary conditions. An arch could be fixed at both ends with no hinges present. We can have an arch with a hinge at its crown. +[81.17s -> 95.73s] And there are two hinged and three hinged arches. The degree of indeterminacy of these arch types varies from three to zero. +[96.30s -> 106.03s] The three hinged arch is considered a statically determinate system. Here we are going to focus on the analysis of a three hinged arch. +[106.77s -> 116.75s] In order to analyze such a structure, we need to be able to define its shape using a mathematical function, often either as a circle or as a parabola. +[121.58s -> 134.96s] Let's refer to the height of the arch as h, and use l to label the horizontal distance between the two supports. Suppose we wish to describe the shape of our arch using a parabolic function. +[135.38s -> 146.42s] We start with a general quadratic equation like this. Our task is to determine the coefficients a, b, and c in terms of h and l. +[146.83s -> 156.50s] We know that the arch has a height of zero at the left support, so we can write. This gives us C equals zero. +[157.87s -> 165.01s] We also know that when x is L over 2, the height of the arch is h, so we can write +[167.22s -> 181.07s] Further, at the right end of the arch, where x equals l, our function should evaluate to zero. Using these two equations, we can solve for coefficients a and b. +[181.65s -> 186.45s] So the shape of our arch can be described using this parabolic function. +[187.22s -> 198.26s] Suppose our arch has a height of 10 meters and spans 50 meters. We wish to analyze it under a concentrated load of 120 kN placed at its crown. +[198.51s -> 211.41s] Knowing H and L, we can rewrite FX like this. Since the arch rests on a pin at either side, we end up with a horizontal force and a vertical force at each end. +[211.98s -> 218.70s] In this case, the two vertical reactions can be easily determined by using the equilibrium equations. +[226.06s -> 239.50s] To determine the horizontal reactions, let's separate the left and the right halves of the arch like this. Since bending moment at a hinge is zero, we end up with only two unknown forces at each cut point. +[240.05s -> 254.06s] Further, due to symmetry, we have the identical forces at the right and left cuts. Now we can easily determine A using the left half of the arch, summing the moments about the cut point, we get +[257.62s -> 269.30s] We can determine BMX in a similar manner. Now that we have all the support reactions, let's put the arch back together. +[271.18s -> 283.54s] Suppose we are asked to determine the internal forces in the arch, including axial force, shear force, and bending moment. To do so, we cut the arch at distance x from the origin. +[284.21s -> 288.69s] The free body diagram of the left segment of the arch looks like this. +[290.26s -> 300.62s] Note the horizontal and vertical distances from the origin to the cut point. We have labeled the horizontal distance x, so the vertical distance becomes f of x. +[301.01s -> 313.81s] This free-body diagram involves three unknown forces, m, h, and r. We can determine m by writing the sum of the moments about the cut point. Here is the equation. +[314.38s -> 324.50s] Solving it for M gives... As the equation suggests, bending moment in the arch varies as a function of X in a nonlinear manner. +[325.04s -> 339.89s] Since sum of the forces in the X direction must be zero, H must be 150 kilonewtons, and R must be 60 kilonewtons in order for the sum of the forces in the Y direction to be zero. +[340.34s -> 353.36s] But note that H and R do not represent axial and shear forces in the member. Axial force must be in the tangential direction at X, and shear force must be in the radial direction, like this. +[354.03s -> 366.16s] If we refer to the angle that the tangent to the curve makes with the horizontal axis as theta, then we can express the tangent of the angle in terms of the derivative of f with respect to x. +[366.16s -> 372.24s] This means at a specific point on the arch, we can determine the tangent of the curve using this equation. +[372.75s -> 383.89s] Knowing the tangent of an angle, we can determine the angle itself. Then we can express n and v in terms of h, r, and angle theta like this. +[386.38s -> 400.27s] Since H is 150 and R is 60, our N and V equations can be written this way. So here are the equations for determining the internal forces in the arch. +[400.82s -> 404.14s] Let's use them to draw a diagram of each force. +[405.74s -> 418.29s] To draw the moment diagram we need to graph this equation. This is for the left half of the arch, but since we have symmetry here, the diagram for the right half of the arch would be identical to that of the left half. +[418.86s -> 423.44s] This is a quadratic equation so we end up with a curve like this. +[424.82s -> 434.51s] Note that bending moment at the hinge at either end of the segment is zero. We can verify this by evaluating the equation at 0 and 25. +[435.06s -> 443.15s] We can determine the point of maximum moment by setting dm dx to zero. Like this. +[445.33s -> 457.36s] The equation tells us that moment is maximum at x equals 12.5. Hence, the magnitude of maximum moment equals 375 kNm. +[457.74s -> 469.33s] Then, the diagram of the right segment looks like this. To draw the diagram for the axial force, we are going to graph this equation. +[471.50s -> 481.71s] Using trigonometric properties, we can write cosine theta in terms of tangent theta this way, and sine theta can be expressed this way. +[482.38s -> 492.40s] Then the algebraic expressions for the cosine and sine of theta become Substituting these expressions in the equation for n we get +[492.88s -> 503.41s] The graph of this equation looks like this. The equation gives us 154.6 when x is 0 and 150 when x is 25. +[503.66s -> 515.60s] To determine the maximum value for axial force in the segment, we set dn dx to zero. That leads to this equation, which gives us x equals 12.5. +[516.08s -> 526.45s] Maximum axial force in the arch develops 12.5 meters from the left support. The magnitude of the force is 161.6 kN. +[526.96s -> 532.37s] Again, the force diagram for the right half of the arch is that of the left half. +[538.61s -> 550.32s] Finally, to draw the shear diagram, we are going to use this equation. Using the same trigonometric expressions as before, we end up with this equation for shear. +[551.06s -> 564.75s] The numerator for the equation tells us that shear is 0 when x is 12.5. To graph the equation, we need to evaluate it at x equals 0 and x equals 25. +[565.30s -> 579.12s] Here is the diagram. Shear is negative 46.85 kN at the left end of the segment and 60 kN at the right end of the segment. +[579.70s -> 590.48s] We mirror what we just drew for the left half of the arch and place it on the right half of the x-axis to complete the diagram. Here is the summary of the results. +[593.17s -> 606.90s] moment diagram, thrust diagram, and shear diagram. We will examine the analysis of an arch bridge in the next lecture. diff --git a/VideoMMMU_ASR_large/Engineering/test_Computer_Science_14.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..261c286698c2554a4c98526614503f2812dce474 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_14.mp4.txt @@ -0,0 +1,33 @@ +[0.08s -> 14.29s] Hurricane Florence came by While I was working on StatQuest Dark clouds filled the sky But that didn't stop StatQuest +[14.29s -> 28.91s] Hello, I'm Josh Starmer and welcome to StatQuest. Today we're going to be talking about some machine learning fundamentals, bias and variance, and they're going to be clearly explained. +[29.23s -> 41.97s] Imagine we measured the weight and height of a bunch of mice and plotted the data on a graph. Light mice tend to be short, and heavier mice tend to be taller. +[42.54s -> 57.26s] But after a certain weight, mice don't get any taller, just more obese. Given this data, we would like to predict mouse height given its weight. For example, if you told me your mouse weighed this much, +[57.58s -> 72.30s] Then we might predict that the mouse is this tall. Ideally, we would know the exact mathematical formula that describes the relationship between weight and height. But, in this case, we don't know the formula. +[72.30s -> 83.12s] so we're going to use two machine learning methods to approximate this relationship. However, I'll leave the true relationship curve in the figure for reference. +[83.54s -> 97.42s] The first thing we do is split the data into two sets, one for training the machine learning algorithms and one for testing them. The blue dots are the training set, and the green dots are the testing set. +[97.87s -> 112.59s] Here's just the training set. The first machine learning algorithm that we will use is linear regression, aka least squares. Linear regression fits a straight line to the training set. +[113.20s -> 125.55s] The straight line doesn't have the flexibility to accurately replicate the arc in the true relationship. No matter how we try to fit the line, it will never curve. +[127.18s -> 135.44s] Thus, the straight line will never capture the true relationship between weight and height no matter how well we fit it to the training set. +[136.18s -> 144.24s] The inability for a machine learning method like linear regression to capture the true relationship is called bias. +[144.91s -> 157.94s] Because the straight line can't be curved like the true relationship, it has a relatively large amount of bias. Another machine learning method might fit a squiggly line to the training set. +[158.38s -> 172.59s] The squiggly line is super flexible and hugs the training set along the arc of the true relationship. Because the squiggly line can handle the arc in the true relationship between weight and height, it has very little bias. +[173.36s -> 181.20s] We can compare how well the straight line and the squiggly line fit the training set by calculating their sums of squares. +[181.55s -> 195.66s] In other words, we measure the distances from the fit lines to the data, square them, and add them up. Psst! They are squared so that negative distances do not cancel out positive distances. +[196.37s -> 204.24s] Notice how the squiggly line fits the data so well that the distances between the line and the data are all zero. +[204.98s -> 213.39s] In the contest to see whether the straight line fits the training set better than the squiggly line, the squiggly line wins. +[214.26s -> 227.50s] But remember, so far we've only calculated the sums of squares for the training set. We also have a testing set. Now let's calculate the sums of squares for the testing set. +[228.08s -> 236.82s] In the contest to see whether the straight line fits the testing set better than the squiggly line, the straight line wins. +[237.90s -> 252.56s] Even though the squiggly line did a great job fitting the training set, it did a terrible job fitting the testing set. In machine learning lingo, the difference in fits between datasets is called variance. +[253.33s -> 261.01s] The squiggly line has low bias since it is flexible and can adapt to the curve in the relationship between weight and height. +[261.55s -> 269.26s] But the squiggly line has high variability because it results in vastly different sums of squares for different data sets. +[270.00s -> 280.59s] In other words, it's hard to predict how well the squiggly line will perform with future datasets. It might do well sometimes, and other times it might do terribly. +[281.49s -> 290.42s] In contrast, the straight line has relatively high bias since it cannot capture the curve in the relationship between weight and height. +[290.83s -> 298.29s] But this straight line has relatively low variance because the sums of squares are very similar for different data sets. +[298.99s -> 309.68s] In other words, the straight line might only give good predictions and not great predictions, but they will be consistently good predictions. Bam! +[310.06s -> 321.90s] Oh no! Terminology alert! Because the squiggly line fits the training set really well, but not the testing set, we say that the squiggly line is overfit. +[322.48s -> 336.59s] In machine learning, the ideal algorithm has low bias and can accurately model the true relationship. And it has low variability by producing consistent predictions across different datasets. +[337.20s -> 343.57s] This is done by finding the sweet spot between a simple model and a complex model. +[344.43s -> 358.29s] Oh no! Another terminology alert! Three commonly used methods for finding the sweet spot between simple and complicated models are regularization, boosting, and bagging. +[358.51s -> 370.93s] The stat quests on a random forest show an example of bagging in action. And we'll talk about regularization and boosting in future stat quests. Double bam! +[371.44s -> 385.28s] Hooray! We've made it to the end of another exciting Stat Quest. If you like this Stat Quest and want to see more, please subscribe. And if you want to support Stat Quest, well, please consider buying one or two of my original songs. +[385.28s -> 388.75s] Alright, until next time, quest on! diff --git a/VideoMMMU_ASR_large/Engineering/test_Computer_Science_141.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_141.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5ddcd8495865846bd081d3214a7fd54c3dbbc236 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_141.mp4.txt @@ -0,0 +1,45 @@ +[0.24s -> 13.95s] In this session, we are discussing a very important algorithm, Ford Fulkerson algorithm for maximum flow problem. Now, what is the maximum flow problem? So, let us discuss the problem at first. +[13.95s -> 27.15s] Then we shall discuss the terminologies and the algorithm as well. See, the problem says that given a graph which represents a flow network where every edge has a capacity. +[27.15s -> 38.88s] So that means one graph will be given and that will be weighted digraph, directed graph and this is the directed graph will be known as the network graph and this particular network. +[38.88s -> 51.97s] will be known as the flow network where each and every edge will have one integer value associated that is the weight of that particular edge or branch and that will be denoting the capacity of that edge that means +[51.97s -> 65.42s] the flow cannot exceed that capacity also given two vertices one is source s and another one is the sink t in the graph that means the flow will be made originated +[65.42s -> 77.68s] from source S and will get terminated at sink T. So, these are the very important two vertices are there, special type of vertices in the graph. +[77.68s -> 91.68s] Find out the maximum possible flow from S to T with following constraints. So this Ford-Falkerson algorithm is nothing but a method which will calculate the maximum flow. +[91.68s -> 105.30s] through our network here the flow can be of anything the flow can be of anything and the maximum possible flow from s to t with the following constraints so while calculating the maximum flow through the network +[105.30s -> 119.02s] when having two constants constant number one flow on an edge does not exceed that given capacity obviously the flow through a certain age should not exceed the respective capacity mentioned +[119.02s -> 124.43s] as an integer value or numeric value associated with that edge. +[124.69s -> 138.45s] Inflow is equal to outflow for every vertex except your source and the sink S and T. So obviously the whatever the flow that will come into a vertex. +[138.45s -> 149.76s] should be equal to the flow out from the vortex. But in case of source only the flow will come out from the source. In case of sink T the flow will go into the +[149.76s -> 162.78s] sink t it will not come out. So except these two vertices where having the flow in and flow out must remain same in all other remaining vertices in this weighted digraph. +[162.78s -> 176.66s] So, while discussing the algorithm we might be facing different terminologies. So, let me go for the terminologies at first, but before going for the terminology let us see the how does one network looks like you see these are network. +[176.66s -> 188.83s] So here A is the source we have written that one and F is the sink or target. So now from A only the flow will come out and to the sink only the flow will go in. +[188.83s -> 199.82s] So, these are the respective flows we are having, these are the respective flows we are having and this is a diagraph you are getting this head and tail for each and every edge. +[199.82s -> 213.94s] the terminology so let me discuss the residual graph it is a graph which indicates additional possible flow if there is such path from source to sink then there is a possibility +[213.94s -> 227.52s] to add flow that means through a certain path we can add flow if there is a possibility possibility means what means the remaining capacity is there and which is non-zero through the path +[227.52s -> 239.33s] that means from the source to the sink all the hs which will be falling on the path they should be having some residual capacity so let me discuss the residual capacity at first +[239.33s -> 252.40s] So, residual capacity, it is the original capacity of the edge minus the flow. Original capacity means these are the original capacities and minus the flow. So, that is known as the residual capacity. +[252.40s -> 257.36s] Next one is the minimal cut also known as bottleneck capacity. +[257.65s -> 269.90s] which decides the maximum possible flow from source to sink through an augmented path. So, I think it will be better if we show that one on this particular diagram what we are trying to +[269.90s -> 281.78s] through this terminologies. Now, see let us consider we are considering one path say AC then D and F. +[282.26s -> 295.04s] So, you are reaching from source to the sink A to F through C and D. Now, see in this particular path, the maximum flow is 11, that means the capacity is 11. +[295.04s -> 300.50s] Here the capacity is 9, here the capacity is 11. So through this path, the maximum flow +[300.78s -> 314.38s] can be 9 because it will decide the maximum flow and that is known as the minimal cut so here i am giving a flow with 9 here 9 and here we are having this +[314.77s -> 316.40s] So now, see. +[318.16s -> 331.95s] Now, see here the residual capacity, here the residual capacity is 2, here the residual capacity is 9 minus 9 that is 0, here the residual capacity is capacity minus current flow +[331.95s -> 343.30s] through that path through that edge will be 2. So, 2 0 2 are the residual capacities for the respective edges. So, we have discussed what is the residual capacity. +[343.30s -> 355.17s] and the graph thus obtained is known as the residual graph and the minimal cut I told you this one that is the minimal cut. So, minimal cut means the maximum flow possible through that particular +[355.17s -> 368.98s] path from the source to the sink is a minimum cut so in this way it is happening now see as it is having some capacity there so if we consider the path say a c b e +[369.26s -> 373.68s] and F. If you consider the path like this. +[375.98s -> 389.50s] So, A, C, B, E and F, here you see, here the residual capacity is 2, here the capacity is 10, here the capacity is 9, here the capacity is 2. +[389.50s -> 403.54s] So that's why we can have the minimal cut here that is the bottleneck. So that is also very important. Bottleneck capacity. This term is very important. So the bottleneck capacity in this particular path is 2. So what I can do? I can make it 11. +[403.86s -> 414.80s] So, I can make it 2 there, I can make 2 here, I can make 2 here. So, here we will be having some residual capacities, but it is quite full. +[415.41s -> 429.22s] In this way, we shall explain in details in the example. Augmenting path can be done in two ways. So, augmenting path can be done in two ways. One is the non-fold forward edges, whatever you have done. It is a non-fold. +[429.22s -> 441.73s] it is a non-full initially it was 9 and the capacity was 11 so it is non-full so non-full forward edges and another one is non-empty backward edges so non-empty backward edges we shall discuss +[441.73s -> 455.15s] in one example for the better understanding. So, let me discuss the algorithm at first. So, Ford-Fulkerson algorithm. The following is a simple idea of the algorithm. We are having three steps. +[455.15s -> 468.16s] Step number 1. Start with the initial flow as 0. So initially I can write here the flow is 0. Initially the flow was 0. Then we made a flow of 9. So flow has become 9. +[468.16s -> 483.06s] Then we made a flow of 2 here. So, the flow has become 11. So, in this way we will be going for incrementing the flow because we are going to calculate the maximum flow through the network. So, initially we will be starting with the initial flow as 0. +[483.50s -> 494.61s] There while there is an augmenting path from source to saying yes, we are getting so many augmenting paths So here you have demonstrated two of them then at this path flow to flow +[494.61s -> 508.30s] So, this path flow should be added with the flow. So, initially it was 0 then I allowed flow of 9. So, it has become 0 plus 9 that is 9 and then I allowed 2 through this. So, 9 plus 2 that is 11. So, now just +[508.30s -> 521.04s] at this path flow to the flow value and in this way you are going to do until there is no augmenting edge paths are possible from source to target source to sync and after doing this +[521.04s -> 534.93s] the value of the current flow will be returned and that is the maximum flow of the network. In this way, the algorithm will work. Please watch the next video where we will be going for one example for the better and crystal clear conception. +[534.93s -> 544.55s] to generate the crystal clear conception and better understanding on this particular algorithm. So that video will be in the continuation of this one. Thanks for watching this video. diff --git a/VideoMMMU_ASR_large/Engineering/test_Computer_Science_227.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_227.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..55e26e2d223bdd0521db693d64e18f6e889960ac --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_227.mp4.txt @@ -0,0 +1,52 @@ +[0.78s -> 15.06s] Hello everyone, and welcome to this video on recurrence relations. So in this video, I'm going to show you how to solve the following recurrence relation in terms of n by using the iteration technique. +[15.76s -> 21.01s] Now the recurrence relation that I have is in blue in the blue rectangle +[21.33s -> 34.58s] first I have the recursive case T of n which states that T of n is equal to T of n minus 1 plus 4 and then underneath it +[35.12s -> 45.04s] I have the base case, or stopping case, which states that when n is equal to 0, the function t is equal to 1. +[46.06s -> 59.18s] Okay, so to get started we're going to first create two columns the first column I will call K And it will contain the number of iterations +[60.02s -> 71.18s] the second column I will call T of n and it will contain the recurrence relation +[71.73s -> 79.31s] At each iteration so it shows what that recurrence relation looks like at each iteration +[79.95s -> 88.18s] Alright, so to start this we will start with our first iteration so under K. I will put the number one +[88.66s -> 101.71s] what does the the function look like at this first iteration well it looks like what we already have stated in the problem so I'm just going to rewrite the function +[102.35s -> 116.85s] So I'm going to put here T of n is equal to T of n minus 1 plus 4. Okay? And now we can go to our second iteration. +[117.74s -> 127.06s] But before we get to our second iteration, we need to know what T of n minus 1 is equal to. +[127.92s -> 138.42s] And that's easy enough. We can just plug in n minus 1 into the original t function or the original t of n function. +[139.92s -> 152.91s] To figure out exactly what this is equal to and I'll show you what I mean by that so T of n minus 1 is equal to +[154.16s -> 168.56s] T of n minus 1 minus 1 plus 4 Okay, and then if I simplify this a little bit I get T of +[169.20s -> 173.90s] n minus 2 plus 4. +[175.50s -> 190.48s] Okay, so now that means I can substitute T of n minus 2 plus 4 for T of n minus 1 in the second iteration And that's exactly what I'm going to do so for the second iteration under column K. We're going to put 2 +[191.25s -> 204.72s] And now the function t of n is equal to, I'm going to put this in blue, t of n minus 2. +[205.10s -> 210.93s] Plus four and then I have to add that other four +[217.94s -> 232.19s] All right, so hopefully you see that T of n minus 1 has been rewritten in blue in the second K iteration and Has become T of n minus 2 plus 4? All right, and then that +[232.19s -> 238.29s] 4 right here comes from the 4 right here +[244.43s -> 252.34s] So now to get to the third iteration we need to know what T of n minus 2 is equal to +[252.72s -> 266.74s] And that's easy enough just by plugging in n minus 2 into the original equation, kind of like what we did before for t of n minus 1. All right, so t of n minus 2. +[267.06s -> 278.38s] Is equal to T of n minus 2 minus 1 plus 4 and if we simplify that we get +[278.80s -> 286.32s] T of n minus 3 plus 4 Okay +[286.90s -> 301.58s] So now I can go to the third K iteration, so I'm gonna put a 3 under the column K And I'm gonna rewrite our function T of n So T of n is equal to T of +[301.87s -> 313.97s] minus 3 plus 4 and then I want to add in the 4 from the previous iteration so that's coming from here +[315.86s -> 328.24s] Alright, and then when I add in another four from the first Kate iteration, which is coming from there Okay +[328.66s -> 336.21s] Now I'm going to actually stop here because I already see a pattern and that's exactly what you want to be able to see a pattern +[337.26s -> 350.66s] So if you don't see the pattern yet, keep doing these K iterations until you do see a pattern. But I already see the pattern, so I'm going to just stop here. And I'm going to make a guess. So for some arbitrary... +[350.66s -> 362.96s] value that we're going to call k, the function t of n will be equal to t of n minus k. +[364.94s -> 376.94s] Plus 4 times K All right, this is also called the general +[378.86s -> 393.81s] form all right now to get this form in terms of n we need to know when it stops +[394.77s -> 408.21s] So I am going to create a new sheet. And I'm going to rewrite that general form. So I'm going to type general. +[409.42s -> 422.22s] form here and the general form is T of n is equal to T times n minus K +[423.34s -> 437.42s] plus 4 times K and Like I said we need to get it in terms of n so we need to know when it stops And know that it stops on the base case so if I go back to +[438.19s -> 452.46s] the other page, then we can see that the base case states that T of 0 is equal to 1. And again, that's right here. +[457.26s -> 471.70s] So now I can go back to our general form page. And what this tells us, it tells us that we want, I'm going to put here we want. +[474.70s -> 485.49s] I'll make it look a little nicer. We want t of 0. So. +[487.22s -> 499.09s] T of n minus K needs to be equal to 0 and Why is that well that's because that is equal to 1 right? +[503.15s -> 516.27s] So we need n minus k to be equal to 0 Then that means that we need n to be equal to k and of course that means that k is also equal to n +[517.20s -> 527.38s] All right, so now let's rewrite this equation in terms of it So now we get t of n is equal to +[527.63s -> 538.99s] T of n minus n. We're just substituting in the variable n for the variable k. +[539.82s -> 549.90s] Alright, so we get T of n minus n plus 4 times it And now if I simplify this +[550.90s -> 556.62s] I get t of 0 plus 4 times n. +[557.20s -> 566.61s] And we know that t of 0 is equal to 1 so we can simplify this a little bit more and we get 1 plus 4 times in +[567.09s -> 573.87s] And then I'm just going to rewrite it one more time. So we get 4n plus 1. +[578.64s -> 584.11s] This is what we believe to be the closed form +[600.14s -> 613.65s] Alright, so what is this in terms of big O? Well, 4n plus 1 belongs to big O of n. +[618.86s -> 632.88s] Now, how do I know this? Well, that's because I have lots of experience with this. But I do have videos showing you how you can prove this as well. So be sure to check those out. I will put them. +[632.88s -> 635.25s] the description below +[635.60s -> 650.06s] I hope that you all enjoyed this video. Please leave any likes, any comments, any questions, any problems that you would like for me to solve in the future. Please leave them in the comments below. And I appreciate you all watching the video. +[650.06s -> 652.53s] And I will see you all in the next one. diff --git a/VideoMMMU_ASR_large/Engineering/test_Computer_Science_310.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_310.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2d944f8c06374a3931ed12c39e3eb43a0e726792 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_310.mp4.txt @@ -0,0 +1,30 @@ +[0.05s -> 14.45s] Hello everyone. In this lecture, we will be studying about minimization of DFA. We have already studied about DFA. We have also studied about NFA. And we have also studied how to convert NFA to DFA. +[14.45s -> 26.61s] And in this lecture, we will be studying about minimization of DFA. But what is minimization and why is it required? Minimization of DFA is required to +[26.61s -> 38.32s] to obtain the minimal version of any DFA which consists of the minimum number of states possible. Alright, so what does this mean? +[38.32s -> 52.67s] example to explain this definition. Suppose you are given the task to design a DFA. Any DFA. And then you design this DFA using 5 states. Alright. And your friend +[52.67s -> 56.37s] Design the same DFA using 4 states. +[56.78s -> 71.09s] Both the DFS are correct. Both the DFS perform the exact same task. But one of them is designed using 5 states and another is designed using 4 states. Both of them are correct. +[71.09s -> 84.21s] Here we see that the same DFA can be designed using a lesser number of states. Now which one do you think is more efficient? 5 state DFA or the 4 state DFA? Obviously it will be the one with the +[84.21s -> 96.78s] lesser number of states. So, we want to design the DFA using the minimum number of states possible. That is known as the minimal version of any DFA. +[96.78s -> 110.16s] If you try to design a DFA directly in such a way to get the minimal version, it may be difficult for you. It is not impossible but it may be difficult. It is possible only after you +[110.16s -> 121.65s] practice and practice but there is a way of minimizing a given DFA. Given a DFA you can apply some technique and minimize it and make it +[121.65s -> 127.09s] to the minimal version. And that is what we are going to study in this lecture. +[127.34s -> 141.04s] So, how can we minimize DFA? So, let's say that you use these 5 states 1, 2, 3, 4, 5. You have these 5 states and you want to minimize this DFA. That means you want to reduce the number of +[141.04s -> 155.12s] states but keep the DFA performing the same thing. So how can you do this? What you can do is you can combine two states. Let's say these two states you combine them together and you make this a single state. +[155.15s -> 169.04s] And then now you have 1, 2, 3, 4 states. So, that is how you can minimize it. But how can you simply combine two states? You cannot just simply combine two states. There is a condition when you can combine two states. +[169.04s -> 183.28s] And what is that condition? Two states can be combined only when these two states are equivalent. Now when are two states said to be equivalent? +[183.28s -> 191.70s] Equivalent. What is the meaning of equivalence? Two states A and B are said to be equivalent if +[192.02s -> 206.46s] A on getting a particular input string x. Here x is any input string. So, if the state A on seeing the input string x goes to a final state. +[206.46s -> 220.90s] And at the same time if state B also on getting that same input string goes to any of the final states then A and B are said to be equivalent. +[220.90s -> 223.57s] or if +[224.05s -> 237.71s] a on getting an input string x does not go to the final state and also b on getting the particular input string x does not go to any of the final states then +[237.71s -> 249.49s] also a and b are said to be equivalent okay and this will become more clear to you when we take some examples and now what we have to study is +[249.65s -> 261.55s] Types of equivalents. There are some different kinds of equivalents like 0 equivalents, 1 equivalents, 2 equivalents and so on. So, next we will be seeing what is that. +[262.35s -> 272.90s] So here we see that if modulo x equal to 0 this means that if the length of the string x here we have taken +[272.90s -> 286.67s] x as any input string. If the length of that string x is 0, then a and b are said to be 0 equivalent. Alright. And if the length of x is equal to 1, +[286.67s -> 300.91s] then a and b are said to be 1 equivalent. And if the length of string x is equal to 2, then a and b are said to be 2 equivalent. So, in general we can write that if the +[300.91s -> 314.14s] length of the string x is equal to n then a and b are said to be n equivalent all right so these are the type of equivalences that we have and we already studied +[314.14s -> 327.63s] When are two states a and b set to be equivalent? It is with these conditions. When on seeing a particular input string x, if both a and b either goes to the final state or +[327.63s -> 339.97s] It does not go to any final state. Then they are said to be equivalent. And why do we need this equivalent property? We need it in order to combine the states, in order to reduce the number of states to get the +[339.97s -> 354.24s] minimum number of states possible in order to design the minimal version of any DFA. So, this was the theoretical explanation and in the next lecture we will be seeing an example which will make it. +[354.24s -> 357.97s] very clear to you. So, see you in the next one with an example. diff --git a/VideoMMMU_ASR_large/Engineering/test_Computer_Science_317.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_317.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5e64f702c77fa47bb77402de69d14a335e04bc06 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_317.mp4.txt @@ -0,0 +1,82 @@ +[0.88s -> 10.86s] Welcome to this video about the k-nearest neighbors for classification. In this video we'll discuss how KNN classify a data point to a certain group. +[10.86s -> 25.46s] We'll also see how we can validate the KNN method by the holdout method and by cross-validation, and how to find an appropriate value for K. I recommend that you first watch my video about different validation techniques. +[25.46s -> 37.01s] KNN is a non-parametric classification method, which means that no parameters of the population distribution are estimated. KNN is a supervised machine learning algorithm. +[37.01s -> 40.59s] which means that we need data with known class or group. +[40.59s -> 52.02s] KNN is a type of lazy learning algorithm because it does not create a model in comparison with most other classification methods. Instead, it predicts directly based on the training data. +[52.02s -> 56.05s] The algorithm can be continuously updated with new data. +[56.66s -> 67.54s] To show how KNN works, let's have a look at the following FICTI dataset, which contains information on 12 patients. The blood concentration of the C-reactive protein +[67.54s -> 78.75s] and the procalcitonin have been measured on 12 patients that have entered a hospital. Once the patients had entered the hospital, the presence of bacteria and viruses were analyzed. +[78.75s -> 92.62s] However, it usually takes several hours or days to determine if a patient has a viral infection or a bacterial infection. After two days at a hospital, these six patients were found to be infected by a virus. +[92.62s -> 103.82s] Whereas these six patients were confirmed to have a bacterial infection. Since antibiotics are only effective on bacteria, only these patients were treated with antibiotics. +[104.11s -> 115.57s] The problem is that we have to wait about two days to confirm the type of pathogen. We therefore need to wait two days to know if the antibiotic treatment is appropriate or not. +[115.57s -> 128.53s] It would therefore be great if we could use the CRP or the PCT concentration to tell if a patient has a bacterial or viral infection, because the measurements of these variables can be done within just an hour. +[128.53s -> 142.91s] If we plot the CRP concentration of the 12 patients, we see that no simple cut-off line can be used to clearly separate the ones with a bacterial infection from the ones with a viral infection. The same is also true for the PCT level. +[142.91s -> 157.14s] Because we cannot completely separate the patients with a bacterial infection from the patient with a viral infection by using only the PCT concentration. However, if we plot the CRP and the PCT concentration in the same plot, +[157.14s -> 167.55s] We see that the following line can separate the two groups completely. This indicates that if we make use of both variables simultaneously, we can make a better prediction. +[167.55s -> 179.50s] This data point represents the CRP and PCD concentration of patient number 1, whereas this data point represents the CRP and PCD concentration of patient number 2, and so forth. +[179.50s -> 191.42s] The KNN algorithm makes use of data with known class or group when it makes predictions. In this example, we have 12 patients with CRP and PCT data. +[191.42s -> 205.42s] And we also know if they had a bacterial or viral infection. For example, let's say that we have a new patient that enters the hospital with a CRP concentration of 40 and PCT concentration of 41. +[205.42s -> 219.02s] KNN then determines the class of the new observation based on the majority class of the k closest neighbors. For example, if k is set to 5, the 5 closest neighbors will be evaluated. +[219.02s -> 231.07s] In this example, the five closest neighbors are patients which are known to have a viral infection, since the majority of the five closest neighbors is a class virus. +[231.07s -> 236.50s] The patient with an unknown infection will be classified as having a viral infection. +[236.91s -> 249.34s] Now, suppose that the patient instead has a PCT concentration of 60 and a CRP concentration of 42, since three out of the five closest neighbors are of class bacteria. +[249.34s -> 260.02s] whereas only two are of class Virus. The patient will be predicted to have a bacterial infection because the majority of the neighbors are of class Bacteria. +[261.36s -> 272.16s] The KNN follows four simple steps. In step one, we determine the distance between the new observation and all the data points in the training dataset. +[272.16s -> 284.70s] The Euclidean distance is by far the most common distance metric that is used. In step 2, we sort the distances. And in step 3, we identify the k closest neighbors. +[284.70s -> 292.05s] And in the final step, we determine the class of the new observation based on the group majority of the k nearest neighbors. +[292.50s -> 305.01s] Let's follow these steps on our example data where we like to predict the class of a new observation with a PCT concentration of 60 and a CRP concentration of 42. In this example, +[305.01s -> 316.40s] We set the value of k to 5, which means that we check the class of the five closest neighbors. We begin by calculating the Euclidean distance to all the data points. +[317.17s -> 331.14s] Let's calculate the distance between the new observation and patient number 1. In two dimensions, the Cladian distance can be calculated by the following formula. We plug in the x and y coordinates of the new data point. +[331.14s -> 338.77s] And for data point number 1. We see that the Euclidean distance between these two data points is 24.1. +[339.09s -> 348.37s] We fill in the distance in the table. The Euclidean distance between the new observation and data point number 2 is 32.3. +[348.69s -> 359.76s] Note that the Euclidean distance in two dimensions can be seen as applying the Pythagoras theorem to a right triangle. We know that the length of this side is 60 minus 30. +[360.14s -> 370.00s] whereas the length of this side is 42 minus 30. The length of this side can therefore be calculated to about 32.3. +[370.93s -> 380.46s] Once we have calculated the clearing distances between the new observation and all the data points, we'll sort this table based on the distances. +[380.82s -> 393.78s] After we have sorted the patients based on the distances to the new observation, we see that three out of the five closest neighbors are of class Bacteria, whereas two are of class Virus. +[393.78s -> 406.22s] Since the majority of the K nearest neighbors are of class Bacteria, we classify the new observation as Bacteria. This means that we predict that the patient has a bacterial infection. +[408.34s -> 411.73s] So, how good is this classifier? +[413.20s -> 423.79s] One way to evaluate how well KNN predicts the class of new cases is to use the leave-on-out cross-validation method on existing data with known class. +[424.56s -> 438.35s] If we leave out the first patient from retaining data, or we pretend that we do not know that this patient has a viral infection, we can let KNN predict this for us, and then see if the prediction is correct or not. +[438.67s -> 451.22s] Since the five closest neighbors around data point number one are of class Virus, the predicted class of this observation is Virus. Since we know that this person had a viral infection, +[451.22s -> 465.30s] We know that the predicted class is correct. Similarly, the second patient is also correctly predicted to have a viral infection because all the five closest neighbors around this point are of class Virus. +[465.30s -> 478.80s] However, when we predict the class of the fourth person, which we know had a viral infection, Kinane predicts that the person has a bacterial infection because three of their five closest neighbors are of class Bacteria. +[479.22s -> 486.83s] Since we know that person number 4 had a viral infection, we know that KNN has made the wrong prediction in this case. +[487.34s -> 499.31s] Based on the Lee-Barnard cross-validation method, we see that we make 10 correct predictions out of 12 possible. This gives us an accuracy of about 83%. +[499.66s -> 512.98s] If we have a very big dataset, the leave-on-out cross-validation may take a long time to run. If we have plenty of data, we can instead use the holdout method, where we split the data into a large training dataset. +[512.98s -> 522.99s] and a smaller test dataset. We then put the training data like this and predict the class of the test data based on the KNN. +[527.34s -> 539.97s] We'll now discuss the problems of an imbalanced dataset. When the groups are of equal size, k and n is unbiased. For example, if k is set to 5, +[539.97s -> 553.30s] We would predict the unknown observation as having a viral infection since 3 out of the 5 closest neighbors are a class virus. However, if the bacteria group includes more data points than the virus group, +[553.30s -> 564.90s] The classifier will favor the bacteria group because of its high density of data points in space. There are many types of methods to deal with an imbalanced dataset. For example, +[564.90s -> 573.33s] One can put more weight on a group with fewer data points when calculating the distances between the unknown observation and the data points. +[574.35s -> 586.70s] We'll now discuss how we can find an optimal value for K. Let's say that we have an additional data point up here, which means that the bacteria group now includes seven observations +[586.70s -> 598.67s] whereas the virus group includes only 6. If we then would set K to 13, and predict the class of the new observation, the class will always be predicted as bacteria, +[598.67s -> 610.05s] Since we have in total 13 data points, the majority class will always be of type bacteria. A high value of K is especially a problem with imbalanced datasets. +[610.05s -> 623.44s] where one group includes more observations than the other group. If we like to predict a class based on two groups, it is recommended that k is an odd number since we then avoid possible ties. +[623.76s -> 637.98s] For example, if we would set K to 4, this means that we should check the four closest neighbors. In this example, two out of the four closest neighbors will be of class Bacteria, and two of class Virus. +[637.98s -> 643.47s] In this case there is no majority that can determine the class of the new observation. +[644.11s -> 656.72s] We therefore need an additional rule in such case, that for example is based on a random process, would that be changed the value of k if this happens. Also, if the value of k is set to 1, +[656.72s -> 667.18s] The classification will be very sensitive to extreme values. For example, the following data point is very far away from the other data points of class Virus. +[667.18s -> 675.57s] If the new observation that we like to classify happens to be close to such an outlier, it will be predicted as the same class as the outlier. +[675.86s -> 683.92s] If we increase K from for example 1 to 9, we see that 8 other than 9 closest neighbors are class bacteria. +[684.85s -> 696.91s] So, in conclusion, the value of k should therefore not be too small or too large. A rule of thumb is to set k equal to the square root of the total sample size. +[697.42s -> 709.18s] We can also train the KNN to find an optimal value of k and at the same time perform validation of the mal. To do this, we could for example use the holdout method +[709.18s -> 719.92s] We split the data into the training dataset and the test dataset. Let's say that our previous example data represents our training dataset in this case. +[720.24s -> 732.21s] Based on the Lee-Warnhard cross-validation method, we know that the accuracy, or the proportion of correct predictions, is equal to about 83% when you set k to 5 for this dataset. +[733.14s -> 746.83s] If we set K to 3 and compute the KNN, we see that we have increased the accuracy to about 92%. The only case that is incorrectly classified, if we set K to 3, is patient number 10. +[746.83s -> 753.04s] where two out of his closest neighbours are of class Virus and only one of class Bacteria. +[753.33s -> 764.16s] If we try four different odd numbers for k, we can select the value of k that results in the best performance. Based on the Leibano cross-validation method, +[764.16s -> 777.46s] We could for example select that the value of k should be equal to 7. Note that we here have used only a small dataset, which may cause big variations due to chance. If we have more data, +[777.46s -> 789.30s] We could make a plot like this one, where the accuracy of the k and n is plotted against different values of k. In this example, an optimal value of k seems to be around 23. +[789.65s -> 798.61s] Once we have determined the value of k based on our training data, we can now validate our k-in-n algorithm by classifying our test data. +[799.12s -> 811.31s] We then test if the KNN correctly predicts this observation as bacteria based on the seven nearest neighbors. Then we take the next data point and so forth. +[811.57s -> 820.46s] Once we have classified all the data points in the test data, we can calculate metrics such as accuracy, specificity and sensitivity. +[822.22s -> 830.22s] We'll now have a look at how we can use KNN with more than two groups, and why it is important to sometimes standardize the data. +[830.74s -> 838.77s] We have previously used KNN to classify bacterial and viral infections. If you also have data on parasitic infections, +[839.12s -> 851.50s] as well as on other clinical variables, such as the body temperature. Then we can use KNN to predict if someone has a viral, bacterial or parasitic infection based on three clinical variables. +[852.14s -> 862.11s] Note that it might be a good idea to standardize the data when we like to include information for variables that have a large difference in variance. For example... +[862.11s -> 874.80s] The body temperature only spans between 36.8 and 41.1, which means that the distance in this dimension will have a very small impact compared to other variables during the classification. +[875.73s -> 886.64s] To give the variables equal weights in the classification process, we can first standardize the data so that all variables have a mean of 0 and a standard deviation of 1. +[887.34s -> 898.14s] The advantage with KNN compared to other classification methods is that it is a very simple method and easy to understand. It is based on local data points. +[898.14s -> 911.50s] which might be beneficial for datasets involving many groups with local clusters. We'll now have a look at some of the disadvantages with KNN. All training data is used every time we should predict. +[911.63s -> 924.18s] This means that the data must be stored everywhere where you like to use the classifier. For very large datasets, the classification might be computationally expensive for prediction. +[924.69s -> 936.59s] And another disadvantage is that KNN is sensitive to imbalanced datasets. This was the end of this lecture about using KNN as a classifier. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/test_Computer_Science_351.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_351.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c52d95360879a705bf04ae3dc26a848d84f8678a --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Computer_Science_351.mp4.txt @@ -0,0 +1,49 @@ +[0.00s -> 12.43s] Hello everyone, my name is Srihar Joshi and in this video I'm going to explain to you about 2-3-3s, the process of execution of different operations and the complexity analysis of those operations in the 2-3-3s. +[14.03s -> 28.29s] So what is a 2-3 tree? A 2-3 tree or 2-3 search tree is a multi-way search tree that was invented in 1970 by John Hopper. It's the simplest example of B-tree. So what is B-tree again? It is a self- +[28.29s -> 40.85s] balancing tree data structure that maintains the sorted data in its nodes which can have more than two children unlike in binary search trees that can have a maximum of two children per node to be more specific two three trees are +[40.85s -> 54.34s] trees of b trees of order three which means that at most they can have three children in a single node and one prominent characteristic of two three trees is that all the leaf nodes regardless of the numbers of leaf nodes they must be at the same level +[54.34s -> 57.36s] which means that the height is always balanced in a 2D tree. +[58.70s -> 72.05s] Since 2-3 trees themselves are a specific instance of a B-tree, they do not have any variations. However, the nodes they contain can vary. The nodes can be either a 2-node or a 3-node. 2 nodes contain exactly one value and +[72.11s -> 78.26s] The values in the left subtree are less than the value in the node and the values in the right subtree are greater than the values in the node. +[78.54s -> 92.16s] for the three node they contain of two values and three children so the values in the left subtree are less than the first value of the node which in turn is less than the value of subtree in the middle the values in them +[92.16s -> 98.48s] Middle subtrees are less than the second value in the node which in turn is less than the value in the third and the rightmost subtrees. +[100.53s -> 113.62s] So why do we need 2-3 trees? As you can see in figure 8, it's a binary search tree and it has an imbalanced height. In its worst case, the binary search trees can have linear height and making the +[113.62s -> 127.60s] binary search effectively impossible. But for the same values inserted, the 2-3 trees can have balanced height as the height of the tree grows upwards. Hence, it is more easier to balance the height in the 2-3 trees. And the second point is that +[127.73s -> 139.12s] when since a two three tree has two values can have two values in a single node and can have three children both direct and indirect accessing is made easier in two three trees +[139.12s -> 149.78s] So this nature of the 2-3-3 to store data in a more compact manner makes it useful in file systems and databases where these seeks are considered expensive and should be minimized as far as possible. +[150.32s -> 163.49s] now let's discuss the common operations in a 2-3-3 first we'll begin with search the method by which we will search is recursion and it goes as follows so if we have to search a value then we compare the value with the values in the node +[163.49s -> 177.78s] if it's less if it's less if it's less than the left value in the node then we'll move to the left subtree if it's if its value is between the values in the node we'll move to the middle subtree and if its value is greater than the right most value the second value in the node +[177.78s -> 188.08s] then we'll move to the right subtree and as we move down as we proceed to the bottom we have three base cases and out of this if the tree is empty then we couldn't find the keys and +[188.53s -> 203.04s] If the current node is the key that we are searching for, then perfect, we found the key. And if the current node doesn't have the value or is some other value, then we conclude that we don't have any values that we are searching for in the 2, 3. +[203.04s -> 217.28s] search let's move on to the process of insertion our insertion can have three cases and the first case is when we want to insert in a node with only one data element so for instance if we if we want to insert four in the +[217.28s -> 231.54s] two three three that we have given on the left hand side so we compare the value with the parent so since four is less than five we move on to the left subtree and since four is less four is greater than two we put it just on the right hand right side of the two on the on the same node +[231.54s -> 235.63s] So in this way, the value was inserted. +[236.66s -> 250.19s] now the second case for insertion is when we want to insert in a node with two data elements whose parents contain only one data element so for instance in the left tree that we have shown here we want to insert 10 so since 10 we compare with the root node +[250.19s -> 263.31s] is greater than 5 so we move to the right subtree and we again compare this value with the existing values in the right subtree so 10 is greater than 6 10 to 10 is greater than 9. so we put we create a temporary node +[263.38s -> 277.65s] in the right subtree but our insertion doesn't end right here what we do is move the middle element in the parent node and we split split the node so here we moved 9 to the parent node and we split the node +[277.65s -> 282.10s] and now 6 and 10 are two different individual nodes in the middle and right subframe. +[282.74s -> 295.79s] So the last case for insertion is when we want to insert in a node with two data elements whose parents also contain two data elements So for instance if we if we want to insert one in the left tree that we have shown so +[295.86s -> 310.14s] Since 1 is less than 5 we move to the left subtree and since 1 is less than 2 and 1 is less than 4 We add we create a temporary node And once we create the temporary node what we do is we split the node we first +[310.14s -> 320.98s] move the middle middle value in the root in the parent node and we split the node for so here we move two to the parent node and we split in the node so now one and four are individual nodes +[321.74s -> 336.08s] And finally, we follow the same process with the parent node, which is we move the middle value to the parent node and we split the node. So here, we moved 5 to the parent node and we split the node so that 2 and 9 are two distinct nodes. +[336.08s -> 346.22s] So in this way the tree's height grows upwards and this is the reason why it's easier to balance height in 2-3 search trees. +[347.76s -> 361.79s] So now let's move on to deletion into three trees. Similar to insertion, there are three cases in which deletion might occur into three trees. So the first case is when we simply delete the value. So if you want to delete 9 in the left tree that we have given, +[361.79s -> 374.22s] we proceed and search and we search and proceed to the nine and simply delete it so for instance here nine is greater than five so we move it must be in the right tree we move to the right and since nine is greater than six so it must be in the uh +[374.22s -> 380.18s] the second second value so we just simply delete there is no change in the tree the structure of the regime +[380.98s -> 394.02s] Our second case of deletion occurs when we want to delete and merge. So for instance, the left tree that we have given, if you want to delete 80, so we first search. Since 80 is greater than 70, it must be the right subtree. So we found it. And then... +[394.02s -> 406.54s] we simply remove 80 but now the step doesn't end here since the nodes containing 80 will be vacant what we do is we merge the node containing 80 and 60 together and we +[406.54s -> 414.10s] pull the value on the parent to the bottom so here the 70 was moved to the bottom as a as a right child now +[414.93s -> 429.33s] Our third and the final case for deletion is when we have to do borrowing. So for instance, the left tree that we have given, we want to delete 60. So search 60. 60 is between 50 and 70. So it must be in the middle sub-tree. So we found the value. +[429.33s -> 442.26s] we delete it since the nodes containing 60 will be vacant now what we do is we borrow values from h7 either left or right so in this instance we are borrowing values from right but we do not borrow values +[442.26s -> 453.18s] directly what we do is we pull the values from the parent down and we uh take out the values on the right or left tree whichever we have borrowed from and we put it as a parent +[453.18s -> 458.83s] so as you can see here 70 was pulled at the bottom in the place of 60 and 80 was moved up +[460.37s -> 474.72s] Now let's discuss the complexity analysis of a 2-3-3. The space complexity is linear which means that for n nodes we need n amount of space. And now let's talk about the time complexity since the height of the tree is always balanced. +[474.72s -> 487.12s] and the complexity of different operations on a tree is directly related to its height a two three tree is highly efficient so since height is in the order of log of logarithmic of n which where n is the number of nodes so all the operations like access and +[487.12s -> 494.74s] searching insertion and deletion all these are both in the worst in average case look at look at the mug of n +[497.04s -> 509.30s] Now let's discuss how we can implement 233 on different programming languages like C++, Python, and Java. So since C++ doesn't have a standard library to implement a 233, +[509.30s -> 522.00s] Some of the functionalities and benefits of using the 2-3-3s can be achieved by using maps from STL containers, which are implemented using RedBuck trees. And we also have libraries like AdOps Forest and CodeTree to create the 2-3-3 in C++. +[522.00s -> 525.71s] similarly in python we don't have any standard libraries but we have +[526.42s -> 539.50s] But these can be implemented using classes and list dictionaries, but the process itself might turn complex and time-consuming. Hence, we have libraries like AnyTree, TreeLib, and NetVortex. +[539.50s -> 552.14s] And last but not the least, for the Java, it's the same as C++ and Python. The standard library doesn't have any implementation for the two or three trees, but tree maps from the standard library can be used. +[552.14s -> 562.45s] to perform certain functionalities as they are based on the red black tree and we also have the aggregates and packages like b3 and java swing tree to implement to future +[563.79s -> 571.22s] Lastly, I'd like to end this video. I hope you enjoyed and had a deep understanding of 2-3 trees. Thank you. diff --git a/VideoMMMU_ASR_large/Engineering/test_Electronics_114.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Electronics_114.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..4fdc5e8c54673d00290915e3a8364b3dcbfba4c4 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Electronics_114.mp4.txt @@ -0,0 +1,101 @@ +[0.69s -> 7.50s] Hello student, I am Mahiru Gondalia and you are watching School of Physics. +[18.80s -> 31.60s] Student, today we will learn about Fourier series of a half wave rectifier signal. Fourier series of a half wave rectifier signal. +[32.53s -> 37.07s] A half wave rectifier signal is represented like this. +[37.97s -> 52.00s] Here, negative cycles of the signal are removed. So, it is defined as f of omega t equal to I m sine omega t for 0 less than omega t less than pi. +[52.00s -> 58.77s] and f of omega t equal to 0 for minus pi less than omega t less than 0. +[59.15s -> 69.26s] From the nature of the function, as in figure or expression of the function, it is clear that it is neither even nor odd. +[69.52s -> 75.22s] If you can't decide about it then follow this procedure. +[75.54s -> 89.90s] For first part of the function, f of omega t equal to I am sine omega t for 0 less than omega t less than pi, say equation 1, take omega t equal to minus omega t. +[89.94s -> 100.72s] Therefore, F of minus omega t equal to I m sin of minus omega t for 0 less than minus omega t less than pi. +[101.17s -> 112.88s] This sin minus omega t equal to minus sin omega t. Therefore, we will write f of minus omega t equal to minus im sin omega t for +[112.88s -> 125.95s] 0 greater than omega t greater than minus pi. Now in this interval we want to change inequality sign less than into greater than. +[125.95s -> 139.57s] So we must have to replace minus omega t by omega t and pi by minus pi. Now in next step we will write this interval in inverse order. +[139.57s -> 149.71s] f of minus omega t equal to minus im sine omega t for minus pi less than omega t less than zero. Say equation 2. +[150.61s -> 160.40s] Now for second part of the function that is f of omega t equal to 0 for minus pi less than omega t less than 0. Say equation 3. +[161.10s -> 172.14s] Take omega t equal to minus omega t and therefore f of minus omega t equal to 0 for minus pi less than minus omega t less than 0. +[172.56s -> 186.72s] Now in this interval we will change the sign of inequality and simultaneously sign of minus pi and minus omega. And therefore f of minus omega t equal to 0. +[186.72s -> 190.90s] For pi greater than omega t greater than 0. +[191.76s -> 204.50s] Now writing the interval in inverse order, we have f of minus omega t equal to 0 for 0 less than omega t less than pi, say equation 4. +[205.68s -> 219.46s] Now from equation 1 and 4 we found that in interval 0 to pi f of omega t is not equal to f of minus omega t and f of omega t is not equal to minus. +[219.46s -> 233.50s] f of minus omega t. Similarly, from equation 2 and 3, we found that in interval minus pi to 0, f of omega t is not equal to f of minus omega t. +[233.50s -> 245.65s] And f of omega t is not equal to minus f of minus omega t. It means f of omega t is neither even nor odd. +[246.13s -> 259.76s] Therefore, we have to calculate all the three coefficients a0, an and bn. For a0, the formula is a0 equal to 1 upon pi integral minus pi to pi. +[259.76s -> 262.32s] f of omega t, d omega t. +[263.25s -> 276.98s] Our function f omega t is divided into two parts. So we write a0 equal to 1 upon pi integral minus pi to 0 f of omega t d of omega t plus +[276.98s -> 282.67s] 1 upon pi integral 0 to pi f of omega t d of omega t. +[283.18s -> 296.05s] In interval minus pi to 0, the value of function f of omega t is 0 and in interval 0 to pi, the value of f of omega t equal to I m sine omega t. +[296.24s -> 310.29s] Putting these values, we get a0 equal to 1 upon pi integral minus pi to 0, 0 into d omega t, plus 1 upon pi integral 0 to pi, I m sine omega t. +[310.29s -> 325.28s] d omega t due to this zero this term becomes zero in this term we take i m outside the integral therefore a 0 equal to i m upon pi +[325.28s -> 329.78s] Integral 0 to pi sine omega t d omega t. +[330.06s -> 344.18s] Now integral sin omega t is minus cos omega t and therefore a0 equal to im upon pi into bracket minus cos omega t limit 0 to pi. +[345.42s -> 356.43s] Putting the value of limits as 0 equal to im upon pi into bracket minus cos pi minus minus cos 0. +[356.78s -> 370.93s] Here cos pi equal to minus 1 and cos 0 equal to 1. Therefore a0 equal to im upon pi into bracket minus minus 1 minus minus plus 1. +[371.54s -> 384.34s] Therefore, a0 equal to 2im upon pi, say equation 5. This is the value of Fourier coefficients a0. Now, an. +[385.58s -> 393.01s] a n equal to 1 upon pi integral minus pi to pi f of omega t cos n omega t d omega t. +[393.36s -> 407.34s] Our function f of omega t is divided into two parts. So we will write it a n equal to 1 upon pi integral minus pi to 0 f of omega t cos n omega t d omega t plus. +[407.34s -> 413.90s] 1 upon pi integral 0 to pi, f omega t, cos n omega t, d omega t. +[414.77s -> 429.18s] In this interval, f of omega t equal to 0. And in this interval, f of omega t equal to I m sine omega t. Therefore, equation becomes a0 equal to 1 upon pi. +[429.18s -> 442.26s] integral minus pi to 0, 0 cos n omega t d omega t, plus 1 upon pi integral 0 to pi, I m sin omega t cos n omega t d omega t. +[443.22s -> 456.59s] This term becomes 0 and this im take outside the integration and multiply and divide this term by 2 so we get a0 equal to im upon 2 pi. +[456.59s -> 463.47s] integral 0 to pi 2 sin omega t cos n omega t d omega t. +[464.05s -> 477.94s] Now by applying trigonometric relation that is 2 sin a cos b equal to sin of a plus b plus sin of a minus b. In our formula a equal to omega t and b equal to +[477.94s -> 491.81s] n omega t therefore a 0 equal to i m upon 2 pi integral 0 to pi and now we put the value of 2 sine omega t cos n omega t from this +[491.81s -> 505.30s] Relation and so it is sin1 plus n omega t plus sin1 minus n omega t into d omega t. Now integration of this term. +[505.78s -> 518.38s] which is minus cos of 1 plus n omega t upon 1 plus n and integration of this term is minus cos of 1 minus n omega t upon 1 minus n. +[519.09s -> 532.37s] Now substituting the value of limit we get a0 equal to im upon 2 pi into bracket minus cos of 1 plus n into pi plus cos 0. +[532.37s -> 544.59s] upon 1 plus n plus minus cos 1 minus n into pi plus cos 0 upon 1 minus n. Here cos 0 equal to 1. +[544.59s -> 558.56s] In expanding the brackets, we have an equal to im upon 2 pi n to bracket minus cos of pi plus n pi plus 1 upon 1 plus n plus +[558.56s -> 564.08s] minus cos of pi minus n pi plus 1 upon 1 minus n. +[564.50s -> 578.38s] Since cos of pi plus n pi equal to minus cos n pi and cos of pi minus n pi equal to also minus cos n pi. Therefore we write a n equal to. +[578.38s -> 592.59s] I m upon 2 pi into bracket cos n pi plus 1 upon 1 plus n plus cos n pi plus 1 upon 1 minus n. Simplifying it, we get a n equal to I m upon 2 pi +[592.59s -> 601.20s] into this. This numerator part is obtained by multiplying this with this and this term by this one. +[601.94s -> 608.05s] Now here this term and this term are cancelled with each other. +[608.75s -> 622.70s] And this minus n is cancelled with this plus n. And therefore a n equal to i m upon 2 pi. And now the remaining terms that is 2 cos n pi plus 2. +[622.70s -> 634.90s] upon 1 minus n square. Taking 2 out of bracket and cancel it with this 2. Therefore, a n equal to i m upon pi +[634.90s -> 639.79s] into bracket cos n pi plus 1 upon 1 minus n squared. +[640.08s -> 653.18s] And this is equal to 2im upon pi into 1 minus n square. Because if we take n equal to even then +[653.18s -> 664.40s] cos n pi equal to 1 and therefore cos n pi plus 1 equal to 1 plus 1 that is 2 and therefore these terms becomes +[664.40s -> 670.29s] 2im upon pi into 1 minus n squared for ne1. +[671.38s -> 685.20s] And when n equal to odd, then cos of n pi equal to minus 1. Therefore cos of n pi plus 1 equal to minus 1 plus 1 equal to 0. And therefore entire term. +[685.20s -> 698.96s] is 0 and therefore we write this a n equal to 0 for n odd say equation 6. This is the value of coefficient a n. +[699.70s -> 708.69s] Now bn. bn equal to 1 upon pi integral minus y to pi f of omega t sin n omega t d omega t. +[709.01s -> 722.06s] We will write into two parts as bn equal to 1 upon pi integral minus pi to 0 f of omega t sine n omega t d omega t plus 1 upon pi integral 0 to pi. +[722.06s -> 732.02s] f of omega t sin n omega t d omega t. Putting the value of f omega t, we get bn equal to this one. +[732.66s -> 747.23s] This term becomes 0 and this term keeping im outside the integral and multiplying and dividing it by minus 2. We write bn equal to minus im upon 2 pi. +[747.23s -> 754.10s] integral 0 to pi, minus 2 sin omega t, sin n omega t, d omega t. +[754.77s -> 764.69s] Now using trigonometric relation that is minus 2 sin A sin B equal to cos of A plus B minus cos of A minus B. +[765.01s -> 778.75s] In our formula, a equal to omega t and b equal to n omega t. Therefore, we get bn equal to minus im upon 2 pi integral 0 to pi into bracket. +[778.75s -> 786.58s] cos of 1 plus n omega t minus cos of 1 minus n omega t into d omega t. +[787.50s -> 794.42s] Now by integrating we get bn equal to minus im upon 2 pi into this. +[795.25s -> 810.05s] Here, integration of cos of 1 plus n omega t be this one and integration of cos of 1 minus n into omega t is this one with limit 0 to pi. +[810.05s -> 820.46s] Now putting the limits bn equal to minus im upon 2 pi into bracket sin of 1 plus n pi minus sin 0 upon 1 plus n. +[820.46s -> 834.80s] minus sin of 1 minus n pi minus sin 0 upon 1 minus n. Since sin 0 equal to 0 and therefore bn equal to minus im upon 2 pi into this one. +[835.25s -> 844.77s] Here sin pi plus n pi equal to minus sin n pi and sin pi minus n pi equal to sin n pi. +[844.77s -> 853.58s] bn equal to minus im upon 2 pi into bracket minus sin n pi upon 1 plus n minus sin n pi upon 1 minus n. +[854.16s -> 866.61s] Simplifying it, we get bn equal to minus im upon 2 pi into bracket this. This part of the equation is multiplication of this term and this term. +[866.93s -> 871.79s] minus multiplication of this term and this term. +[872.72s -> 887.02s] In which these two terms are cancelled and therefore bn equal to minus im upon 2 pi into bracket minus 2 sin n pi upon 1 minus n square. +[887.18s -> 898.21s] By removing the negative sign and cancelled the two in numerator and denominator. Therefore bn equal to im upon pi. +[898.21s -> 911.47s] into bracket sin n pi upon 1 minus n square. Now in this equation if n equal to 1 then denominator 1 minus n square becomes 0. +[911.89s -> 916.75s] And bn tends to infinity, which is not acceptable. +[917.07s -> 930.37s] Therefore except n equal to 1 that is n equal to 2, 3, 4 etc. sin n pi equal to 0 and therefore bn equal to 0. Therefore we write. +[930.37s -> 940.85s] bn equal to 0 for n is not equal to 1. For n equal to 1 we will calculate bn that is bn equal to b1 separately. +[941.81s -> 955.12s] The equation for Bn is Bn equal to 1 upon pi integral 0 to pi Im sin omega t sin n omega t d omega t. For n equal to 1 we write B1 equal to +[955.12s -> 966.82s] 1 upon pi integral 0 to pi. I am sin omega t, sin omega t, d omega t. Now take I am in front of the integral. Therefore b1 equal to. +[966.82s -> 978.51s] I m upon pi integral 0 to pi and here sin square omega t d omega t. Using trigonometric relation sin square omega t equal to +[978.51s -> 992.50s] 1 minus cos 2 omega t upon 2. Therefore, b1 equal to im upon 2 pi integral 0 to pi into 1 minus cos 2 omega t into d omega t. +[992.69s -> 1006.70s] Separating two parts, we have b1 equal to im upon 2 pi integral 0 to pi d omega t minus im upon 2 pi integral 0 to pi cos 2 omega t d omega t. +[1006.74s -> 1018.51s] By integrating we get integration of d omega t that is omega t and integration of cos 2 omega t that is sin 2 omega t upon 2. +[1018.51s -> 1029.07s] By putting the limit, we get b1 equal to im upon 2 pi into pi minus 0 minus im upon 2 pi into bracket sin 2 pi minus sin 0 upon 2. +[1029.78s -> 1038.51s] Here, sin 2 pi equal to 0 and sin 0 is also equal to 0. Therefore, entire term is 0. +[1039.25s -> 1049.04s] And therefore b1 equal to this first term that is im upon 2 say equation 7. +[1049.84s -> 1058.86s] Now Fourier series is f of omega t equal to a0 by 2 plus summation a n cos n omega t plus summation b n sin n omega t. +[1059.28s -> 1071.12s] Substituting the values of coefficient a0, an and bn from equation 5, 6 and 7, we get f of omega t equal to this one. +[1072.05s -> 1079.95s] Here a n is available for even value of n. Therefore we write here n equal to even. +[1080.82s -> 1089.55s] And all the b's are 0 except b1. Therefore we put here b1 equal to im upon 2. +[1090.03s -> 1102.80s] Now simplifying and rearranging the terms, we get f of omega t equal to i m upon pi plus 2 i m upon pi summation n equal to even. +[1102.80s -> 1117.10s] cos of n omega t upon 1 minus n square plus i m upon 2 sin omega t. In expanded form, f of omega t equal to i m upon pi plus 2 i m upon pi into bracket. +[1117.10s -> 1130.64s] Cos 2 omega t upon 1 minus 2 square plus cos 4 omega t upon 1 minus 4 square plus cos 6 omega t upon 1 minus 6 square plus so on. Plus I m upon 2 into sin omega t. +[1131.18s -> 1136.14s] This is the Fourier series of given half wave rectified signal. +[1138.13s -> 1151.26s] In next video, we will learn about Fourier series of a triangular wave function. Write your suggestion in comment box. Please like and share this video and subscribe my youtube channel. +[1151.26s -> 1154.67s] school of physics. Thanks. diff --git a/VideoMMMU_ASR_large/Engineering/test_Electronics_116.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Electronics_116.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1efcd1f6655fc5dfee833be82a1692cb53c4da85 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Electronics_116.mp4.txt @@ -0,0 +1,49 @@ +[0.59s -> 11.66s] In this video we're going to focus on the concept of impedance. What is impedance? Before we can answer that question, let's talk about resistance. +[12.56s -> 21.55s] So what does a resistor do in a circuit? A resistor opposes the flow of electrical current. +[24.98s -> 38.10s] Here's a symbol of a resistor and the unit for resistance is ohms. Whenever you increase the resistance of a circuit, the current flowing in that circuit decreases. +[38.26s -> 48.37s] And so resistance provides opposition to the flow of DC current or direct current. It can also oppose the flow of AC current as well. +[50.67s -> 55.28s] Now impedance is very similar to resistance +[58.93s -> 70.80s] Impedance is represented by the letter Z, and like resistance, the unit is ohms. But impedance represents the opposition to the flow of electrical current in +[70.80s -> 85.20s] AC circuits as opposed to DC circuits. Now the elements that impede the flow of AC current include the resistor, inductors and capacitors. +[86.77s -> 95.12s] The opposition that a capacitor provides to the flow of AC current is known as capacitive reactance. +[95.50s -> 108.98s] The opposition of an inductor towards AC current is known as inductive reactants. Both capacitive reactants and inductive reactants are measured in the same unit as resistance. +[108.98s -> 110.61s] That is in ohms. +[111.50s -> 126.19s] The formula for impedance is as follows. It's equal to the square root of R squared plus the difference, the square difference, of the inductive reactants and the capacitive reactants. +[127.02s -> 139.73s] The inductive reactance is 2 pi times the frequency times the inductance. The capacitive reactance is 1 over 2 pi fc. +[140.43s -> 144.46s] So what you need to know is that as the frequency increases +[145.26s -> 159.82s] the inductive reactance increases while the capacitive reactance decreases. And as the frequency decreases, the reverse is true. So at high frequencies, +[160.43s -> 172.05s] inductors offer a very high impedance and capacitors offer a very low impedance at low frequencies +[172.69s -> 179.82s] inductors offer or provide low impedance to the flow of AC circuit whereas capacitors +[180.11s -> 194.58s] they oppose high, I mean low frequency signals. So capacitors have high impedance towards low frequency signals and inductors have low impedance towards them. Now there is a middle ground. +[195.02s -> 208.96s] And this middle ground is known as the resonant frequency. At the resonant frequency, the inductive reactance is equal to the capacitive reactance. So that's the only impedance provided by the circuit is the resistance. +[208.96s -> 213.36s] of the circuit. Now let's work on some example problems. +[213.87s -> 228.62s] So let's say we have an AC signal as the power source of this circuit and it's connected to a resistor and a capacitor Now let's say +[229.17s -> 244.02s] The capacitance is 5 microfarads and the resistance is 400 ohms. And we have a 60 hertz, 120 volt AC signal. Calculate the current flowing in this circuit. +[244.46s -> 254.67s] Feel free to pause the video if you want to. To calculate the current, we need to take the RMS voltage and divide it by the impedance of the circuit. +[255.15s -> 266.77s] So we have the RMS voltage. It's 120 volts. What we need to calculate is the impedance. And so we could use this formula to do so. +[268.94s -> 280.34s] Now, there are no inductors in a circuit, so XL is 0. But we need to calculate XC, the capacitive reactants. It's 1 over 2 pi times FC. +[283.06s -> 293.04s] The frequency is 60 Hertz and the capacitance is 5 microfarads which is 5 times 10 to the minus 6 farads. +[301.30s -> 312.66s] So the capacitive reactance is 530.5 ohms. So now that we have that, we can calculate the impedance of the circuit. +[313.30s -> 322.22s] So it's going to be the square root of 100 squared plus 0 minus 530.5 squared. +[330.00s -> 337.01s] So the impedance of the circuit is going to be 539.8 ohms. +[338.03s -> 352.59s] So most of the impedance of the circuit is due to the capacitor of the circuit. As we can see at low frequencies, the capacitor has a high reactance towards low frequency signals. +[353.71s -> 367.82s] Now that we know the impedance, we can now calculate the current in the circuit. So it's going to be the RMS voltage of 120 volts divided by the impedance. And so that's going to be... +[371.25s -> 386.16s] 0.222 amps, which is 222 milliamps. So that's the current that's flowing in this circuit. Now for the sake of practice, let's work on another example. +[389.14s -> 402.67s] So this time, we're going to have three elements. A resistor, a capacitor, and we're going to introduce the inductor to it. So we have an RLC circuit. +[405.01s -> 416.88s] So the resistance is going to be 100 ohms. The capacitance, 20 microfarads. And the inductance, 200 millihenries. +[417.33s -> 429.20s] And this is going to be a 120 volt signal at the same frequency of 60 hertz. So go ahead and calculate the current that is flowing in this circuit. +[429.74s -> 443.34s] First, we need to calculate the capacitive reactants, and that's 1 over 2 pi times fc. So it's 1 over 2 pi times the frequency of 60 hertz. +[443.70s -> 449.26s] times 20 microfarads or 20 times 10 to the 6th farads. +[455.70s -> 467.06s] And so that's going to be 132.6 ohms. Next, we need to calculate the inductive reactants. And that's 2 pi FL. +[467.57s -> 475.60s] So 2 pi times 60 times 200 millihenries, or 200 times 10 to the minus 3 henries. +[482.48s -> 491.92s] So then that's going to be 75.4 ohms. Now to calculate the impedance, we could use this formula. +[498.48s -> 512.30s] So it's going to be the square root of r squared, so that's 100 squared, plus xl, which is 75.4, minus xc, which is 132.6. +[512.37s -> 513.65s] squared. +[523.50s -> 532.30s] So you should get 115.2 ohms. So that is the impedance of the circuit. +[532.69s -> 546.67s] Now once you know the impedance, you can calculate the current. The current is going to be the RMS voltage divided by the impedance, and so it's going to be 120 volts divided by 115.2 ohms. +[550.48s -> 559.41s] And that's equal to 1.04 amps. So that is the current that is flowing in this particular circuit. +[559.73s -> 573.17s] Now, let's calculate the frequency at which the inductive reactance equals the capacitive reactance. And as was mentioned before, that frequency is known as the resonant frequency. And it's equal to 1 over 2 pi. +[573.17s -> 575.34s] times the square root of LC. +[577.90s -> 591.57s] So L is going to be 200 millihenries, so that's 200 times 10 to the minus 3, which is 0.2 henries, and then times the capacitance of 20 times 10 to the minus 6. +[607.28s -> 617.58s] So you should get 79.6 Hz. So at that frequency, XL will equal XC. +[618.96s -> 631.67s] So now you know how to determine the resonant frequency of an RLC circuit. You also know how to determine the impedance of the circuit, and also the current that is flowing in the circuit. So that's it for this video. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Engineering/test_Electronics_118.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Electronics_118.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f554b0cd8af80dcfc374f35b57bcc6d8cf193a13 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Electronics_118.mp4.txt @@ -0,0 +1,38 @@ +[1.49s -> 6.61s] L-R circuit Question Find I of T +[6.93s -> 21.30s] In this circuit, we have to find this I . As we can see, this circuit consists of various resistors and one inductor. So, this is a RL circuit. +[23.95s -> 37.81s] First of all, when the switch is closed, that time when t is less than zero. Now when t is less than zero, that time +[38.45s -> 51.79s] the switch will be closed now when the switch is closed when the switch is closed that time this inductor will act as a short circuit +[52.18s -> 55.25s] Now here this will act as a short circuit. +[58.77s -> 68.98s] Now here we can see both the terminals of this 16 ohm are short circuited. So this resistance value will be zero. So we can remove it from here. +[70.42s -> 84.14s] Now, we can easily find the value of this i of t. Now, this time we are considering t is less than 0. So, this will be i of 0. Here we can write it is +[84.78s -> 93.39s] i of 0. Now, +[93.71s -> 105.68s] first of all we have to find the value of this current let's say this current is total current i as we can see this 12 ohm and 4 ohm are connected in parallel so 12 ohm parallel with +[105.71s -> 120.37s] So, this will be 12 multiplied by 4 divided by 12 plus 4. So, this will be 12 into 4 divided by 12 plus 4. +[120.91s -> 131.38s] So, it is 3. Now, this 3 ohm. Again, we will redraw this circuit first. Then, we will find the value of Io. +[131.63s -> 142.70s] Now we can replace these resistors with a single resistor of 3 ohm. So here this will be of 3 ohm now. +[144.62s -> 158.48s] Now we can easily find the value of current I and I is equal to V by R. V is 10 volt and resistance value is 2 plus 3. So 2 plus 3. Now this will be. +[158.74s -> 168.18s] 10 by 5. So 10 by 5 means it is 2 ampere. Now we got the value of current I. We can easily find the value of IO. +[168.66s -> 182.83s] so therefore here we can write IO is equal to by current division rule by current division rule +[183.92s -> 197.20s] now here this IO is equal to this current that is 2 ampere multiplied by opposite branch resistance that is 12 ohm so 12 divided by +[197.68s -> 212.05s] 12 plus 4. 12 plus 4. So this will be. 2 multiplied by. 12 divided by. 12 plus 4. +[212.56s -> 219.18s] So it is 1.5, 1.5A is the value of initial current. +[220.56s -> 233.17s] Now we got the value of I of 0 or I0. Now next is when t is greater than 0. Second condition is when +[234.00s -> 245.87s] T is greater than 0. Now when T is greater than 0, that time, again we will copy this circuit from here. +[249.33s -> 262.10s] Now when T is greater than zero that time this switch will be open. Now when the switch is open this part will be removed from here. +[263.73s -> 275.28s] we can remove this part for simplicity now and this current will be the initial current that is I0 +[275.89s -> 283.70s] This current will be initial current I0 and we know the value of initial current is 1.5 Ampere. +[284.14s -> 298.72s] here we can write 1.5 ampere now as we can see this 12 ohm and 4 ohm are connected in series so its resistance will be 12 plus 4 so 12 ohm plus 4 ohm is equal to +[298.72s -> 313.14s] 60 no home now here we can see this 60 no home we will take this here so this will be like this now +[313.42s -> 326.56s] this 60 ohm and this 60 ohm are connected in parallel and we know that when two resistances of same value are connected in parallel that time it can be replaced by +[326.56s -> 336.18s] one single resistance of half of its value. That means we have to replace this by a single resistor of 8 Ohm. +[337.74s -> 344.14s] Because half of this 16 is 8. So this will be of 8 ohm. +[344.62s -> 359.18s] Now, let's find time constant Tau. So, for this LR circuit, the time constant is Tau is equal to L upon R. +[359.73s -> 369.33s] The value of L is 8 and the value of R is 2. +[370.35s -> 380.72s] That is inductance and the value of resistance is 8. So, it will be tau is equal to 2 by 8. +[381.20s -> 394.96s] So, 2 divided by 8, that means it is 0.25. 0.25, this is the value of tau. Then next, we have to find +[397.87s -> 408.27s] i of t. Now i of t is equal to i of 0 into e to the power minus t by tau. +[408.62s -> 422.03s] Now we have the value of this I of 0 or initial current and it is 1.5 ampere. So this will be 1.5 e to the power minus T by tau. So minus T. +[422.03s -> 426.35s] divided by Tau. So, Tau value is 0.25 +[427.09s -> 438.03s] we can further simplify it and write it like this 1.5 e to the power minus 4t because 1 by 0.24 will be +[438.29s -> 450.86s] 1 divided by 0.25 will be 4. So we can write it like this. So this will be I of t is equal to this value. What we have to find in this question? +[451.92s -> 461.58s] We have to find I of t. So, here this I of t is this value. So, this is the final answer. diff --git a/VideoMMMU_ASR_large/Engineering/test_Electronics_140.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Electronics_140.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1efcd1f6655fc5dfee833be82a1692cb53c4da85 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Electronics_140.mp4.txt @@ -0,0 +1,49 @@ +[0.59s -> 11.66s] In this video we're going to focus on the concept of impedance. What is impedance? Before we can answer that question, let's talk about resistance. +[12.56s -> 21.55s] So what does a resistor do in a circuit? A resistor opposes the flow of electrical current. +[24.98s -> 38.10s] Here's a symbol of a resistor and the unit for resistance is ohms. Whenever you increase the resistance of a circuit, the current flowing in that circuit decreases. +[38.26s -> 48.37s] And so resistance provides opposition to the flow of DC current or direct current. It can also oppose the flow of AC current as well. +[50.67s -> 55.28s] Now impedance is very similar to resistance +[58.93s -> 70.80s] Impedance is represented by the letter Z, and like resistance, the unit is ohms. But impedance represents the opposition to the flow of electrical current in +[70.80s -> 85.20s] AC circuits as opposed to DC circuits. Now the elements that impede the flow of AC current include the resistor, inductors and capacitors. +[86.77s -> 95.12s] The opposition that a capacitor provides to the flow of AC current is known as capacitive reactance. +[95.50s -> 108.98s] The opposition of an inductor towards AC current is known as inductive reactants. Both capacitive reactants and inductive reactants are measured in the same unit as resistance. +[108.98s -> 110.61s] That is in ohms. +[111.50s -> 126.19s] The formula for impedance is as follows. It's equal to the square root of R squared plus the difference, the square difference, of the inductive reactants and the capacitive reactants. +[127.02s -> 139.73s] The inductive reactance is 2 pi times the frequency times the inductance. The capacitive reactance is 1 over 2 pi fc. +[140.43s -> 144.46s] So what you need to know is that as the frequency increases +[145.26s -> 159.82s] the inductive reactance increases while the capacitive reactance decreases. And as the frequency decreases, the reverse is true. So at high frequencies, +[160.43s -> 172.05s] inductors offer a very high impedance and capacitors offer a very low impedance at low frequencies +[172.69s -> 179.82s] inductors offer or provide low impedance to the flow of AC circuit whereas capacitors +[180.11s -> 194.58s] they oppose high, I mean low frequency signals. So capacitors have high impedance towards low frequency signals and inductors have low impedance towards them. Now there is a middle ground. +[195.02s -> 208.96s] And this middle ground is known as the resonant frequency. At the resonant frequency, the inductive reactance is equal to the capacitive reactance. So that's the only impedance provided by the circuit is the resistance. +[208.96s -> 213.36s] of the circuit. Now let's work on some example problems. +[213.87s -> 228.62s] So let's say we have an AC signal as the power source of this circuit and it's connected to a resistor and a capacitor Now let's say +[229.17s -> 244.02s] The capacitance is 5 microfarads and the resistance is 400 ohms. And we have a 60 hertz, 120 volt AC signal. Calculate the current flowing in this circuit. +[244.46s -> 254.67s] Feel free to pause the video if you want to. To calculate the current, we need to take the RMS voltage and divide it by the impedance of the circuit. +[255.15s -> 266.77s] So we have the RMS voltage. It's 120 volts. What we need to calculate is the impedance. And so we could use this formula to do so. +[268.94s -> 280.34s] Now, there are no inductors in a circuit, so XL is 0. But we need to calculate XC, the capacitive reactants. It's 1 over 2 pi times FC. +[283.06s -> 293.04s] The frequency is 60 Hertz and the capacitance is 5 microfarads which is 5 times 10 to the minus 6 farads. +[301.30s -> 312.66s] So the capacitive reactance is 530.5 ohms. So now that we have that, we can calculate the impedance of the circuit. +[313.30s -> 322.22s] So it's going to be the square root of 100 squared plus 0 minus 530.5 squared. +[330.00s -> 337.01s] So the impedance of the circuit is going to be 539.8 ohms. +[338.03s -> 352.59s] So most of the impedance of the circuit is due to the capacitor of the circuit. As we can see at low frequencies, the capacitor has a high reactance towards low frequency signals. +[353.71s -> 367.82s] Now that we know the impedance, we can now calculate the current in the circuit. So it's going to be the RMS voltage of 120 volts divided by the impedance. And so that's going to be... +[371.25s -> 386.16s] 0.222 amps, which is 222 milliamps. So that's the current that's flowing in this circuit. Now for the sake of practice, let's work on another example. +[389.14s -> 402.67s] So this time, we're going to have three elements. A resistor, a capacitor, and we're going to introduce the inductor to it. So we have an RLC circuit. +[405.01s -> 416.88s] So the resistance is going to be 100 ohms. The capacitance, 20 microfarads. And the inductance, 200 millihenries. +[417.33s -> 429.20s] And this is going to be a 120 volt signal at the same frequency of 60 hertz. So go ahead and calculate the current that is flowing in this circuit. +[429.74s -> 443.34s] First, we need to calculate the capacitive reactants, and that's 1 over 2 pi times fc. So it's 1 over 2 pi times the frequency of 60 hertz. +[443.70s -> 449.26s] times 20 microfarads or 20 times 10 to the 6th farads. +[455.70s -> 467.06s] And so that's going to be 132.6 ohms. Next, we need to calculate the inductive reactants. And that's 2 pi FL. +[467.57s -> 475.60s] So 2 pi times 60 times 200 millihenries, or 200 times 10 to the minus 3 henries. +[482.48s -> 491.92s] So then that's going to be 75.4 ohms. Now to calculate the impedance, we could use this formula. +[498.48s -> 512.30s] So it's going to be the square root of r squared, so that's 100 squared, plus xl, which is 75.4, minus xc, which is 132.6. +[512.37s -> 513.65s] squared. +[523.50s -> 532.30s] So you should get 115.2 ohms. So that is the impedance of the circuit. +[532.69s -> 546.67s] Now once you know the impedance, you can calculate the current. The current is going to be the RMS voltage divided by the impedance, and so it's going to be 120 volts divided by 115.2 ohms. +[550.48s -> 559.41s] And that's equal to 1.04 amps. So that is the current that is flowing in this particular circuit. +[559.73s -> 573.17s] Now, let's calculate the frequency at which the inductive reactance equals the capacitive reactance. And as was mentioned before, that frequency is known as the resonant frequency. And it's equal to 1 over 2 pi. +[573.17s -> 575.34s] times the square root of LC. +[577.90s -> 591.57s] So L is going to be 200 millihenries, so that's 200 times 10 to the minus 3, which is 0.2 henries, and then times the capacitance of 20 times 10 to the minus 6. +[607.28s -> 617.58s] So you should get 79.6 Hz. So at that frequency, XL will equal XC. +[618.96s -> 631.67s] So now you know how to determine the resonant frequency of an RLC circuit. You also know how to determine the impedance of the circuit, and also the current that is flowing in the circuit. So that's it for this video. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Engineering/test_Electronics_22.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Electronics_22.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ad33e31144fa8b4817c310300c638735ef3e1f35 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Electronics_22.mp4.txt @@ -0,0 +1,38 @@ +[0.27s -> 7.70s] Okay, in today's video, I am going to go over some basic circuit analysis for RC circuits. +[7.70s -> 17.60s] Those circuits are circuits that contain both resistors, hence the R, and capacitors, hence the C. We have a resistor and a circuit. +[17.60s -> 31.89s] capacitor right here. So we have an RC circuit. Now this is the circuit we're going to use for this video. We have a 12 ohm resistor, a 3 microfarad capacitor, and we have a 9 volt +[31.89s -> 44.96s] power supply and we're going to look at this circuit in two different time zones two different times one is immediately after the switch has been closed which we often call +[44.96s -> 55.17s] Time equals zero. Now, I think of it not really as time equals zero. It's right after the switch has been closed. So it's not really zero. It's a fraction of time. +[55.17s -> 69.25s] second or a very small amount of time but what happens what does this circuit look like right after the switch has been closed we want to know what is the charge on the capacitor what is the potential difference across the capacitor +[69.25s -> 81.41s] What is the current through the circuit and the resistor? And what is the potential difference or the voltage drop across the resistor? And this is right after the switch has been closed. And this is the way I think about this type of problem. +[81.41s -> 92.85s] right after the switch is closed, all of the current, the total amount of current, the highest current, is flowing through the circuit and the resistor. But none of this current +[92.85s -> 106.99s] or no charge has yet reached, or no charge has been put onto the capacitor. There's no charge on the capacitor. Okay? None of the charge has reached the capacitor. So, really, right after... +[106.99s -> 120.16s] the switch has been closed, the charge on the capacitor is zero. Nothing has reached the capacitor. Now, if the charge on the capacitor is zero, and we know Q equals C times V, if we were to solve for V, +[120.16s -> 133.44s] we would know then that the voltage, there's no potential difference across the capacitor. No charge and no potential difference. But the current is actually flowing through the circuit. It's just that none of it has really reached the capacitor yet. +[133.44s -> 146.32s] The current we're going to use, V equals I times R. We're going to solve I equals V divided by R. We have a voltage. It's 9 volts. We have a resistance. It's 12 ohms. That means that the... +[146.32s -> 157.31s] Current through the circuit, through the resistor, is 0.75 amps. Okay? We have current, but no charge. +[157.31s -> 168.51s] Well, where is all the power that's in the circuit? Not the power, but where is all the voltage that's in the circuit? Well, it's on the resistor, and the voltage is equal to the current times the resistance, and that means that... +[168.51s -> 178.51s] The voltage is equal to 0.75. We figured out earlier that's the current. That current is flowing through the resistor. That's the only thing that's using any of that energy or any of that voltage. +[178.51s -> 192.13s] and therefore we have nine volts, and that should match the battery. Nine volts, all of it is on the resistor. None of it is on the capacitor yet. +[192.13s -> 206.61s] Okay? So, pretty straightforward. Now, we're going to talk about time equals infinity, or after a long time. What is the charge on the capacitor? What is the potential difference across the capacitor? +[206.61s -> 220.70s] what is the current through the circuit, and what is the potential difference across the resistor. Now, the key here is after a long time, the capacitor is fully charged. That's basically what they mean when they say after a long time. +[220.70s -> 234.88s] the capacitor is fully charged. And when the capacitor is fully charged, there is no current flowing through the circuit. That's the key. On the previous slide, we had current, but no charge. Now we have charge, but no current. All right, so... +[234.88s -> 247.28s] I'm going to answer these not in one, two, three order. We're going to do number three first. After the capacitor is charged, after a long time, there's no current flowing in the circuit anymore, so therefore the current is zero amps. +[247.95s -> 262.42s] And if there's no current flowing through the circuit, we can do V equals I times R. V equals I times R, I equals zero. So that means that V is equal to zero. So there's no current flowing through the circuit. There's no voltage across the region. +[262.42s -> 274.51s] Across the resistor no voltage drop well Where is all that voltage the voltage is now on the capacitor? At time equals infinity at time equals a long time +[275.02s -> 284.21s] The voltage is on the capacitor the voltage of the capacitor is equal to the voltage of the battery All right +[285.78s -> 293.20s] Now we can solve for the charge how much charge is there because all the charge is there we've put all the charge on the +[293.20s -> 307.18s] capacitor Q equals C times V. We have a three microfarad capacitor. We said after a long time the charge, excuse me, the voltage of the capacitor is equal to the voltage of the battery, in this case nine volts. So it's three times nine. +[307.18s -> 319.33s] 27 micro coulombs okay that is after a long time after time equals infinity okay so those are the two cases i'm just going to summarize them right here +[319.33s -> 327.87s] and we have a time equals zero right after the switch is closed. The voltage on the capacitor is zero. The charge on the capacitor is zero. +[327.87s -> 339.74s] Well, there is current. The current is equal to the voltage of the battery times the total resistance. In this case, we just had one resistor. And the voltage of the resistor is equal to the voltage of the battery. +[339.74s -> 353.20s] Now, after a long time, it's kind of the opposite. The voltage of the capacitor is equal to the voltage of the battery. Now, we have charge. We would solve that by using Q equals C times V. Q equals... +[353.20s -> 359.79s] capacitance times the voltage of the battery okay because all the charge is now on the +[360.21s -> 369.71s] Capacitor, there's no current and the voltage across the resistor is zero. All right now one more thing before I finish I just want to show you these quick curves +[369.71s -> 377.87s] These are often curves that are used for RC circuits. I'm not going to go into a lot of detail, but you'll notice this is the voltage of the capacitor. This is at... +[377.87s -> 391.01s] This is over time now, okay? This is time down here. This is the voltage of the capacitor. This is just time. This is tau. These are the time constants, one time constant, two, which we didn't talk about, but just realized time is increasing. +[391.01s -> 405.17s] okay and the voltage here is increasing and you can see over time the voltage on the capacitor goes from zero to 100 of the battery and the here this one is the same thing time down here +[405.17s -> 414.00s] voltage of the resistor so over time the voltage on the resistor is the greatest in our case it was nine and then it goes down +[414.00s -> 427.92s] To zero volts in this case here was zero volts, and it would go up to nine here. It's shown in percentages Okay, so that's how RC dots in general how RC circuits work especially simple RC circuits +[427.92s -> 441.50s] And I hope you found that video helpful. If you found that video helpful, you could give me a thumbs up or a nice comment in the comment section. Thank you very much for watching. I hope you found that helpful. And you... +[441.50s -> 445.23s] And we will see you in the next video. diff --git a/VideoMMMU_ASR_large/Engineering/test_Electronics_6.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Electronics_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1d951ebb33f840360d03d3984665762c3b7eda49 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Electronics_6.mp4.txt @@ -0,0 +1,51 @@ +[2.32s -> 15.60s] In this video, we're gonna introduce the idea of a step response. This is one of the most common occurrences in all of electronics, and it happens anytime there's some resistance and some capacitance. +[15.60s -> 29.55s] and series, and in particular, it happens billions of times a second inside every computer. So that's why we want to study this very carefully. So the step response is something that happens in a circuit when we drive the circuit. +[29.55s -> 40.37s] with a step voltage. That's a step voltage shown right there. And this response is going to be related closely to the natural response. +[42.70s -> 53.39s] of an RC circuit. And if you haven't seen that video yet, I want to encourage you to take a moment and go to watch the video on the RC natural response. +[55.60s -> 65.62s] because I'm gonna use that result right here. Now, in the RC natural response, what we had was no energy going into a circuit. We had an RC circuit like this. +[66.77s -> 76.50s] and there was nothing connected here. So the source was removed and we had a C and an R and there was a voltage. +[76.91s -> 86.96s] on the original capacitor. There was some charge on this capacitor right here. And we worked out what's the response of the current +[87.89s -> 101.33s] and what's the response of the voltage V of t across this capacitor. And there we found that V of t equals +[101.62s -> 107.25s] V naught times e to the minus t over RC. +[108.05s -> 119.87s] So this is the natural response of an RC circuit. And now what we're gonna do in the step response is we're gonna actually kick this circuit with a step. We're gonna make this circuit do something. +[119.87s -> 133.98s] add some sort of stimulus from the outside that pushes this RC circuit in some direction. And we're gonna see what that means. And it's gonna be related to the natural response. So, Vs here starts at some voltage V naught. +[133.98s -> 146.86s] Then at time zero, right here, it makes a step, a sharp step up to some other voltage step, Vs. And what we want to do is we want to see what this circuit does. And again, we'll label this +[146.86s -> 155.10s] we want to find out this v of t. So what's gonna happen is, in the past, before t equals zero, +[155.10s -> 165.55s] This circuit will be in some state, and we'll figure out what that is, and then we're gonna disturb the circuit, and it's gonna settle down in some new state, and that's gonna be called the step response of the circuit. +[166.22s -> 174.74s] So our approach here is gonna be to look at this, first we're gonna do this intuitively, and we'll just look at a long time ago, we'll look at +[174.74s -> 187.18s] a long time from now, well after the step. We'll see what the circuit's doing then. And then we'll look at what, we'll guess at what happens in between. So first we'll do this intuitively, and then we'll do it with the formal mathematics. +[187.66s -> 192.94s] So I said we're gonna break it down into three things. The first thing we're gonna look at is long ago. +[199.50s -> 209.84s] What was this circuit doing yesterday when it was sitting here at v naught? Well, long ago, vs equals v naught. +[210.74s -> 219.79s] and what was gonna happen is some sort of current was gonna flow out of here and around into this capacitor, and it's gonna leave some charge here. +[222.64s -> 232.43s] And that charge is gonna pile up on the capacitor. And we know that it's related to the voltage on the capacitor by CV. +[233.49s -> 248.46s] One of the things we're gonna do as we analyze this circuit is track what happens to this Q. That's a good approach to thinking about what's going on here. So if a long time ago, Vs was V zero, basically what happened? Some current flowed. +[248.94s -> 260.82s] until v here reached v zero. So v equals v zero. +[261.07s -> 274.70s] at some time in the past, V became V naught. And what happened to I? Then I went to zero. And the reason we know I went to zero is because the voltage across this resistor, let me label it like this. +[275.34s -> 277.23s] We'll call it VR. +[277.74s -> 291.18s] Eventually, this side was V naught and this side became V naught. And that's zero volts across the resistor, so that means the current goes to zero. So this is the state a long time ago. +[291.28s -> 297.97s] I want to start sketching this. We'll do some time plots of this. +[303.18s -> 313.84s] And we'll make this I and this V. And so we decided a long time ago, V was V naught. +[320.34s -> 330.42s] And the current, we decided, was zero. So I can put that on there like that. So that's our long time ago. +[330.80s -> 336.94s] Next what we do is we go to super long time. Let's let t go to infinity. +[337.58s -> 347.89s] That's a long time from now. And what's the state gonna be then? Well, the Vs is gonna be, the source voltage is gonna be Vs. +[348.85s -> 357.78s] I'll tell the part between capital letters and lowercase letters here. Capital letters is a fixed voltage and Vs is something that changes with time. +[360.75s -> 372.50s] And we can do the same sort of analysis. There's gonna be some current that will flow. Q will build up until the voltage on the capacitor is, there'll be some current. +[374.10s -> 386.22s] the voltage on the capacitor will go to Vs, and the same story, the voltage across the resistor then will be zero again, and that means that I will be zero again. +[387.44s -> 399.76s] This is for a long time from now. So as we continue our intuition here, a long time from now, Vs is gonna be the step voltage. +[400.21s -> 414.06s] Big V, S. And what's I gonna be? I, we decided, was gonna be zero. So, a long time from now, out in the future, I's gonna be zero again. Okay. +[416.53s -> 419.54s] So now let's go back and look at what happens between. +[424.30s -> 438.72s] Okay, this is after the switch happens and before a long time from now. And what we can guess, what we can estimate is that V naught is gonna become Vs somehow and that the current's gonna start at zero. +[438.72s -> 453.71s] and it's gonna do something and it has to end up back at zero. Okay, let's get a little more detailed. Let's make some little better guesses. The moment after the step happens, the voltage on this side goes to Vs. +[455.66s -> 470.22s] And the voltage on this side is what? Well, the charge, there's a bunch of charge sitting here on the capacitor, and it hasn't had time to go anywhere. So if that's the case, then the voltage, right after the switch changes, is gonna still be V naught. +[471.12s -> 485.20s] So that's gonna be the voltage right after here is not gonna jump anywhere, and that's because we physically have some charge stored on this capacitor, and it hasn't had time to go anywhere yet. That means on this side of the resistor, just after this, +[485.20s -> 488.11s] the step happens, this is gonna be V naught. +[488.43s -> 501.04s] Oh look, see, now we have a voltage difference across here. So there's gonna be a current. All of a sudden there's gonna be some current here. Let's scribble that in, let's see what that does. There's gonna be some sort of current that happens. +[502.42s -> 513.10s] And it's gonna be I is what? It's gonna be Vs minus V naught divided by R. That'll be the current. +[516.62s -> 522.58s] We'll label the current there. That's the current we're talking about. Alright, so we got our current to hop up. +[523.22s -> 537.10s] And now there's more charge, there's charge flowing onto our capacitor. So the capacitor voltage is gonna start changing. More charge, more voltage. And what's gonna happen, we can estimate this, it's gonna just do something like that. +[537.39s -> 539.22s] I can sketch that in. +[540.40s -> 555.18s] More and more charge will start flowing onto this capacitor and the voltage will gradually rise until V equals VS. It's till the voltage across the resistor again is zero and then current will stop. +[555.31s -> 567.12s] we had a sudden step of current caused by the change in the step voltage input, and then it's gonna just fade out, something like that, until the current goes back to zero. +[568.56s -> 583.18s] V will go from, how do I write this? It'll go from V naught and it'll eventually become VS. And I will have a step. +[585.81s -> 598.74s] and then go back to zero. So that's our intuitive understanding of how this step response will look for a driven RC circuit. +[599.12s -> 607.54s] And next what we'll do is we'll work this out in detail and we'll get mathematically accurate versions of what these two curves look like. diff --git a/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_20.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..19127a8c44d00f6bdc2bcdbf2716cb733a3683f0 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_20.mp4.txt @@ -0,0 +1,38 @@ +[0.00s -> 13.33s] Hey internet, welcome to Thermodynamics Tutorial 4-20. So we have a polytropic process, so that is PV to the power of N is equal to C. +[14.00s -> 28.11s] so we've got a piston cylinder device of 0.15 kilograms of air at 2 MPa of pressure 350 degrees Celsius +[28.75s -> 39.92s] it is expanded isothermically to 500 kPa then it is compressed with the exponent power of 1.2 +[41.10s -> 49.46s] Then we want to find the boundary work Through all the process so the total work +[50.38s -> 57.46s] Alright, step one, draw your free body diagram, your FBD. You get a point for drawing a picture related to the question. +[58.64s -> 72.45s] Step 2, find your gas constant of air. You can find this at the back of your textbook. If you bought the PDF, you can type in Table A-2, Ctrl F, and then type in A-2. +[72.45s -> 84.40s] Go to air for your gas go to your gas constant R. Your R value is 0.2870 kilojoules per kilogram Kelvin +[85.10s -> 89.71s] Step three, find your initial volume. So that's V1. +[89.97s -> 103.60s] which is equal to MRT divided by P1, which is your initial pressure. So M is mass, R is your gas constant, T is your absolute temperature because this is an ideal +[103.60s -> 105.04s] Guess equation. +[105.58s -> 120.14s] So you plug in the values these values are given from the question and it and it is also found in table a Dash 2 and step 2 for your gas constant So your mass is here +[120.14s -> 133.20s] this is your R, your gas constant and this is your absolute temperature and then you've got your 2 MPa which is converted to kPa to match the units +[133.20s -> 146.51s] So you will get your initial volume of 0.01341 meters cubed Step 4 find your +[147.63s -> 159.38s] Final volume or V2. Repeat the process. Only the pressure changes. So P2 is 500 kPa. +[159.86s -> 173.97s] So your final volume V2 is equal to 0.05364 meters cubed Step 5 you want to find the boundary work through the process of 1 through 2 +[174.83s -> 188.21s] so W boundary 1 through 2 is equal to P1 V1 natural log and Then you've got your volume ratio V2 divided by V1 +[190.51s -> 201.62s] So if we plug in the values, that's 2000 kPa. And then your initial volume is what you found in step three right over here. +[203.15s -> 217.68s] Then you've got your natural log and then you divide by your final volume by your initial volume So your final volume is over here in step 4 your initial volume is in step 3 over here +[218.74s -> 230.00s] And you get a value of 37.18 kilojoules for work through the process 1 through 2. +[232.59s -> 244.34s] Step six, find your final volume of process three. Should probably write that. +[247.25s -> 252.78s] So we equate P2 V2 +[253.39s -> 267.34s] to the power of n which is 1.2 is equal to P3 and we're trying to find V3 to the power of n which is 1.2 again. So you equate these together you solve for V3 +[268.05s -> 277.01s] V3 is equal to 0.01690 meters cubed. +[278.06s -> 283.38s] Step 7. Find the boundary work process 2 through 3. +[283.79s -> 296.53s] So that is P 3 V 3 minus P 2 V 2 divided by 1 minus in So if we plug in the values +[297.17s -> 302.70s] We've got 2000 kPa you've got your +[303.66s -> 317.95s] V3 volume which is 0.01690 meters cubed which you found in step 6 and then P2 is 500 kPa that's given and V2 +[317.95s -> 324.62s] is what you worked out in step four right over here +[326.64s -> 337.39s] And then we divide by 1 minus 1.2. So 1.2 is your polytrophic exponent given in the question. +[338.00s -> 351.73s] And that will give you minus 34.86 kilojoules. Step eight, find the boundary work through the process three through one. +[352.37s -> 366.64s] so W boundary 3 through 1 that is P3 multiplied by initial volume minus the final volume of 3 +[366.96s -> 374.83s] So that's 2000 kPa multiplied by 0.01341 minus +[375.92s -> 386.58s] 0.01690 meters cubed and that will give you minus 6.97 kilojoules +[388.27s -> 403.18s] Step 9 now we can finally find the total amount of work done or the network so we add all these work together and We will get +[403.73s -> 417.26s] minus 4.65 kilojoules. Disclaimers, the method is correct. However, I do make calculation mistakes. I encourage you to solve it yourself. +[417.26s -> 419.86s] and see if you get the same answer. +[420.21s -> 434.93s] Thanks for watching. Hope you had a great day. Be sure to like, subscribe, share with your friends, ring the bell, turn on all notifications, leave a comment below if this was helpful. Until next time. +[434.93s -> 435.96s] See ya. diff --git a/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_220.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_220.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7e522e8088f752f8384c05a0a6e30ed94fcd0707 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_220.mp4.txt @@ -0,0 +1,83 @@ +[0.85s -> 10.35s] Okay, this is another example of solving for the hydrostatic forces on curved surfaces, and this happens to be a solved midterm example. +[11.79s -> 23.14s] The problem reads gate AB is a quarter circle with radius 8 meters and the gate has a width into the page of 10 meters. +[23.14s -> 34.19s] The gate is hinged at point B, and the fluid has a standard specific weight of 9,790 newtons per cubic meter. And we're asked to calculate... +[34.19s -> 45.39s] the horizontal and vertical hydrostatic forces on the gate. We want both the magnitude and direction of those forces and we're asked to calculate in part b the force +[45.39s -> 55.41s] the downward force applied at point a that will keep the gate from opening and for simplicity in an exam question we're told to neglect the weight of the gate +[56.34s -> 66.74s] Oh, I should also point out that, in case you don't know this, all of the hard copies of these solutions can be downloaded from my personal website, drdavidnailer.net. +[68.88s -> 78.32s] Now before I get into the detailed solution, I just wanted to say a few words about the general physics of the solution I've drawn here the pressure distribution +[78.32s -> 92.24s] on the gate so this is the force of the water on the gate the hydrostatic pressure increases linearly with depth and it's always perpendicular to the surface so each of these pressure vectors are +[92.24s -> 103.17s] upward and to the left so if we think about the problem in this way it should be completely obvious that the horizontal force is going to be to the left +[103.17s -> 108.62s] and the vertical force is going to be upwards. So that needs to be part of our final answer. +[109.58s -> 118.26s] We start this kind of problem by drawing a free body diagram. And in this case, I've drawn a free body diagram of the gate showing the +[118.26s -> 131.31s] vertical and horizontal forces, the hydrostatic forces, the force applied at A, and the hinge forces at B. And I've also shown the water immediately adjacent to the gate. Now, there are other +[131.31s -> 139.92s] Approaches to solving this problem and I'll talk about that at the end but this free body diagram approach I find is the most reliable +[140.56s -> 154.94s] And so notice that here we have the horizontal force of the water acting on the gate. Of course, the gate pushes back equally, but in the opposite direction. So the force of the gate on the water is to the right. +[154.94s -> 169.18s] Similarly, we have the force of the water on the gate upwards and the force of the gate on the water acting downwards. In addition, we have the weight of this quarter disc of water and +[169.18s -> 182.83s] This surface here is at a depth of R, so it has a uniform pressure distribution on it, and so we have an upward hydrostatic pressure force, which we're going to call FBC. So with these... +[182.83s -> 196.82s] Free body diagrams we can now find the horizontal and vertical hydrostatic forces and we should keep in mind that the problem statement says that this gate is 10 meters into the page so we're +[196.82s -> 198.90s] dealing with this kind of geometry. +[200.53s -> 212.48s] Okay, so here I've simply reproduced the free body diagram for the water, showing all the forces on this little disk of water adjacent to the gate. I'm going to start. +[212.48s -> 224.82s] by solving for the horizontal force. This horizontal force here on surface AC is just a vertical surface is equal to the specific weight of the water. +[224.82s -> 238.14s] the depth of the centroid of that surface, that's a vertical plane surface, so its centroid is going to be at r upon 2, 4 meters, times the surface area of AC, which is going to be the radius. +[238.14s -> 252.50s] eight meters times 10 meters into the page so the surface area is 80 square meters and we can make those substitutions 9790 newtons per cubic meters the depth of the centroid and our 80 square meters of +[252.50s -> 265.65s] surface area gives a force on the gate of 3,133 kN and as we discussed in the previous slide, the force of the water on the gate is to the left. +[266.10s -> 272.40s] And that's part of the answer for part A. We can now move on to solve for the vertical force. +[272.40s -> 282.86s] The vertical force requires us to apply static equilibrium in the vertical direction, which I'm going to call y. So sum of the forces in the y direction equals zero. +[283.47s -> 296.22s] FBC is upwards I'll take that as positive so FBC minus W the weight of the water minus the vertical force on the water must sum to zero and we're +[296.22s -> 307.79s] Looking for FV, so we can solve for FV. FV is the pressure force on surface BC minus the weight of the water. So now we've got to find FBC. +[307.79s -> 319.42s] the weight of that quarter circle of water that's what I do on the next slide so I've reproduced our static equilibrium equation here FBC is that +[319.42s -> 329.04s] pressure force on surface BC it's equal to the gamma times the depth of the centroid times the area of that surface the +[329.04s -> 342.45s] depth of the centroid of that surface is eight meters in fact the entire surface is at eight meters so we have a uniform pressure distribution on that surface so the center of pressure is going to be at the centroid the +[342.45s -> 351.66s] force FBC is going to act directly at the centroid. And we can make the substitutions, 9790 for the specific weight, the surface +[351.66s -> 361.14s] depth is 8 meters and the surface area again is 80 square meters and that gives 6266 kilonewtons upward +[361.49s -> 374.32s] We can now calculate the weight of this volume of water. It's going to be the specific weight, so the weight per unit volume times the volume of ABC. +[374.93s -> 386.74s] The volume of ABC is going to be this area, so pi r squared divided by 4 times the depth times the specific weight of water. We can make the substitutions. +[386.74s -> 399.49s] 9790 pi r squared r is 8 meters divided by 4 and our depth into the page is 10 meters and that gives 4921 kilonewtons downward of course +[399.49s -> 405.20s] now we can make our substitutions back into our static equilibrium equation to get fv +[406.16s -> 417.12s] And FV is so 6,266 minus 4,921, which gives 1,345. +[417.12s -> 422.91s] Here's where students tend to make the mistake as we discussed on I think the first slide of this problem the +[422.91s -> 435.42s] force of the water on the gate is upwards as we saw from the pressure distribution and be careful because the force of the gate on the water is downwards. So that's the answer to +[435.42s -> 450.18s] part A. We've now done both the horizontal and vertical hydrostatic forces on the gate. Now we can move on to part B, where we are looking to find the force applied at A. This requires us to +[450.18s -> 457.52s] Locate the lines of action of the vertical horizontal forces. I'm sure you've done this sort of problem before what we're going to do is +[457.52s -> 471.20s] We know the magnitude of FH and FV. We now need to find out where they act on the gate, and then we're going to apply the condition for static equilibrium that the sum of the moments about the hinge are zero. +[471.20s -> 479.44s] And why do we use the hinge? Well, we use the hinge because we want to avoid calculating these hinge forces. It just makes the problem simple. +[479.98s -> 494.05s] So now we move on first to finding the line of action of FH. This is called the center of pressure. And recall that the center of pressure for this vertical surface AC acts below the centroid. +[494.05s -> 507.54s] And it acts below the centroid by an amount Ixx sine theta over 8C times the surface area. Ixx is the second moment of area of surface AC. +[507.54s -> 512.08s] taken about a horizontal axis through the centroid. +[513.07s -> 527.04s] So for surface AC, for a rectangular surface, you may recall that it's the width times the height cubed divided by 12. The width is 10 meters. The height of the surface is 8 meters. +[527.04s -> 538.83s] cubed divided by 12 and we get the second moment of area about the centroid through horizontal axis is equal to 426.7 meters to the fourth. +[538.83s -> 553.14s] Now we can make the remainder of the substitutions. Note that the angle here, this surface AC, is at 90 degrees with respect to the free surface. So theta equals 90 degrees. So we can make the remainder of the substitutions. +[553.14s -> 567.49s] substitutions. YCP is minus 426.7 meters to the fourth sine of 90 degrees, which is one. The depth of the centroid of the surface is four meters. +[567.49s -> 578.93s] and the surface area is 80 square meters and so that gives minus 1.333 meters that's ycp that's the distance below +[578.93s -> 585.89s] the centroid for the location of the center of pressure that's what the minus sign means so the +[585.89s -> 600.18s] Total distance from the free surface to the center of pressure is 4 plus 1.33. That's 5.33 meters. We can subtract that from the total distance, 8 meters, to find the moment arm of FH relative to B. +[600.18s -> 613.49s] which is what we want and that works out to be the radius upon three which is two point six six seven meters now we can move on to finding the line of action of the vertical force +[614.86s -> 627.47s] The line of action of FV here is probably the most difficult part of this problem. I need to find this distance. I'm going to call it X bar, the moment arm of FV from... +[627.47s -> 633.46s] the hinge at point B, and to do this we consider the free body diagram of the water. +[634.10s -> 643.57s] And here I've got all the forces on the water here. We've got the weight, this force FBC that we calculated, the horizontal forces. +[643.57s -> 657.30s] It was given in the exam and you can find it in most textbooks. You can find the centroids of a quarter circle and the centroid of a quarter circle is located at 4r upon 3pi. So I've located the distance of... +[657.30s -> 668.46s] of this edge to the centroid which would be the center of gravity and of course if this is 4r upon 3 pi and this total distance here is r then the distance +[668.46s -> 678.38s] From the weight to the moment arm at b is r minus 4r upon 3 pi. It turns out for this kind of problem, this... +[678.38s -> 692.82s] Little quarter circle of water is in perfect static equilibrium You can take moments about any point But it makes sense to take moments about B because we really want to find out this moment arm X bar in order to +[692.82s -> 704.27s] calculate the force at A. So we're going to take moments about B, set them to zero, static equilibrium. And so I'm going to take +[704.27s -> 718.54s] Counterclockwise is positive, so FBC, it acts at the center of this surface because we have a uniform pressure distribution on BC. So FBC times R2, the moment arm of the weight force is R minus 4R upon. +[718.54s -> 731.25s] three pi and it's in the opposite direction it's in the clockwise direction so it's negative and fv also acts in the clockwise direction about b so it's fv times the unknown distance x bar +[731.25s -> 744.86s] And we can solve this equation for x bar, which I've done here. You can check my algebra. Note that I didn't have to deal with the horizontal forces here because they're equal and opposite. +[744.86s -> 757.97s] They're equal and opposite, and they're at the same moment arm from B, so they cancel out. So now we can evaluate X bar, the moment arm of the vertical force. +[759.54s -> 773.62s] And here I've reproduced the free body diagram again, and I've inserted the known values for the vertical force, the weight force, and the hydrostatic force on the lower surface, FBC. +[773.62s -> 784.03s] So we can make the substitutions. FBC times the moment arm of 4 meters, because it acts in the center of the surface. +[784.03s -> 791.90s] The weight force, 4921, has a moment arm of r minus 4r upon 3 pi. +[791.90s -> 805.81s] 8 minus 4 times 8 divided by 3 pi, and then all divided by the vertical force, which is 1,345. And that gives that our moment arm of the vertical force here, x bar, is... +[805.81s -> 817.41s] 1.787 meters so now we can go back to our free body diagram of the gate and apply those forces +[817.41s -> 830.98s] in the opposite direction because the force of the water on the gate is in the opposite direction and do our sum of the moments about the hinge. And that's what I do on the next slide. So we have the free body diagram of the gate. +[830.98s -> 844.11s] I've got the horizontal and vertical forces and their lines of action that we've just calculated. Notice that FAA acts at a moment arm of R from B, so we can take them. +[844.11s -> 854.66s] some of the moments about b as zero for static equilibrium so fa acts downward and produces a +[854.66s -> 864.83s] clockwise moment, so I'm going to take that as positive F A times 8 and F H and F V have a counterclockwise moment and so F H times +[864.83s -> 878.93s] 2.667 and FV times 1.787 meters must sum to zero. Now we can solve this equation for FA and make the substitutions. +[879.54s -> 894.13s] And that means that the force at A required to keep the gate from opening is 1,345 kilonewtons. And that's the answer to part B. Now coincidentally, that turns out to be equal to the vertical force, but that's kind of a fluke of the particular... +[894.13s -> 897.78s] geometry of this problem. That won't always be the case. +[898.80s -> 911.31s] So that completes the solution. Just as one final comment, I'll just make a note that there is an alternate way to find the vertical force. Some books call it the missing water approach. +[911.31s -> 920.03s] It's fine, but I don't find it as generally applicable as the free body diagram method that I've shown you. But if you have... +[920.03s -> 932.29s] Water if you imagine water being in this location then that would balance the pressure force across the gate and the vertical force on the gate would be zero so you can make the argument that the +[932.29s -> 940.02s] weight of the water required to balance the vertical force on the gate is equal to the vertical force. +[941.42s -> 954.61s] It's okay to use this approach, but if you use this approach you'd have to come up with a different method to find the line of action Okay, and that completes this example diff --git a/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_276.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_276.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e8ceaff58bbd7ad722b69d4800ef6c0cb761fe89 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_276.mp4.txt @@ -0,0 +1,82 @@ +[5.01s -> 19.71s] So from a subscriber request, let's do an example to solve for the hydrostatic force that acts on a slanted surface that's submerged. So we know here we have a 5 meter long by 1 meter wide slanted gate. +[19.71s -> 34.00s] and has a hinge at point o as shown by the figure below so what we have is a gate down here that's submerged below a top water surface and it's five meters long and the width into the page is one +[34.00s -> 45.17s] meter and we have a hinge in this particular case and we're told the fluid on the left side of the gate has a density of 1500 kilogram per meter to the third +[45.17s -> 58.80s] So this is the density for the fluid on this side. And based on this case, we want to look at the hydrostatic force in kilonewtons required to keep the gate closed is most nearly what? +[58.80s -> 69.04s] So we know this side will have the fluid, it has this density, and the fluid always distributes some pressure. +[69.04s -> 83.63s] So we have a distribution of pressure and what we want to find is the force. So we want to relate that pressure to a force and that's what we're finding here in kilonewtons. The hydrostatic force due to the fluid and at the bottom we will also solve this. +[83.63s -> 98.54s] and find the location of this force for that slanted gate. So the first thing I recommend we do is draw the pressure distribution. And we know in the handbook, this is also provided in the new FE handbook. They drew the pressure distribution for us. +[98.54s -> 104.46s] And from this pressure distribution we can find the force. So let's draw this pressure distribution. +[104.98s -> 117.26s] And it would look something like this. We know that pressure is always perpendicular to the surface we're looking at. And in this case, it's the gate. So this is our pressure distribution. +[119.15s -> 128.46s] So from this pressure distribution we want to find a resultant force. And I'll use blue for that. And let's say it acts somewhere here. +[128.88s -> 142.24s] This is what we want to find, the hydrostatic resultant force in units of kilonewtons. So based on that, we know that we can develop two basic shapes if we choose to. +[142.24s -> 153.82s] But that's the more complicated approach. So that approach is more complicated when you're looking at these slanted gates. So what I recommend for the FE is make use. +[153.82s -> 164.59s] of the equations in the handbook. So it's under fluid mechanics. It's under the forces on submerged surfaces and center of pressure. The major equation you have to know +[164.59s -> 176.88s] is the hydrostatic resultant force equation. So let's write that down. So the hydrostatic resultant force equation, which is what we want to find, FR equals to +[177.94s -> 187.79s] It says we take the density times g times yc. So we take the density times g times yc. +[189.84s -> 202.24s] And then we do the sine of theta and all of this times the area. So we know that let's look at what we have and what we don't have. We have the density. +[202.24s -> 212.50s] which is the fluid density, right? That's 1500. We know G is 9.81 in SI. YC we do not know. We do not know theta. +[212.50s -> 223.25s] and we know the area we know the area because it's just the five meter by the one meter wide gate so we're looking at it in 3d so we're looking at it into the page +[223.25s -> 232.11s] So let's say this is our gate. We want to look at it into the page. And we're considering this gate, right? +[232.75s -> 246.86s] We have something that looks like this. And we know this distance is essentially like the height, right? It's the length, which is the height if we look at it from that view. So it's going to be the 5 meters. +[247.06s -> 254.22s] And this distance, we are told, into the page is one meter wide. It's essentially the base. +[254.32s -> 268.05s] So you want to look at it in that view when you're doing the area. So the area is the cross sectional area and we know that's where the pressure is going to act. The pressure distribution right. Let me use red as I denote it in the figure. +[269.65s -> 277.97s] So that's what we have. This is the pressure distribution. And what we want to do is find the resulting force. +[278.90s -> 290.59s] So that's just the 3D view of that gate, the slanted gate. So we know we need YC and theta. The area we can find is just 5 by 1, right? +[290.59s -> 297.58s] So let's first find theta real quick. So theta is going to be this angle. +[297.94s -> 309.20s] So it's that angle and that's what's denoted in the figure in the handbook. They denote the angle here so it's similar to this angle. We know this angle is the same as this angle. +[309.20s -> 322.35s] So that's your theta always. It's the angle with respect to the horizontal up to the slanted gate. This is the horizontal and we move this angle to the slanted gate. Or if you look at it from this view. +[322.35s -> 335.95s] This is the horizontal. We move this way at this angle to the slanted gate. So that's theta. And we can find theta by doing what? Rule. So we know SOH CAH TOA. Which one can we use? SOH. +[335.95s -> 346.42s] Because we have the opposite and we have the hypotenuse, right? So we do the SOHCAHTOA, which says, let me denote that. It says sine. +[347.09s -> 357.70s] of theta equals the opposite over hypotenuse. So we do sine of theta. What's the opposite? It is 4 meters, right? +[357.70s -> 362.38s] The opposite is this side, so it's 4 meters. The hypotenuse is this, so it's 5 meters. +[363.15s -> 373.68s] And you can do sine inverse now. So theta equals sine inverse in the calculator of 4 meters over 5 meters. +[374.22s -> 383.86s] So we can find theta, and I believe you should get 53.13 degrees. +[384.30s -> 397.14s] So we have the angle theta. We need that in order to plug it in this equation. Now let's find yc. So yc is the tricky part. So y always for slanted surfaces. +[397.14s -> 411.02s] from the very top water surface and it will be a slanted angle it's not a vertical it's not a vertical distance it's a slanted distance so it's going to be +[411.02s -> 420.34s] parallel to the gate always remember y is parallel to the gate so we know in this particular case let's say i draw this +[420.69s -> 433.82s] line all the way to the top surface right I want to match the top surface so that's my line here so this is the top surface right we always start at the top +[433.82s -> 448.00s] at the top so y is going to be the distance yc is going to be from that distance to the centroid of the gate so the dead center of the gate the centroid of the gate it's just at the center right +[448.00s -> 459.97s] So in the last slanted gate example that I uploaded, the top surface was just here, right? It made it easier. But here, our top water surface is at the very top. +[459.97s -> 473.30s] So we have to account for this entire distance from the top to the centroid. So we know here I'll denote it by this color, actually green. +[473.30s -> 488.18s] going to go to the centroid of the gate so the centroid is somewhere here of the gate and we start at the very top and go all the way to the centroid and that's what we need to find +[489.07s -> 502.86s] That's what we're finding and that's going to be our yc. So that's what we need to find in order to finally solve this equation. But we know in the handbook it makes it easy for us. +[502.86s -> 506.16s] They just give us the equation. So why C? +[507.38s -> 520.77s] is going to be hc divided by sine of theta. And we know theta, right? We just found that. So we can easily solve for yc. And let me denote that with green. +[520.77s -> 534.50s] That's the YC we want to solve for. And plug it in here. We just take HC divided by sine theta. And we know HC is always vertical. It's strictly vertical from the top water surface. +[534.50s -> 548.05s] So what we have to do for hc is start at the top and go strictly vertically downwards to the centroid. That's what we denote by c. This is hc. +[548.50s -> 561.30s] So we know 8C can be easily found, right? We just take the 8 and take the 4 divided by 2. 4 divided by 2 is what? 2. We take 8 plus 2. Once again. +[561.30s -> 563.82s] We take this distance. +[564.27s -> 576.70s] which is 8, right? Then we add this distance to the centroid, which is 4 divided by 2, right? So the total hc is 8, this distance. +[576.70s -> 590.22s] plus this distance, which is 4 divided by 2, which is 2 meters. So 8c is 10 meters. So let's denote that. We can say in the equation, we take the 8 meters. +[590.22s -> 600.30s] plus 4 meters divided by 2. Then we do sine of theta, and we know theta is 53.13. +[601.62s -> 613.14s] degrees so now we can solve for YC and you should get 12.5 meters +[613.94s -> 626.22s] So we just found YC. Basically what they did is trig, right? All they did was use trig, use the trig rules and use the sign, the Sokotoa, right? They use sign. +[626.22s -> 638.30s] of opposite over hypotenuse, then they rearrange that and solve for yc. That's all that was done because we have a triangle, right? This is the triangle that we're focusing on, right? +[638.30s -> 650.88s] And we just found Yc by doing SOHCAHTOA. We just found this since we know Hc. So that's where that comes from. We found Yc. Finally, we can find the hydrostatic force. +[650.88s -> 665.07s] Because we have YC and we have the angle, we can find the area easily by doing base times height. So we know FR. We take the row, the density is 1500. +[665.49s -> 676.91s] kilogram per meter to the third then you multiply by 9.81 meter per second squared and you take YC which is this 12.5 +[677.94s -> 689.87s] 12.5 meters. Then you do sine of theta. So this is a s sine of theta. We know theta is 53.13 degrees. +[689.87s -> 703.66s] Then close parentheses all of this, multiply by the area. So the area is into the page, right? You want to look at it from this view. So it's just base times height, 1 times 5 meters. So you take 1 meter. +[704.14s -> 717.68s] times 5 millimeters. So then we can solve for the resultant force. And for that, you should get about 736 kilonewtons. +[717.68s -> 726.35s] So here, the output will be newtons. You divide by 1,000 to get kilonewtons, and we get approximately 736 kilonewtons. +[728.08s -> 741.76s] So this is the answer for this portion. 736. Once again, I just used the equation in the handbook. I didn't want to complicate it here. I know some people can use, they use volumes. You can take in... +[741.76s -> 750.96s] take account for the volume and just add up all the volumes, shapes of volumes. There's also other methods to solve this. +[750.96s -> 764.27s] But I want to make it simple and just use the equation in the handbook for slanted surfaces. So we have that. And the last step is the location of this hydrostatic force. So we know in the handbook, if you look at the figure carefully, +[764.43s -> 778.32s] It says that we have a centroid and we have a center of pressure. The force always acts at the center of pressure. It is slightly below the centroid. Always. The force always acts at the center of pressure. +[778.32s -> 790.03s] So it doesn't act at the centroid, it acts somewhere here at the center of pressure. So let's call it Cp. +[790.35s -> 801.41s] X at the center of pressure. It's below the centroid. And that's denoted in the figure in the handbook. So let's find that distance. And it's going to be YCP. +[801.41s -> 808.62s] There is an equation for that in the handbook. So the equation is YCP, the distance to the center of pressure, +[810.48s -> 820.11s] going to equal to the YC which we did find in green right YC we have then we do plus +[820.50s -> 834.90s] The Ix about the centroid. It's the moment of inertia about the centroid for this basic shape. Here it's just a rectangle, right? So that's going to be that. And then we take Yc on the bottom. +[835.47s -> 846.53s] I see this is the same as this. Then we multiply by the area for that shape, the rectangle. So we know this. We know this. We solved it from the last question. +[846.53s -> 860.72s] And Ixc is going to be simply what? So you should notice for simple shapes, if you don't try to memorize this equation, all you do is base times height to the third divided by 12. +[860.72s -> 871.23s] about the centroid. This is under the static section for those basic shapes. So in this case we take the base. What's the base? We know based on the width +[871.23s -> 884.78s] is 1 meter, the height is 5 meters. So we take 1 meter times 5 meters to the third divided by 12, then we know I x about the centroid +[884.78s -> 893.90s] will give us about so it should be units meter to the fourth and i got 10.42 +[898.96s -> 910.26s] Neither to the fourth so we have that all we do is plug it here and solve for YCP that distance YCP equals +[911.18s -> 920.08s] yc we said is 12.5 as we determined above plus we take this which is this 10.42 +[921.46s -> 935.82s] meter to the fourth. It's the moment of inertia about the centroid. We take yc, the same as this, 12.5 meters, and you multiply by the area. In this case, it's just one meter. +[935.82s -> 949.74s] times 5 meters. So then we can solve for that answer and we should get 12.67 +[951.57s -> 964.64s] meters. So this is the distance where this force actually acts from that slanted distance from the top water surface. So it should be C. +[964.64s -> 977.74s] And we can tell that this is below the yc because we said that yc is 12.5. This is slightly below that, right? It's 12.67. +[977.74s -> 983.80s] so it makes sense the final answer does make sense and i think that's all for this video thank you diff --git a/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_33.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_33.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3f6212e369b1ad9dc658ac7a1aa7ea86cf1b32e9 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_33.mp4.txt @@ -0,0 +1,9 @@ +[0.00s -> 11.82s] Welcome to another simple engineering snippet. In this instructional video, we will convert Neely's equation example to determine the necessary air pressure to double the flow from a tank draining to atmosphere. +[12.72s -> 26.93s] We have a large tank that has a vent valve installed. When the vent is open, the volume above the water is at atmospheric pressure. The vent can be shut and pressurized with air. In this example, we determine the velocity with the vent open. +[26.93s -> 30.48s] and what air pressure is necessary to double that flow. +[30.80s -> 43.97s] The water level in the tank is 10 feet for all of our analysis. Then we shut the vent valve and pressurize the volume above the water surface to double the flow rate. Starting with the vent open, we calculate the flow. +[43.97s -> 57.12s] Using Bernoulli's equation, we simplify it based on a large tank draining the atmosphere. Velocity at the outlet, B, is equal to the square root of two times the gravitational constant times the height of the water. +[57.12s -> 70.05s] This is the well-known Torricelli's relation and is likely for you to write it down without simplifying Bernoulli's equation. The calculated velocity with the vent open is 25.4 feet per second. We want to double the flow. +[70.05s -> 81.49s] The outlet area is constant, so we need to double the velocity. Once again, we set up our noise equation. This time the air pressure is not zero PSIG. It is our unknown. +[85.81s -> 98.67s] Plugging in the known quantities and unit conversions, we obtain 13 psig. Note that this is gauge pressure since we used zero psig for the atmospheric pressure. +[100.08s -> 106.51s] I hope you found this example useful. If so, then please like and subscribe. Thanks and have a great day. diff --git a/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_352.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_352.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d2d5bf7ba8879ad8c46db4ca44c4c2940dd82181 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_352.mp4.txt @@ -0,0 +1,14 @@ +[0.66s -> 6.86s] In this lesson, we will discuss the difference between absolute pressure and gauge pressure. +[8.78s -> 16.21s] When the pressure of a fluid is measured with a device it must be measured relative to the pressure somewhere else. +[16.78s -> 25.62s] If we measure the pressure of a fluid relative to the pressure in a vacuum, which is zero, we are measuring the absolute pressure +[25.87s -> 33.10s] The absolute pressure, denoted by P abs, is more often used in thermodynamics calculations. +[34.35s -> 45.17s] If we measure the pressure relative to the ambient pressure, which is usually the local atmospheric pressure, we are measuring the gauge pressure, denoted by P gauge. +[45.62s -> 58.99s] Since we live in a pressurized environment, in practice it is usually much easier and cheaper to construct pressure measuring devices that measure the gauge pressure compared to measuring the absolute pressure. +[59.79s -> 71.09s] The gauge pressure is frequently used in fluid dynamics calculations for convenience, because often the force caused by the ambient pressure cancels in all directions and can be neglected. +[72.02s -> 82.32s] The equation relating absolute pressure and gauge pressure is P gauge equals P absolute minus P ambient. +[83.82s -> 96.43s] For most car tires, the recommended gauge pressure is between 28 and 36 psi. You can purchase an inexpensive pressure gauge at any auto parts store which measures the gauge pressure. +[96.98s -> 108.43s] So let's say a pressure gauge reads 32 psi, and you are able to determine the local atmospheric pressure is approximately 14.7 psi absolute. +[108.94s -> 123.41s] Rearranging the formula, and plugging in 32 psi for P gauge and 14.7 for P ambient, the absolute pressure in the tire is 46.7 psi. +[124.75s -> 133.04s] When writing a pressure down, it is important to specify whether you are using absolute pressure or gauge pressure. +[133.49s -> 147.47s] In the British gravitational unit system, sometimes the letter A is added to the end of psi to indicate an absolute pressure, and sometimes the letter G is added to the end of psi to indicate a +[147.47s -> 158.93s] gauge pressure. However, gauge pressure is used so frequently in fluid mechanics that many people will leave off the G and simply report gauge pressure in psi. diff --git a/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_86.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_86.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ecbb3fb4c25b5c8a5a945cc2a70e3e67adcd5f34 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Energy_and_Power_86.mp4.txt @@ -0,0 +1,66 @@ +[2.26s -> 14.50s] This video will discuss heat pumps and their coefficient of performance. So a heat pump is a device that moves energy +[14.50s -> 28.58s] from one location to another where the movement is from the cold region to the warmer region. So this is not spontaneous movement of energy. +[28.58s -> 42.45s] The laws of thermodynamics say that will never happen, that spontaneously energy will move from the cold area to the warmer area. But we can create heat pumps that do this. +[42.45s -> 55.41s] heat pumps for homes that can warm the home in the winter months and cool the home in the summer months with the same piece of equipment and you possibly have a refrigerator in your home +[55.41s -> 64.48s] And that device takes energy from the cold region inside the refrigerator and moves it to the room that is at a higher temperature. +[64.48s -> 78.29s] at least i hope your refrigerator has a lower temperature inside than the room temperature so let's discuss the diagrams here for the heat engine and a little bit on the pv diagram +[78.29s -> 87.89s] But the situation for the heat engine is reversed for the heat pump. For a heat engine, energy was leaving the high temperature reservoir. +[87.89s -> 101.02s] being captured partially by the engine and delivering some useful work and then there was energy rejected to the cold reservoir. For the heat pump, work is put into the mechanism. +[101.02s -> 113.98s] So hook this up to electrical power supply. Electrical energy will make the engine do its job. And in the process, energy is +[113.98s -> 128.34s] taken from the cold reservoir and moved to the high temperature reservoir. Now you might ask why would we want to do this? Why not just put work directly into the high temperature reservoir? Well it turns out that the heat pump can deliver +[128.34s -> 139.28s] more energy to the high temperature reservoir than the work energy that is used in the process. So it's kind of a multiplier. +[139.28s -> 153.04s] And we'll talk about the coefficient of performance, which is the ratio of QH divided by W. So you can have multiple times the energy delivered to the inside of the house. +[153.04s -> 165.84s] compared to what is required to run the device. So here's our PV diagram. Where is the network illustrated on this diagram? +[166.32s -> 174.86s] And you should say inside the more heavily purple colored area. And is this work a positive or a negative? +[175.28s -> 189.66s] We're not going to do the calculation, but take a look here. We have a compression on this isotherm. We're going from a higher volume here to a lower volume here. The gas is being compressed. That work is a negative number. +[189.66s -> 202.22s] and down here we have a positive number underneath the lines here as the volume increases so a big negative work number a smaller positive work number +[202.22s -> 216.40s] and our network is a negative value. And look at the energies as well here. We have Q delivered to the room, the Q sub H here. +[216.40s -> 229.94s] occurring at this higher pressure situation, higher temperatures in the PV diagram. And here we have the situation where the temperature is lower, and we have the +[229.94s -> 242.85s] energy extracted from the low temperature reservoir. So that's kind of illustrated. I kind of like the diagram on the left better. It gives you a feel for what's going on. We put energy into the heat pump. +[242.85s -> 253.70s] we pick up we move energy from the cold reservoir to the hotter reservoir as far as a little bit of the details of what's happening inside there +[253.70s -> 268.10s] Is a loop here and the working fluid moves around this loop because the electrical pumps that Do the job here and so if we compress this we put work in we're gonna +[268.10s -> 282.02s] make this temperature hotter and here we now deliver to the inside of the house this condenser temperature is higher than the room temperature in the house so energy will naturally move from +[282.02s -> 292.99s] this condenser mechanism into the house we come through an expansion valve and when the working material here expands it cools off it +[292.99s -> 303.60s] has a temperature now out in the outside that is lower than the air temperature outside or if it's a heat pump that uses groundwater. +[303.60s -> 317.23s] then we have a temperature here that's lower than the groundwater temperature. So energy is going to come in to our working fluid because the working fluid is colder than the outside air or the groundwater. +[317.23s -> 330.24s] that is brought back here that fluid carries energy with it and then the compressor does work to make the temperature higher than room temperature and we have moved energy +[330.24s -> 339.73s] from the outside to the inside and multiplied. The numbers turn out to multiply the energy that goes into Q sub h. +[340.62s -> 351.15s] In real heat engine, of course, we're going to lose some of our work. It doesn't get to the inside of the house. So we're not going to worry about that in my class. +[351.15s -> 364.93s] talk to your instructor on whether you need to concern yourself with this or not. Another illustration here of what's happening we have outside air perhaps at minus five degrees Celsius and then +[364.93s -> 376.70s] we want to take energy from that air and move it into the house so the working mechanism picks up the energy from the outside air and then +[376.70s -> 386.51s] Using the compressor makes the working fluid of the heat pump at a higher temperature than the inside of the house and energy is delivered to the inside. +[386.51s -> 396.77s] We've moved energy from the outside to the inside is an important feature here. We have to pay for the work done to run the heat pump, but the energy here is free. +[396.77s -> 410.77s] the energy in the air or the energy in groundwater that we're picking up, we do not have to burn a fuel to create this energy. It exists in the air, it exists in the groundwater, and we'll get to that discussion shortly. +[410.77s -> 424.78s] So here's a drawing of a heat pump. It can run both ways, depending on which way the fluid goes around the circuit. My class is not going to concern itself with that. But let's take a look at a calculation. So we have this definition. +[424.78s -> 438.27s] it's kind of the equivalent to the efficiency of a heat engine but coefficient of performance for a heat pump cp coefficient of performance we can measure how effective a heat pump is by +[438.27s -> 448.27s] taking a ratio here of the energy that reaches the high temperature region inside of the room for the case of a heat pump delivering energy to a house +[448.27s -> 460.91s] So Q sub H, the energy that comes into the house, divided by our work number that goes into the heat pump. Q sub H divided by W. For a Carnot heat pump, our best... +[460.91s -> 464.90s] coefficient performance can be calculated using temperatures +[464.90s -> 478.74s] The T sub H, the high temperature inside the house, and then the difference of temperatures between inside the house and outside. Notice these are single Ts. So in doing this calculation, you must use Kelvin. Don't use degrees Celsius. +[478.74s -> 492.08s] When will the coefficient performance be high? When will we be getting a lot of energy moved into the house compared to the work done? When will the coefficient performance be high? +[492.27s -> 504.16s] Well, if we have a small difference in temperature, so if we're not in the very coldest months where there's a big temperature difference between the inside and the outside of the house, it's difficult. +[504.16s -> 516.43s] to move energy from the cold reservoir to the hot reservoir when there's a big temperature difference between the two regions. We get our best result when TH is not too much different than TC. +[516.43s -> 522.45s] And we get our best delivery of energy inside the house. +[523.18s -> 536.02s] If you're using a groundwater system, then you don't have to worry quite so much. The air temperature is very variable through the winter months. A groundwater system, this T sub c is more reliable and has steady value. +[536.02s -> 547.09s] and not as cold as the air because it's still liquid water it's not below zero celsius oh let's suppose we're in nebraska and running a heat pump and let's suppose on a particular day +[547.09s -> 556.61s] The air temperature in the inside of the house thermostat setting caused CP to be 6. We used $10 of electricity. +[556.61s -> 563.18s] And maybe not in a day, maybe in a couple days. But we used $10 worth of electricity for the heat pump. +[563.44s -> 576.24s] What's the value of the energy delivered to the home? So I'm doing this calculation with dollars instead of joules, and that's fine So if we have CP is 6 and we use $10 worth of energy for W +[576.24s -> 586.58s] What's the value of Q sub H? Well, that's not too bad. Six here, $10 here. $60 for Q sub H. I used $10 of energy in the heat pump. +[586.58s -> 598.22s] I get $60 of energy delivered to the house. Again, assuming no losses, an ideal engine, ideal heat pump. But CP is 6. +[598.22s -> 609.42s] ten dollars for the w sixty dollars for q h how much of this energy is free sixty dollars came into the house worth of energy how much of that energy is free +[609.71s -> 621.44s] i had to pay ten dollars for the work fifty dollars is free fifty dollars is free i spend ten i get fifty there aren't too many businesses that run that way but heat pumps do run that way +[621.44s -> 633.39s] You put in a little bit of work, you get a lot of energy moved into the inside of the house. Well, so free energy, what's the source? I've already mentioned air or groundwater. +[633.39s -> 646.59s] Is air at minus 5 degrees Celsius, does it have energy? Air at minus 5 degrees Celsius? Well, yes. For a simple gas, the energy inside the material... +[646.59s -> 657.95s] is three halves of the number of moles times the gas constant times the temperature, but not temperature in Celsius, temperature in Kelvin. So for at minus five Celsius, +[657.95s -> 668.85s] We've got 268 here to put in for the temperature in Kelvin. Minus 5 plus 273 to convert to Kelvin. So 268 for the Kelvin temperature. +[668.91s -> 677.74s] The outside air in winter does contain energy and heat pumps can extract that energy and deliver it to a home. +[677.74s -> 689.07s] So that's the mechanism of the heat pump. For my class, I'm not going to go over the equations for the refrigerator. They change slightly in measuring the coefficient of performance for refrigerators. +[689.07s -> 700.48s] Just going to do the heat pump that gives you the basic understanding. The heat pump is a device where you spend a little bit of energy to run the mechanism. You gather free energy from the cold reservoir. +[700.48s -> 711.54s] and then you deliver more energy than you pay for through the heat pump working process. Remove free energy from the cold reservoir to the hot reservoir. +[711.54s -> 725.73s] and we get a value here more energy is delivered than what we spend for now heat pumps are expensive the equipment is expensive to install and depending on where you're located you know roughly might take 10 years to +[725.73s -> 733.78s] get back your money in your investment and then after the 10 years your utility bills are smaller. +[733.78s -> 747.02s] They're smaller right away after you install the heat pump, but you've got this perhaps debt that you have to pay off for the heat pump equipment, or you lowered your savings account to pay the installation cost. +[747.02s -> 760.50s] After 10 years, roughly, you start putting money back into your savings account that you don't have to spend on the utility bills. You're making money. You're paying it off. You're breaking even after about 10 years. +[760.50s -> 773.65s] of your savings on utilities, balancing off the cost of the initial investment. So talk to your local heating contractor to get more details, but it's worth considering. +[773.65s -> 779.70s] So that's where we're going to end this particular video. And I hope you keep working problems and stay safe. diff --git a/VideoMMMU_ASR_large/Engineering/test_Materials_239.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Materials_239.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cc98ec838f8530a36c992c3db876d16be48847c4 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Materials_239.mp4.txt @@ -0,0 +1,7 @@ +[1.07s -> 14.82s] Two solid cylindrical rods AB and BC are welded together at B and loaded as shown. What is the magnitude of force P so that the stresses in rods AB and BC are the same? +[14.82s -> 28.05s] This is the second example for the axial loading main video. Links to that video and example 1 are in the description below. If we write the stresses in terms of the internal loads FAB and FBC, +[28.05s -> 38.85s] We see that to solve for P, we need to find those two internal forces in terms of P. The areas would once again be the areas of the circular cross sections. +[38.85s -> 48.11s] Based on the conclusion from example 1, we'll perform the cuts starting at C. That way, we don't need to find the reaction force at A. +[48.11s -> 62.34s] Once again, we'll assume that the internal forces will cause tension so that positive values do in fact yield tensile stresses and negative values compressive ones. Fcb or Fbc would be equal to p +[62.34s -> 72.85s] and FBA or FAB would be equal to P plus 12. Solving for load P, we find a value of 6.75 kips. +[72.91s -> 81.35s] For more examples on axial loading, make sure to check out the links in the description below. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/test_Materials_319.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Materials_319.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0f1fe14d7d79e2ea547368205f52ba0433b2ee3b --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Materials_319.mp4.txt @@ -0,0 +1,35 @@ +[0.00s -> 10.93s] Welcome back to the channel. In today's video, we will show you how to determine the maximum stresses in a concrete beam and the steel reinforcing rods. +[10.99s -> 25.09s] All beams subjected to pure bending must resist both tensile and compressive stresses. Concrete, however, is very susceptible to cracking when it is in tension, and therefore by itself +[25.09s -> 39.60s] it will not be suitable for resisting a bending moment. In order to circumvent this shortcoming, engineers place steel reinforcing rods within a concrete beam at a location where the concrete is in tension. +[39.70s -> 53.42s] To be most effective, these rods are located farthest from the beam's neutral axis, so that the moment created by the forces developed in them is greatest about the neutral axis. Furthermore, +[53.42s -> 65.44s] The rods are required to have some concrete coverage to protect them from corrosion or loss of strength in the event of a fire. Codes used for actual reinforced concrete design +[65.44s -> 75.46s] Assume the concrete will not be able to support any tensile loading since the possible cracking of concrete is unpredictable. As a result, +[75.46s -> 88.02s] The normal stress distribution acting on the cross-sectional area of a reinforced concrete beam is assumed to look like this. The stress analysis requires locating the neutral axis. +[88.02s -> 100.69s] and determining the maximum stress in the steel and concrete. To do this, the area of steel is first transformed into an equivalent area of concrete using the transformation factor +[100.69s -> 114.26s] young's modulus of steel divided by modulus of elasticity of concrete this ratio which gives n greater than one requires a greater amount of concrete to replace the steel +[114.35s -> 125.55s] The transformed area is N, times the area of steel. Here, D represents the distance from the top of the beam to the thin strip of transformed steel. +[125.68s -> 133.23s] B is the beam's width, and H' is the yet unknown distance from the top of the beam to the neutral axis. +[133.39s -> 146.54s] To obtain H', we require the neutral axis to pass through the centroid C of the cross-sectional area of the transformed section. With reference to the neutral axis, therefore, +[146.54s -> 159.81s] the moment of the two areas together must be zero, since y bar equals zero. Thus, b times h dash, times half h dash, minus n times the area of steel, +[159.81s -> 172.69s] times d minus h dash equals zero. Once h dash is obtained from this quadratic equation, the solution proceeds in the usual manner for obtaining the stress in the beam. +[172.75s -> 186.06s] Let's take a worked example. We have a reinforced concrete beam with a width of 300 mm, and a depth of 450 mm, 50 mm concrete cover. +[186.10s -> 199.25s] If the beam is subjected to a 60 kNm bending moment, we need to determine the normal stress in each of the steel reinforcing rods, and the maximum normal stress in the concrete. +[199.31s -> 210.48s] We will consider the Young's modulus of steel to be 200 GPa, and the modulus of elasticity of concrete to be 25 GPa. +[210.70s -> 224.59s] First, we will work out the total area of steel, which equals 2 times pi, times the bar diameters 25 mm, divided by 1000 squared, divided by 4. +[224.69s -> 238.30s] This gives us a value of 0.3125 pi, times 10 to the power of minus 3 square meters. This area will be transformed into an equivalent area of concrete. +[238.30s -> 251.68s] As we mentioned earlier, equivalent area of concrete would be Young's modulus of steel 200 GPa, divided by modulus of elasticity of concrete 25 GPa. +[251.68s -> 264.45s] times the total area of steel.3125 pi times 10 to the power of minus 3 meters squared. This results in a value of 2.5 pi. +[264.45s -> 278.05s] times 10 to the power of minus 3 meters squared we require the centroid to lie on the neutral axis thus 0.3 meters times h dash times half h dash +[278.05s -> 289.39s] minus 2.5 pi times 10 to the power of minus 3 times 0.4 minus h dash solving for the positive root +[289.39s -> 302.77s] we get h dash point 1209 meter using this value for h dash the moment of inertia of the transformed section about the neutral axis is 1 divided by 12 +[302.77s -> 315.34s] times 0.3 meters times 0.1209 meters to 3 plus 0.3 times 0.1209 times half 0.1209 squared +[315.34s -> 328.90s] plus 2.5 pi times 10 to the power of minus 3 times 0.2791 squared. This gives us a value of 788.52. +[328.90s -> 339.87s] times 10 to minus 6 meters to 4. We should now be able to obtain our stresses. Applying the flexure formula to the transformed section +[339.87s -> 353.58s] the maximum normal stress in the concrete is 60 kilonewtons meters times 1000 to convert it to newton meters times 0.1209 meters divided by the moment of inertia +[353.58s -> 365.55s] 788.52 times 10 to minus 6 meter to 4. This results in a value of 9.2 newtons per square millimeters. +[365.58s -> 377.58s] Next, the normal stress resisted by the concrete strip that replaced the steel is 60 kNm, times 1000, times 0.2791. +[377.58s -> 386.35s] divided by the moment of inertia 788.52 times 10 to minus 6 meter to 4 +[386.48s -> 398.30s] This gives us a value of 21.24 newtons per square millimeters. Therefore, the normal stress in each of the two reinforcing rods is 200. +[398.30s -> 407.82s] divided by 25 times 21.24 giving us a value of 170 newtons per square millimeters +[410.03s -> 418.29s] Thanks for watching. We hope you found some useful tips. Check out our website at structuralengineercalcs.com +[418.77s -> 432.88s] Please like and subscribe, and let us know what would you like to see next. The human footprint is a masterpiece of engineering and a work of art. Stay safe. Goodbye, and see you soon. diff --git a/VideoMMMU_ASR_large/Engineering/test_Materials_358.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Materials_358.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6d33df6370d4735fea423fd58834c33d76d90a6e --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Materials_358.mp4.txt @@ -0,0 +1,33 @@ +[4.21s -> 13.23s] Welcome to my channel. If you like my video then kindly subscribe, like and watch. Thank you. +[15.41s -> 27.14s] Welcome back problem 2-3. The statement is that rigid beam is supported by pin at A. So you can see this is a rigid beam that is supported by pin at A. +[27.14s -> 39.50s] and wire bc and cd so this is bd and this is wire ce if load p on the beam causes the end c to be displayed by 10 centimeter downward 10 millimeter downward +[39.50s -> 51.44s] So due to this force, the C moves 10 millimeter downward, determine the normal strain developed in YCE and BED. So what we have to find is +[53.71s -> 66.48s] we have to find strain BD and the second one is strain EC +[67.86s -> 81.71s] so let's start with the solution you can see it is given that due to this load p the c and moves downward 10 millimeter downward so for that i will draw the free body diagram so +[81.71s -> 92.88s] let this is the beam clear and this is point c due to this load due to the load p +[93.46s -> 98.42s] this end moves 10 mm downward so this +[99.18s -> 114.16s] use 10 millimeter downward let this length is change in length is l delta l c e is equal to 10 millimeter here so the beam will +[114.80s -> 126.83s] Act like this. The total length of the beam is 3 plus 47. Let this is point B. +[127.66s -> 141.10s] This is point A so distance between point A and B is equal to 3 meter and distance between point B and C is equal to 4 meter +[141.10s -> 155.18s] Also due to the deflection of this point C to this new point here, this point B will also deflect and let this length will be equal to delta L B D. +[156.43s -> 169.73s] And that is not known. So from here you can see we have two similar triangles. One is AB and at this point is D. +[169.73s -> 183.02s] this point is x and let this point is y so we have two similar triangle triangle a c y and a b x so from similar triangles +[186.26s -> 188.21s] similar triangles +[193.20s -> 203.70s] right angle triangles we can take that the ratio of this Delta LBD divided by 3 Delta L +[204.27s -> 217.55s] BD divided by 3 will be same as ratio of delta LCE divided by 7, the whole triangle 7. +[218.10s -> 232.11s] LCE divided by four. I will repeat. We have two similar triangle ACY and another one is BABX. So the ratio of this +[232.11s -> 243.50s] Delta LBD over three will be same as the ratio of Delta LCE divided by seven. So from here you can get Delta +[243.89s -> 258.10s] LBD. So delta LBD will be equal to 3 by 4 delta LCE and also delta LCE is given as 10 mm. So it will be 30 divided by +[258.51s -> 266.64s] Which is equal not for this is salmon? this is +[267.12s -> 275.98s] Because we have taken the whole length so 30 divided by 7 +[280.02s -> 290.26s] you have to be very careful so this will give you four point two eight six millimeter +[290.96s -> 304.53s] It means that this point B are the strain in wire BD will be change in length of wire BD will be 4.286. Now we will find the strain in +[305.68s -> 317.04s] CE which is equal to change in length of CE divided by original length +[317.62s -> 321.17s] so change in length of CE is 10 +[322.38s -> 335.60s] and change and this wire CE is 4 meter so this is 10 millimeter and this is 4 meter which is equal to 4000 +[335.82s -> 346.64s] millimeter so 10 divided by 4000 will give you 0.00250 +[348.05s -> 361.04s] So strain in CE is equal to 0.00250 Now strain in +[361.58s -> 374.80s] BD will be equal to change in length of BD divided by original length. So change in length of BD was calculated 4.286 mm. +[376.53s -> 385.07s] divided by original length and original length is again 4000 mm they are same length there so 4000 mm +[386.74s -> 400.82s] so if you calculate it, it will give you 0.00107 so it means that strain in BD is equal to 0.00107 +[402.38s -> 414.61s] So these are the answers of our problem 2-3. I hope you have now clear understanding about this problem. Thank you for watching. diff --git a/VideoMMMU_ASR_large/Engineering/test_Materials_72.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Materials_72.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..739b71c51e34c7fec8aff053bccc87624ef0b94f --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Materials_72.mp4.txt @@ -0,0 +1,53 @@ +[0.46s -> 11.90s] Hello everybody, welcome back. Today we're doing another strengths and materials problem. And today we're going to be looking at stress again, specifically normal stress. And we're going to be relating it to something we covered before, which is actually the analysis of trusses. +[11.90s -> 25.87s] And the question goes as follows. We have a pin-connected truss, which is loaded and supported as shown below. We're asked to determine the normal stress in member CD, which is this one right here, if it has a cross-sectional area of 624 mm2. +[25.94s -> 35.92s] And then the second question is the minimum cross-sectional area is asked to be determined for member DF if the normal stress for that member is limited to 25 MPa. +[36.34s -> 48.80s] So the problem is giving us a lot of variables right off the rip, so we should probably look into C, what we actually need to know before hopping into each part. So for part A, we know that it's asking for normal stress in the member CD. +[48.80s -> 58.58s] So what's normal stress again? Normal stress is represented by the force perpendicular to the cross-sectional area. +[59.15s -> 73.84s] And we know in part A that we're given the area of the member, which is 624 millimeters squared. So we know that normal stress is going to equal to P over 624. +[73.84s -> 75.63s] millimeters squared. +[76.56s -> 90.96s] But what's P? Well, if we're looking at member CD, we can identify that the force that's referring to here is going to be that internal force within the member. So that leaves us with a final formula for normal force at CD. +[91.02s -> 105.14s] which is going to equal to FCD over 624 millimeters squared. So what type of methods are available for us to solve this type of problem? +[105.39s -> 119.14s] Well, we can look at section method and consider a cut something like this. However, due to the complex geometry and knowing that we need to solve for CD and DF. +[119.14s -> 132.42s] for both parts of this problem section method just really isn't viable based on the geometry of the truss however we do have another method which is the joint method which is going to be a lot simpler in our case +[132.42s -> 140.43s] where we have joint E which we can look at. So why joint E if we need to look at CD and DF? Why am I starting here? +[140.82s -> 148.05s] Well, I can tell from the geometry of the truss that we have two members at this joint. +[148.30s -> 162.51s] So if we have two members, one member has one x component and no y component, and the second member has a y and an x component. So if we actually analyze a joint E, we can first solve for this y component. +[162.51s -> 174.99s] to get the magnitude of the force within this member to solve for the next member, DE, which can then be transferred over to the next joint to get all of those other important members. So let's start with part A. +[174.99s -> 188.18s] look into that joint E and see what we're dealing with. Alright so now that everything's set up we have the free body diagram of joint E so that we can analyze for these simple forces and then carry those over into the joint D so that we can get the forces we're actually looking for. +[188.18s -> 200.27s] which are FCD and FDF. Now I've also brought over this convention from a previous video, which is just showing you the tension and compression forces within the truss and how to understand what's what. +[200.27s -> 213.54s] uh based on the arrows and the way they're pointing uh in the free body system so let's start with joint e we have written down that we have a 10 kilonewton external force we have d e which is going to be pulling away from that joint +[213.54s -> 227.12s] Then we have FFE pointing upwards to resist that 10 kilonewton force. And there's two different ways that you can go about getting the components for this force. You can recognize that we have a 3-4-5 triangle, as we have a 3-meter here. +[227.12s -> 241.01s] and a four meter here composing that three four five or we could also take a theta about this point here or about this point here and then use z pattern to get that angle so that would just be tan inverse of four over three +[241.36s -> 255.17s] But we have the special triangle, so we can just proceed as follows. We know that we have only one unknown y, so it would be wise to start with summation of y equals 0. And we're going to be looking at 0, which is equal to negative 10. +[255.17s -> 265.30s] which is that external force pointing down. And then we're going to be adding the Y component of the FFE, which is going to be 4 over 5. +[266.26s -> 273.04s] Solving for that the signs are going to work out and we're going to be left with 12.5 kilonewtons. +[273.42s -> 287.50s] And that's going to be in compression because it's pushing towards the joint. And then we can move on to get fx equals 0 so that we can solve for that x component in fde. So we have 0, which is going to be negative fde. +[288.05s -> 300.40s] And now we consider the x component of FFE, which is going to be positive FFE 3 over 5 now, since we want that x component here. +[301.01s -> 312.66s] Positive, obviously, because we have a convention like this for X and like this for Y. And we know FFE is 12.5. So plugging that in and solving for FDE. +[313.30s -> 317.97s] We are left with 7.5 kilonewtons, and that's going to be in tension. +[318.51s -> 331.15s] All right, now we can carry over the FDE component that we calculated before, which is 7.5 kilonewtons. We can move on to joint D, and we can take a look at what FDC is and FDF is so that we can solve A and B respectively. +[331.15s -> 343.25s] First thing we need to do is figure out what this data is, because FDC has components Y and components X. And as we can see on this diagram, we know the height corresponding to this member CD. +[343.25s -> 357.78s] but we don't know the base or the length that we need to use in order to determine that data. So we can use similar triangles based on the entire geometry of the truss structure in order to create a relationship between this data and this data. +[358.19s -> 368.43s] So we don't know this x value, which is here. But we do know the height of this opposite side to the angle, which is going to be 2 meters. +[369.14s -> 380.24s] We also know that this angle here, which is parallel to the joint, is following the same line of action as this member at the bottom here. So that means these angles are going to be the same. +[380.94s -> 394.48s] So if we consider the base of this angle and the height that it's corresponding to, we actually have 3 meters plus 3 meters, which is going to be 6 on the bottom. And then we have 2 plus 2 plus 2, which is going to be 6 on the side. +[395.15s -> 407.25s] Now, relating these together, we know that 6 over 6 is going to be equivalent to x over 2. Therefore, x will equal 2 meters. +[408.21s -> 420.53s] And then we can use that information to solve for the angle theta, which will be the tan inverse of 2 over 2, which will simply be equal to 45 degrees. +[421.07s -> 432.72s] Now we can use the fun part and start solving for the components. We know that we have only one x component to solve for, but there are two y components. So we're going to start with f at x, which is equal to 0. +[433.26s -> 444.53s] And we're going to be looking at an equation that looks something like this. We have the negative FDC component, which is going to be the cosine of 45. +[446.32s -> 459.73s] And then we're going to be adding that FDE that we found earlier. Solving for that, we're left with FDC, which is equal to 9.86 kN in tension. +[460.69s -> 464.69s] And then we can do the same for summation of forces at y. +[465.58s -> 476.11s] We're going to have 0, which is equal to negative 12 minus 9.86, which we just solved for, the sine of 45. +[477.20s -> 484.02s] And we're going to be adding that component FDF since it's positive in this direction. +[485.23s -> 495.33s] Looking at FDF and isolating for it, we're going to be left with 18.4 kN. And now we have the forces of both the members that we need for A and B. +[495.33s -> 509.79s] So let's proceed to part A and solve and let's proceed to part B after. Alright so now we can finally get solving. We have all the variables we need to solve part A finally. So we know the normal stress is going to equal to FCD over the area given. So that is simply going to be 9. +[509.79s -> 521.78s] 0.86 times 10 to the 3 Newtons over 624 millimeters squared. Why did I do times 10 to the 3 though? +[522.00s -> 525.36s] I converted it because we know that MPA +[526.48s -> 539.58s] which is megapascals will be newtons over millimeters squared. So it's just a simple conversion in order to avoid any confusion during solving. We like to keep all of our stresses in a consistent unit. +[539.58s -> 550.83s] and MPa tends to be that unit. So solving this we're left with the normal force created in CD based on the area is equal to 15.8 MPa. +[551.76s -> 565.81s] Final answer one. Now for part B, we're going to take the same concept. We're looking for the minimal cross-sectional area for remember DF if the normal stress is limited. So we have the normal stress formula, but now we're going to be looking at DF. +[566.22s -> 578.16s] If we're looking at DF, that means we have to consider the force at DF over the area. But now area is unknown. So we have to isolate for area. +[578.48s -> 589.68s] which is going to be the minimum, which is equal to the force at DF over the normal stress in DF. +[590.61s -> 600.72s] Now solving this formula, we just need to plug in the values that we solved for previously. So we have 18.4 times 10 to the 3 newtons. +[601.17s -> 611.09s] And we're going to have the restriction, which is 25 MPa. So 25, and that's newtons per millimeter squared. +[611.44s -> 624.85s] Our newtons will cancel out, the millimeters will be brought to the top, and we'll be left with a final answer for area minimum, which is 736 millimeters. And that's your second final answer. diff --git a/VideoMMMU_ASR_large/Engineering/test_Materials_91.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Materials_91.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..22ba7ce51de0b8799782dd98298184c8a2d27fb2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Materials_91.mp4.txt @@ -0,0 +1,60 @@ +[0.30s -> 12.16s] Welcome back. Problem example 1.6. This problem is taken from chapter number 1 stress and book name is mechanics of material by R.C. Hibbler and 9th edition. +[12.16s -> 23.89s] The statement is the 80 kg lamp is supported by two rod AB and BC shown in figure. If AB has diameter of 10 mm and BC has a diameter of 8 mm. +[23.89s -> 38.16s] determine the average normal stress in rod in each rod so you can see this is the lamp clear and that is supported by rod bc and ac and the weight of the rod lamp is going to act downward +[38.16s -> 49.36s] so due to this downward weight there will be a tension in this ab and bc as a result of newton third law the rod will exert force on lamp in this +[49.36s -> 61.15s] direction so i have shown this in free world diagram the weight of the lamp is acting downward and the force this rod bc acting on lamp is fbc while the +[61.15s -> 67.41s] Force of rod AB on lamp is FAB. FAB makes an angle of 60 degree with the +[67.41s -> 81.68s] horizontal while this fc the ratio of the triangle is shown as 3 4 5 so you have to determine the average normal stress in each rod so let's start with the solution the first step is that this +[81.68s -> 95.89s] weight is acting downward and weight is equal to mass into g so mass is given as 80 kg and g is 9.81 so when you solve this this weight acting downward will be equal to 7 +[95.89s -> 106.90s] 84.8 newton now we will apply equation of equilibrium so first equation of equilibrium is that sum of all forces +[106.90s -> 118.35s] Along x direction must be equal to 0 and force toward right is taken as positive. So you can see that this FAB will have two component 1 along x. +[118.35s -> 126.35s] which will be equal to FABX component and one along Y, which will be equal to FAB. +[126.35s -> 137.90s] y similarly this fbc will have two component which will be fbc x and one along y which will be equal to fbc +[137.90s -> 147.98s] So from here this minus FAB X component plus FBC. +[148.40s -> 162.30s] x will be equal to zero so you can see that this angle is 60 degrees so it's one component that this is fab so this component will be equal to fab +[162.30s -> 169.90s] Cos of 60 degree. And this vertical component will be equal to FAB. +[170.64s -> 185.36s] sine of 60 degree why how because if you take cos 60 degrees so cos 60 degree will be equal to this FBX FBX divided by FAB +[187.54s -> 197.17s] So, FABX will be equal to FAB cos of 60 degree. Similarly, this FAB +[197.39s -> 211.18s] y component will be equal to f a b y and same is the case if you take this component which is that this force will be f b c so this f b +[211.18s -> 217.89s] cx component will be this one and fbcy component fbc +[217.89s -> 231.90s] y component will be this one so for example if this is theta angle so if you take cos of theta so cos of theta is equal to 4 divided by 5 and this fbc x component will be equal to +[231.90s -> 245.74s] fbc into cos of theta so fbc into 4 divided by 5 this will be fbcx and this fbc +[245.84s -> 260.08s] y component will be equal to fbc sine of theta so you can put the value of sine of theta sine of theta is perpendicular over the hypotenuse which is 3 over +[260.08s -> 273.89s] So FBCY will be equal to FBC into 3 divided by 5. Now you can just plug it in this. So FAB is this one. +[273.89s -> 276.88s] So I can write minus FAB. +[277.55s -> 290.90s] into cos of 60 degree plus FBC x. So this is plus FBC into 4 over 5 is equal to 0. +[291.95s -> 300.27s] Let this become your equation number. This is your let we name this equation number 1. +[300.27s -> 314.32s] now we will apply another equation of equilibrium that sum of all forces along y direction must be equal to zero and upward force is taken as positive so one upward force is this one which is equal to f a b +[315.38s -> 329.76s] sine of 60 degree another one is this FBCY which is this one plus FBC into 3 over 5 clear and the downward force is weight which is minus +[329.76s -> 341.07s] 784.8 newton their sum must be equal to zero so i can rewrite it this f a b +[341.30s -> 353.30s] into sine of 60 degree plus FBC into 3 over 5 minus 784.8 is equal to +[353.30s -> 358.99s] zero so it means that you are this +[359.38s -> 372.75s] FAB into sine of 60 degree will be equal to 784.8 minus FBC into 3 over 5. +[372.75s -> 385.36s] And this FAB will be equal to 784.8 minus 3 by 5 times FBC. +[386.10s -> 395.25s] Divide by sine of 60 degree. Clear? So this is your equation number 2. Now put. +[396.24s -> 407.71s] equation 2 in equation number 1 so this is your equation number 1 so FAB will be replaced with this so minus +[407.71s -> 420.46s] 784.8 minus 3 over 5 times FBC divided by sine of 60 degree into +[420.98s -> 430.46s] Cos of 60 degree plus FBC into 4 over 5 is equal to 0. +[430.46s -> 444.98s] you know you will get this equation so if you solve this equation so you will get fbc will be equal to 395.2 newton now put the value of this +[445.30s -> 446.54s] Put +[447.15s -> 461.14s] FBC is equal to 395.2 Newton in equation number two. So you will get FAB is equal to 784. +[461.14s -> 475.25s] 0.8 minus 3 by 5 multiplied by 395.2 divided by sine of 60 degree so you will get this +[475.47s -> 488.80s] FAB will be equal to 632.4 Newton. Now you have forces in both the rods. So we will go towards the Newton. +[488.80s -> 500.18s] the average normal stress in each rod since rod a b and b c both are in tension so we will find for for rod +[500.82s -> 511.33s] AB average normal stress in rod AB will be equal to force in rod AB divided by area of AB +[511.33s -> 522.58s] so force in rod ab is 632.4 newton and diameter of rod ab is given as 0.01 meter so pi by 4 +[523.02s -> 526.86s] pi by 4 d squared. +[527.63s -> 538.48s] Let me write pi by 4D. Diameter is 0.001, not 001. +[538.86s -> 552.98s] 0.01 square so when you solve this you will get the average normal stress in rod a b comes out to be 8.05 mega pascal now for rod +[553.55s -> 567.70s] BC we have average normal stress in rod BC will be equal to force in BC divided by area of BC so force in BC is 395.2 +[567.70s -> 581.33s] newtons here and area is pi by 4 what is the diameter so diameter is given as 0.008 pi by 4 0.008 +[581.33s -> 591.79s] square so when you solve this you will get average normal stress in rod bc is 7.86 mega pascal +[592.11s -> 605.73s] So that was all about this average normal stress in rod A, B and B, C. Now what if I represent this average normal stress in rod A, B. So let this was the rod. +[605.73s -> 618.80s] clear for example this is the rod having this diameter clear so this is the load fab +[619.25s -> 632.66s] This is FAB, which is equal to 632.4 Newton. And if you want to represent this element. +[633.55s -> 646.06s] clear stress on this so the stress will be like for example this is the same rod a b so stress on this rod will be like this +[650.35s -> 654.58s] and if you represent them on element of +[654.86s -> 666.88s] cubes cubic element so this stress will be tensile it will be like this that is uh 8.05 +[666.88s -> 672.27s] mega pascal same is the case you can draw this stress +[672.75s -> 686.27s] and force diagram for rod bc so that is all about this problem example 1.6 i hope you have enjoyed this video and you have learned from it those who are new to my channel then subscribe it +[686.27s -> 697.94s] and don't forget to press the bell icon so that you can get notification about my latest videos if you have any question you can ask me in comment section thank you for watching diff --git a/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_203.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_203.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a87b5bf0ba45c82ce5b9e5018731ba7cbd6448ce --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_203.mp4.txt @@ -0,0 +1,31 @@ +[5.65s -> 19.23s] Orthographic projection. In engineering drawing, we often have to produce 2D and 3D drawings of parts or components. These 3D objects need to be shown on 2D planes, that is, X and Y planes. +[19.23s -> 32.13s] in such a way that we get to see all the views that is front view side view top view etc this projection system is known as orthographic projection and in this system of projection +[32.13s -> 43.84s] the views have to be drawn following certain standard projection rules that is first angle and third angle method the first and third angle methods are largely used in any designing industry +[43.84s -> 56.54s] To understand this, we first need to learn about the quadrant system. In quadrant system, we have got two planes in 2D, that is, X and Y plane, or, horizontal and vertical planes respectively. +[56.54s -> 69.97s] When the axes of the 2D system divide the plane into four infinite regions, these regions are known as quadrants. These quadrants are designated in an anticlockwise direction, starting from the first quadrant. That is, +[69.97s -> 74.74s] upper right corner to the last which is lower right corner fourth quadrant +[75.47s -> 86.06s] Rule of orthographic projection. According to this rule, to draw the projection of a 3D object on the 2D plane, the horizontal plane is rotated in the clockwise direction. +[87.50s -> 95.98s] First angle method. In the first angle method, the object is placed in the first quadrant such that it lies between the viewer and the plane of projection. +[96.27s -> 108.19s] While considering the observer is standing here, view from this point is considered as the front view. When the viewer views the object from the front view its projection is projected on the vertical plane of the first quadrant. +[108.19s -> 112.37s] You can see from the viewer's eye how the front view of this object looks. +[112.85s -> 126.38s] And when the viewer views the object from the top, its top view is projected on the horizontal plane of the first quadrant. This is how the top view looks from the top. For the left-hand side view, we consider another parallel plane. +[126.38s -> 138.22s] which is placed on the right side of the object. And when the viewer views the object from the left-hand side of the object, the left-hand side view is projected onto the profile plane. This is how it looks. +[139.34s -> 154.02s] For the right hand side view, we consider another parallel plane, on the left side of the object, and when the viewer views the object from the right hand side of the object, the right hand side view is projected onto the profile plane, which is placed on the left side of the object. +[154.02s -> 155.92s] This is how it looks. +[156.21s -> 170.50s] For drawing these projections onto the drawing sheets we follow the rule of orthographic projection. According to this rule, to draw the projection of a 3D object on the 2D plane, the horizontal plane is rotated in the clockwise direction. +[170.50s -> 183.36s] and the profile planes are also unfolded. By doing so, we have the following projections. The front view of the object is on top. The top view is on the bottom. The left-hand side view is on the right side of the front view. +[183.36s -> 194.43s] and the right hand side view is on the left side of the front view. This is how we draw on drawing sheets using the first angle method. If you are enjoying this video, please give this video a thumbs up. +[194.43s -> 207.09s] as it helps the YouTube algorithm to recognize good content, and suggest others who want to learn, and if you are new to ADTW Learn, click on the subscribe button and turn on the notification to get more informative videos like this. +[208.50s -> 217.50s] Third angle projection method. In this projection method, the object is placed in the third quadrant and the plane of projection lies between the object and the viewer. +[217.50s -> 232.46s] As the vertical plane of the third quadrant lies between the viewer and the object the viewer cannot see the object. Therefore, we will make the vertical plane transparent and then we can see the front view, which will be projected on the vertical plane lying between the viewer and the object. +[235.73s -> 244.91s] Similarly, while viewing from the top, the horizontal plane will come between the point of view and the object, therefore the top view will be projected on the horizontal plane. +[247.47s -> 261.04s] For the right-hand side and left-hand side view, we will have the two profile planes on either side of the object. Now when the viewer sees from the right side, the right side view will be projected on the right profile plane of the third quadrant. +[261.65s -> 265.52s] and the left side view will be projected on the left profile plane. +[266.42s -> 280.72s] When we unfold the planes according to the orthographic rule, we will get a front view on the bottom of the XY line, a top view on the above XY line, and left side view on the left side of the front view, and a right side view in the right side of the front view. +[280.72s -> 291.66s] This is how first and third angle projection method works. Symbols used to represent. These are the symbols used for representing first angle and third angle method. +[293.71s -> 306.99s] Why don't we use the second angle and fourth angle method? It is not possible to show a 3D view of an object on the 2D plane, therefore we use orthographic projection. According to the rule of orthographic projection, +[306.99s -> 321.49s] The horizontal plane needs to be rotated in the clockwise direction to view the top and front view on the 2D plane. Once the horizontal plane is rotated in the clockwise direction, the projections present on the horizontal plane are also rotated along with the plane. +[322.19s -> 335.39s] Now consider the second angle view in which the object is placed on the second quadrant and the plane lies between the object and the viewer. The top view is projected on the horizontal plane and the front view is projected on the vertical plane. +[335.39s -> 347.95s] and when the horizontal plane is rotated in the clockwise direction, the top view projected on the horizontal plane will overlap with the front view projected on the vertical plane. A similar problem will occur while using the fourth quadrant. +[347.95s -> 359.70s] Therefore, we don't use the second and the fourth angle method. I hope you have understood the first and third angle methods. It takes lots of effort to make such informative videos. You can help a DTW learn. +[359.70s -> 372.80s] to make more videos by joining our channel and contributing to developing more such videos your support will help us make great educational videos other ways of helping us is by sharing our videos with your friends thank you diff --git a/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_359.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_359.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..9e41a9317ef6cfe5a66b51c539400b794faeec4e --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_359.mp4.txt @@ -0,0 +1,88 @@ +[0.46s -> 10.29s] So in this question we're asked to solve for the transfer function g which is equal to the angle theta2. So that's the angle of this part of the shaft here. +[10.67s -> 19.34s] and it's divided by T which is the applied torque and we can see from the diagram it's applied onto this other part of the shaft. +[19.34s -> 33.68s] So to start off this question, what we're going to want to do is draw one free body diagram for every degree of freedom that we have. And the minimum number of degrees of freedom is going to be how many inertias that you have. +[33.68s -> 44.06s] the rule when they're not going to be equal is sometimes you might end up with components in series without the inertia in between in which case you would need to put in another +[44.06s -> 53.12s] angle, so like theta three or whatever, to measure in there and draw an extra free body diagram of what's going on in that section of the shaft. +[53.12s -> 61.62s] Looking at this we don't have any components in series which aren't already being measured so we don't need to worry about that. +[62.42s -> 70.96s] So what I'll start with is drawing the free body diagram of the first mass or inertia. +[75.38s -> 85.14s] all right so separating this component out so we have a applied torque onto this component +[85.81s -> 95.04s] And we can see it's drawn clockwise. And we're going to have some resistance due to this inertia being attached to a damper and a spring. +[95.04s -> 108.08s] So if we look at the damper first, so the damper is going to try and resist the direction of motion. So if the torque is applied this way, so clockwise, I'd also expect the shaft to spin clockwise. +[108.08s -> 114.67s] So let me put that in. That's my inertia term, the constant multiplied by the angular acceleration. +[115.06s -> 128.29s] So what I would expect is this damper is going to try and oppose the direction of motion. So it's going to go backwards and the size of it is going to be the constant multiplied by the angular velocity. +[128.29s -> 139.15s] of this part of the shaft. So since it's butted up against a wall it's basically just going to be how fast this part is rotating which is theta one dot. +[140.34s -> 152.40s] So the other part that I need to include is from the spring. Again if my inertia is going clockwise I would expect my component, the spring, to resist that motion and try and bring it back to where it was. +[152.40s -> 158.50s] and the size of it is going to be the constant k multiplied by the +[158.50s -> 170.03s] angular displacement of my shaft through this component. So because it's between two different inertias here we need to take the difference between them. +[170.03s -> 182.48s] So it's going to be equal to whatever theta1 is minus whatever theta2 is, the difference between their angles. Alright, so that's the complete free-body diagram. +[183.18s -> 188.72s] Let's just repeat this for the second one and then we'll go through and develop the equations of motion. +[190.64s -> 203.89s] So taking out this component here and going through the same process. So I'm going to assume that if this torque is applied clockwise and this one's spinning clockwise, this one's probably going to spin the same way as well. +[203.89s -> 214.96s] So we'll start by marking that in. So this is the size of the inertia multiplied by the angular acceleration. This one's theta2 measured here. +[215.86s -> 228.72s] And then we need to put in the spring and the dampers effect. So let's start with the damper again. It's going to try and resist the motion so it's going to go backwards and since it's butted up against a wall +[228.75s -> 239.95s] we're just going to take the damper and multiply it by the velocity of this which is theta 2 dot obviously the you know yeah put it up against the wall so we don't need to take the difference +[240.59s -> 255.47s] So now we can put in the spring. So again, it's going to try and resist the motion. And it's going to be equal to theta2, the one we're looking at relative to j2, theta2, minus... +[255.47s -> 269.49s] the other one, theta 1. So as long as you always follow this pattern, for the ones where you need to take the difference, it's going to be the angle on the component that you're looking at, so J2 in this case, minus the one it's attached to, which was theta 1. +[269.90s -> 284.34s] Alright, so let's go through and develop our equations of motion. So the equation that we need to satisfy for the rotational systems is that the sum of the torques applied to our shaft have to be equal to J +[284.34s -> 297.62s] multiplied by theta double dot. So for the left hand side here it's going to relate to all the lines that I've drawn in solid and the right hand side is going to be the ones that are dotted in, that's the inertia term. +[297.62s -> 309.84s] So I'm going to say that this is the positive direction for the sake of this calculation. It doesn't really matter which one you pick as long as you're consistent. So we're going to have the torque T applied in the positive direction. +[310.13s -> 318.51s] We've got the damper part applied in the negative direction and we've got this applied in the negative direction as well. +[320.88s -> 330.13s] And on the other side of the equation, this relates to this, and it's in the positive direction, so it's going to be j1 theta1 double dot. +[331.47s -> 343.41s] Alright, so I may as well at this point try and get this in a form that's going to make it easy to solve. It's going to turn into simultaneous equations between the one we get here and the one we get for the other side. +[343.41s -> 354.90s] So for that I'm going to leave the t on one side of the equation and move everything else to the other because everything else has theta terms in it. So let me just do that. +[358.00s -> 371.31s] And I might also expand this while we're here. Alright, the next thing I'm going to want to do is Laplace transform it. And what I'm going to do is assume that all... +[372.85s -> 386.35s] initial conditions are zero. So initial velocity and positions are zero. Okay. +[387.82s -> 399.06s] So that means when I Laplace transform it, if things have dots, they're just going to get the equivalent number of s's. So t is a function of time, so when we transform it... +[399.06s -> 409.86s] it just basically becomes itself i would capitalize it except i already used a capital so all good j is a constant it's not changing with time and theta is it's got two dots +[409.86s -> 417.65s] so that means when we Laplace transform it it gets two s's and again you would capitalize this variable but it's kind of hard to capitalize theta. +[418.38s -> 432.05s] Next we have d, and I think I've dropped the, that should be d1, and it is a constant with time, so it just stays the same, and this needs to be transformed, it becomes s theta 1. +[432.88s -> 439.73s] K is a constant. This has no time derivatives on it, so it's just going to stay the same. +[440.40s -> 450.80s] And same with the one on the end. So the last step that I'm going to do here, just to make it easier to solve, is I'm going to factorize. So everything with a theta 1. +[451.50s -> 462.70s] We've got j1s squared, d1s and k. And then everything with theta2, all we've got is k. And notice the signs on these. +[462.70s -> 476.18s] I'll come back to it in a moment but yeah this has worked out everything in this bracket is positive and this has worked out to everything is negative. So let's go through and repeat this process on the other one. +[481.30s -> 492.56s] Alright, so we've got this talk here applied in the negative direction. So it's minus d2, d2 dot. This is also in the negative direction. +[494.61s -> 500.94s] And the other side of the equation relates to this part here. It's drawn in the positive direction. +[503.09s -> 517.30s] Alright, so let's go ahead and shift everything to one side of the equation again. The intention here is to have everything with thetas in it on one side and everything else on the other, but we don't actually have anything else, so it's just going to be 0 left on the left-hand side. +[517.30s -> 526.83s] I'll move everything else and at the same time I'll expand again. +[530.74s -> 544.02s] Alright, so now we can go ahead and Laplace transform. So 0 is just going to remain 0. The first term is going to become j2 s squared theta2. The next one gets 1s. +[544.27s -> 557.90s] And the others remain the same. Alright, and we're going to go ahead and factorize it again. So I'm going to take out theta1 first. Okay, and this is the only one with theta1. +[560.02s -> 567.18s] And then theta 2, we've got all this stuff. I've dropped the 2 again. Here we go. +[572.62s -> 580.27s] Okay, and what we can notice is that we've got a negative on the theta1 this time and positives for all the theta2 stuff. +[581.01s -> 592.56s] So there's two ways to solve this equation. One is to just do simultaneous equations. So rearrange this equation and then substitute it into the other one. +[592.88s -> 605.10s] The other way to do it is to use the matrix method with Cramer's rule. And that's the one that I'm going to use. But I think they're probably equally time consuming in their difficulty. +[605.30s -> 615.41s] So let's just double check what transfer function we're actually looking for. So we want theta2 divided by t. So that's what we're going to go for. +[616.85s -> 630.00s] So we'll start by setting it up in our matrix method. So matrix A is the one of all of the constants in front of the unknowns. X is the unknowns, so in our case theta1 and theta2. +[630.00s -> 643.76s] And B is the matrix of values on the other side of the equation. So we have T and we have 0. So this is just a standard maths thing, not specific to control at all. Alright, so our A matrix. +[644.75s -> 654.80s] It's going to start with j1s squared plus d1s plus k. Well, what's in front of theta1? Theta2, it's just going to be negative k. +[656.05s -> 669.01s] Maybe it'll leave me a bit more space. Alright, so our two unknowns was theta1 and theta2. And on the other side, it's equal to the constant, so t. +[670.03s -> 679.54s] So we can go through and fill it out for our second equation now. So for theta1 we have negative k, and for theta2 we have this. +[684.08s -> 689.30s] and we've already filled in our two unknowns and we have zero on the other side. +[690.35s -> 703.23s] So just to quickly point out how we can kind of double check at this stage that we've picked up all the terms that we wanted to. So I'll just copy down the +[703.23s -> 715.54s] thing that we had before the original question so what we're going to see is that on the diagonal just like with the spring mass damper systems we end up with positive values +[715.54s -> 729.84s] so what that relates to is if we take this first one for example this was the one that was related to j1 inside our free body diagram and what you'll notice is that you pick up the positive of everything attached to that part of the shaft so you've got the +[729.84s -> 743.98s] actual inertia itself which is this j1 s squared but you also pick up it was attached directly to a damper so that appears and it was attached directly to the spring so that appears for the second +[743.98s -> 749.38s] that related to this line of the equation and you can see in this bottom +[749.38s -> 761.31s] corner one, we've ended up picking up the inertia term for that mass, we've picked up the damper that it was directly attached to and we picked up the spring that it was directly attached to. +[761.31s -> 773.55s] And finally on these diagonals what we're going to find is that we end up with the negative of what's in between the two different parts of the shaft. So between J1 and J2 we've only got a spring. +[773.55s -> 786.45s] and it's ended up being a negative in there. So that's how you can go ahead and double check that you've picked up everything in your system and that also you've got the correct signs on everything in your system. +[786.54s -> 801.14s] So I've just quickly noted down the pattern here so you can see that on the diagonals we've got everything that's attached to our various different inertias and then on the other sides reflected across the diagonal we have the negative of what +[801.14s -> 813.14s] in between those components theta1 and theta2 are the angles and on the right hand side we're going to pick up any external torques applied to our system so we had an external torque applied to j1 +[813.14s -> 826.29s] So that's why the t appeared. We had no external torques on this one, so that's why this ended up being 0. So that's basically the pattern, so you can double check that you've got everything that you need within your equation. +[826.42s -> 838.80s] Okay, so getting back to solving this, what we want to get out is theta2 divided by t. So using Cramer's rule, we can get that from our matrix. +[843.38s -> 857.81s] So we're going to solve for theta 2, since that's what we want inside our equation. And what we need to develop is our two determinants. So on the top line of our equation, we're going to have one, and on the bottom line we have another one. +[857.81s -> 870.67s] So since we're looking for theta2, which is the second variable, this is the first one, this is the second one, we need to slot this matrix into the second column of our A matrix. So that's the first column. +[870.67s -> 883.23s] that's the second column. If we were wanting to solve for theta1 we would take this and put it in the first column of our A matrix. So let's go ahead and fill this in. So since we're looking for the second one +[883.23s -> 895.54s] The first column stays the same and the second one has been replaced with t and 0. And now for the bottom line's determinant, we just copy straight down this A matrix. +[909.04s -> 923.22s] Okay, so now we just need to go and solve for these determinants. So for the top one, it's going to be this times this, which is 0, minus this times this, which is tk. +[924.59s -> 928.05s] And for the bottom line, we've got this times this. +[936.85s -> 941.55s] minus this times this, so it's like negative k squared. +[942.58s -> 956.08s] Alright, keeping on going. So the transfer function we were looking for was theta2 on t. And we can get that just by dividing down to the bottom line. So k stays at the top. +[956.08s -> 970.35s] and I'm going to make the effort to expand this out because what you should see with these two degree of freedom systems which are purely rotational is that whatever ended up in this minus part on the end from the determinant should cancel with something else inside the +[970.35s -> 974.64s] equation. So let me take the effort to expand out all these brackets. +[996.14s -> 998.77s] I might continue this on the next line. +[1006.77s -> 1016.85s] So all of that is from these two brackets and then this one's going to become negative k squared is k squared and we've got another negative in there. +[1017.62s -> 1030.29s] So what we can see is that that k squared is going to cancel with that k squared. And we can conclude our final answer by grouping together all the different powers of s. +[1030.29s -> 1043.15s] It's not 100% necessary but it will make it easier when you have to go on and use this transfer function in other things. So for the S to the fourths, we only have that. +[1043.82s -> 1048.27s] For the S to the cubes, we end up with this one and this one. +[1054.10s -> 1059.98s] For the s squareds we end up with a couple. We've got 1, 2, 3. +[1068.34s -> 1072.53s] And we've got a couple of s terms as well on the end. +[1079.22s -> 1094.00s] So this becomes our final answer for the transfer function, and it's even in a nice form to be able to keep working with it. So that's all there is for this question, and I'll see you in a different video. diff --git a/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_382.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_382.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e82f252308d2e2e67f8b4b5a010eafda2a724984 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_382.mp4.txt @@ -0,0 +1,26 @@ +[0.43s -> 13.07s] Welcome to iLectra Online. Now let's take a look at the relative pipe roughness. Remember with the Moody diagram, it was one of the factors that we needed to come up with the frictional factor. +[13.07s -> 26.70s] Going back a little step further, we're looking for the frictional head loss. In other words, the component that goes in Bernoulli's equation that accounts for the frictional forces inside the pipe. +[26.70s -> 38.11s] And so for that, besides the length of the pipe, the velocity of the fluid, the diameter of the pipe, and the acceleration due to gravity, we needed something called the friction factor. Now when we have laminar flow, +[38.11s -> 46.14s] That was relatively easy to calculate. We take the number 64 and divide it by the Reynolds number. But when we had turbulent flow, +[46.14s -> 59.76s] we needed to figure out what we call the relative pipe roughness, because we started from the Reynolds number, we then calculated the relative pipe roughness, and then from that, we can, from the Moody chart, figure out... +[59.76s -> 72.13s] what the friction factor is so therefore it's all about knowing the relative pipe roughness now how do we do that well the relative pipe roughness is some constant divided by the diameter of the pipe +[72.13s -> 85.46s] where the constant can be found by applying a table. So notice for the different kinds of pipes, we have different kinds of constants. The rougher the pipe, the greater constant, the smoother the pipe. +[85.46s -> 98.54s] the less the constant for coarse concrete it's 0.25 but for smooth new concrete it's only 0.025 so the number is 10 to 1 between smooth concrete and coarse concrete +[98.54s -> 109.06s] We have what we call drowned tubing or glass or plastic. You can see that the constant is very very small which indicates very small opposition to the flow of fluid. +[109.06s -> 115.94s] Now iron cast has a much bigger number and old sewers typically made out of cast iron and +[115.94s -> 128.83s] cast iron that is corroded to a great extent has very rough surface on the inside so it has a very big constant indicating you'll have a very large relative pipe roughness for mortar line steel is +[128.83s -> 141.79s] quite a bit less but for rusted steel is quite a bit more forged steel is in pretty good shape and water mains especially old ones notice you have a lot of a lot of friction losses because of the +[141.79s -> 151.63s] a lot of roughness on the inside of the pipe. So what we do then is we take that constant appropriate to the type of pipe we're dealing with and divide it by the diameter of the pipe. +[151.63s -> 159.04s] Notice the constant has units of millimeters, which means the diameter of the pipe must be expressed in terms of millimeters. +[159.04s -> 170.58s] So let's do a quick example to see how we would come up with the relative pipe roughness. Let's say we have an iron cast pipe that is 6 inches in diameter. What is the relative pipe roughness of that? +[170.58s -> 178.61s] So we can say that RPR, relative pipe roughness, is equal to, well let's go here, cast iron is right here. +[178.61s -> 190.61s] And it's 0.15, so 0.15, but that's in millimeters. We divide it by 6 inches, but then we have to convert from inches to millimeters. +[190.61s -> 195.92s] And so we can say that millimeters per inch +[195.92s -> 208.56s] and so we have 25.4 millimeters for one inch so now we see that the inches cancel out the millimeters cancel out and we just get a fraction so now we can calculate what that is equal to +[209.20s -> 222.26s] And so we end up with 0.15 divided by 6 and then divided by 25.4. And we get, whoa, lost my calculator here. +[223.02s -> 231.07s] and lost my number on my calculator so let me do that again and we get a relative pipe roughness +[231.07s -> 243.89s] equal to 9.84 times 10 to the minus 4 which is about equal to 0.001 so that's a relatively small relative pipe roughness +[243.89s -> 257.20s] The reason why it's so small is because it has a fairly large diameter. With a fairly large diameter, you typically end up with a much smaller relative pipe roughness, which means that we'll have a smaller fraction called... +[257.20s -> 267.04s] the where are we here the friction factor here and so there we go we put in a much smaller number and we'll have a much smaller frictional head loss because we use the much +[267.04s -> 281.14s] larger pipe diameter if the pipe diameter was smaller we'd have a much greater rpr if the flow was turbulence at laminar then we can calculate the friction factor which would be then a much bigger number and from that we'll end up with a much +[281.14s -> 286.03s] bigger frictional head loss and that is how we determine that diff --git a/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_420.mp4.txt b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_420.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6fa6bbf00b2a7043ebc0546ce2ced96916d12ea2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/test_Mechanical_Engineering_420.mp4.txt @@ -0,0 +1,27 @@ +[0.46s -> 13.95s] Welcome to ElectronLine and now let's do an example of how to calculate the force associated with the drag coefficient. In other words, let's drop a small sphere in a liquid and let's watch it fall down. And so as it... +[13.95s -> 27.39s] falls down, but rather slowly of course, because it's being buoyed up by three forces. One is the buoyancy force, one is the viscosity of the fluid, and one is the drag coefficient. So let's just simply find the force associated with the drag coefficient. +[27.39s -> 41.68s] And the drag coefficient is caused by the object having to push aside fluid as it goes on down. It has to push the fluid out of the way. So it has to give momentum to the fluid. It has to push it out of the way. So there's a whole kind of forces involved to be able to do that. +[41.68s -> 52.96s] of course caused by the shape of the object and the drag coefficient associated with that shape. Now let's say that the sphere is pretty small, small metal sphere. Let's say the radius is one millimeter. +[52.96s -> 64.61s] And let's say that the fluid is water, and that the velocity, let's say it reaches thermal velocity, and it's moving down at a speed of 5 centimeters per second. So what would be the force associated with that drag coefficient? +[64.61s -> 68.14s] Well, the equation is right here, so that means that the force +[68.66s -> 80.59s] is equal to the force caused by the drag coefficient is equal to one half times the coefficient times the density of the fluid times the cross-sectional area and times the velocity squared. +[80.59s -> 85.95s] So plugging in some numbers and let's see what we get. So this is equal to 1 half times... +[85.95s -> 99.22s] For a sphere, the drag coefficient is 0.47, as you could see in the previous video. So it's 0.47. It has no units, the drag coefficient. The density of water is equal to 1,000. +[99.22s -> 113.97s] kilograms per cubic meter the cross-sectional area well let's see here that would it's a sphere so it's kind of like the cross section of a sphere which is these the area of a circle that would be pi times r squared +[113.97s -> 127.50s] and r is 0.001 meter so we have to square that one millimeter is one 1000 of a meter and then finally the velocity squared so in this case the velocity is 0.05 meters per second +[127.50s -> 135.44s] And we have to square that. Now, I'm assuming that all these units put together will give us newtons. We'll check that in just a moment. +[136.75s -> 145.81s] So go again and work all that out. So we have 0.5 times 0.47 times 1000 times pi. +[147.73s -> 153.39s] times 0.001 squared 0.001 squared +[154.29s -> 168.34s] times, and then we have 0.05 squared, 0.05 squared equals, and let me put on my glasses so I can see what I'm doing here. All right, so the force would be equal to 1.85. +[168.34s -> 179.66s] 5 times 10 to the minus 6 newtons. Now let's check the units and make sure that the units do come out to newtons. Remember a newton +[179.66s -> 186.90s] if you look at the units, that's equal to a kilogram times meters per second squared. +[186.90s -> 195.82s] So it's the force that gives a mass of one kilogram, the acceleration of one meter per second squared. So let's see what we get for units here. So I have kilograms. +[196.62s -> 208.96s] meters cubed so multiply that times meters squared multiply times meters squared divided by seconds squared and that is it so let's see if that adds up to the proper units +[208.96s -> 222.22s] So I have meters squared, gets rid of two of those, this goes down to that, and that looks like it's kilograms meters per second squared, so that's indeed units of Newton, so the units work out as well. +[222.22s -> 230.40s] So that's how we calculate that. Notice for very small objects that have a very small cross section, less than one square meter, notice that +[230.40s -> 244.72s] as the cross-section gets smaller the drag coefficient gets much much smaller as well and then also notice that if the speed is very slow the drag coefficient again is very small so you can see that for a very small sphere the drag coefficient is really insignificant +[244.72s -> 255.70s] and that doesn't really play a factor. And I'm sure that the buoyancy force and the viscosity of the fluid has a much greater influence on the movement of the small sphere than the drag coefficient. +[255.70s -> 269.87s] It's only when the object becomes bigger and that the velocity becomes bigger that the drag coefficient really starts playing a role. So in the next video, we're going to compare what the force due to the viscosity of fluid looks like under similar circumstances. +[269.87s -> 284.14s] compared to the drag coefficient. And we can see which one becomes more important. And now we'll do an example where maybe we'll drop a big bowling ball into a bucket of water or a big object of water because, of course, a bowling ball needs a little bit more room. And we'll see how the drag... +[284.14s -> 292.96s] that compares to the viscosity, the force associated with the viscosity coefficient. Alright, but that's how we calculate the force associated with the drag coefficient. +[292.96s -> 300.46s] fairly straightforward, and you can see how it does really depend on the velocity and on the cross-sectional area of the object. And that's how we do that. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Agriculture_2.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..028a6380e4d2883c646db0d775cccddcbfbc5388 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_2.mp4.txt @@ -0,0 +1,77 @@ +[0.40s -> 14.26s] Sometimes, plants get sick, and no matter how much you talk to your plant, they won't talk back. The initial step in determining if a plant has a disease is to look at the signs and symptoms. This can give you a clue about what's going on. +[14.26s -> 28.56s] I'm Dr. DeBusk and this video provides background on plant diseases and the signs and symptoms common for plant pathogens. A plant disease is any abnormal condition that alters the appearance or function of a plant. +[28.56s -> 41.31s] It is a physiological process that affects some or all plant functions. Disease may also reduce yield and quality of harvested product. Disease is a process or a change that occurs over time. +[41.31s -> 50.32s] It does not occur instantly like injury . Injury or abiotic disorders will be covered in another video. +[50.38s -> 62.40s] Infectious plant diseases are caused by living organisms that attack and obtain their nutrition from the plant they infect. The parasitic organism that causes a disease is a pathogen. +[62.40s -> 73.87s] Numerous fungi, bacteria, viruses, and nematodes are pathogens of crops and landscapes. The plant invaded by the pathogen and serving as its food source is referred to as a host. +[73.94s -> 88.72s] Pathogens are capable of producing infection and causing a disease. Fungal spores, bacterial cells, virus particles, and nematode juveniles or adults are examples of plant pathogens. Fungi are the most common plant pathogens. +[89.17s -> 95.23s] About 85% of plant diseases are caused by fungi. Multi-celled +[95.23s -> 109.58s] microorganisms that may be seen without a microscope during certain stages of their life cycles. Fungi have no chlorophyll and their cell walls are composed of chitin and other polysaccharides instead of cellulose, which composes plant cell +[109.58s -> 118.27s] walls. Many species of fungi can be identified by the microscopic spores they produce, reproductive structures that aid in dispersal and survival. +[118.27s -> 129.63s] Some fungi have no spores, such as Rhizoctonia, which can be identified microscopically by the very characteristic right-angle branches of its fungal threads . +[129.63s -> 142.19s] Wind often disperses many fungal pathogens. Spores can be carried for miles by wind. Splashing water from rainfall or irrigation will also move fungal spores from plant to plant. +[142.19s -> 154.67s] Fungi that live in the soil can move from plant to plant by growing along intermingled roots or out from infested plant debris in the soil. Some fungi, for example Rhizoctonia, +[154.67s -> 168.82s] can survive on their own for long periods of time without a host by living in plant debris or soil. Fungi can also be spread by human activity through movement of already diseased plants or the use of contaminated gardening tools. +[168.82s -> 179.26s] While fungi may enter a plant through its natural openings, for example, stomates, or through wounds, they can also penetrate directly through the plant's cuticle as well. +[179.26s -> 186.82s] Bacteria are one-celled microorganisms that are so small they can be seen only with a powerful light microscope. +[186.82s -> 201.14s] Most plant pathogenic bacteria do not produce spores. Although some bacteria can survive in the soil in decaying plant material for a time, they usually need a host to survive. Bacteria are dependent on outside agents for dispersal from plant to plant. +[201.14s -> 209.65s] plant. Splashing water, irrigation, wind-driven rain is the chief means by which bacteria are disseminated. +[209.65s -> 223.92s] Another important means of dispersal is through human contact. Many bacterial diseases can be spread simply through the process of touching an infected plant and then touching a healthy plant with hands or pruning tools. Bacteria cannot penetrate the cuticle of +[223.92s -> 229.36s] but must enter the plant through a wound or natural opening to initiate disease. +[229.36s -> 243.63s] Special subgroups of bacteria require an insect host for dispersal and entry into the plant. One such example is citrus disease Huanglongbing, also known as HLB or citrus greening. +[243.76s -> 257.94s] Viruses are the smallest of the three pathogens described here and can only be seen with an electron microscope. They are made up of genetic material which is usually wrapped in a protein coat. +[257.94s -> 270.83s] They must have a living host in order to reproduce, because they use plant host cells in the reproduction process. Most fungi and bacteria reproduce independent of the plant host. Viruses are usually spread from diseased +[270.83s -> 277.42s] to healthy plants by insects but can also be spread by mites, nematodes, fungi, and even humans. +[277.42s -> 286.91s] The organism spreading the virus is referred to as a vector. In Florida, most viruses are vectored by insects, primarily aphids or whiteflies. +[286.91s -> 301.20s] Nematodes are microscopic, non-segmented, round, slender worms. Several thousand species of nematodes are found in soil, in fresh and salt water, in animals, and within or on plants throughout the world. Most feed on dead or decaying +[301.20s -> 314.90s] organic material. Some are parasites on animals, plants, insects, fungi, or other nematodes. A single acre of cultivated soil may contain hundreds of millions of nematodes, but due to their small size, +[314.90s -> 327.58s] They are seldom, if ever, seen. Most adult parasitic nematodes of plants cannot be seen unless magnified. They seldom exceed 1⁄8 of an inch and may be smaller than 1⁄64 of an inch. +[327.58s -> 334.22s] Plant parasitic nematodes have a hollow, needle-like feeding structure called a stylet that is used to puncture +[334.22s -> 343.60s] plant cells. Nematodes inject substances into host plant cells through their stylets and then withdraw nutrition from the plant cells through their stylets as well. +[343.60s -> 358.00s] The life cycle of a nematode includes an egg, four juvenile stages, and an adult. Females lay eggs that hatch into juveniles, and after four molting periods, juveniles become adults and the egg-laying process is repeated. The average life cycle of a nematode is 20 to 60 years. +[358.00s -> 372.21s] 60 days. Nematodes overwinter mainly in the egg stage. Most plant parasitic nematodes live in the soil and feed in or on plant roots. Some nematodes live a part or all of their lives inside plant roots. Most important plant +[372.21s -> 384.13s] nematodes feed on plant roots and directly interfere with water and nutrient uptake by the plant. Root injury causes above-ground symptoms similar to those produced by other conditions that damage root systems. +[384.13s -> 392.72s] Plants frequently appear to be suffering from lack of moisture or nutrient deficiency, even when water and minerals are adequate. +[392.78s -> 403.86s] When nematodes occur in high population densities, stunting, yellowing, loss of vigor, general decline, and eventual death of plants are typical above ground symptoms. +[404.11s -> 418.70s] Visible effects of disease on plants are called symptoms. Any detectable changes in color, shape, and or functions of the plant in response to a pathogen or disease-causing agent is a symptom. Leaf spots or blights, discoloration of plant tissues, +[418.70s -> 424.82s] stunting, and wilting are symptoms that may be evidence of disease. Symptoms can occur throughout the plant. +[424.82s -> 438.00s] or they may be confined to localized areas. Although certain symptoms are characteristic of a particular disease, a number of pathogens may produce the same or similar symptoms. Furthermore, symptoms often change over time and their expression +[438.00s -> 450.26s] is influenced by environmental conditions and plant variety. Signs of plant disease are physical evidence of the pathogen. For example, fungal fruiting bodies, bacterial ooze, +[450.26s -> 463.15s] or cis-nematode females. Signs can help with plant disease identification. Symptoms are abnormal features of the plant that indicate something is wrong. It is important to learn the proper name. +[463.15s -> 477.47s] for a symptom. Many are self-explanatory. A spot is just that, a spot. It is necessary to mention the part of the plant exhibiting this symptom. If there are spots on the leaves, they will be called leaf spots, spots on the fruit. +[477.47s -> 488.90s] are fruit spots. The technical term for a spot is lesion, which means localized disease area or wound. As spots grow together , the symptom is called a blight. +[488.90s -> 500.82s] This differs from a spot because larger amounts of tissue are affected. Galls or tumors may be found on stems, roots, or sometimes on leaves. These are masses of undifferentiated tissue growth +[500.82s -> 514.80s] similar to cancerous tumors in people. They can be easily confused with those caused by insects. Cankers are sunken lesions which are found most often on stems but can also occur on tree trunks. +[514.83s -> 524.03s] Wilson rots are just what the names imply. It is important to note that a rot does not have to be wet and yucky. There are dry rots. +[524.03s -> 537.79s] A rot simply means the plant tissue is being degraded by the pathogen. To tell if a pathogen is responsible for a wilt, make a vertical cut near the base of the plant or individual wilted stem. If a pathogen is +[537.79s -> 549.47s] present, the vascular water conducting tissue will appear dark. A plant wilting from water stress will have normal white, off-white, or light green vascular tissue. +[549.47s -> 554.58s] Wilk can also be caused by nematodes since they feed on and damage the root system. +[554.90s -> 569.49s] Damping off is a term used to describe the rotting of seedlings as they emerge from the soil or potting mix. There are two types of damping off diseases. Pre-emergence damping off occurs when a germinating seed is infected and dies before it emerges from the ground. +[569.49s -> 583.18s] Post-emergence damping off occurs when a fully emerged seedling is infected at the soil line and dies. Terms also used to describe turfgrass diseases include patch and decline. These terms are describing +[583.18s -> 596.18s] areas or affected turf and not individual plants. The individual plants of the patch or decline area will exhibit symptoms of spots, blights, rots, or wilts. +[596.59s -> 608.30s] Most of the symptoms described above are normally associated with fungal or bacterial pathogens. Symptoms of viral diseases include mottling in the color of the leaves and fruit mosaics +[608.30s -> 618.96s] yellowing or crinkling of leaves, misshapen leaves, yellow or necrotic rings on leaves or fruits, and plants that appear dwarfed because they have shortened internodes. +[619.22s -> 625.74s] A positive diagnosis of a plant is often difficult or nearly impossible to make on the basis of symptoms alone. +[625.74s -> 637.39s] Too often, symptoms of specific diseases and some abiotic disorders overlap. To properly identify a fungal or bacterial disease, one must look for the signs of the +[637.39s -> 646.56s] the most significant of which is the presence of the pathogen itself viewed with the unaided eye, a hand lens or a microscope. +[646.56s -> 658.18s] With fungal diseases, one can often see the actual fungal growth. Examples of these signs are mycelium, spore masses such as molds or rust, sclerotia, conchs, and mushrooms. +[658.18s -> 672.62s] A mycelium is a mass of fungal threads that can often be seen on or around a lesion spot, canker, blighted area. Sclerotia are small, hard bodies that are the resting state of some fungi. +[672.62s -> 677.62s] Fungi can survive for years in this state. They are most often found +[677.62s -> 691.60s] inside plant tissue such as stems. If a fungus is suspected as the cause of a disease but there is no sign of the fungus, a moisture chamber can be made to induce fungal growth. This is a sealed chamber, for example a plastic storage container, +[691.60s -> 702.51s] in which a piece of the diseased tissue is placed on a moist paper towel. After a day or two in the closed container, mycelium will often be evident if the disease is indeed caused by a fungus. +[702.51s -> 709.01s] This works best if the infection is relatively recent or the symptom is a spot, blight, or canker. +[709.01s -> 718.51s] plant tissue is degraded, starting to rot, additional fungi are likely to grow from the infected tissue, making it difficult to identify their original pathogen. +[718.99s -> 726.82s] Along with the symptoms described above, bacterial infections will often produce water soaking around the area where the pathogen entered. +[726.82s -> 741.17s] Later, the lower surface of the leaf will take on a dark, greasy appearance. This greasy appearance is most evident in foliar infections, but can sometimes be seen on other plant organs. Although these are good indications of a bacterial disease, one must look again for +[741.17s -> 742.64s] signs of the pathogen. +[742.64s -> 756.75s] Often bacterial ooze can be seen coming from a lesion, especially in the morning hours. Some bacterial diseases also have distinctive odors. An easy test to determine whether wilt symptoms are caused by bacteria is called a bacterial streaming test. +[756.75s -> 769.34s] This may be done by cutting the stem horizontally and inserting the cut end into a clear glass container filled halfway with water. If bacteria are present, they will produce a cloudy stream within a few minutes. +[769.34s -> 772.27s] This stream is composed of millions of bacteria. +[772.56s -> 784.93s] In order to obtain a definitive diagnosis of a virus, samples must be sent to a clinic that has the special equipment and materials necessary to do the proper tests. As indicated in this video, +[784.93s -> 796.70s] A few simple tools are useful for preliminary diagnosis of plant diseases. These include a hand lens, sharp knife, clear glass container or jar, plastic storage container, and rubbing alcohol. +[796.70s -> 809.14s] A hand lens is often necessary to see the fungal growth on a lesion. The knife is used to make cross sections of stem tissue. Clean the knife after each use with a tissue or cotton ball soaked with rubbing alcohol. +[809.14s -> 818.24s] The glass jar is used for the bacterial streaming test, and the storage container becomes a moisture chamber for inducing fungal growth from infected tissue. +[818.24s -> 832.42s] Additional help is available through several plant diagnostic clinics run by university plant pathologists around the state. There are some things you should consider. First, it is almost impossible to make a diagnosis if the plant is dead or very close to death. +[832.42s -> 845.58s] A good sample will include multiple examples of the symptoms and, ideally, multiple samples illustrating how the disease progresses in the plant. Include information regarding how the plants are affected, when symptoms appeared, +[845.58s -> 858.50s] the pattern of development in the field or garden, the severity of the disease, any recent cultural practices, for example use of pesticides or fertilizers, and any weather conditions that might have affected the plants. +[858.50s -> 870.98s] In summary, the major plant pathogens responsible for disease development in plants are fungi, bacteria, viruses, and nematodes. Understanding the difference between a sign and a symptom is key in identifying a plant disease. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Agriculture_7.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7ab4430adeba2760baf314f535d9c3a2867d8e45 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_7.mp4.txt @@ -0,0 +1,18 @@ +[0.00s -> 13.33s] Hi there. Today we are going to differentiate between early blight and late blight. All blight diseases are caused by fungi. And the fungi in your crop production unit is normally caused by two major conditions. +[13.33s -> 24.35s] Kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, +[24.35s -> 38.61s] Kwa hivyo kutumia kutumia kutumia kutumia kutumia kutumia kutumia kutumia kutumia +[38.61s -> 49.79s] Kwa hivyo kwenye kwa hilo ni kwa kwa kwa kwa kwa kwa kwa kwa kwa kwa kwa +[49.79s -> 63.74s] Kwa hivyo, hivyo kufanya kutumia kwenye kutumia. Kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo +[63.74s -> 76.64s] Kwa kufanya kwa kufanya kwa kufanya kwa kufanya kufanya +[76.64s -> 87.95s] Kwa hivyo, kwa hivyo, kwa hivyo +[88.27s -> 100.85s] Kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo. +[101.14s -> 113.36s] Kwa sababu, kufikia kufikia kufikia kufikia kufikia kufikia kufikia. +[113.36s -> 127.86s] which changed the microclimate of the area around the crop production unit thereby causing humidity problems on to why poor fault management practices may cause high temperatures or moisture levels one +[128.24s -> 140.32s] How you do your spacing between the crops certainly affects the population of crops per square meter. Low spacing between crops may contribute to high humidity due to the resulting high populations. +[140.32s -> 154.37s] na kwa hivyo kutumia kwa mkwa mkwa. Kwa kutumia kwa mkwa kwa mkwa kwa mkwa kwa mkwa kwa mkwa kwa mkwa kwa mkwa kwa mkwa +[154.37s -> 167.10s] Kufanya kufanya kufanya kufanya kufanya kufanya +[167.10s -> 181.33s] Kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo +[181.33s -> 195.60s] fangisides. Mwisho kufikia kufikia kufikia kufikia kufikia kufikia kufikia kufikia kufikia kufikia kufikia +[195.86s -> 202.64s] Back to our first question. Which leaf is affected by early blight and which one has late blight? +[203.25s -> 216.74s] Kwa hivyo, kwa hivyo, kwa hivyo, +[216.74s -> 223.50s] Subscribe to our channel or log in to our website www.grandwarafrica.com diff --git a/VideoMMMU_ASR_large/Engineering/validation_Agriculture_8.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..028a6380e4d2883c646db0d775cccddcbfbc5388 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_8.mp4.txt @@ -0,0 +1,77 @@ +[0.40s -> 14.26s] Sometimes, plants get sick, and no matter how much you talk to your plant, they won't talk back. The initial step in determining if a plant has a disease is to look at the signs and symptoms. This can give you a clue about what's going on. +[14.26s -> 28.56s] I'm Dr. DeBusk and this video provides background on plant diseases and the signs and symptoms common for plant pathogens. A plant disease is any abnormal condition that alters the appearance or function of a plant. +[28.56s -> 41.31s] It is a physiological process that affects some or all plant functions. Disease may also reduce yield and quality of harvested product. Disease is a process or a change that occurs over time. +[41.31s -> 50.32s] It does not occur instantly like injury . Injury or abiotic disorders will be covered in another video. +[50.38s -> 62.40s] Infectious plant diseases are caused by living organisms that attack and obtain their nutrition from the plant they infect. The parasitic organism that causes a disease is a pathogen. +[62.40s -> 73.87s] Numerous fungi, bacteria, viruses, and nematodes are pathogens of crops and landscapes. The plant invaded by the pathogen and serving as its food source is referred to as a host. +[73.94s -> 88.72s] Pathogens are capable of producing infection and causing a disease. Fungal spores, bacterial cells, virus particles, and nematode juveniles or adults are examples of plant pathogens. Fungi are the most common plant pathogens. +[89.17s -> 95.23s] About 85% of plant diseases are caused by fungi. Multi-celled +[95.23s -> 109.58s] microorganisms that may be seen without a microscope during certain stages of their life cycles. Fungi have no chlorophyll and their cell walls are composed of chitin and other polysaccharides instead of cellulose, which composes plant cell +[109.58s -> 118.27s] walls. Many species of fungi can be identified by the microscopic spores they produce, reproductive structures that aid in dispersal and survival. +[118.27s -> 129.63s] Some fungi have no spores, such as Rhizoctonia, which can be identified microscopically by the very characteristic right-angle branches of its fungal threads . +[129.63s -> 142.19s] Wind often disperses many fungal pathogens. Spores can be carried for miles by wind. Splashing water from rainfall or irrigation will also move fungal spores from plant to plant. +[142.19s -> 154.67s] Fungi that live in the soil can move from plant to plant by growing along intermingled roots or out from infested plant debris in the soil. Some fungi, for example Rhizoctonia, +[154.67s -> 168.82s] can survive on their own for long periods of time without a host by living in plant debris or soil. Fungi can also be spread by human activity through movement of already diseased plants or the use of contaminated gardening tools. +[168.82s -> 179.26s] While fungi may enter a plant through its natural openings, for example, stomates, or through wounds, they can also penetrate directly through the plant's cuticle as well. +[179.26s -> 186.82s] Bacteria are one-celled microorganisms that are so small they can be seen only with a powerful light microscope. +[186.82s -> 201.14s] Most plant pathogenic bacteria do not produce spores. Although some bacteria can survive in the soil in decaying plant material for a time, they usually need a host to survive. Bacteria are dependent on outside agents for dispersal from plant to plant. +[201.14s -> 209.65s] plant. Splashing water, irrigation, wind-driven rain is the chief means by which bacteria are disseminated. +[209.65s -> 223.92s] Another important means of dispersal is through human contact. Many bacterial diseases can be spread simply through the process of touching an infected plant and then touching a healthy plant with hands or pruning tools. Bacteria cannot penetrate the cuticle of +[223.92s -> 229.36s] but must enter the plant through a wound or natural opening to initiate disease. +[229.36s -> 243.63s] Special subgroups of bacteria require an insect host for dispersal and entry into the plant. One such example is citrus disease Huanglongbing, also known as HLB or citrus greening. +[243.76s -> 257.94s] Viruses are the smallest of the three pathogens described here and can only be seen with an electron microscope. They are made up of genetic material which is usually wrapped in a protein coat. +[257.94s -> 270.83s] They must have a living host in order to reproduce, because they use plant host cells in the reproduction process. Most fungi and bacteria reproduce independent of the plant host. Viruses are usually spread from diseased +[270.83s -> 277.42s] to healthy plants by insects but can also be spread by mites, nematodes, fungi, and even humans. +[277.42s -> 286.91s] The organism spreading the virus is referred to as a vector. In Florida, most viruses are vectored by insects, primarily aphids or whiteflies. +[286.91s -> 301.20s] Nematodes are microscopic, non-segmented, round, slender worms. Several thousand species of nematodes are found in soil, in fresh and salt water, in animals, and within or on plants throughout the world. Most feed on dead or decaying +[301.20s -> 314.90s] organic material. Some are parasites on animals, plants, insects, fungi, or other nematodes. A single acre of cultivated soil may contain hundreds of millions of nematodes, but due to their small size, +[314.90s -> 327.58s] They are seldom, if ever, seen. Most adult parasitic nematodes of plants cannot be seen unless magnified. They seldom exceed 1⁄8 of an inch and may be smaller than 1⁄64 of an inch. +[327.58s -> 334.22s] Plant parasitic nematodes have a hollow, needle-like feeding structure called a stylet that is used to puncture +[334.22s -> 343.60s] plant cells. Nematodes inject substances into host plant cells through their stylets and then withdraw nutrition from the plant cells through their stylets as well. +[343.60s -> 358.00s] The life cycle of a nematode includes an egg, four juvenile stages, and an adult. Females lay eggs that hatch into juveniles, and after four molting periods, juveniles become adults and the egg-laying process is repeated. The average life cycle of a nematode is 20 to 60 years. +[358.00s -> 372.21s] 60 days. Nematodes overwinter mainly in the egg stage. Most plant parasitic nematodes live in the soil and feed in or on plant roots. Some nematodes live a part or all of their lives inside plant roots. Most important plant +[372.21s -> 384.13s] nematodes feed on plant roots and directly interfere with water and nutrient uptake by the plant. Root injury causes above-ground symptoms similar to those produced by other conditions that damage root systems. +[384.13s -> 392.72s] Plants frequently appear to be suffering from lack of moisture or nutrient deficiency, even when water and minerals are adequate. +[392.78s -> 403.86s] When nematodes occur in high population densities, stunting, yellowing, loss of vigor, general decline, and eventual death of plants are typical above ground symptoms. +[404.11s -> 418.70s] Visible effects of disease on plants are called symptoms. Any detectable changes in color, shape, and or functions of the plant in response to a pathogen or disease-causing agent is a symptom. Leaf spots or blights, discoloration of plant tissues, +[418.70s -> 424.82s] stunting, and wilting are symptoms that may be evidence of disease. Symptoms can occur throughout the plant. +[424.82s -> 438.00s] or they may be confined to localized areas. Although certain symptoms are characteristic of a particular disease, a number of pathogens may produce the same or similar symptoms. Furthermore, symptoms often change over time and their expression +[438.00s -> 450.26s] is influenced by environmental conditions and plant variety. Signs of plant disease are physical evidence of the pathogen. For example, fungal fruiting bodies, bacterial ooze, +[450.26s -> 463.15s] or cis-nematode females. Signs can help with plant disease identification. Symptoms are abnormal features of the plant that indicate something is wrong. It is important to learn the proper name. +[463.15s -> 477.47s] for a symptom. Many are self-explanatory. A spot is just that, a spot. It is necessary to mention the part of the plant exhibiting this symptom. If there are spots on the leaves, they will be called leaf spots, spots on the fruit. +[477.47s -> 488.90s] are fruit spots. The technical term for a spot is lesion, which means localized disease area or wound. As spots grow together , the symptom is called a blight. +[488.90s -> 500.82s] This differs from a spot because larger amounts of tissue are affected. Galls or tumors may be found on stems, roots, or sometimes on leaves. These are masses of undifferentiated tissue growth +[500.82s -> 514.80s] similar to cancerous tumors in people. They can be easily confused with those caused by insects. Cankers are sunken lesions which are found most often on stems but can also occur on tree trunks. +[514.83s -> 524.03s] Wilson rots are just what the names imply. It is important to note that a rot does not have to be wet and yucky. There are dry rots. +[524.03s -> 537.79s] A rot simply means the plant tissue is being degraded by the pathogen. To tell if a pathogen is responsible for a wilt, make a vertical cut near the base of the plant or individual wilted stem. If a pathogen is +[537.79s -> 549.47s] present, the vascular water conducting tissue will appear dark. A plant wilting from water stress will have normal white, off-white, or light green vascular tissue. +[549.47s -> 554.58s] Wilk can also be caused by nematodes since they feed on and damage the root system. +[554.90s -> 569.49s] Damping off is a term used to describe the rotting of seedlings as they emerge from the soil or potting mix. There are two types of damping off diseases. Pre-emergence damping off occurs when a germinating seed is infected and dies before it emerges from the ground. +[569.49s -> 583.18s] Post-emergence damping off occurs when a fully emerged seedling is infected at the soil line and dies. Terms also used to describe turfgrass diseases include patch and decline. These terms are describing +[583.18s -> 596.18s] areas or affected turf and not individual plants. The individual plants of the patch or decline area will exhibit symptoms of spots, blights, rots, or wilts. +[596.59s -> 608.30s] Most of the symptoms described above are normally associated with fungal or bacterial pathogens. Symptoms of viral diseases include mottling in the color of the leaves and fruit mosaics +[608.30s -> 618.96s] yellowing or crinkling of leaves, misshapen leaves, yellow or necrotic rings on leaves or fruits, and plants that appear dwarfed because they have shortened internodes. +[619.22s -> 625.74s] A positive diagnosis of a plant is often difficult or nearly impossible to make on the basis of symptoms alone. +[625.74s -> 637.39s] Too often, symptoms of specific diseases and some abiotic disorders overlap. To properly identify a fungal or bacterial disease, one must look for the signs of the +[637.39s -> 646.56s] the most significant of which is the presence of the pathogen itself viewed with the unaided eye, a hand lens or a microscope. +[646.56s -> 658.18s] With fungal diseases, one can often see the actual fungal growth. Examples of these signs are mycelium, spore masses such as molds or rust, sclerotia, conchs, and mushrooms. +[658.18s -> 672.62s] A mycelium is a mass of fungal threads that can often be seen on or around a lesion spot, canker, blighted area. Sclerotia are small, hard bodies that are the resting state of some fungi. +[672.62s -> 677.62s] Fungi can survive for years in this state. They are most often found +[677.62s -> 691.60s] inside plant tissue such as stems. If a fungus is suspected as the cause of a disease but there is no sign of the fungus, a moisture chamber can be made to induce fungal growth. This is a sealed chamber, for example a plastic storage container, +[691.60s -> 702.51s] in which a piece of the diseased tissue is placed on a moist paper towel. After a day or two in the closed container, mycelium will often be evident if the disease is indeed caused by a fungus. +[702.51s -> 709.01s] This works best if the infection is relatively recent or the symptom is a spot, blight, or canker. +[709.01s -> 718.51s] plant tissue is degraded, starting to rot, additional fungi are likely to grow from the infected tissue, making it difficult to identify their original pathogen. +[718.99s -> 726.82s] Along with the symptoms described above, bacterial infections will often produce water soaking around the area where the pathogen entered. +[726.82s -> 741.17s] Later, the lower surface of the leaf will take on a dark, greasy appearance. This greasy appearance is most evident in foliar infections, but can sometimes be seen on other plant organs. Although these are good indications of a bacterial disease, one must look again for +[741.17s -> 742.64s] signs of the pathogen. +[742.64s -> 756.75s] Often bacterial ooze can be seen coming from a lesion, especially in the morning hours. Some bacterial diseases also have distinctive odors. An easy test to determine whether wilt symptoms are caused by bacteria is called a bacterial streaming test. +[756.75s -> 769.34s] This may be done by cutting the stem horizontally and inserting the cut end into a clear glass container filled halfway with water. If bacteria are present, they will produce a cloudy stream within a few minutes. +[769.34s -> 772.27s] This stream is composed of millions of bacteria. +[772.56s -> 784.93s] In order to obtain a definitive diagnosis of a virus, samples must be sent to a clinic that has the special equipment and materials necessary to do the proper tests. As indicated in this video, +[784.93s -> 796.70s] A few simple tools are useful for preliminary diagnosis of plant diseases. These include a hand lens, sharp knife, clear glass container or jar, plastic storage container, and rubbing alcohol. +[796.70s -> 809.14s] A hand lens is often necessary to see the fungal growth on a lesion. The knife is used to make cross sections of stem tissue. Clean the knife after each use with a tissue or cotton ball soaked with rubbing alcohol. +[809.14s -> 818.24s] The glass jar is used for the bacterial streaming test, and the storage container becomes a moisture chamber for inducing fungal growth from infected tissue. +[818.24s -> 832.42s] Additional help is available through several plant diagnostic clinics run by university plant pathologists around the state. There are some things you should consider. First, it is almost impossible to make a diagnosis if the plant is dead or very close to death. +[832.42s -> 845.58s] A good sample will include multiple examples of the symptoms and, ideally, multiple samples illustrating how the disease progresses in the plant. Include information regarding how the plants are affected, when symptoms appeared, +[845.58s -> 858.50s] the pattern of development in the field or garden, the severity of the disease, any recent cultural practices, for example use of pesticides or fertilizers, and any weather conditions that might have affected the plants. +[858.50s -> 870.98s] In summary, the major plant pathogens responsible for disease development in plants are fungi, bacteria, viruses, and nematodes. Understanding the difference between a sign and a symptom is key in identifying a plant disease. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Agriculture_9.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..bf746234d8abcf2631915ca6ce1c147c431105a1 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Agriculture_9.mp4.txt @@ -0,0 +1,63 @@ +[0.50s -> 12.27s] Good morning, everyone. On behalf of TerraView, I would like to welcome you to what I would call the first video of these disease series. We're going to be talking about +[12.27s -> 25.50s] grapevine pathogens how exactly what exactly is their dynamics and well hoping that understanding how they work will be able to provide strategies to growers along +[25.50s -> 38.46s] with well how exactly we use sensors for that and what's the role of terraview and all this to prevent that these diseases don't cause unnecessary damage to to everyone's vineyards +[38.46s -> 49.22s] so today we're talking about downy mildew and downy mildew is a fungus and it's one it's like included in this very specific category +[49.22s -> 63.04s] of these types of diseases because it's very weather dependent. So it needs very specific conditions in order to thrive in this environment. And apart from that, it's what we... +[63.04s -> 72.30s] what we would call an obligate parasite. It means in this case that downy mildew needs a host in order to survive and to feed on. +[72.30s -> 85.66s] So that's what actually makes it incredibly dangerous in case there is a potential outbreak. So, well, just to begin with, let's understand a bit about the life cycle. +[85.66s -> 99.20s] So we can divide downy mildew infections into two types of infections. The first one is what we call a primary infection. By reading the definition, we see the initial... +[99.20s -> 111.71s] it's an initial infection of a host by a pathogen that has completed its dormancy period in this case we have a host in this which will be obviously the grapevine and the pathogen down emailed you and +[111.71s -> 125.07s] well in this case for a primary infection we we stand in a situation where well there's actually zero downy mildew in our vineyards so our plants are not infected but +[125.07s -> 139.12s] well for for i mean for there to be an infection there needs to be obviously a primary infection and downy mildew needs to needs to try to reach the grapevine in order to +[139.12s -> 149.89s] well to cause that initiation of its life cycle so we can divide that into three stages uh stage one two and three and we see like stage one is obviously a +[149.89s -> 160.82s] the ospor formation. So there's going to be a formation of spore bearing organs. And the stage two will be the transmission of those spores from their location. +[160.82s -> 174.64s] to the grapevine and obviously stage three will be the inoculation which obviously that will lead to an infection and the initiation of an outbreak as we can see in the next slide +[174.64s -> 185.31s] so the the the all spores will actually be on soil so that's that's where that's where the the dormancy period +[185.31s -> 195.95s] occurs so downy mildew will be present in the soil and in leaf debris so with after harvest and during fall when leaves start +[195.95s -> 209.79s] obviously falling on soil that's that's a primary source of inoculum which are called macrosporensia as we can see here and macrosporensia are going to be formed and you can see here all the spores +[209.79s -> 220.62s] it's bearing and uh well for there to be a transmission we need rain and downy mildew +[220.62s -> 233.78s] for there to be a primary infection needs free water in order to go from soil to green tissue. So there could be a potential infection. +[233.78s -> 248.37s] as you can see here for obviously to to have to begin like the potential outbreak we need macrosperangia and that's what downy mildew needs so for there to be the formation of macrosperangia +[248.40s -> 259.98s] all we all we need here according to this graphic is well as long as we have a temperature between 10 and 24 degrees within obviously with sufficient +[259.98s -> 271.28s] relative humidity above 70 percent we need around between 16 and 24 hours so as long as those requirements are met +[271.28s -> 285.42s] we're going to have macrosperangia on soil and downy mildew in that form is going to be ready to attack our grapevines when the opportunity comes. +[285.42s -> 292.75s] as you can see here obviously as long as there's rain above five millimeters uh +[293.14s -> 302.21s] there can be a transmission from the soil into our grapevine's green tissue. +[302.21s -> 316.34s] which is very important because that's exactly the kind of things that we need to monitor. And since obviously we have weather data and well understanding how the disease cycle works. +[316.34s -> 326.67s] we'll be able to hopefully prevent that from happening. And now stage three. So the thing is, it's not just about. +[327.18s -> 341.42s] having those macrosperangia reaching the grapevine green tissue tissue but also there's another requirement for there to be an inoculation so for that the leaves +[341.42s -> 355.50s] need to be wet so without that obviously the spores will die and they won't be able to reach the leaf go through the what we call the stomates which are the leaf pores +[355.50s -> 368.03s] So as we can see here through this graphic as well, also depending on temperature between six and 29 degrees Celsius, the leaves. +[368.03s -> 381.65s] obviously we will have an inoculation like we would say between two and around nine hours so as long as leaves are wet and we have this temperature obviously depending +[381.65s -> 395.49s] on the temperature. If we have that duration of leaf wetness and there's spores in the free water, then we can call that an inoculation. +[395.49s -> 408.77s] being obviously successful and our grapevines will be infected um so this this is what happens for a primary infection that's what happens when we don't have +[408.77s -> 422.29s] obviously downy mildew in our vineyards and downy mildew reaches for the first time after its dormant period from soil to your grapevine and it affects the first grapevine and now that +[422.48s -> 430.59s] your plant has been infected, that opens a door for an epidemic to occur. +[430.59s -> 443.94s] which is obviously a secondary infection so by reading the definition it's an infection resulting from a pre-existent one includes leaf to leaf and leaf to bunch infection so this is what could potentially cause +[443.94s -> 455.57s] yield loss and we can also divide that into three stages obviously the infected plant will have to sporulate it's not just about being infected +[455.57s -> 467.92s] So it needs to sporulate, it needs to create spores so it can later be transmitted and reach the neighbor healthy vines. And obviously there's again the inoculation process. +[467.92s -> 480.53s] and we have a bunch of requirements that need to be met so illustrating it here we have an infected grapevine and in this case an infected leaf which is the green tissue where the +[480.53s -> 494.38s] where there will be sporulation from downy mildew they'll create zoospores that with rain and wind will have to reach the other neighboring vines so for sporulation to occur +[494.70s -> 509.49s] We need, well, I mean high, really high relative humidity. And well, and as long as we have that range of temperature between 12 degrees and 28. +[509.94s -> 522.45s] between 10 to around three hours, our plants, our infected plants will sporulate. And this is the thing, like when our plants are infected, there's a latency period. +[522.45s -> 536.32s] so they can be infected but they don't really show any symptoms so that once they start sporulating and once these conditions are met that's when we know they're ready to infect other vines +[536.32s -> 549.33s] um so there's something really interesting about the sporulation of downy mildew uh because not only not only i mean it not only needs like um +[549.33s -> 563.73s] high relative humidity and that range of temperature, but this process can only happen at night. So downy mildew needs total darkness to sporulate because otherwise it won't. +[563.73s -> 577.84s] So if we have all these conditions at night, that's really important because then we know when we should be monitoring the grapevines and the weather data, which is really, really good. +[577.84s -> 590.30s] also for the transmission to occur we already know that they need free water to be to be transmitted to reach the other neighboring vines so they go with rain splashes +[590.30s -> 604.59s] and after spore formation obviously they need to avoid light at any cost so if it rains at night there's well high chance that they'll be able to reach other vines obviously if it doesn't rain +[604.59s -> 615.38s] They also can be transmitted through the wind. But what we already know is that for the inoculation to occur, for primary and secondary infection, +[615.38s -> 628.85s] it's the same requirement so the leaves need to be wet so if there's wind that can transport our our spores from one grapevine to another there has to be some sort of rain or something that could make our leaves wet +[628.85s -> 641.84s] So we need to fulfill that requirement of leaf wetness duration in order to be an inoculation for the spores to cross, obviously, the stomates. +[641.84s -> 656.06s] Well, and obviously that would cause the beginning of an epidemic of downy mildew and we don't want that. So here the role of TerraView, there are several issues to take into account, starting with optimizing fungicide application. +[656.06s -> 667.07s] and in this case we implement models to make sure that growers know exactly how the disease is developing and obviously that +[667.07s -> 680.11s] provide such valuable information because then growers don't have to unnecessarily just spray and obviously that reduces a bunch of costs for growers more important than that i feel that downy mildew +[680.27s -> 690.34s] I mean, we should emphasize the importance of preventive practices because, well, this is where if we don't have downy mildew in our vineyards. +[690.34s -> 702.64s] it's important to reduce the primary source of inoculum and for that by monitoring soil canopy moisture leaf area and seeing how +[702.64s -> 716.05s] how the I mean how the soil profile is developing with time especially after harvest during fall and I mean during winter as well before before other viticultural practices will be able to +[716.05s -> 728.05s] at least reduce that primary source of inoculum to reduce macrosporangia population and make sure we reduce the chance of a primary infection, which is, well, the first step in. +[728.05s -> 741.01s] in preventing a potential outbreak. And finally, by tracking the other weather data, including temperature, humidity, and rainfall, we can +[741.01s -> 753.63s] know exactly what is going on and uh i'll make sure if the conditions are met if that's if there's really a high risk for a primary or secondary infection to occur whatever +[753.63s -> 767.76s] is happening in our vineyard. So that's how useful sensors can be. And also depending on how early we can predict weather conditions. +[767.76s -> 782.11s] that's going to be the difference between success and failure, which is obviously successfully preventing an outbreak and failure, which is obviously the start of an epidemic. +[782.11s -> 790.26s] That concludes my presentation for Downy Mildew. If you have any feedback, please don't hesitate to contact me and see you in the next video. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_1.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3b676df368e44fd883d9567cafc856d936c0873d --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_1.mp4.txt @@ -0,0 +1,41 @@ +[1.17s -> 12.50s] Okay, in this problem we want to find the forces of member HI, which is this member right here, HB, which is this member right here. +[12.50s -> 18.93s] And BC, which is this member right here. So if I'm only trying to find a couple of these members. +[18.93s -> 33.20s] I don't need to do the joint analysis, which is pretty tedious. I can do much more direct route, which is the method of section. However, the first step I need to do is find those reactions just like before. So we'll start with that before we get ahead of ourselves. We'll go AX. +[33.20s -> 37.78s] and a y and then we've got e over here +[37.78s -> 49.98s] Okay, so if I sum the forces in the x, well, the only thing I've got there is ax equals 0. That's the only horizontal force I've got, so essentially this ax is non-existent. +[49.98s -> 56.02s] Okay, so we don't have to worry about that based on the loading. So in the Y direction, I've got AY. +[56.53s -> 66.37s] I have e, and then I have negative 30, negative 20, negative 20, negative 40 equals 0. +[66.37s -> 75.17s] just like that and then i've got the sum of the moments i'll do it about point a since there are two forces there even though one is zero okay 30 also goes through it +[75.17s -> 87.78s] Okay, so I'll start with my E, 16 meters over, so it'll be 16 times E, and then I'm going to have these three other moments, right? The 30 kilonewton goes right through A, but I've got the 20, 20, and the 40. +[87.78s -> 92.82s] And these are all going to be negative. So that's going to be negative 4 times 20. +[93.10s -> 106.51s] Negative 8 times 20. And negative 12 times 40. Like so. Equals 0. From that, I learned that E... +[107.50s -> 109.62s] E equals 45. +[110.16s -> 124.42s] And I learned that Ay then equals 65. Okay, so I've got those reactions, okay? Now, we're going to do what's called the method of sections to figure out what those members are. +[124.42s -> 134.77s] what i do is i basically make a cut and i can only cut through three members i have to cut all the way through okay and i can only go through three members because i'm only gonna get three +[134.77s -> 148.22s] equations. I'm going to get two force equations and a moment equation this time. So I make this cut right there, okay? And I'm going to basically separate this, thereby making those internal forces that I had now external. +[148.22s -> 158.42s] okay so i'll have this side here right where i've got a y which i now know is 65. +[159.12s -> 165.14s] I've got 30 right here. And I've got 20. +[165.94s -> 180.14s] Right there. And I've got these forces. I'm going to assume they're all tension, so they're all going to be outward. That'll be F-H-I. And then I'll have... +[181.07s -> 194.22s] FBH and then I'll have FBC okay I also have the other one okay +[197.97s -> 210.27s] Okay, which will look like this. Okay, I'm going to have 20 right here. I'm going to have 40 right there. I've got my reaction at E, which I've calculated, and it is 45. +[210.27s -> 216.56s] okay now i've got the same forces i'll assume their intention f b c like this +[217.04s -> 229.95s] FBH, so they're all equal and opposite of the other one, and then FHI like this. Now, at this point, I drew both of them, okay? +[229.95s -> 242.10s] we only need one of them but i do want to represent that you're cutting it separating and you've got two halves you can draw either half i'm going to do the left half and that's just because it's smaller +[242.51s -> 255.60s] There's lots of different reasons you choose one half over another. You can't be wrong, though, which is the nice thing about this. But I'm going to go ahead and do the left half because it's smaller. +[255.60s -> 270.42s] And what I'll do here is I'll go ahead and I'll sum the forces in the x direction. And I'll have that FHI. I'll have FBC. +[271.95s -> 282.26s] Okay, and these are all 45 degree angles, 4 by 4, so I'm going to be a little sloppy with it. Sines and cosines are the same, but I'll call this FBH. +[284.05s -> 297.46s] Cosine of 45. Okay. Those are all my horizontal components that I've got there. So set that equal to zero. They're all to the right. FBH is at that cosine of 45. Okay. +[297.49s -> 312.30s] Move on to the yy direction, which will have 65. I'll have minus 30. And I'll have minus 20. And I'll have plus FBH sine of 45. +[314.38s -> 323.90s] Okay, then I'm going to go ahead and I have a moment equation now I get to choose a point and the best point to choose is B because +[323.90s -> 338.24s] That is that point right there. I have two unknown forces acting at that point. They both go away. So I'm only going to have one unknown that's going to show up here, which is going to make my life a lot easier. Okay. Recognize I could have also chose point. +[338.24s -> 352.11s] H over here off of the member. It doesn't have to be on the member. Sometimes it's best to choose something off the member. I don't need to do that here. B is just fine. I'm going to stick with that one. But just recognize H would have been... +[352.11s -> 365.90s] Pretty good choice as well. So now with this one, I'm going to have negative 4 times 65. And then I'm going to have plus 4 times 30. +[368.72s -> 378.58s] The 20 is 0. FBC is 0. FBH is 0. So I only have negative 4 times FHI. +[379.34s -> 391.70s] And those equal 0. So now from this, I can go ahead and solve these three unknowns. So here I can find FHI. And when I do that, I find it to be negative 35. +[391.82s -> 405.42s] From here, I can find FBH, which I get to be negative 21.2. Plugging those two values into this top equation, and I can find FBC. +[406.90s -> 418.80s] equals 50 so once i do all of the solving then i go switch them to tension or compression so this guy becomes 50 kilonewtons in tension +[418.80s -> 430.48s] My assumption was correct on this one. These two assumptions were incorrect, so I'm going to call that 21.2 kN in compression and call this one 35 kN. +[430.48s -> 444.78s] in compression so with the method of section find your reaction forces make a cut that goes through no more than three unknowns but you've got to cut all the way through so you can separate them out choose one half probably the easier half draw that expose the +[444.78s -> 448.74s] Those cut forces assume them all to be tension. +[448.74s -> 463.15s] Section is going to be in equilibrium, so you apply your equilibrium equations and solve up to those three unknowns. If you get a negative answer, that assumption of tension then becomes compression. But do that once you get all the way through the math, just so you don't get confused about what's positive. +[463.15s -> 465.71s] and what's negative as you go through things. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_10.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ca2bec9dcf80fbdf94fae74cf04bfbf1e2283e7e --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_10.mp4.txt @@ -0,0 +1,55 @@ +[0.00s -> 7.02s] Hello everyone, let us now apply the DMD method to an example. So as you can see right here, we have a table. +[7.02s -> 16.85s] with adjusted latitude and adjusted departures. So let us compute for the area using the DMD method. Now if you notice this is the same. +[16.85s -> 23.41s] Same given that we have in the previous example. So let's see if we get the same area using this method. +[24.11s -> 36.59s] okay so the first thing that we're going to do is we're going to so let's write it down so number one we're going what we're going to do is compute compute for +[37.36s -> 50.45s] the double marine distances. And the second thing that we're going to do is to compute for the double areas. +[55.38s -> 61.20s] And finally, we can find the area. +[64.21s -> 78.42s] So you can find the area by summing up the double areas and dividing it by 2. Okay, so let's now compute for the double median distances. So let's write it down first here. The DMD of 1 to 2 is equal to... +[78.42s -> 92.91s] what so the dmd of one to two is equal to the departure of one to two right and then the dmd of two to three +[93.33s -> 106.80s] sorry of 2 to 3 is equal to the DMD of 1 to 2 plus the departure of 1 to 2 then plus the departure of 2 to 3 +[107.15s -> 121.87s] So you will see a pattern here. So DMD, how about the DMD of 3 to 4? So this is equal to the DMD of 2 to 3 plus the departure of 2 to 3. +[122.00s -> 132.43s] Plus the departure of 3 to 4. And then the DMD of 4 to 5. +[132.91s -> 146.99s] So this is equal to the DMD of 3 to 4 plus the departure of 3 to 4 and then plus the departure of 4 to 5. +[148.34s -> 159.25s] And then, last two here, DMD of 5 to 6, okay, is equal to +[161.87s -> 163.79s] The DMD. +[167.86s -> 179.38s] 4 to 5 plus the departure of 4 to 5 plus the departure of 5 to 6 +[179.73s -> 185.55s] And finally, we have the DMD of 6 to 1. +[186.16s -> 199.54s] DMD of 6 to 1 is equal to the DMD of 5 to 6 plus the departure of 5 to 6 and then plus the departure of +[199.54s -> 214.51s] six to one okay so let us now substitute the values substitute the values and see let's zoom out a little bit so we have more space +[215.41s -> 228.75s] So this is equal to the departure of 1 to 2. Departure of 1 to 2, that would be 47.27. +[229.62s -> 237.74s] Next we have still 47.27 the DMD plus 47.27 +[238.26s -> 251.44s] plus the departure of 2 to 3. So that would be 608.89. Okay, so we will have 703.43. +[252.40s -> 266.93s] So the next thing that we're going to do is the DMV of 223. What is that? DMV 223 is 703.43, right? Plus the departure of 223. That is 608.89. +[267.57s -> 279.18s] And then plus the departure of 3 to 4. So that would be 786.78. So this will equal. +[279.79s -> 284.56s] 2099.10 +[286.00s -> 298.32s] Next thing, so we have 2099.10 plus the departure of 3 to 4. Okay, the departure of 3 to 4 is... +[298.32s -> 311.57s] a 786.78 plus the departure of four to five that is 218.32 so sorry for the bad handwriting so this will be +[311.57s -> 325.20s] So next one, so we have 3104.20 plus a departure of 425. +[325.58s -> 338.58s] So what's that? 218.32. And then the departure of 5 to 6, that is now negative. Negative, so minus 1, 1. +[338.58s -> 351.98s] 16.62 so we will now get 2205.90 okay so here we have 2205.90 +[351.98s -> 365.17s] I mean minus. This should be minus. Minus 1116.62 and then minus 544.64. So this will equal. +[365.17s -> 378.46s] 544.64 okay so those are our double meridian distances okay so now let us compute for the double areas double areas +[378.46s -> 383.18s] So the double area for 1 to 2. +[384.82s -> 398.21s] is equal to the DMD of 1 to 2, that is 47.27, right? And then we multiply that by the latitude of 1 to 2, which is 490.71. +[398.21s -> 406.80s] So what will we get? You will get 23,195.86. Okay. +[407.22s -> 413.23s] So the double area for 2 to 3. So this is equal to. +[414.32s -> 424.85s] The DMD of 223, which is 703.43 multiplied by the latitude of 223, 587.12. +[425.68s -> 433.04s] So that will give us 412,997.82. +[434.06s -> 444.30s] Next one, we have the double area of 3 to 4. So the same thing. So this will be 2, 0. +[444.30s -> 458.26s] 99.10 multiplied by the latitude of 324 so this is take note this is negative negative 327.41 so we will get +[459.31s -> 472.40s] negative six eight seven thousand two six six point thirty three okay moving on da four to five is equal to +[475.63s -> 489.17s] Is equal to the double median distance of 4 to 5. That is 3104.20 multiplied by the latitude. So negative 1002.76. +[489.17s -> 500.37s] so we will get negative three million one one two thousand and then 767.59 +[503.18s -> 509.49s] Okay, so we have five to six. We were almost done here. +[510.03s -> 524.21s] five to six so this is equal to so what is five to six two two zero five point nine zero multiplied by the departure of five to six is still negative negative one +[524.21s -> 537.71s] 22.67 so you will get um negative 270 597.75 +[540.37s -> 547.92s] And then finally, we have the double area of 6 to 1. So this is equal to. +[549.65s -> 560.69s] 544.64 multiplied by the latitude 375.01 so you will get +[561.20s -> 573.92s] 204,245.45. Now that we have our double area, so what are we going to do next? We're just going to add them all up. +[573.92s -> 586.19s] Summation of our double areas is equal to negative 3,430,192.54 square meters. +[586.54s -> 590.54s] So, this is the double area, right? So therefore... +[590.96s -> 605.23s] Therefore, the area is equal to summation of dA divided by 2, right? So we will get negative 1,715,000. +[605.23s -> 611.31s] 096.27 square meters +[612.14s -> 625.17s] Okay, so don't mind the negative. You can disregard that the area is 1,715,096.27 square meters. +[625.17s -> 637.86s] Okay, so that's how you apply the double meridian distance method. Okay, so if you're wondering where this came from, then you can refer to the previous video. +[637.86s -> 650.40s] because um it is all explained there okay so thank you for watching this video i hope um you learned something new and i will see you in the next videos diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_11.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..15ee36d0418e63b1ad3765d77c8c9aae833da6d1 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_11.mp4.txt @@ -0,0 +1,60 @@ +[4.37s -> 18.72s] Compaction test, which is one of the most important tests in the field of geotechnical engineering, helps engineers to determine the maximum dry unit weight that may be attained for a given soil with a standard amount of compaction effort. +[18.72s -> 30.61s] hello and welcome back to the master civil engineering and in this video we will learn that how to find the maximum dry unit weight and the optimum moisture content from the results of the compaction test +[30.61s -> 42.83s] you can see that i have been given the results of the standard proctor test in the following table that is the mass of the moist soil in the mold and moisture content for different trials +[42.96s -> 55.49s] I have to determine the maximum dry unit weight of compaction and the optimum moisture content. And if the specifications calls for 97% relative compaction in the field, +[55.49s -> 60.75s] what would be the field dry unit weight and the range of the acceptable moisture content +[61.78s -> 75.87s] The first thing which we will do is to find the dry unit weights for different trials and then we will plot a graph between the dry unit weights and the moisture content which is called the compaction curve. +[75.87s -> 88.27s] from the compaction curve we will find the maximum dry unit weight and the optimum moisture content so first let's find the dry unit weight for different trials in excel +[88.66s -> 102.16s] now that we are in excel so you can see that i have already constructed the table for the compaction test in which i have six columns the first column is the trial number +[102.16s -> 110.02s] second column is the mast of moist soil in kg and third column is the moisture content in percentage +[110.02s -> 124.24s] The value for these two are already given in the question that is the mass of the moist soil and the moisture content and we need to find the values for these three columns. The fourth column which is the weight of the moist soil in kilonewton. +[124.24s -> 137.90s] As we know that weight is equal to mass into the acceleration gravity. So we need to multiply the mass of the moist soil with 9.81 to get the weight of the moist soil. To get the value for the +[137.90s -> 150.18s] first trial number we will select the first row of this column and then we will write equal and then we will select the mass of the +[150.18s -> 162.42s] moist soil for the trial number first and then we will multiply it with the 9.81 this will give us the weight of the moist soil in +[162.42s -> 174.74s] newton to convert it into the kilonewton we will divide it by thousand so and then press enter and this will give us the weight of the moist soil in kilonewton +[175.15s -> 186.80s] to get the weight for the other trials we will simply select the weight of the moist oil for first trial and then we will drag it +[187.12s -> 191.66s] and we will get the weight for the different trials. +[192.14s -> 206.53s] Then after that we have to find the bulk unit weight in kN per m3. This is obtained by dividing the weight of the moist soil by volume of the mold. You can see the value for the volume of the mold. +[206.53s -> 219.65s] So to get the value for the first trial, we will select the first row, write equal, and then we will select the weight of the moist soil for trial number first. +[219.65s -> 230.91s] And then we will divide it with the volume of the mold, which is 0.0009433. And then press Enter. +[230.91s -> 243.98s] we will get the bulk unit weight in kilo Newton per meter cube for the first trial. For different trials, select the first row and then drag it. +[243.98s -> 250.48s] and you will get the bulk unit weight for other trials +[251.86s -> 264.22s] Then to get the value of the dry unit weight you can see that the formula for the dry unit weight is bulk unit weight divided by 1 plus water content or moisture content. +[264.22s -> 277.42s] So to get this value, select the first row, then write equal and select the value of the bulk unit weight for the first trial, then divide it. +[277.42s -> 282.67s] with first write the bracket, then 1. +[282.96s -> 296.05s] plus and select the moisture content for the trial number first and then divide it by 100 since this is in the percentage so we need to convert it into the fraction we need to divide it by 100 +[296.05s -> 303.92s] so divide it by 100 and then close the bracket and press enter and you will get the dry unit weight for the trial number first +[304.72s -> 318.26s] Similarly for other trials, select the dry unit weight of the first trial and drag it in the downward direction and you will get the dry unit weight for other trials. +[318.80s -> 331.20s] So this is how we can find the dry unit weights for different trials in Excel Now to plot the compaction curve We need to plot a graph +[331.20s -> 342.32s] between the moisture content on the horizontal axis and dry unit weights on the vertical axis to get the graph of the compaction curve so let's plot the compaction curve +[342.93s -> 355.86s] now that in sheet second you can see that i have already constructed a table having two columns the first column is the moisture content and second is the dry unit weight which we just found out +[355.86s -> 369.98s] and we will plot a graph between these two values which is also known as the compaction curve to find the value of the maximum dry unit weight and the optimum moisture content to get the graph we will select the values +[369.98s -> 383.38s] then click on the insert and then go to the charts and select this scatter with smooth lines and marks so this will give us our compaction curve we will increase the size of the compaction curve +[384.98s -> 396.50s] The first thing which we will do is that we will delete this chart title and these series labels and then we will add Xyz titles. +[397.62s -> 407.09s] for horizontal axes we will write moisture content in percentage +[410.29s -> 424.50s] And for the vertical axis, we will write dry unit weight. This is n. +[425.62s -> 429.23s] kilo Newton per meter cube +[432.05s -> 444.91s] okay now after that we will make some modifications to the chart before finding the value of the maximum dry weight and the optimum moisture content first we will select the horizontal axes +[444.91s -> 459.60s] And we will make the tick marks visible for the major type as cross and minor type as inside. Also to see the values more clearly, we will change the color of the axes. +[460.37s -> 473.46s] that is from gray to black and increase the weight to one point. Also for the vertical axes, we will change the color from the gray to black. +[474.51s -> 488.56s] and increase the weight to one point we can see for the vertical axis we don't have any value of the dry unit weight less than 12 so we will select the minimum value for the vertical axis as 12 +[489.07s -> 496.37s] make the tick marks visible for major type as cross and minor as inside. +[497.52s -> 509.14s] For the compaction curve, select the compaction curve, change its color from orange to black, and increase the weight to two point. +[510.06s -> 515.38s] for the marker points also change their color from orange to black +[525.14s -> 536.50s] increase the width to 1.5 points so this gives us our compaction curve +[536.82s -> 551.31s] now to find the maximum dry unit weight and the optimum moisture content we have to find the peak value in the graph so we can see this is the peak value in the graph to get +[551.92s -> 563.02s] the value of the maximum dry unit weight we will draw a horizontal line from this peak value so draw a horizontal line from this peak value +[569.23s -> 582.59s] this is the value of the maximum dry unit weight and to get the corresponding moisture content which is the optimum moisture content draw a vertical line from this so this gives us the +[582.59s -> 594.45s] value of the optimum moisture content so i can see from the graph the value of the maximum dry unit weight is 18.3 kilo newton per meter cube +[594.45s -> 598.19s] and the optimum moisture content is 15 percent +[599.57s -> 613.01s] From the compaction curve, we just found out that the value of the maximum dry unit weight for this soil is 18.3 kN per m3 and the optimum moisture content for this soil is 15%. +[613.42s -> 622.94s] Now for the second part of this question, we have to find the field dry unit weight and the range of the acceptable moisture content for 97% of the relative compaction. +[622.94s -> 632.50s] Relative compaction is given as the ratio of the field dry unit weight divided by the maximum dry unit weight achieved in the laboratory. +[632.50s -> 642.02s] So for this question, relative compaction is given as 97% and maximum dry unit weight, which we found out is 18.3. +[642.02s -> 648.50s] so the field dry unit weight will be equal to 17.8 kilo newton per meter cube +[651.25s -> 664.88s] We can see that in the compaction curve 17.8 kilo Newton per meter cube value lies here So from this value, we will draw a horizontal line This will cut the compaction curve +[664.88s -> 673.58s] at two points from these two points we will draw a vertical line for from the first vertical line we get the value of the +[673.58s -> 687.66s] water content as 13.8 and from the second vertical line we get the value of the water content as 16.6 so you can say that the range of the acceptable moisture content for the field +[687.66s -> 696.24s] dry unit weight of 17.8 kN per m3 is 13.8% to 16.6%. +[697.52s -> 708.88s] So in this video, you learned that how to plot the compaction curve for the results of the compaction test and find maximum dry unit weight and the optimum moisture content. +[708.88s -> 721.65s] I hope this solution video was clear and you find this video helpful. If you like my videos, please help the channel by subscribing to the channel and sharing this video with your friends. Thanks for watching and stay tuned. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_12.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..402a5a5a5ea068ab62c2ecb14a24e56cac6e8376 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_12.mp4.txt @@ -0,0 +1,60 @@ +[0.62s -> 15.02s] Hi guys, welcome to the channel. Today I'm going to be teaching you how to do calculations of preliminary coordinates using the triangulation method. So this method uses +[15.02s -> 26.74s] your observed directions as well as coordinates to calculate your p-value which is the station you are standing at well in this case you have three stations where you stand +[26.74s -> 40.75s] But at P, it will be the one that you're trying to determine. Now, just two things I want to highlight on this information. You'll see that these two points have been observed by P, so 128. +[40.75s -> 51.04s] 149 as well as P has been observed by both of the points so these directions will be +[51.04s -> 63.46s] almost 180 degrees difference because they are the opposite directions because these two stations are looking at P as the and they also look at each other +[63.46s -> 73.54s] while p looks at them. So that means there's incoming and outgoing row. So when we do the calculations, remember that when you calculate, for example, +[73.54s -> 81.52s] T 149 to P that's 133 degrees the opposite direction will be that plus 180 +[81.52s -> 95.30s] which is P to 149, which is 313 degrees. So that is about 180 degrees difference to that one. Alright, so we start with the direction table. +[95.30s -> 108.18s] Now you'll see that all the observed directions have been plotted into the table as well as the final directions. These final directions that are underlined are +[108.18s -> 122.61s] the final directions you determine using your coordinates, using joins. So I've said before, joins and polars are extremely important in calculating anything in geomatics or surveying. +[123.44s -> 135.79s] Alright, then when you have these final directions, you put them into this column. Then you determine the difference between the observed and the final direction. And you'll see that it's this final direction. +[135.79s -> 147.36s] minus observed direction gives you minus 10 seconds. A way to check yourself is if you say, okay, 38 seconds plus this value, so it's a negative 10. +[147.36s -> 157.78s] give you 28 then you know you've calculated it correctly you do the same for the second one final direction minus observed direction gives you your final correction +[157.78s -> 170.67s] Then you get the average of these two. Since there's two of them, you divide by three. If there were three of them, you divide by two. If there were three of them, you divide by three. Then you get the average, which is... +[170.67s -> 179.62s] negative 11 seconds, which you put over here. You apply this negative 11 seconds to your observed 2p. +[179.62s -> 191.30s] Then you'll get 133 degrees, 37 minutes and 45 seconds. So that's your first direction to P. This one we do the exact same. +[191.30s -> 202.42s] You take your two final directions, you subtract your observed directions, you get two final corrections. You add them together, divide by two to get the average. +[202.42s -> 216.56s] Then it's plus 7 seconds, which you add over here. Then you say there's 22, 33 and 8 plus 7 seconds gives you your orientated forward direction. +[216.56s -> 228.72s] Alright, once you've calculated these two orientated forward directions, you move them to your orientated backwards directions. Now you take these two and you say these... +[228.72s -> 242.69s] minus your observed directions and they give you preliminary corrections. You get the average of these preliminary corrections and you apply them to +[242.69s -> 251.86s] you basically say that plus six you apply it to them to get your orientated forward directions all right now the way we do this +[251.86s -> 266.00s] you would see that is on the side here we have 15 seconds which is this 15 seconds over here and 17 seconds which is a 17 seconds over here so we have to actually orientate or +[266.00s -> 276.59s] We have to use these corrections to work out the proper correction. Now the way we do that, well not the proper correction, but the proper direction. +[276.59s -> 290.58s] You'll see this 15 is now our oriented backwards direction. So this is from T128 to P. But from P to 128... +[290.58s -> 303.63s] We have 17 seconds. So we always consider from P as the more important one. It's got double the value. That's why we would take. +[303.63s -> 316.62s] Essentially what we're doing is we're taking this whole direction and this whole direction. But since the degrees in minutes are the same, we only have to apply the seconds. Then we say 2 times. +[316.62s -> 328.42s] the 17 seconds because the 17 is from P to the other point which is double as important as the 15 which is from the other point back to P. +[328.42s -> 341.31s] Hope that makes sense. So basically you're saying you're 15 times 1 plus you're 17 times 2. Then you divide by 3 because you've got 1, 2. +[341.31s -> 353.89s] three directions you're trying to average here and then that's 16 we move put over here so essentially we're taking two of these directions plus one of these getting the average of them +[353.89s -> 368.18s] to get our final direction the same applies to this one we have a 43 degrees which is this one over here it is from p it is our forward direction or our outgoing direction +[368.18s -> 382.64s] So this means that it's going to be times two. And then we take one of these directions because it's not as important as the one from P. And we divide them by three because there's three of them and we get 44. +[382.64s -> 391.73s] which is our average direction and our final direction. Then we just apply these six seconds to both of these directions. +[392.53s -> 401.84s] All right. From there, we've basically, you can pause on the screen if you want the six-plane step-by-step what you must do in the direction sheet. +[402.10s -> 416.35s] I'm not going to go into too much detail because this is what I explained to you now. I can just show you that the forward ray represents double weight and the backward ray is single weight. That refers to this two times and this one times over here. +[416.35s -> 428.91s] So now since we have those directions, we now have oriented directions from P to 149, P to 11, P to 128 and P to 140. +[428.91s -> 435.76s] So these, if I go back, are these final directions over here. All right. Now. +[436.02s -> 445.54s] What we do is we have to look for the two that have the smallest angle or the angle closest to 90 degrees between them. +[445.54s -> 457.18s] So if you were to go and minus each of these from each other, you will see that 149 and 11 have the closest to 90 degrees difference. +[457.18s -> 464.93s] so that's why we use this triangle and the resection we do corrections but in this we only +[464.93s -> 479.01s] use this try are we already determined final direction or orientated directions so we skip straight to determining our angles we're in the cue point method you have to go through the whole process before you get to your triangle +[479.01s -> 489.41s] Alright, so now what we'll do here is we know the difference between these two directions is 102 degrees, which is the closest to 90. For this angle, +[489.41s -> 503.26s] we'll have to use 11 to 14, 149, 149 to 11, that direction relative to these directions to determine these angles. All right. So. +[503.26s -> 515.50s] As you can see, T149 and T11 are chosen for fixed rate because the angle is the closest to 90. That's extremely important. Then we work out the join of 149. +[515.50s -> 529.23s] to t11 as explained we need to first find this direction then we have the angles now let's just see 106 degrees is from 149 to 11. so this +[529.23s -> 540.78s] to 11 is 106 degrees if we use our join so 106 degrees relative to 149 p +[541.14s -> 554.58s] We remember when you work clockwise, it's positive. When you work anticlockwise, it's negative. So this angle here, we'd have to say this plus this angle gives this. Or we could say this angle. +[554.58s -> 568.94s] of this direction minus this direction gives us this angle over here now since this is 313 this way the opposite direction will be 313 minus 180 which will give you +[568.94s -> 582.54s] 133 then you say that minus this direction and will give you your angle so it's this direction 149 P minus +[582.54s -> 595.30s] This direction will give you this angle the same goes for this angle over here besides angles in a triangle adding up to 980 degrees we must see that 11 to 149 +[595.30s -> 608.51s] which is this direction. The opposite to that would be plus 180 degrees, which would be 286 degrees. So 286 degrees minus 56, the opposite of 56. +[608.51s -> 611.57s] which would be 56 plus 180. +[612.30s -> 625.55s] Then we say this one minus this angle gives us 50 degrees. Then we have our three angles. So these are the formulas over here. If they add up to 180, you know you've done it correctly. +[625.55s -> 639.44s] Alright, then to determine our distances to P from each of the two points, each of these two points, these distances to P, we already have this distance because we calculated it using +[639.44s -> 646.90s] the join. Alright, so distances to P, we use the sine rule, where we say +[647.31s -> 661.73s] the distance which we determined from the join times sine of the angle over sine of angle at p so this would be angle 11 and this would be angle 149 and we get our two +[661.73s -> 673.89s] distances for directions we have to use these formulas over here so direction from 11 to p +[673.89s -> 686.61s] Well, basically, while we have determined it already. For example, 11 to P will be this 56 plus 180. And that's what we use over here to calculate our polar. +[688.27s -> 701.44s] Sorry, I meant this one. Then this one is the opposite direction to this, so it's 313 minus 180, so 133. We'll use that with this distance to work out. +[701.44s -> 714.22s] coordinates from t11 to p then we get the average of these two and that'll be our preliminary coordinates for p all right so the second part is actually the same as the q point method +[714.22s -> 719.75s] But this is where we use triangulation to determine our preliminary coordinates for P. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_14.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5e60bc750914f61da25a6a4bbef72b98b3919a95 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_14.mp4.txt @@ -0,0 +1,68 @@ +[0.00s -> 14.30s] Welcome back everyone. Today we are talking about deflections of beams and frames calculated using the principle of virtual work which is also known as the unit load method. To get started let's do a recap on the principle of virtual work. +[14.30s -> 27.54s] So this principle states that the total work done by a set of forces in equilibrium on any kinematically admissible displacements is equal to zero. So the core idea is that we'll have two separate systems that I'll be analyzing. +[27.54s -> 40.08s] I'll have the real system here, which is the real structure with the real loads applied. And we'll calculate the displacement at some given location. We'll call that delta R. And I don't know what that displacement is. +[40.08s -> 44.88s] But I can calculate my strains throughout that structure, and we'll call that epsilon r. +[45.74s -> 60.18s] Second, I'll be considering a virtual system. This will be my set of forces in equilibrium. I'm going to place a force of unit one located at the location and in the direction of the displacement I want to calculate. +[60.88s -> 73.82s] Now for this system, I can calculate the stresses throughout the entire volume. And now I can combine these two systems. I can calculate the work using the forces and stresses from my virtual system. +[73.82s -> 86.88s] and my displacements and strains from my real system to come up with the principle of virtual work expression for delta r which is the integral over the entire volume of the stresses in the virtual system +[86.88s -> 96.59s] multiplied by the strains in the real system. Now we've seen how to apply this for trusses. Let's expand that concept to beams and frames. +[97.33s -> 110.21s] Now the main difference for beams and frames is that we're going to have three different internal forces, and each of those could contribute to my displacements, at least in theory. So we'll have axial term, we'll have a shear term, and we'll have a moment term. +[110.21s -> 120.58s] So if we add all these together, we'll have, starting with the axiom term, an integral from 0 to L of ni and r divided by ea. +[120.58s -> 134.51s] where E is our elastic modulus, A is a cross-sectional area, and Ni and R are the internal forces for the axial force for my virtual system or for my real system. +[135.12s -> 147.70s] Similarly, we can do this for shear. So for shear, I'm also going to integrate from zero to L, and I'm going to have VI, VR divided by GA, where G is the shear modulus. +[147.70s -> 158.03s] and then I'm going to multiply this by some cross-sectional factor kappa, which tells me how this year's stresses are distributed through my section, and then integrating over dx. +[158.42s -> 171.49s] Finally, we have the moment term, and that's integral from 0 to L of mi, mr, divided by ei, where the new term here, i, is the moment of inertia of our section. +[171.49s -> 173.68s] integrated over DX. +[174.45s -> 188.02s] Now, in theory, all three of these can contribute to my displacements, but in practice, the moment one is by far the most important term for pretty much any civil engineering structure and any beam type structure. +[188.02s -> 202.51s] The axial force term and the shear force term are minor contributions and we'll sometimes consider axial force. Shear force can be important for deep beams, but most of the time just the moment alone will give a very good approximation of the total displacement. +[202.67s -> 212.98s] Now in the example that we'll do today, I will also calculate the displacements due to the axial force term just to show that it is in fact negligible in most circumstances. +[213.23s -> 226.77s] So now that we've got the theory down, let's dive into an example problem. So here I have a simple two-member frame. It has a column AB and a beam BC. All of them have the same cross-sectional properties. +[226.77s -> 240.30s] Here I have a concentrated load of 20 kilonewtons down, and I'm interested in calculating my vertical displacement here at C. So for the virtual system for this problem, I'm going to be considering a unit load down at location C. +[240.30s -> 247.94s] And again, we have properties here for cross-section and moment of inertia. And we also have a Young's modulus in terms of gigapascals. +[247.94s -> 257.58s] If I want to convert that to kilonewtons per meter squared, this would be equal to 30 times 10 to the sixth kilonewtons per meter squared. +[258.13s -> 268.58s] So we'll start with calculating the real system. The first thing that we'll do is calculate our reaction forces. So I'll see that I need a 20 kilonewton force up at location A. +[268.58s -> 279.86s] Sum of moments about A will give me a reaction force at C in the horizontal direction, and we'll find that's 8 kilonewtons. And then sum of forces in the X direction means that this is also 8 kilonewtons. +[280.46s -> 289.58s] Now if we go to the axial force throughout the frame The column is in compression of negative 20 and then the beam is going to be in compression of negative 8 +[290.06s -> 302.96s] For shear, this column has a shear of negative eight, and the beam is going to have a shear of 20, but then it drops down to zero once I apply that concentrated load. So this has a magnitude 20. +[302.96s -> 315.81s] And for my moment, I have two lines, so I have a first line segment, and that's going to be 8 multiplied by the distance of 4 meters, so that goes to negative 32 kilonewton meters. +[315.81s -> 325.36s] So I'm going to start at negative 32 over in the beam, and it rapidly goes to zero, and then it's zero for the remainder of that segment. +[326.67s -> 339.79s] Now, when applying the principle of virtual work, it's useful to have equations for each of your diagrams. And so what I'm going to do is I'm going to say for my moment diagram, I have X1 for my column and an X2. +[339.79s -> 348.34s] for the coordinate of my beam, and I'm going to find the equations for these. So for this line, it's going to be negative eight times X1. +[348.34s -> 356.82s] The negative eight is coming from the shear diagram. So we just integrate shear to get to moment. So negative eight becomes negative eight times X. +[357.10s -> 369.14s] And similarly for this segment in the beam, it's going to be a positive 20. And then I need to subtract 32 to make sure that it has the correct intercept right here at x2 is equal to 0. +[370.58s -> 383.65s] Now moving on to the virtual system. My unit load down is going to be countered by a load of 1 up at point A. Taking my sum of moments about point A will give me a force of 0.8. +[383.65s -> 397.65s] acting to the left, and so therefore I'll have a 0.8 acting to the right at point A. Now all these forces actually are unitless, so we're not going to have a unit for any of these quantities, except for the moment, which is going to have a unit of... +[397.65s -> 410.75s] blank, no load, times meters. So if I do a similar idea of getting my axial shear and moment diagrams for the virtual system, axial is going to be a compression of minus one here in the column. +[410.75s -> 424.22s] and minus 0.8 in the beam for the shear i have a minus 0.8 in the column and then i'm going to have a positive 1 in that beam and for the moment i'm going to have two lines +[424.22s -> 434.67s] so line here and a line here for that beam the moment here at the corner is negative 3.2 taking the area under my shear diagram +[434.74s -> 447.49s] And once again I can find the expressions for those two lines. So in the column it is negative 0.8 times x1. And in this beam it's going to be... +[447.49s -> 457.33s] x minus 3.2. So now that we have our structural analyses for axial shear and moment let's apply the principle of virtual work. +[458.19s -> 466.61s] So I'll start off with my axial strain energy term. Again, we're going to find this is relatively negligible, but let's go through the whole exercise of computing that. +[467.02s -> 479.07s] So my integral expression here from 0 to L, I'm really integrating over the whole structure. So I'm going to break this into two components. So I'm going to have an integral from A to B for my column and for B to C. +[479.07s -> 493.20s] for that beam. So let's break this down. If I'm looking from A to B for the column, that varies from zero to four meters. And then NI in that region is a negative one. And NR in that region is negative 20. +[493.20s -> 498.38s] kilonewtons, and it's going to be divided by EADX. +[498.90s -> 512.83s] Also, I'll have a second expression from 0 to 3.2, so this is for my beam. My Ni is negative 0.8, and my Nr is negative 8 kilonewtons. +[512.83s -> 526.16s] divided by EABX. Now, if I evaluate those integral terms, we'll find that this is equal to a 100.48 kilonewton meters. +[526.16s -> 538.74s] divided by ea so now we can substitute in our values for ea so this is 100.48 kilonewton meters divided by e which is 30 times 10 to the sixth +[538.74s -> 541.42s] kilonewtons per meter squared. +[541.68s -> 556.05s] And then my cross-sectional area is 0.09 meters squared. So I can see unit-wise, I'm going to be left with just a meter. So because I prefer this in millimeters, I'm going to multiply my result by 1000. +[556.05s -> 569.58s] millimeters per meter and we'll find that this displacement is equal to 0.0372 millimeters. So again a very small displacement for the axial term alone. +[569.87s -> 578.82s] Now let's compare that to the moment. Once again, I'm going to break my integral up into two segments where I'm going to look at the column from A to B. +[578.82s -> 589.62s] But for the beam, I'm only going to look at this first 1.6 meters because my moments in the second region is equal to zero. So obviously that integral in that region will also be equal to zero. +[589.74s -> 602.32s] So if I define my displacement due to the moment contribution, we'll first integrate from 0 to 4 for my column. Mi is negative 0.8x1. +[602.45s -> 610.48s] And then MR is negative 8 times X1 divided by EI, and I'm integrating over X1. +[611.73s -> 625.49s] My second contribution will be from 0 to 1.6, where mi is going to be x2 minus 3.2, and then mr is 20 times x2 minus 32. +[625.49s -> 630.48s] Again, divided by EIBX2. +[630.80s -> 641.87s] Now we can go ahead and evaluate these integrals. Skipping the TDS calculus part, we'll find that this is 204.8 kNm3. +[641.87s -> 654.74s] Divided by EA so let's talk a little bit about where that unit of kilonewtons meters cubed came from So my mr. My real moments are going to be kilonewton meters +[654.74s -> 658.99s] and my MI for the virtual system is just meters. +[659.79s -> 671.63s] Furthermore, we'll have a unit for my length of meters. So we'll see that we have meter, meter, and kilonewton meter. So that's kilonewton meters cubed, and then divide by EI. +[671.73s -> 685.60s] So now I can go ahead and plug in my values for EI. So this is going to be 204.8 kilonewton meters cubed divided by E, which is 30 times 10 to the sixth kilonewtons. +[685.60s -> 695.50s] per meter squared multiplied by i which is 6.75 times 10 to the negative 4th meters to the 4th +[695.76s -> 709.66s] And once again, we see that our units all cancel out. Kilonewtons cancels. I'll have all that's left is a meter. And so I'm going to multiply this by 1000 millimeters per meter to make sure that the units are in millimeters. +[709.66s -> 715.12s] and my result is going to be 10.11 millimeters. +[715.63s -> 728.80s] So again, that is substantially larger than my axial force contribution, hence why axial force is often ignored in design. However, if we want to consider the combination of these two, we would just add them together. So I can take... +[728.80s -> 741.23s] 10.11 millimeters plus my fraction of a millimeter that I got beforehand and I'd see in total I would have 10.15 millimeters. +[741.71s -> 753.12s] Now that displacement is going to be acting down at location C and the reason I know it's down at that location is because I've computed my total displacement to be a positive number +[753.12s -> 765.17s] and my unit load was applied down at that location. So if we find a positive displacement, that means that displacement is in the same direction as my unit load that I placed on the structure. +[766.16s -> 775.18s] So that wraps up principle of virtual work for beams and frames. I hope you learned something. Please subscribe and I will see you next time. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_17.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_17.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..bf134899b99edc1c3d9a18f38a61be0ab6aec9c3 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_17.mp4.txt @@ -0,0 +1,51 @@ +[0.98s -> 15.63s] I am Dr. Satish Kumar Kashyap, Professor in Civil Engineering, Valchand Institute of Technology, Sulapur, presenting a topic from Reservoir Planning. The topic is Estimating Reservoir Capacity of a Dam Reservoir. +[16.62s -> 29.01s] Learning outcomes of this session. At the end of this session, the students will be able to describe how storage capacity of a dam reservoir changes with elevation of water surface. +[29.87s -> 38.42s] and the students will be able to calculate storage capacity of a reservoir using contour map of a particular reservoir site. +[39.57s -> 48.69s] Firstly, we will have an idea of a river valley development. Then we will see few views of a typical dam reservoir. +[48.98s -> 63.57s] Then we will see a typical Qatar map and thereafter we will have a look on two formulae for estimating reservoir capacity and then one small numerical example to estimate the reservoir capacity. +[64.46s -> 70.48s] Now this is a typical river valley development plan for Damodar +[71.63s -> 83.15s] This is a catchment area or the watershed area of the river and you will find that Dams are constructed in this valley +[83.31s -> 97.31s] at certain locations such that every dam gets a certain catchment at the same time a good reservoir is formed so when we construct a barrier across the river and when +[97.31s -> 101.55s] a pool of water is formed that is called as a reservoir. +[101.90s -> 115.98s] you know that reservoirs are used for human consumption and industrial use also for irrigation also for hydropower also for hydropower plants we also construct dams +[115.98s -> 129.07s] as a flood control dams and we also construct dams and form reservoirs for the amenity use this may include for boating water sports fishing sightseeing and so on this is full reservoir level +[130.61s -> 142.19s] This is the storage which is used at the time of flood control level. And this is the surcharge storage. It matches with the highest. +[142.45s -> 156.18s] flood level this is the conservation storage which which is used for satisfying the demands let it be for irrigation let it be for hydropower and so and below this dead storage level +[156.18s -> 169.84s] whatever the storage is there that is called as a dead storage so in this way these storage zones are important for us dead storage this is a live storage this is the flood control storage and the search +[169.94s -> 171.79s] Now, here you can see. +[172.21s -> 185.33s] Tehri Dam from India. So a barrier which is constructed across the river is called as a dam and a pool of water which is formed that is called as a reservoir. +[185.39s -> 199.22s] So here you can imagine this is the well-known Terry Dam which is constructed as an earth dam. Over 250 meters is the height of the dam. And this is a reservoir which is formed. +[199.47s -> 205.94s] Now here you observe that the water level is quite low. And one more picture I will show you. +[206.26s -> 220.91s] Here you find the dam is almost full and water is passing over the spillway which is constructed at the end of this particular dam. So here you can see a reservoir. +[220.91s -> 234.58s] which is having water level very less and then here you can see a reservoir which is almost full so you can imagine at every level the storage capacity will be different +[235.57s -> 248.69s] This is a Koinar Dam and its reservoir from Maharashtra State. This figure will show you that the periphery of this particular pool of water reservoir follows a contour line. +[248.69s -> 254.80s] And this principle we are going to use whenever we go for estimating storage capacity of freezer bars. +[256.27s -> 267.73s] Now capacity of reservoir. Dams are constructed for water supply, irrigation, hydropower. A contour map is used to estimate capacity of a reservoir which is formed by a dam. +[267.79s -> 280.64s] As we discussed the periphery of still water body always follows a contour and all the contours are closed lines within the reservoir area. So if we find out +[280.64s -> 287.09s] the areas enclosed by contour say at level 1 a1 a2 a3 and a n +[288.02s -> 299.41s] and which are spaced vertically at a contour interval say d meters, then it is possible to estimate capacity of a reservoir by adopting certain formulae. +[300.02s -> 312.21s] Now this picture will give you the idea about reservoir water elevation and reservoir capacity. So this is a dam and this is a reservoir. So water level may be here. +[312.21s -> 327.02s] water level may be here water level may be here and maybe here it means water level goes on varying so you can imagine here that this is a contour line say matching with this level +[328.34s -> 329.65s] A3. +[330.26s -> 343.92s] matching with h3 area a2 enclosed is matching with h2 area a1 is matching with h1 so you can imagine +[343.92s -> 357.71s] This point if you transfer here or this point if you transfer here or this point if you transfer here. This will give you idea about the contours which are enclosed. By using planimeter one can find out these areas. +[357.71s -> 365.20s] It may submerge areas at different elevations. So here we will go for two small questions. +[366.16s -> 378.86s] The storage created on the upstream side of a river by construction of a dam is technically known as a reservoir or a tank or lake or none of these. Second question. +[378.86s -> 393.84s] The area covered by reservoir water at a particular level is known as subvergence area, catchment area, watershed area or none of the above. Here are the answers. The storage created upstream side of river by dam is called as a reservoir. +[394.86s -> 407.31s] Not a lake, not a tank. The area covered by the reservoir water at a particular level is known as a submergence area. Okay. Now, let us see how one can compute. +[407.66s -> 412.59s] The volume of water the first very simple rule is a trapezoidal rule +[413.01s -> 426.69s] According to this rule, volume by trapezoidal formula V is d by 2, d is the distance between two successive, vertical distance between two successive contours into bracket first area. +[426.69s -> 431.66s] plus last area plus two times sum of areas of +[431.92s -> 444.94s] other. It means v is equal to d by 2 into bracket a1 plus an plus 2 times a2 plus a3 up to an minus 1. Now +[444.94s -> 456.05s] There is one more formula which is called as a prism model formula. This formula is better than the formula which we discussed that is the trapezoidal rule. +[456.69s -> 471.65s] The volume v is equal to d by 3 into a1 plus an plus 4 times a2 plus a4 plus an minus 1 plus 2 times a3 plus a5 plus an minus 2. That is. +[471.65s -> 485.55s] Volume is given by contour interval divided by 3 into area enclosed by first contour plus area enclosed by last contour plus 4 times sum of areas enclosed by even contours and 2 times sum of areas enclosed by odd contours. +[485.65s -> 498.72s] So this formula is applicable when there are odd number of sections. If the number of sections are even the end section is treated separately. The volume of the remaining section is calculated. +[498.72s -> 512.32s] in the usual manner by trapezoidal formula and then it is added to that so this is an example you are given the contour elevations and area enclosed in hectare meters +[512.32s -> 524.08s] 100, 105, 110, 115, 120, 125 and these are the areas enclosed in hectares. So here we adopt the Prismodel formula. +[524.85s -> 535.74s] So, d by 3 into a1 plus a5 first and last plus 4 times the even and 2 times the odd areas. +[535.74s -> 548.34s] So, when you do this, you get this 122. So, here we are adopted up to 120 meter. The section from 120 meter to 125 meter is calculated here. +[548.34s -> 559.84s] by using a trapezoidal rule that is d by 2 into a5 plus a6 it gives you additional capacity of 130 hectometers so in first step whatever we calculated here +[559.84s -> 573.49s] up to 120 meter and in second step we have calculated volume from 120 meter to 125 meter we get this 383.33 hectometer as an area so in summary +[573.52s -> 587.47s] You understood from this video how storage capacity of a dam reservoir changes with elevation of water surface and now you can calculate storage capacity of reservoir using contour map of a particular reservoir site. +[587.82s -> 591.73s] These are the references used. Thank you. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_2.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..788011452152fba8439ccce0e401cd9fdf28ad67 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_2.mp4.txt @@ -0,0 +1,50 @@ +[4.56s -> 19.01s] Hello everyone, now let us look at the numerical problems of flight planning. So the first numerical is the scale of an aerial camera photograph is 1 cm is equal to 100 m. The scale given to us is +[19.01s -> 23.47s] 1 centimeter is equal to 100 meters. +[24.02s -> 38.51s] This is the scale. It means 1 centimeter on photograph is equal to 100 meters on the ground. What is scale? Photo distance. +[39.25s -> 44.59s] upon ground distance +[45.81s -> 59.89s] and photo distance is given as 1 centimeter and ground is given as 100 meters. To write them in the form of ratio, these two units should be equal. So, 1 centimeter is equal to +[59.89s -> 66.45s] we can write 100 cm now this will be in the form of representative fraction +[66.99s -> 80.96s] this this is the scale of the photograph okay in the form of ratio next thing which is given is the photograph size is 20 centimeter into 20 +[80.96s -> 93.47s] is given as 20 centimeter into 20 centimeter. +[93.47s -> 108.11s] Determine the number of photograph required to cover an area of 100 square kilometer. Third thing that is given is total area and the total area is given as 100 square kilometer. +[108.72s -> 122.06s] If the longitudinal overlap is 60%, means PL is given as 60%, that is 0.60 and the side overlap is given as 30%. +[122.06s -> 136.42s] pw is 30 percent that is 0.30 this all the details are given and we have to calculate the total number of photographs okay so the formula is n is equal to +[136.42s -> 150.22s] A upon A. This is the basic formula. Here, the capital A is given as 100 km2 and we have to calculate this A. Okay? +[151.15s -> 163.89s] The value of small a is L into W and the formula of L is equal to 1 minus PL dot S dot L. +[163.89s -> 175.15s] And the formula of W is 1 minus pw dot s dot w. We will put in the values of all the thing. +[175.15s -> 188.98s] L is equal to 1 minus PL will be 0.60. S is the scale. We have taken the value of scale in the ratio. Write the denominator part as it is here. +[188.98s -> 201.87s] When we calculate it, its value is 80,000. 80,000 in the terms of centimeter. Okay. +[202.45s -> 211.70s] 800 meters and 0.8 kilometers respectively now let us calculate W +[212.46s -> 227.02s] W is equal to 1 minus PW. PW value is 0.30 into S dot small w. So S is 1 minus 0.30. S is 1. +[227.15s -> 239.78s] two three four okay and W is this 20 centimeter when this into Kia so Amari value at the one four zero triple zero centimeters +[239.78s -> 254.00s] when we convert it into meter it will come 1400 meters and in kilometer it is 1.4 kilometer okay so the net ground area will be like a is equal to l +[254.00s -> 258.38s] into w okay and l is +[259.57s -> 273.30s] L is 0.8 into W is 1.4. Okay. So, A will be equal to 1.12 kilometer square. +[273.30s -> 281.30s] 1.12 kilometer square so the formula of capital n is equal to a upon a a is +[281.81s -> 295.49s] given as 100 kilometer square hundred one point one two this will be coming as eight point nine two that will be equal to nine photograph +[295.49s -> 299.60s] nine photo graph +[300.91s -> 311.38s] Now let us look at the numerical number 2 the scale of an aerial photograph is 1 centimeter is equal to 100 meter same +[311.92s -> 317.78s] 1 centimeter is equal to 100 meter that means 1 upon +[318.38s -> 331.50s] This is the scale. 1 cm upon 10,000 cm. If it is divided by cm, it will be a representative fraction. +[331.50s -> 342.82s] The size of the photograph is given. Small l into small w. 20 cm into 20 cm. Area is given in the terms of. +[342.82s -> 356.03s] 10 kilometer into 10 kilometer that is l1 into l2 is 10 kilometer into 10 kilometer if the longitudinal overlap means +[356.03s -> 369.68s] PL is given as 60% that is 0.60. Side overlap 30% that is 0.30. So let us calculate by formula number 2. +[370.38s -> 384.83s] So, first formula will be number of photograph in each strip is given by N1 is equal to L1 1 minus PL S dot L plus 1. L1 ki value humko di hui hai 10 km. Itko of centimeters mein change kar do. +[384.83s -> 386.61s] so this value will be 10 +[388.27s -> 402.26s] like this okay and 1 minus PL PL is given as 60% PL is equal to 0.6 1 minus 0.6 into scale value given as 1 upon +[402.26s -> 414.42s] 100 meters to 1 upon 100 into double zero this will convert it into centimeters scale ki value likdi into 20 kyunki photograph ka size kya diya ho hai +[414.42s -> 426.18s] small l is 20 cm and small w is 20 cm all the values are done in cm and in last there is plus 1 in formula this will come as 100 upon 8 plus 1 12.5 +[426.18s -> 439.60s] plus 1 that is 13.5 and 14. 14 is the number of photograph in each strip. N2 is the number of flight line required. N2 formula is L2 upon 1 minus +[439.60s -> 452.56s] pw dot s dot w s dot w here also we have given l2 as 10 km from 10 km we have converted it to cm that will come as +[454.70s -> 468.32s] This value. Okay, we will put up this value upon here. This is 10 kilometer written in centimeters 1 minus 0.3 PW is 30 percentage 30 percentage +[468.32s -> 477.23s] that is we will be written as this 0.3 into this scale value denominator part into 20 plus 1. +[477.55s -> 491.73s] 100 upon 14 plus 1, 7.14 plus 1 gives 8.14 that is equal to 9. Hence, the number of photograph required will be n is equal to n1 into n2, 14. +[491.73s -> 506.03s] Let us take another example, numerical 3. The scale of an aerial photograph is 1 cm is equal to 100 m. 1 cm is equal to 100 m. +[506.03s -> 517.09s] The photograph size is 20cm x 20cm +[517.09s -> 528.35s] determine the number of photographs required to cover an area of 8 kilometer into 12.5 kilometer l1 is given as 12.5 kilometer l2 is given as 8 kilometers +[528.35s -> 539.81s] If the longitudinal lap is 60%, 0.6. Side lap is 30%, 0.3. N1's formula is L1 upon 1 minus PL dot S dot L plus 1. +[539.81s -> 551.39s] N2 formula is L2 upon 1 minus PW dot S dot W plus 1. Here, L1 is converted from 12.5 km to 1 meter by 1000. +[551.39s -> 562.62s] Then convert cm into 100. 1-pl 0.6. Take the denominator part of scale. 20 cm. Take this value of plus 1. +[562.62s -> 575.87s] This is 16.625 which is equivalent to 17. To calculate N2, L2 is 8 Km. First, convert it to meter and then to centimeter. 1 minus 0.3, scale this. +[575.87s -> 590.37s] 20 cm plus 1. 6.714 is equivalent to 7. Number of photographs will be N1 x N2. 17 x 7 will be equal to 119. +[590.37s -> 594.54s] Done for the numerical part of the flight planning. Thank you class. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_20.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e86b4e5eae981f4245b749b51d133c854f17452e --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_20.mp4.txt @@ -0,0 +1,43 @@ +[10.48s -> 17.74s] Hi. Kwa hivyo, kutoka kwa kwa hivyo. Kwa hivyo, kutoka kwa kwa hivyo. +[18.00s -> 29.33s] So this is a July series 2021 paper under building civil engineering and architecture diploma 3 students. +[30.35s -> 44.38s] Let's go ahead and we look at the question paper. So that will be question 6A. The reduced ground level and the formational level of an embankment at 0 meter. +[44.38s -> 57.68s] 30 metri na 60 metri cheneges inaweza kwenye tabla kwa hivyo kwenye tabla inaweza cheneges kwa hivyo kwa hivyo kwa hivyo kwa hivyo kwa +[57.68s -> 62.77s] Kwa hivyo kwenye mita. Kwa hivyo kwenye mita. Kwa hivyo +[63.34s -> 78.16s] Kwa sababu kwenye njia. Kwa sababu kwenye njia. Kwa sababu kwenye njia. Kwa sababu kwenye njia. +[80.05s -> 93.31s] Traverse slope in horizontal. And the embankment side slope at 1 into 2. Calculate our first. +[93.31s -> 104.66s] so we calculate the width of the embankment our second question we calculate the volume using trapezoidal and prismoidal rule +[107.15s -> 118.93s] Kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo +[119.57s -> 128.83s] In the long constructions which we have constant formational width and side slopes, it is possible to +[128.83s -> 136.27s] Simplify the computations of cross sectional areas by the use of the formulas. +[137.26s -> 144.85s] Kwa hivyo kutoka kutoka kutoka kutoka kutoka. +[146.80s -> 155.02s] Kwa mwisho, kuilustrua kutumia kwenye diagrama. Kwa hivyo kwenye format kwa diagrama. +[155.54s -> 169.97s] uh you can see the diagram there uh in our diagram so an embankment that is like a road formation or some hip uh yeah some soil yeah +[170.45s -> 183.18s] There where our B is equals to the formational width. You can see it in the diagram. H is the height. And M is the side slope. And again. +[183.18s -> 191.15s] w inaweza kutoka kutoka uh kwa hivyo inaweza kutoka kutoka kutoka +[191.70s -> 206.21s] Kwa hivyo kutoka kutoka kutoka kutoka kutoka kutoka. +[206.21s -> 213.01s] kwa hivyo unaweza kutoka diagrama kwa hivyo nilikuwa kwa hivyo +[213.90s -> 226.10s] In general, the formula for finding the width will be equal to a half b plus m h. +[227.02s -> 241.44s] So that is the formula for finding the width of the embankment. The W there in the diagram. Then our height will first be calculated from the difference in the. +[241.44s -> 252.24s] cheneges interval kutoka formula kwa hivyo, wakatiweza kutoka kweli kwa kutoka kutoka +[254.16s -> 262.26s] So you can look at the screen there I have already done the heights +[262.58s -> 276.08s] by subtracting the reduced level from the formational level. So formational level is found on top. The reduced ground level is found in the ground level. +[276.40s -> 289.18s] uh after having that that i apply my formula uh so the w will be half b plus m h giving me uh three +[289.18s -> 298.42s] Mungu kwa mungu. Mungu kwa mungu. +[299.28s -> 308.82s] Na kwa hivyo kutoka kutoka kutoka kutoka kutoka +[311.31s -> 325.49s] Kwa hivyo kwa trapezoidu, kwa hivyo kwa trapezoidu, kwa hivyo kwa trapezoidu, +[326.99s -> 340.21s] uh by adding two and the remainder of our areas we do a sum of them as illustrated uh there here +[340.21s -> 353.22s] Kwa hivyo kutoka kutoka kutoka kutoka kutoka kutoka kutoka kutoka kutoka +[353.22s -> 367.15s] Kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo. +[367.15s -> 377.58s] areas as illustrated in the equation there. We find the different areas in meters squared. +[379.12s -> 385.74s] Kwa hivyo, kutumia formula kwa kutumia volume kwenye rola trapezoidal. +[386.58s -> 399.98s] Kwa sababu kutoka kwa kwa kwa kwa kwa kwa kwa kwa kwa +[400.05s -> 412.10s] So the volume will be equals to 30 over 2 into brackets our first area plus our last area plus 2 times the remaining. +[412.10s -> 425.47s] kwa hivyo hivyo hivyo hivyo hivyo hivyo hivyo hivyo hivyo hivyo hivyo +[425.47s -> 440.02s] mita kwa hivyo kutoka kwa hivyo kwa hivyo kwa hivyo kwa hivyo kwa hivyo +[440.59s -> 451.95s] Kwa hivyo, kwa hivyo, kwa hivyo, kwa hivyo, +[454.26s -> 467.18s] uh as the end areas of the successful press model uh will have the formula uh going by so our formula for finding the press model +[467.34s -> 470.45s] A volume by press module will be +[470.70s -> 484.59s] 2D over 6 into brackets our first area plus 4 multiplied by our second area plus our third area. We close our bracket. +[484.59s -> 497.58s] uh here our d will be the interval in the changes and our interval there was 30 as observed earlier uh so uh having applied those +[497.58s -> 511.38s] uh we have finished our question uh if you have a question uh you can get to me through my email or in the comment below +[511.38s -> 520.60s] Kwa hivyo, kufanya link ya PDF. Kwa hivyo, kufanya link ya PDF. Thank you. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_26.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_26.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6c00188857bfd37d5abc2d01119e27abbedbeaca --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_26.mp4.txt @@ -0,0 +1,42 @@ +[1.68s -> 11.92s] all right this video is going to show you how to do an angle resection three-point angle resection i think in the galani wolf book it just calls it a three-point resection +[11.95s -> 24.53s] So maybe they do a distance one too, but this one just the angles. You have angle X and angle Y. Zoom in on this. There's angle X and there's angle Y. And then this included angle. +[25.46s -> 38.22s] the interior angle but we can calculate that because of the you know ABC we have let's say those are points ABC and that's also angles ABC so come over here +[38.51s -> 49.84s] Point A would be in point C. Angle A. F3, angle C. +[51.79s -> 60.02s] Then we have angle alpha and angle X and angle Y. So this is a four-sided polygon and +[60.40s -> 72.46s] what we're trying to do is find out what's the a plus c right and that's all you know is this a plus c is equal to a number right so in this case it's uh we have x we have y and we have this +[72.46s -> 85.71s] This is a four-sided polygon, so n minus 2 times 180 gives you 360. So 360 minus, in parentheses, or you can just go 360 minus x minus y minus alpha. +[85.71s -> 93.52s] then what's left is a plus C that's one number that's going to go in there and then +[94.22s -> 107.87s] So these formulas here, you can plug that number in, and then you'll get the formulas pretty easy. But knowing what AC was probably the tricky bit. Let me go over here. Let's say I'm going to... +[107.87s -> 121.36s] just show you how this gets calculated or calculated but how to try if you had those two angles how to do it geometrically so i'm gonna just come up here and get uh trim these to the here +[123.02s -> 131.79s] because now these would be equal i can grab them and then p here this is level two let's go to layer +[132.08s -> 143.15s] Turn off layer 2 so we don't know what it is. And then, so we don't have that location at that point. But we have, let's do this. +[147.38s -> 157.81s] if you add those two angles out delete that and then i'm going to just take these and control h paste them onto here +[163.86s -> 173.74s] Now what we're creating is the trim out to each other. +[182.29s -> 197.04s] just gonna show this because it's a good way to check to make sure you're drawing it right they should all three come together in one spot like perfectly okay and this creates a circle +[199.28s -> 211.25s] So I'm going to three-point circle that. And you can calculate this circle now. Because you have the distance here. And you have this angle. Out M A. +[212.14s -> 214.54s] So you have this angle right now. +[217.68s -> 231.89s] because it's half of the 10.8 right so there you go so you can calculate the diagonal you can calculate this leg calculate the difference divide that by two and you get the center of the circle so we're just going to grab and set it to the center of the circle +[232.30s -> 234.10s] Do the same thing over here. +[243.57s -> 249.46s] I don't think this is going to come up on an exam. It's an old kind of technique. +[249.87s -> 262.53s] But uh, you know, you've got menus to do it on the total station. I think even the digital theodolites have a resection in them, but Maybe I used one once +[262.53s -> 267.12s] I don't think I used either the memory or the... +[267.57s -> 279.25s] I think the memory is just for remembering angles, right? So you could take it and put it in your, and do the calculations externally. But I think there might be a resection in one of the digital. +[280.37s -> 286.96s] The old ones I can't remember anyway, so you go there now we got the second one +[291.31s -> 303.54s] And we're going to do the same thing here, drag it to the center. Create those circles. Well, let's leave this, this one. +[305.68s -> 316.27s] Anyway, so the two, yeah, I'm going to delete this. Let's get rid of this. This was, don't even know why that's there yet. +[318.19s -> 324.91s] oh because i said yeah let's delete that let's just go v from there to there +[325.33s -> 339.02s] Actually, let's do this. B, just so we can check and see. It's the intersection of those two circles, right? From this point to that point. And it's perpendicular to this line. B, J. +[340.21s -> 354.00s] particular to this okay enter and then uh let's see so this circle would be kind of the one they should all come together in the same spot these three let's see how we did and then uh +[355.02s -> 362.22s] It's good that there's no error, right? Well, maybe there is. I just zoomed in too far. +[363.12s -> 377.07s] It's a layer turn P back on and it should be on the P that would give it This is how you calculate the location of P, right? I zoomed in so pretty far. There's an error because sometimes the circles have a little +[377.74s -> 387.22s] Yeah circles intersecting I'll give you like +[388.56s -> 399.66s] Maybe if I drew it, it'd be better than that. But maybe there's something that wasn't exactly right. Anyways, that's how you do it. Oh, actually, you know what? I'll bet you it'd get better if you intersected that to this. +[401.87s -> 414.77s] What the hell? Oh, no, so it's not. It's not perpendicular. It's just the intersection of those. Oh, that's because it moved. +[417.36s -> 432.08s] i should uh trim it out right to that center maybe better you know under the set yeah and that's exactly to the center the intersecting circles i'm getting a little bit of a +[433.62s -> 448.59s] Little bit of an air because they didn't you know, they're not exactly true circles that they are Look at their little nodes about everything If this circles divided up into some certain number +[448.94s -> 455.76s] But that's how you would get that, right? And then you have the location of P. +[456.27s -> 469.81s] Well, I hope that doesn't come up on an exam, but if it does the one thing you got to remember if you go 3.3 section So if you go type in the PDF search on because if you're doing it on the computer +[470.16s -> 481.81s] PDF search resection, three-point resection, you just need to know that the A plus C is what you calculate. And then you plug that into that one number. A plus C is one number. +[482.35s -> 489.36s] that you calculate. And that's these angles here, right? Those two together. +[489.87s -> 503.50s] And hope that helps you in your career or taking an exam. You know, it's good to know how to do the geometry. And it would have been better if I could have figured out how they derived the formula. Bugged me a little bit. +[504.18s -> 506.54s] Good luck and thanks for watching. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_6.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6fabcff37b5c38914bf4456cbc50174f00babdaf --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_6.mp4.txt @@ -0,0 +1,67 @@ +[11.12s -> 17.26s] I am Dr. Subash Karandi, Assistant Professor, Department of Geography, Chhatrapati Shivaju College, Satara. +[17.58s -> 32.29s] Today we will learn about the scale of aerial photography. The scale of aerial photography is the important part in the photogrammetry. The scale of an aerial photograph is the ratio +[32.29s -> 44.59s] the distance between two point on photographs and distance between same corresponding point on the ground +[46.48s -> 52.85s] Scale is an important describing factor of the vertical photograph. +[53.20s -> 62.19s] It is important to know that one photographs how many area covered or +[62.58s -> 76.37s] how many informations are covered in the specific photographs that is the less detail or more detail and so these are the important for the interpretation +[76.37s -> 81.84s] Scale also feature in the image to be measured. +[82.22s -> 96.35s] Now most of the photographs are with the scale or some without the scale. But some mathematical calculations or formula you can calculate scale of +[96.35s -> 97.87s] ERL photographs. +[99.70s -> 112.11s] not only you can calculate scale of aerial photographs but also you calculate height of aircraft or drone or any aerial platform and +[112.75s -> 117.26s] focal length of camera also scale of a particular +[117.65s -> 130.14s] or specific point also you can calculate using the some mathematical formulas recently most of the photographs having scale first method +[130.14s -> 139.79s] for the calculation of scale of aerial photograph by establishing relationship between photo distance and ground distance. +[140.62s -> 153.74s] The formula for the calculation of scale of aerial photographs means photo distance divided ground distance means PD. +[154.93s -> 167.63s] and GD, the ratio between PD and GD. Here is the example that the distance between two trees measure on an aerial photographs is 1 centimeter. +[167.63s -> 181.50s] and the corresponding distance on the ground to be 100 meter what is the scale of photographs in the here is the distance between two trees on aerial photographs is one centimeter and distance between +[181.50s -> 185.97s] two same trees on the ground is 100 meters. So, +[186.90s -> 200.06s] The formula is the scale of aerial photograph is equal to PD upon GD photo distance upon ground distance, photo distance 1 centimeter, ground distance 100 meter. Here is the scale of +[200.06s -> 212.66s] pd and gd is different. Here is the centimeter and here is the meter. So, you can calculate 100 into 100 because +[213.17s -> 226.08s] 1 meter is equal to 100 centimeter and here is the 1 is the centimeter. So, we can convert this 100 into centimeter 100 into 100 is equal to 1 as 10,000. +[226.08s -> 239.66s] These are the scale of aerial photographs. Finally, the scale of aerial photographs is 1 as 10000. These are the first method for the calculation of scale of aerial photographs. +[239.66s -> 254.35s] by establishing relationship between photo distance and ground distance. Second method for the calculation of scale of aerial photographs by establishing relationship between photo distance and map distance. +[255.60s -> 267.95s] Here is the formula for the calculation of scale of photographs photo distance divided map distance into scale of map means the PD upon MD into SM. +[268.56s -> 280.70s] Example, length of Krishna river on the vertical photographs is 4 centimeter and map covering the same area is 1 as 10,000. +[280.70s -> 294.70s] the length of river is 8 centimeter find the scale of the photo so here is the length of krishna river 14 4 centimeter on the aerial photographs and 8 centimeter on the +[295.02s -> 300.59s] map and scale of this map is the one as 10000. +[300.88s -> 310.13s] As per our formula sp is equal to Pd upon md into sm 4 centimeter divided 8 centimeter into 1 as 10000. +[311.09s -> 324.02s] 8 centimeter into 10000 is equal to 80000, 4 upon 80000, 4 1 to 4 and 80 here is the 2. +[325.39s -> 334.86s] means the one as 20,000 the scale of aerial photographs is one as 20,000 next example +[335.22s -> 349.73s] by establishing relationship between focal length and flying height. These are the next method for the calculation of scale of aerial photographs formula. Scale of aerial photographs is equal to +[349.73s -> 361.34s] focal length upon flying height means the ratio between focal length and flying height ratio of f and h. Now, the example a camera equipped with a +[361.34s -> 373.54s] 150 mm focal length lens is used to take a vertical photographs from flying height of 1500 meter above mean sea level. What is the? +[373.54s -> 384.02s] scale of photographs. Here is the focal length of this camera 150 millimeter and flying height of the aircraft is the 1500 meter. +[384.43s -> 392.34s] As per our formula SP is equal to F upon H 150 mm upon 1500 meter. +[392.78s -> 407.25s] Here is the millimeter and here is the meter. Now, you convert unit same as a millimeter 1 meter is equal to 1000 millimeter. So, 1500 into 1000. +[407.92s -> 419.31s] Finally, 150 upon 15 lakh, then this 0, this 0, 15 by 15, 1. +[420.24s -> 429.55s] 1 as 10000, the scale of aerial photographs as a 1 as 10000. +[430.03s -> 444.18s] scale of aerial photographs at a specific point. For example, you can calculate scale of aerial photographs on a particular height. Scale of aerial photographs is equal to focal length upon flying height minus +[444.18s -> 449.58s] height of a specific point means the capital H minus small a. +[450.03s -> 461.36s] Vertical photographs was taken at a flying height of 1500 m above sea level using a camera with 150 mm focal length. +[461.46s -> 472.59s] Determine the photo scale at the point of A which lies at elevation of 250 meter in the scale of these particular +[472.94s -> 487.12s] Now, as per our formula SP is equal to F upon H minus small h 150 mm upon 2500 meter minus +[487.12s -> 488.30s] 50 meter. +[488.59s -> 502.51s] 150 mm upon 2250 meter. Here is the millimeter and here is the meter. So, you can convert in a same unit means 1 meter is equal to +[502.51s -> 514.67s] 1000 millimeter 2500 into 1000 two lakh twenty five thousand 150 upon two lakh twenty five thousand now +[515.44s -> 526.19s] Here is the 0 0 15 1 means 1. +[526.45s -> 535.92s] as 15000. Scale of aerial photographs one as a 15000 at a specific point. +[536.21s -> 550.51s] location of the A. Next formula calculation of flying height from focal length and scale of aerial photographs means if focal length and scale of aerial photographs are given +[550.51s -> 561.97s] So, we can calculate flying height of aircraft. So, here is the formula. Scale of aerial photographs is equal to focal length upon flying height means the f upon h. +[562.38s -> 576.86s] For example, a camera equipped with 150 millimeter focal length lens is used to take a vertical photograph with scale of 1 as 20,000. What is the flying height of airplane? +[576.86s -> 588.40s] so we calculate the height of this airplane using the above formula now formula sp is equal to f upon h 1 +[588.53s -> 602.00s] upon 20000 is equal to 150 mm upon capital H. Capital H are not given. So, we calculate by using this formula. So, here is the 20000 on this position if you see. +[602.22s -> 603.92s] on this position. +[604.69s -> 618.86s] The position of 20000 is changed as a multiplication. The sign of this number is changed in the multiplication. H is equal to 150 into 20000. +[618.86s -> 622.26s] 150 into 20000 is equal to 30 lakh. +[625.10s -> 639.07s] 30 lakh are given into millimeter. So we convert into meter. 1 meter is equal to 1000 millimeter. 30 lakh upon 1000, 0 minus 0, 0 minus 0, 0 minus 0. +[639.07s -> 652.93s] means finally 3000 flying height of the aircraft is the 3000 meter next example calculation of focal length of camera same formula +[652.93s -> 662.29s] Scale of aerial photographs is equal to focal length upon flying height. Here is the we calculate focal length. +[662.29s -> 673.65s] Example, a vertical photograph was taken at flying height of 1500 meter above sea level with scale of 1 as 10000. What is the focal length of camera? +[673.65s -> 687.47s] what is the focal length of this camera here is the two things are given first things is the flying height and second is the scale of aerial photographs with the help of these two things we calculate focal length of the camera +[687.50s -> 701.94s] SP is equal to F upon capital H, SP means the scale of photographs 1 upon 10000 is equal to F upon 1500 meter. Now, F is equal to +[702.48s -> 713.68s] 1500 means 1500 upon 10000 here is the 1500 on this position if we shift this position. +[714.42s -> 724.94s] change the position of these things 1500 upon 10000 is equal to f is equal to 0.15 but +[726.13s -> 740.66s] These are in meter and most of the focal length is given in millimeter or centimeter. We can convert these things in millimeter. 1 meter is equal to 1000 millimeter. So 0.15 into +[740.66s -> 754.19s] 1000. Answer is the 150 millimeter. These are the focal length of camera which is the 150 millimeter. +[755.18s -> 769.33s] Today we learn different methods of calculation of scale of aerial photography. We can easily calculate by using this formula scale of aerial photographs. +[769.39s -> 779.76s] flying height of aircraft, focal length of camera and many more things related to the photogrammetry. Thank you very much. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_7.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..368e8ed75f9fe5194e88de59158ae16127cad913 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_7.mp4.txt @@ -0,0 +1,20 @@ +[0.00s -> 13.10s] Hello viewers, welcome to my channel Highway Guide हमारे काफी viewers ने demand किया है कि Bitmasper के बारे में बताएं, उसके design के बारे में बताएं, उसके testing के बारे में बताएं +[13.10s -> 20.46s] तो उसी सिलसिले में आज मैं specific gravity के बारे में चर्चा करना चाहता हूँ +[21.07s -> 32.37s] जो विटमस वर्क के डिजाइन में यूज होगी तो चलिए शुरू करते हैं +[33.78s -> 45.07s] बल्क स्पेसिफिक ग्रिविटी क्या है? बल्क स्पेसिफिक ग्रिविटी में क्या है? कि पहली बात तो हम इसको फीगर में समझ लेते हैं, यह हमारा डाइग्राम बना हुआ है, यह एग्रिगेट है, +[45.07s -> 57.25s] इसमें ये एमपरमिल वैट्स है, एमपरमिल वैट्स का मतलब इसमें कुछ जा नहीं सकता, ये परमिल वैट्स है, परमिल वैट्स का मतलब उसमें कुछ जा सकता है, और इस वैट्स में ये पानी भरा हुआ है, +[57.25s -> 63.50s] और ये जो है परमिल बैट्स है जिसमें की वो विटमन भरा हुआ यानि तीन चीज हो गई +[65.58s -> 78.70s] और एक है यह एस्पार्ट बाइंडर है यह देखिए यह एस्पार्ट बाइंडर है जब हम लोग विटमन्स वर्क करेंगे तो यह हम लोग इसको चिक करेंगे इससे ही पता चलेगा कि कितना विटमन है तो यह हमारी +[78.70s -> 92.62s] चीज़ों के लिए एक बार फिर से हम लग देख लेते हैं क्या है aggregate में यह है impermeable weights और यह है permeable weights जिसमें पानी भरा हुआ है और यह है हमारा aggregate +[92.78s -> 106.42s] बल्क स्पेसिपिडियोटी क्या होती बल्क स्पेसिपिडियोटी टोटल जो एग्रिगेट का है मास ओवन ड्राइ डिवाइडिट बाई वॉल्यूम आफ सॉलिड एग्रिगेट यानि ये एग्रिगेट का टोटल वॉल्यूम +[106.42s -> 116.66s] प्लस फॉल्म ऑफ इन पर बेट्स यानि क्या है यह प्लस फॉल्म ऑफ वाटर पर बेट्स यह तो +[118.26s -> 130.11s] इससे इसको डिवाइट करेंगे तो हमको GSB मिल जाता है तो इसको बोलेंगे bulk specific beauty इसका मतलब इसमें हम लोग पानी भी लेते हैं और +[130.11s -> 135.92s] वॉल्यूम सॉलिड एग्रिग्रेट भी लेते हैं और इसमें इंपर्बिल बैटरी सब कुछ ले लेते हैं +[136.85s -> 149.54s] उसके बाद क्या आ गया, apparent specific gravity, apparent specific gravity में क्या रहता है, bulk specific gravity के ही तरिके से रहता है, लेकिन इसमें जो 24 वर्ष पानी में, +[149.54s -> 163.42s] समझ करने के बाद दुबाने के बाद ये चीज नहीं लेते हैं हम लोग ये सब कुछ वही रहता है तो क्या हो गया ये GSA क्या हो गया mass oven rate divided by volume of solid aggregate यानि ये +[163.42s -> 167.73s] प्लस बॉल्लू और इंपरबिल पैट्स यह होता है +[168.02s -> 182.61s] तो इसमें यह क्या होगा इसलिए यह और specific gravity से यह सबसे ज्यादा रहता है यानि जो ज्यादा specific gravity रहती है वो हमेशा apparent specific gravity होगी क्या हो गया +[182.86s -> 194.83s] effective specific gravity इसमें सब कुछ bulk specific gravity की तरीके से रहेगा लेकिन इसमें ये portion घट जाएगा parambil white portion filled with asphalt minder +[194.83s -> 208.86s] मतलब क्या हुआ, the bulk specificity का मतलब क्या हुआ, weight of die aggregate, ये die aggregate, divided by volume of solid aggregate, यानि ये, plus volume of impermeable weights, यानि ये, +[208.86s -> 216.56s] प्लस वॉल्यूम ऑफ वाटर पंप्री वाइट्स यानि ये माइनस वॉल्यूम ऑफ एस्पॉर्ट +[217.01s -> 231.39s] ये इसमें से घटा देंगे तो ये effective specific gravity बन जाएगी तो आशा करता हूँ आपको बहुत अच्छी तरिके से समझ में आ गया होगा thank you for watching my video diff --git a/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_9.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..4b693a7d8fa135c52990419d93e2626ec7a74f05 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Architecture_and_Engineering_9.mp4.txt @@ -0,0 +1,75 @@ +[0.46s -> 12.50s] Hello and welcome to my channel Civil Construction आज का शो हमारा टॉपिक है यह है Earthwork Quantity of a Road by using Prismoidal Method +[12.50s -> 26.69s] लास्ट दो वीडियो में मैंने आपको मीन एरिया मेथड बताया था और मिड सेक्शनल मेथड बताया था कि उन दोनों मेथड से अर्थवर्क क्वांटिटी कैसे कल्बिलेट करते हैं तो आज मैं थर्ड मेथड लेकर आओं वो है +[26.69s -> 36.75s] prismoidal method इससे हम calculate करेंगे earthwork quantity of a road तो example same रहीगी जो last दो videos में रही थी +[36.78s -> 50.26s] तो example क्या है, work out the quantity of earthwork for an embankment, अब जब embankment है, that means कि road हमारा किस में है, filling में होगा, यहाँ पे, +[50.26s -> 64.32s] cutting तो होगी नहीं, तो embankment की length कितनी दे रखी है, 150 meter long, यानि कि जो road है, वो 150 meter long है, जिसकी हमने earthwork निकालनी है, और वो embankment में है, यानि कि filling में है, +[64.32s -> 78.38s] and 10 meter wide at the top जो formation width है road की top पे यानि की ये एक cross section है road की जो 150 meter long है embankment +[78.38s -> 91.14s] और उपर क्या है formation width 10 meter wide है, ठीक है, side slope is 2.1, यह जो side slope है, embankment की, यह 2.1 slope में है, and depth at, +[91.14s -> 100.94s] each 25 meter interval are 0.6 1.2 1.4 1.6 1.4 1.6 and 1. +[100.94s -> 115.31s] 5. यानि क्या बोला है ना जो depth है at each 25 meter interval यानि कि जो 25-25 meter की change यानि कि 150 meter अगर long road है उसकी 25-25 +[115.31s -> 127.02s] meter की chain age पे हमारी depth क्या है embankment की filling की वो ये है अब हम ये solve out करेंगे by using prismoidal method +[127.02s -> 135.95s] बिफोर स्टार्टिंग इस वीडियो अगर आपने मेरे चैनल को सब्सक्राइब नहीं किया है तो मेरे चैनल को सब्सक्राइब करें और बैल आइकन को प्रेस कर दीजिए +[135.95s -> 150.29s] और इस पर earthwork quantity पर मैंने already एक detail में वीडियो बना रखा है, जिसमें formation level कैसे calculate करते हैं, L section कैसे plot करते हैं, cutting, filling एक ही वीडियो में, complete वीडियो है, वो भी मैं आपको description में उसका link provide. +[150.29s -> 160.94s] कर दूंगा वो भी वीडियो आप देख सकते हैं तो हम शुरू करते हैं इस टॉपिक से तो यह एक हमारे पास +[161.68s -> 172.77s] 3D view है एक embankment का जिसकी क्या इन्होंने length कितनी दे रखी है 150 meter long दे रखी है यानि कि 150 meter इसका +[172.77s -> 185.14s] लेंथ दे रखी है इसमें हमारे बीच में क्या है चेन इज दे रखी है 25 25 मेटर के इंटरवल पर हमारी अलग-अलग डाप्ट है यानि कि अगर मान लीजिए हमारी +[185.14s -> 198.69s] 0 rd है यहां पर depth हमारी कितनी है 0.6 है और यह हमारी 25 meter rd है तो इस पर हमारी depth कितनी होगी 1.2 so on 25 25 +[198.69s -> 211.25s] meter के interval पे हमारे कितनी हो जाएगी 150 meter और हमारे depth ये given है अब हमें prismoidal method से हमें earthwork quantity calculate करनी है अब prismoidal method को +[211.66s -> 223.87s] शुरू करने से पहले मैं आपको बता दूँ जो मीन एरिया मेथड होता है मीन एरिया मेथड में क्या करते थे हम इस क्रॉस सेक्शन का एरिया लेते थे और इस क्रॉस सेक्शन का +[223.87s -> 231.63s] area लेते थे यानि कि zero chain age पे जो area आएगा cross section का और 25 जो +[232.30s -> 246.50s] chain edge पे area आएगा, उन दोनों का mean लेके हम area calculate करते थे, वो होता था mean area method में, अब mid section method में क्या होता था, जैसे कि हमारी ये depth है 0 पे, +[246.50s -> 258.08s] और 25 पे change पे ये depth है तो इन दोनों का हम depth का mean ले लेते थे फिर उससे हम area calculate करते थे वो हो जाता था mid sectional area but +[258.08s -> 269.87s] जो prismoidal method में हम क्या करते हैं, हम quantity कैसे find out करते हैं, उसके लिए हमारे पास formula होता है, quantity find out करने के लिए, L divided by 6, +[270.29s -> 284.66s] a1 plus a2 plus 4 times a1, यहां पे a1 और a2 क्या है, cross section areas है, at the given, +[284.94s -> 296.75s] चेन एज ठीक है बट एम क्या है एम इट दा मिड सेक्शनल एरिया तो ये कैसे कैल्कुलेट करते हैं मैं आपको आज इस वीडियो में बताऊंगा +[296.98s -> 308.53s] तो सबसे पहले हमने table बना लेना है as usual तो इसमें पहले column में क्या है change लिखी है 0 to 150 क्योंकि हमारा +[308.53s -> 316.86s] रोड की लेंथ कितनी है? 150 मीटर है, 0, 25, 50, 75, 100, 125 and 150, ठीक है? +[316.86s -> 328.18s] उसकी corresponding हमें depth भी दी गई है, 25, 25 meter के interval पे हमारे depth गिवन गया है, तो हमने ये note down कर ली, अब हमें, +[328.75s -> 340.38s] A1 और A2 calculate करना है यानि कि हमें cross section area find out करना है तो cross section area तो हम find out करेंगे यानि कि हमारा जैसे +[340.38s -> 354.64s] ये हमारी cross section बन जाती है embankment की कुछ ऐसे तो इसमें क्या होता है embankment की cross section एक trapezium form में बने तो इसमें हम क्या से area calculate करते हैं पहले तो हमारा ये जो +[355.12s -> 369.70s] यह मान लीजिए हमारा B है, जो हमारी formation weight है, वो हमें given है 10 meter, और यह हमारी D है, तो हमारा पहले center area क्या निकल जाएगा, तो वो बन गया B into D, +[369.70s -> 383.78s] ठीक है, B into D हमारा यह center area निकल जाएगा, अब हमारे पास side के दो triangle बचते हैं, तो उनका area कैसे निकालेंगे, हमारे पास slope given है इसमें, +[383.78s -> 395.22s] 2 is to 1, ठीक है, तो 2 क्या होता है, हमारा slope होता है, यह horizontal है, यह vertical है, जो horizontal है, वो हमारे slope है, तो हमें क्या निकालना है, हमें, +[395.22s -> 408.05s] इसका triangle का area निकालना, तो triangle का area क्या होता है, triangle का area होता है, half into base into altitude, +[409.78s -> 412.75s] ठीक है यानि की height +[413.14s -> 427.49s] तो base क्या है, इसका आ जाएगा, base आ जाएगा, s इंटू, ये जो d आ जाएगा, s इंटू d, ये आ जाएगा, base, 1 by 2, इंटू, base आ गया, s इंटू d, s क्या है, slope, +[427.49s -> 435.79s] S x D x altitude, यानि कि height क्या है इसकी, D ही हुआ है, height तो यही है, ठीक है, +[436.27s -> 443.34s] तो यह आ गया half into SD square, यानि कि एक triangle के area, अब हमारे पास, +[443.34s -> 457.89s] ऐसे जो embankment होती है उसमें क्या होता है साइड में दो triangle बनते हैं यहां पे भी यहां पे भी तो इसको into 2 कर लेंगे 2 और यह 2 cancel हो जाएंगे तो हमारे पास area आ गया SD square यानि कि इन दोनो triangle का +[457.89s -> 470.99s] एरिया आ गया टोटल एरिया आएगा SD स्क्वेर और सेंटर के एरिया आ गया BD तो टोटल एरिया कितना आ गया BD प्लस SD स्क्वेर हमारे पास टोटल एरिया आ जाएगा क्रॉस सेक्शन का +[470.99s -> 481.71s] तो वही हमने next column कर लेना cross section area यानि कि a जो हो गया वो आ गया bd plus sd square वो मैंने आपको +[482.13s -> 494.91s] यहां से बता दिया कि कैसे आ गया BD प्लस SG स्क्वेर अब BD प्लस SG स्क्वेर एक मैं आपको करती दूँगा बता दूँगा B, B तो यहां पे +[494.91s -> 508.98s] 10 ही रहेगा हर एक में, b की value हम 10 put कर लेंगे, और d की value हमें यहां से, यह d की value है, यह यहां पर रख लेनी है, तो b into d, +[509.49s -> 522.83s] आ गया, plus SD, S हमारे पास slope है, जो है 2, ठीक है, slope भी same रहेगा, 2, plus D, again value यहां से put कर लेंगे, तो for example, पहले का मैं आपको calculate, +[522.83s -> 530.22s] करके बता दूँगा पहले में BD, B क्या है 10 है और D क्या है 0.6 है +[531.28s -> 540.45s] plus SD square S हमें 2 put करना है D क्या है 0.6 का whole square तो ये कितना आ जाएगा 6.72 +[540.45s -> 553.26s] तो यह हमने note down कर लिया, same इसी formula से use करके, b की value 10 put करेंगे, s की value 2 put करेंगे, और d correspondingly यह हो होगा, उसके accordingly हम, +[553.26s -> 567.73s] cross section area calculate करेंगे BD plus S2 square का यह हमारे पास आ गया अब हमें क्या करना है हमें जैसे हमें पता है कि इस formula में हमें AM भी निकालना है यानि कि mid +[568.05s -> 581.50s] area भी निकालना है तो वो कैसे निकालेंगे हमें mean depth उसके लिए हमें calculate करनी पड़ेगी तो mean depth कैसे करेंगे इन दोनों का mean इन दोनों को plus करेंगे divided by 2 +[581.50s -> 593.90s] यानि कि अगर इन दोनों का mean कैसे आएगा 0.6 plus 1.2 divided by 2 वो आगया 0.9 तो यह आगया तो इन दोनों का +[593.90s -> 607.70s] मीन ले लेंगे वह गया 1.3 इन दोनों को मीन ले लेंगे 1.5 इन दोनों को मीन 1.5 इन दोनों को मीन 1.5 इन दोनों को मीन 1.55 तो यह हमारे पास मीन डैप्ट आ गया अब मिट क्रॉस सेक्शन एरिया +[607.70s -> 616.24s] यानि कि हमें am निकालना है तो उसके लिए हमें क्या करना है हमें formula लिखाना पड़ेगा bdm यानि कि +[617.17s -> 627.57s] सेम यही रहेगा बस इसमें जो हम depth ले रहे हैं वो हम mean depth ले रहे हैं ठीक है तो वही हमने सिर्फ change formula में +[627.57s -> 642.56s] depth की जगह हमने main depth use करनी है, यानि कि ये column use करना, तो formula same रहेगा, BDM plus SDM को whole square, यानि कि ये formula ही रहेगा, but instead of depth हमें क्या लेनी है, main depth लेनी है, +[642.56s -> 654.80s] तो हम ये calculate कर लेंगे तो एक मैं आपको again calculate करके बता देता हूँ कैसे आप calculate करेंगे जैसे कि हमारे पास ये हमें बी तो हमें given होगा 10 meter ही +[654.80s -> 668.02s] तो हमें b की value को लेनी है 10 foot dm यानि की dm ही 0.9 रख लेंगे plus s as usual हमारी slope 2 ही रहेगी और dm को whole square +[668.02s -> 673.50s] 0.9 का whole square यह आ जाएगा 10.62 +[673.50s -> 685.36s] तो 10.62 यहां पर लग लेंगे अगेंद ऐसे ही पूरा हम यह कॉलम कैलकुलेट करेंगे बाय यूजिंग इस मेथाइड और डीएम की वैल्यू पोट किया गए नहीं यह कॉलम पंदी ठीक है +[685.62s -> 698.34s] अब इस formula में जैसे मैंने आपको बताया था, quantity कैसे calculate होती है, length divided by 6 plus a1 plus a2 plus 4 times am, तो ये ऐसे calculate होती है, +[698.34s -> 709.84s] अब हमारे पास लेंथ इसमें जरूरत है तो लेंथ हमारे पास क्या जाएगी पहले तो 0 चेनेज पर तो हमारी 0 लेंथ होगी ठीक है तो 25 चेनेज पर हमारी 25 +[709.84s -> 723.95s] लेंथ होगी, फिर 25, 25 का interval है, तो तुम्हारे पास length कितनी आगी, 25, 25, 25, 25, throughout 25 meter length आगे, तो अब हमारे पास, ये जो हमारे formula मैंने आपको बताया था, +[724.34s -> 736.43s] कि quantity calculate करने के लिए prismoidal method से कैसे calculate होती है q is equal to l by 6 a1 plus a2 plus 4 times am ठीक है +[736.43s -> 750.66s] अब इसमें हर एक value हमारे पास length given है, a1 यानि कि यह put करेंगे, a2 यह put करेंगे, plus 4 times am, यह put करेंगे, तो मैं आपको एक value calculate करके बता दूँगा, +[750.66s -> 763.94s] यसे कि पहले में हमारे पास length भी 0 होगा तो हमारे पास हर एक चीज ही 0 हो जाएगा तो वो तो हमारे पास पहले में quantity आएगी नहीं तो second में हमारे पास क्या आजाएगा +[763.94s -> 774.54s] Q is equal to L by 6A1 plus A2 plus 4 times AM. तो इसमें हम value put करेंगे. +[774.54s -> 788.91s] लेंथ की value है आगे, length 25 meter है, divided by 6, plus a1, अब इस quantity के लिए a1 क्या रहेगा, ये वाला, a1 रहेगा 6.72 plus a2, +[788.91s -> 802.70s] यानि कि यहां से A2 यह रहेगा 14.88 प्लस 4 times AM, AM क्या है यहां से, इसकी corresponding नहीं देखना है, +[802.70s -> 810.35s] 10.62 तो यह हमारे पास आ जाएगा 20, 267 +[810.90s -> 825.23s] तो यह हमारे पास पॉंटेट ही आ गई, 267, ठीक है, तो ऐसे ही हमें same इसी formula में इनकी value बननी है, इस case में a1 क्यों हो जाएगा, a1 ही हो जाएगा, +[825.23s -> 838.85s] A2 क्या हो जाएगा, यह हो जाएगा, AM यह हो जाएगा, तो उससे हमारे values calculate होके आ जाएगी, यह है, तो उसके बाद हम total quantity of earth work निकाल लेंगे, +[838.85s -> 845.41s] सबको सम करके वो आ जाएगा 2647.26 मेटर क्यों +[845.41s -> 859.84s] अब जैसे कि same मैंने example को कर रहा था by using mean area method, mean area method से क्यों होता है, जो हमारी quantity calculate होके आती है, वो सबसे ज़ादा होती है, वो आई थी 2651. +[859.84s -> 870.78s] और mid sectional method से जो quantity calculate होकी आती है वो कम होती है वो होती है 2645 और जो prismoidal method है +[870.78s -> 881.52s] उससे जो quantity calculate होके आती है वो mean area method और mid sectional method के दोनों के बीच वाली quantity calculate होती है +[881.65s -> 895.78s] जब भी हम mean area method यूज़ करते हैं, उससे हमारी quantity थोड़ी जादा आती है, mid sectional method से कम आती है, और presumably method से हमारी क्या आती है, एक दोनों की average value आती है, +[895.78s -> 909.79s] इसलिए हम prismoidal method को ज़्यादा accurate method मानते हैं as compared to other two methods. तो अगर यह आपको वीडियो अच्छी लगी हो, please like करें, share करें, till then take care of yourself. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_10.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1dfdf9a22670e0b7f0846d80bdfa18a4d15e9abb --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_10.mp4.txt @@ -0,0 +1,66 @@ +[0.24s -> 9.55s] hi in this tutorial we are going to study brems algorithm we are also going to implement brems algorithm programmatically +[9.55s -> 17.04s] So we have already seen in the previous tutorials all the spanning trees that we can generate from this given graph. +[17.04s -> 28.14s] We will implement the primzel goitem and we will find out the minimum of all these all the spanning trees that we've obtained so far and we will also do it programmatically. +[28.14s -> 41.54s] So what I just want you to do is you have to see this video and after this you can implement this whole PRINCE algorithm in C++. The link of that video is in the description below. +[41.54s -> 50.91s] Alright, so let's start with the Prim's algorithm now. So now you can see in Prim's algorithm, we try to find out the minimum cost. +[50.91s -> 58.78s] out of all the given spanning trees. So if we have a graph here you can see we have some vertex in this graph. +[58.78s -> 72.26s] And we have some weighted edges in this graph. And we're visualizing this graph in the form of a two-dimensional array, which you can see here. Now, what we're going to do is we're going to find out the... +[72.26s -> 83.54s] we'll have to find out a minimum spanning tree so now if you will see we have a lot of spanning trees that we can generate from this graph but we will have to find out +[83.54s -> 97.36s] the minimum one the one which gives me the minimum value when i will consider these vertex and edges we will have to find out the cost of the whole spanning tree should be sum up to minimum +[97.36s -> 109.15s] Right. So now here are the vertex and edges. And so let's see how we can do that. So Prim's algorithm. One important thing about Prim's algorithm. +[109.15s -> 122.35s] is that we have to first our objective is to generate the minimum spanning tree that's the objective of brems algorithm and it is a greedy algorithm so i'm going to write greedy here +[122.35s -> 131.68s] it is a greedy algorithm so at each and every step we are going to this algorithm is going to make a greedy move right so +[131.68s -> 138.80s] If we consider any particular vertex, let's suppose we consider 3 as a vertex. Let's suppose I consider 3 here. +[138.80s -> 153.41s] And if I consider this vertex, you can see there are edges going from this vertex, which has weights 8, 3, 5 and 2. So what we have to do is in the prims algorithm, it will find the edge. +[153.41s -> 165.02s] it will find the x which has the minimum cost so you can see 4 3 is the minimum cost which is 2 here so this algorithm will do this recursively again and again +[165.02s -> 177.38s] so let's see how we can do that in our program and now you can see here we have created a two-dimensional array so basically we are going to use an adjacency +[177.38s -> 191.18s] matrix to perform the prims algorithm. So we are going to visualize this graph in a form of two-dimensional matrix which you can see here. These are the columns and rows. +[191.18s -> 200.80s] So how can we generate this type of two-dimensional array? As you can see, we have index positions here, 0, 1, and 2, 3, 4. +[200.80s -> 215.15s] These are the basically the vertex numbers 0, 4, 3, 1, 2 like these and we have the edges and if you will particularly see a particular vertex you can actually find out. +[215.15s -> 228.45s] the edge under that index for example if we will have a unvisited array we will also have an unvisited array and a visited array we will create two additional arrays +[228.45s -> 241.36s] the unvisited array will have those vertex which we have not visited yet which is the 0, 1, 2, 3, 4 and the visited array will be initialized at +[241.36s -> 248.02s] null initially and then we're going to push the vertex in the visited array to find +[248.08s -> 261.95s] to find and see whether we have visited a particular vertex or not. So if we have visited 3 or we have visited any particular vertex, we are going to push it inside the V array. Alright, so the next step +[261.95s -> 272.75s] is that we will have to generate the solution. So let's see how our solution which is also the output. This is our output. +[273.07s -> 282.22s] So let's see how we can generate the output here. So in the output, we will have the minimum planetary with the edges. +[282.22s -> 295.28s] And first, we are going to pick up the first element from our unvisited array, which is 0. So we are going to push it in the V array. You can see that this is the 0 in the V array. So we are going to actually +[295.28s -> 309.34s] pick up a particular vertex you can pick up any vertex we are put we will first pick up zero and you can see these are the vertex which are connected to zero so in the visited array we have +[309.34s -> 319.44s] 0 as the picked or the visited vertex, you will have to visit the row number 0. You can see that +[319.95s -> 329.87s] Here we have 0 and here we are going to visit the 0th row of this two-dimensional array. So we are going to visit it. +[329.87s -> 340.93s] the zero then we are going to visit one two three and so on and in this manner we are going to cover the whole vertex which we have in the spanning tree all right so let's visit +[340.93s -> 353.60s] 0 and let's see how the Prince's algorithm will proceed. So you can see that this is the whole column. This one is the whole, sorry, row. This one is the row which corresponds to 0 vertex. +[353.60s -> 367.68s] and you can see there are some non-zero values here we are going to only pick the non-zero values so we have crossed the zero values so you can see four five and two are the remaining values and +[367.68s -> 381.28s] we are only considering those values. The reason is that because the zero values are not corresponding to any particular edge. So here in this row, in the row number zero, +[381.28s -> 395.06s] we have 4 and we have 5 and we have 2 as the non-zero values. Now these are the values that the Prince algorithm is going to proceed with. +[395.06s -> 406.32s] The greedy algorithm will pick up the minimum cost out of all these. You can see if we visit four vertex, then you can see the value is actually two. +[406.32s -> 419.41s] So let's see how we can actually pick up the minimum value. First, what we will do is we will actually write an algorithm which will be able to pick the minimum element. So the idea is basically. +[419.41s -> 431.44s] to assign the first value as the min value. We will create an integer min. We will assign it to 4 and then we will start comparing it with the other non-zero values. We will compare it with 5. +[431.44s -> 443.36s] And if it is less than 0, we are going to update the value of min. So min will become 5 if it is less than, but you can see that 5 is greater than 4, so min will not hold the value 5. +[443.36s -> 452.14s] Then we will visit the next non-zero value which is 2 here you can see and since 2 is less than 4 we will assign the minimum as 2. +[452.18s -> 466.59s] So now you can see how greedy algorithm we are using greedy algorithm to find out the minimum value which is 2. And we are going to do this with each and every vertex. Now since you can see 4 is the corresponding column. +[466.59s -> 480.93s] of this value which is also the vertex so now we are going to push we are going to first write the output here so if we visit zero we will be able to reach four because the minimum cost +[480.93s -> 488.50s] at four is you can see it's two so we will write the value here so zero to four gives me two +[488.82s -> 501.54s] So you can see we will write 2 here in the output. And this is basically the minimum spanning tree, the output that we will get. We will write 0, 4, 2. All right. So now since we have visited. +[501.54s -> 513.01s] 2, we will see that the corresponding edge is 4. So we are going to push 4 in the visited array. After pushing 4 in the visited array, we are going to consider the fourth row. +[514.03s -> 528.24s] So this is the vertex 4. We are visiting the vertex 4 and the fourth row is here. And in this row, we are again going to slash out all the zero values because they are not the edges. +[528.27s -> 542.75s] Then you can see we have two values and both are 2. Now the next step is to find that the value corresponding to this value which is 2 here is already inside the visited array or not. So you can see that 0 here. +[542.75s -> 557.17s] is actually inside our visited array so it's in our visited array so we are going to skip that value we are going to slash it and again we are going to in the visited array we are going to move to the next value which is you can see here +[557.17s -> 571.17s] it will be 2 so after going after this regarding 0 we are going to reach 2 here so we will in the solution we will use 4 so 4 +[571.17s -> 584.83s] and you can see the corresponding value of the column is 3 and the value that we get is of the edge is 2. So I'm going to write 2 here. So it means that when we are going from 4 to 3, we have +[584.83s -> 595.15s] visited four and the value is two. Now you can see the value three, we are going to visit three now. So we are going to push three inside our visited array, which is three here. +[595.15s -> 608.59s] Now we are going to visit the third row of the two-dimensional array. You can see here that we have visited three now. Now we can use the array. Let's suppose we have our array as +[608.59s -> 620.06s] I'm going to write, let's say we have a multidimensional array G. We can actually try to access a particular row by using, let's say we want to visit 4, so we can write 4 here. +[620.06s -> 634.98s] And we will be able to access the whole row in this manner. So now we're going to visit 3. And you can see this is the vertex 3. Again, we're going to slash out the 0 values, which we have done now. +[634.98s -> 648.32s] Now the remaining values, we have to slash out those values which we have already visited, right? So 5 is, you can see 0 is already visited and 4 is also visited. So we are slashing out 2. +[648.32s -> 661.46s] so we have the remaining values 3 and 8 and then we are going to again use the algorithm to find out the minimum value which is 3 here again we are going to push the solution inside our solution you can see +[661.46s -> 669.36s] that three goes uh the value that it gives is three and the corresponding column is one so three to one gives me three +[670.32s -> 684.38s] So the next step is you can see we are going to push one now because the corresponding column is one. Now we will visit the first vertex and the corresponding visited. +[684.38s -> 696.34s] array we are going to view the corresponding row. Here we will again slash out the zero values and again we will slash out those values corresponding to the column numbers which we have already visited. +[696.34s -> 707.12s] so three will also get cancelled and we have the remaining value as one only so now what we're going to do we're going to push it in the output one two two +[707.12s -> 721.42s] gives me the value is 1 here. So I'm going to write 1. So this is my whole solution. This is the minimum spanning tree that we have obtained. We have covered all the vertices. +[721.42s -> 733.86s] Now you can see we have covered 0 and we have covered 4, 3, 1, 2. We have covered all the vertices. So it is a spanning tree and the cost is also a minimum cost of the spanning tree. +[733.86s -> 745.94s] So this is how our solution will look like, how we are going to implement the Prince algorithm. So if you have watched this video, you can actually check out a new video. +[745.94s -> 759.89s] on Prince's algorithm in C++. I will give the link to that in the description below so you can implement it yourself. So let's construct the minimum spanning tree. First, I will write all the vertices. +[760.05s -> 772.59s] 0, 4, 1, 2, and 3. These are the vertices. And now I will assign the cos. Then 0, 4 gives me 2. Then 4, 3 gives me 2. +[773.94s -> 788.24s] And then 3, 1 gives me 3. 1, 2 is 1. So in this manner, we have got this minimum spanning tree, MST. And that's how we can use the Prenzel-Wytham to find out. +[788.24s -> 790.78s] the minimum spanning tree of a given graph. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_12.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d82785048afc2478244b6ae5ee8612a0b6a623ec --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_12.mp4.txt @@ -0,0 +1,66 @@ +[0.02s -> 8.34s] In this lesson we will study about pre and post visited times. Sometimes these are also called start or end times. +[10.38s -> 15.06s] And sometimes you may also see this arrival. +[15.60s -> 25.95s] and departure times of different vertices when we do dfs so just a brief recap when we do dfs we start from one node +[25.95s -> 38.54s] and go as deep as possible for example if we start from a we will go to b from b we will we will go to c and from c there is no way to go anywhere else so we will come back to b +[38.54s -> 52.38s] again we have no option so we will come back to a then from a we will see what are different paths so this we have already taken so we will not take it this we have not taken but it goes to a vertex which we have visited so we will not visit it +[52.38s -> 63.86s] this is incoming then next is d so we will go to d and then from d there are two paths take one of them so let's say we take e and then we take f +[63.86s -> 76.08s] this way we visit and this is called DFS so here we will add a few a couple of more values while doing the DFS so we will do DFS just as our earlier method +[76.08s -> 89.30s] only thing is that the first time we visit a vertex we record its time so in the beginning time will be zero so starting node we will discover at time equal to zero +[89.58s -> 91.92s] then we will go to next node +[92.50s -> 106.51s] let's say we took this path so we reached b at time equal to 1 and every time we reach a node or we depart from a node we increment the time then from b we went to c so we reached here at time 2 +[106.51s -> 118.29s] and we have not finished with b yet we are still discovering from here onwards similarly for a and these have not yet been discovered so their times are empty +[118.45s -> 132.96s] then from c there is no way to go so we will finish with this node and we will never come to it again so we return from it at time 3 then we come back to b from b there is no way to go so we come back to a +[132.96s -> 140.24s] from a we will not take this path already visited d is there so we reach d at +[140.91s -> 154.34s] 4 you can also increment time in between but let's keep if there are 5 vertices or here in this case 6 then exactly we should have start from 0 and go till 11. +[154.34s -> 158.38s] So exactly 12 values, 2 for each. +[159.09s -> 172.29s] unnecessarily incrementing the count that will not impact anything but let's keep it simple so we return from c at 3 then we came to b from b there is no way to go so we return from b +[172.29s -> 183.89s] At 4, we will never come back here again. Then we reach A. From A, there is still some undiscovered path. So we will come to D at time 5. +[184.78s -> 197.44s] Then we will go to E at time 6. Then from E we will neither go to A nor to C. These are already visited. So we return from here at 7. Then we come back to D. +[197.44s -> 200.11s] Then we go to f at time 8. +[200.37s -> 214.34s] and we return at time 9 and then from we reach d and from here we return at time 10 and then we come back to a and there is no other option so we we are done with a also +[214.34s -> 222.83s] at time 11. so you see timings are from 0 to 11 that is 12 values and we have six nodes +[223.12s -> 234.77s] So, these are called pre-visit times and post-visit times or these are also called start end times, arrival departure times, whatever you may like, you may call it. +[234.77s -> 246.43s] uh it it will be used in a lot of problems that we will solve later now one of the application would be to classifying the tree edges so when you +[246.43s -> 258.42s] do a d dfs traversal of a graph then you only take a few edges you don't take all the edges let's see we came here then here +[258.99s -> 271.01s] Then this one, this one and this one. These are the only five edges that we took. Other edges we did not took. So these edges we will call tree edges. +[271.01s -> 281.10s] Then this one is going from ancestor to descendant. So we will call them forward edge. Similarly descendant to ancestor will be back edge. +[281.10s -> 294.29s] and we will also have crossh the remaining one like e to c it's neither ancestor nor descendant so we will see all of this later and we will see that we can use this pre and post widget times +[294.29s -> 306.98s] for classifying edges into these four categories and another use of this would be that you can do topological sort using this so just look at the departure times forget about arrival times +[306.98s -> 319.57s] and sort them in descending order so maximum is a then next is d then next one is f +[320.82s -> 326.61s] then we have E and then we have +[326.93s -> 341.49s] b and c so you will see that this is a topological order and all the edges will go in left to right direction so let's draw them a to b this direction +[342.32s -> 348.11s] A to D this direction, D to E this direction. +[348.43s -> 360.94s] you can verify that all the edges will go from left to right if we sort them in descending order of departure times so these we will see in separate lessons here the topic is to +[360.94s -> 373.70s] find out the pre and post wasted times which we already roughly saw how to calculate so how we will do it in code so let's see the earlier dfs code this is our plain dfs code we start +[373.70s -> 385.54s] dfs on a graph g and there is a notion of starting vertex so what we do we level it as visited then we look at all its adjacent edges and if +[385.54s -> 398.58s] and edge is going to a vertex which is not visited then we trigger again a dfs on that node so what extra is required here we start dfs from here so its time is zero +[398.93s -> 412.08s] then we will go to this so its adjacent edges are this one 0 1 and 0 3 and both are going to unlisted nodes so we will take one of them let's say this at time 1 +[412.14s -> 423.60s] here again this call will be made only one edge is outgoing and it's going to unlisted node so we come here at time two from here there is nowhere to go so we return from here +[424.08s -> 438.90s] So when we mark a node as visited, first time we write, let me write in different color, pre of that node s equal to whatever time is currently. +[439.25s -> 450.38s] and then also increment the time after storing it and in the beginning time will be zero before starting the tfs from any node +[450.74s -> 463.76s] So S will get a time of 0, this one. Then it will call DFS on 1. So when DFS of 1 is called, again 1 will be marked wasted. +[463.76s -> 477.78s] storing the time it was incremented so one will get a time of one then it will call dfs on two so two will get a pre of two and again it will call it and after +[477.78s -> 490.03s] we have done for all the nodes or all the paths going out from a given vertex we are done with everything so we return from this so then we record the post time +[497.10s -> 505.65s] and that's all these are the two lines that you need to add and obviously you need to add these time equal to zero some global counter +[506.16s -> 516.88s] so before starting just when you visit it you record the time the time at which we reached here and when this all the recursion terminates finally here +[516.98s -> 530.37s] and we go back to the calling function then also record the time so these are basically the two timings so from 3 it returns at time 3 then at 4 then we come here at time 5 +[530.37s -> 544.78s] then we go here at time 6 then we return from here at 7 then 8 and finally 9 here we have 5 nodes so we have times from 0 to 9 that is 10 values +[544.98s -> 559.62s] So let's write the code for this. So I will modify it for C++ and it should be very trivial to do it for Java and Python. For those of you who are writing in Java and Python, we had already seen the code for DFS in our earlier lessons. +[559.62s -> 574.06s] So these are very trivial changes. So this was our earlier code and it's the same graph. So this is our recursive DFS. So what we need to do here. +[574.54s -> 576.27s] Pre is... +[576.56s -> 590.24s] equal to time++. We have not defined time, we have not defined pre, we will do that and when we are done with it, we write post s equal to time++. +[590.24s -> 604.34s] we have made the changes only thing required is to define these so what we will do we will keep a counter time and in the constructor we will initialize it to zero +[607.89s -> 612.21s] And what else we need? We need pre and post. So let's pass it here. +[641.81s -> 654.13s] So this will be of again the same size number of vertices since for each vertex we will have a pre-visit time and also for each vertex we will have a post-visit time. +[657.26s -> 666.16s] and we need to pass it here and similarly here +[669.74s -> 674.00s] So let's run it if there is any compilation issues here. +[675.18s -> 688.69s] So there is no compilation issue. It just prints the order in which the vertices are visited. So let's say we want to also know the actual timings for each vertex. So what we will do. +[688.69s -> 698.06s] It is just for our visualization purpose that it correctly calculates the time or not. So you can print it. +[709.58s -> 720.82s] Let's print the index also, which will be the vertex number. Here we have vertices labeled from 0 to mv-1. So that makes... +[721.17s -> 725.17s] Coding simpler here. Then pre I. +[733.84s -> 748.38s] this is just for our purpose only change we did is this one we added this line before just when we visit a node and we add this line post visit time when we are done with this node that's +[748.38s -> 761.33s] that's two line now let's print it so you see for zero it's zero and nine start and end time so for zero it's zero and nine +[762.06s -> 773.97s] or it may vary for these two depending on whether we took this path or this path for one it's one four one four it matches again +[774.96s -> 784.46s] for 2 it's 2 3 which was same there for 3 it's 5 8 for 3 it's 5 8 and for 4 it's 6 7 +[785.04s -> 798.30s] so for 4867 so that exactly matches what we had seen so this is how you can calculate pre and post widget times in further lessons we will need to add these for our +[798.30s -> 804.11s] other applications related to DFS. We will also see DFS tree and edge classification. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_13.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..db4029da65487eaafc5af39b86fedf9521cb0833 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_13.mp4.txt @@ -0,0 +1,4 @@ +[1.39s -> 13.30s] so what we actually did in the previous diagram was to find out the mean squared error that is the difference between the actual y values and the predicted y values +[14.06s -> 21.78s] So the main purpose of doing that was to find out m and b, that are the weights that we'll need for finding out a prediction line. +[22.96s -> 36.91s] Now, there can be different cost functions depending on our function, but for the purpose of linear regression, we use mean squared error. Mean squared error measures the average squared difference between an observation's actual and predicted values. +[37.01s -> 50.68s] The output is a single number representing the cost or score that are associated with our current set of weights. Our goal is to minimize MSE and to improve the accuracy of our model. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_14.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ea2d9af1529516f4026922466d9201e1f04176bc --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_14.mp4.txt @@ -0,0 +1,26 @@ +[5.78s -> 18.56s] hello everyone welcome to tech turd so in this question we have been given a schedule having transaction t1 t2 and t3 and we have to find out that among the given three +[18.56s -> 30.22s] options which one is the equivalent serial schedule of the given schedule okay so let's say this is schedule s and we have been given three order and +[30.26s -> 44.37s] it is like which which of the serial schedule is equivalent to given schedule right so to check this first we draw precedence graph so how do we draw precedence graph we start with +[47.66s -> 55.22s] taking node equal to the number of transaction that is we have three transaction here so we will take three nodes +[55.54s -> 66.90s] so 1 which will represent transaction 1 2 for transaction 2 t2 and 3 fine now what we will do +[67.60s -> 74.74s] we will find out what is the conflicting operations so what are conflicting operations pair +[75.25s -> 83.70s] So only read read is not conflict right otherwise other peers that is right right read right and +[84.18s -> 98.61s] right read all three are conflicting operations okay so according to the time this is increasing order of time right so according to time we will say what are the conflicting operations are there +[98.61s -> 101.10s] and then what we will do +[101.81s -> 116.34s] we will draw a directed edge in the graph and the direction of the edge will be lower timestamp value that is lower time value to higher time value ok so +[116.34s -> 120.21s] understand this what we will do we will first +[120.50s -> 134.02s] see what is so let's say this is first operation here is read on y okay so we will try to find out is there any other transaction than t3 exist for which +[134.02s -> 138.45s] we have conflict with this ok so +[139.22s -> 152.46s] here it is read and y so we will look for is there any other operation on y so yes see here we have write operation on y okay and read write has conflict right +[152.50s -> 167.26s] similarly here we have write operation on y and read write has conflict so from t3 which is which is obviously have lower time value which started earlier we will draw a edge to +[167.26s -> 181.46s] t1 okay so from 3 we will draw a edge to t1 similarly from 3 we will draw a edge to second fine so now this is +[182.26s -> 195.02s] first now the second one is we have on z variable we have read so we will see whether we have some conflicting operation on z so here it is read z no conflict +[195.86s -> 209.52s] so no other operations right here we have right z but it is in the same transaction so it is not conflicting operation now redex so let's find out whether we have +[209.84s -> 214.58s] any conflicting operation with this retex so +[215.76s -> 228.67s] Here it is read x, here it is write x. So, we have on the same variable x, we have write. So, this read and this write is conflicting operation. +[228.67s -> 238.96s] so we have one edge from transaction one to transaction two so we have one is from transaction one to transaction two fine +[239.47s -> 253.78s] similarly we can keep on checking so this is the final graph which we will get I have already solved now what can be a serial schedule equivalent to this so we can have as you can see +[253.78s -> 254.99s] This is... +[255.66s -> 270.02s] giving us a serial schedule that is we have an edge from 3 to 1 and we have an edge from 1 to 2. So we can take 3 then 1 and then 2. +[270.02s -> 284.62s] fine so this is a equivalent serial schedule to the given schedule but in our option we don't have this thing that is we don't have t3 followed by t1 followed by t2 okay +[284.69s -> 294.98s] So none of these three options are equivalent to the given schedule. So correct option for this question will be D. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_19.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_19.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6f3fe418f966bdb345b93a2b9b250e612e3d06be --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_19.mp4.txt @@ -0,0 +1,14 @@ +[0.00s -> 14.51s] Hi, let's solve one previous question of greedy technique this question was asked in gate CS 2009 question number 38 Consider the following graph which one of the following is not the sequence of edges added to the minimum spanning +[14.51s -> 28.05s] using Kruskal's algorithm and four options are given in Kruskal algorithm first we sort all the edges then at every step we include one edge according to the order +[28.05s -> 41.62s] and we repeat this process till number of edges equals to number of vertices minus one so first we'll write all the edges in sorted order minimum vertex two first we'll include +[41.62s -> 53.82s] wet 2s that is be in every option first edge is be next will include wet 3 that is sc and ef +[53.82s -> 67.66s] both weight are same and both are not creating any cycle so will include both so in second and third position ac and ef can possible here ef ac correct ef ac correct +[67.66s -> 79.49s] AC EF correct here EF BC BC weight is 4 and after BC it include AC AC weight is 3 +[79.49s -> 93.66s] So first it include a edge having weight 4 then weight 3. So this is wrong. Answer will be option D. Let's run option A. First we will include BE. +[93.66s -> 107.54s] then EF weight is 3 then AC weight is 3 BC weight is 4 FG weight is 4 CD weight is 5 +[107.54s -> 117.25s] this is a manual sphagnum tree next in option b be ef sc here these two are altered both weight is four +[117.25s -> 129.18s] fg and bc here both are altered so this is also minimum spanning tree by using kruskal algorithm next b e a c e f so weight 3 +[129.18s -> 143.42s] this sc efr auto we can write in any sequence this is also a minimum spining tree so you can run one one option and check whether it is a minimum spining tree or not next option d b e +[143.42s -> 154.83s] EF weight is 3 next BC weight is 4 next AC weight is 3 so due to this after 4 we cannot select 3 +[154.83s -> 164.77s] and if there is a edge having word 3 we cannot choose 4 so before hc we cannot choose bc that's why it is wrong +[164.77s -> 174.60s] I already discussed Kruskal algorithm just go through that you can easily solve this question and if this lecture is helpful for you please like and subscribe thank you diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_2.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6373b053a045b1ecda6622f06fd2152bb62d4e0b --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_2.mp4.txt @@ -0,0 +1,15 @@ +[0.30s -> 15.06s] Today we're going to learn about heaps. You'll often hear the word heap when discussing storage for garbage collection in languages such as Java. But this video is about the heap data structure that is used to manage information. +[16.11s -> 25.52s] Heaps are sometimes called binary heaps and are nearly complete binary trees. Here's an example of a heap. +[26.19s -> 37.55s] By a nearly complete binary tree, I mean that all levels are filled except the lowest, and the lowest level is filled up to a certain point starting from the left. +[39.12s -> 51.63s] Uses of heaps include heap sort and priority queues. And there are two kinds of heaps, max heaps and min heaps. On the left, we have a max heap. +[52.91s -> 66.58s] The condition for a max heap is that the value of the node i is less than or equal to the value of its parent. Max heaps are used for heap sort. +[70.06s -> 83.25s] Similarly, for the minheap, the value of the node i is greater than or equal to the value of its parent. Minheaps are great for priority queues. +[86.42s -> 99.09s] Because we said heaps are nearly complete binary trees, we know that the height of a heap is O , which you'll see in various operations that we'll learn later. +[101.07s -> 109.97s] I'd also like to show heaps represented as an array. Here's our max heap, and here it is as an array. +[113.33s -> 124.72s] The root of the tree is at index 1 of the array. To get a node's left child, you simply take the index times by 2. +[126.77s -> 140.82s] And to get the node's right child, you take the index times by 2 and add 1. Finally, to retrieve a node's parent, it's the floor of the node's index divided by 2. +[142.74s -> 156.53s] We choose to put the root at index 1 instead of 0 as It keeps this arithmetic cleaner and most computers can do these operations with fewer instructions Let's take a look at 15 +[157.17s -> 170.10s] which is at index 3. The left child of 15 is equal to 2 times 3, which is the 6th index and a node value of 12. +[172.18s -> 181.94s] The right child of 15 is 2 times 3 plus 1, which is the index of 7, or the node 13. +[184.69s -> 195.44s] Lastly, the parent of 15 is the floor of 3 divided by 2, which is the first index and the root of our tree, 21. +[198.35s -> 208.69s] You know I prefer brevity, so we'll end the video here and in the next one I'll show you how to create a heap from an unordered array. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_3.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1b587dfeb060ef8bad7ea4dc71d32d8d87b0c1e3 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_3.mp4.txt @@ -0,0 +1,9 @@ +[9.30s -> 20.72s] We've all sat down and sent out an email message before, but have you ever thought about how the message gets from one place to another? This is Internet Protocol Explained. +[20.91s -> 33.84s] Our language is very different from the language that a computer uses, so the messages that we create need to be translated from an alphabetic text into an electronic signal before they can be sent. +[33.84s -> 46.66s] this translation is handled in the computer by the separate modules in the communication protocol because these protocols or rules of conduct usually communicate with two or more modules +[46.66s -> 59.86s] They are best described as layers in a stack of protocols. These layers are the application layer, transport layer, internet layer, the link layer, and physical layer. +[62.19s -> 73.55s] The messages that we send are filtered through these layers and broken down into small chunks of data called packets. We start with the application layer to create our message. +[73.55s -> 83.47s] One example of a protocol from the application layer that you may be familiar with is the Hypertext Transfer Protocol, or HTTP. +[83.47s -> 97.71s] The Transport layer uses the Transmission Control Protocol, or TCP, to encapsulate the data blocks from the Application layer. It then moves to the Internet layer, where the Internet Protocol, or IP, +[97.71s -> 110.13s] is used to deliver the packets. These packets are delivered through the link layer which is an Ethernet cable to the physical layer which is the basic hardware of your computer network. +[110.32s -> 124.62s] The computer that receives these data packets moves them through the protocol stack in a reverse order so that the message can be reconstructed and understood. This has been Internet Protocol Explained. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_30.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_30.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..71bfd9d8d2adf73e79f82eab34544b7a746e47b8 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_30.mp4.txt @@ -0,0 +1,34 @@ +[0.08s -> 11.18s] Okay, let's dig in on concurrency control. Remember that concurrency control exists to provide isolation across multiple transactions. And the naive approach to achieve it is to simply forbid concurrency. +[11.18s -> 16.99s] and only allow serial execution where one transaction is running at any given time this is safe +[16.99s -> 29.90s] but it's slow. As we discussed, we would like to have interleaved actions from multiple transactions to get better performance, and in essence, to allow background tasks to work on our hardware while we're computing foreground tasks for our transaction. +[29.90s -> 38.05s] With concurrent execution, though, problems arise. The first is how do we define what's correct behavior? What interleavings of actions should be allowed? +[38.05s -> 49.84s] And then the second is how do we ensure that correct behavior? So in the coming slides, we'll look at both of these issues, beginning with definitions and formalisms for correctness and following up with mechanisms to achieve that formalism. +[50.32s -> 64.91s] We're stopped by defining what we call a transaction schedule. A schedule is a sequence of actions on data from one or more transactions. These actions can include beginning a transaction, doing reads and writes on particular objects in the database, and then concluding with a commit or +[64.91s -> 70.48s] abort for the transaction. Of course, we have to start with the begin, and we end with one of commit or abort. +[70.48s -> 85.04s] We'll use two sorts of notations to annotate transaction schedules. On the left, we see a tabular schedule notation, where every row is sort of a time slot, and every column is a different transaction. And so you can expect only one value to be filled in. +[85.04s -> 90.83s] row from one of the transactions, but they can be different columns on different rows. +[90.83s -> 105.23s] And in the middle of the slide on the right, we see a string representation of a schedule, which corresponds in this case to the table on the left. So we have a read by transaction 1 of A, a write by transaction 1 of A. +[105.23s -> 119.44s] transaction 1 of A, a read by 1 of B, a write by 1 of B, and then a read by 2 of A, a write by 2 of A, a read by 2 of B, and a write by 2 of B. By convention, in the string notation will only include committed transactions, and we will omit, begin, and commit. +[119.44s -> 122.83s] unless they're necessary for discussing what is going on. +[123.47s -> 138.06s] Given a definition of a schedule, we still need a touchstone concept for correct behavior. And the one that we can work with, because we're familiar with it as programmers, is the notion of a serial schedule. So a serial schedule will look something like this picture on the right, in which each transaction... +[138.06s -> 150.03s] runs from start to finish without any intervening actions from other transactions. This is the behavior that we've long known how to program in a computer. It's like having the computer to yourself. Complete isolation. +[150.67s -> 165.26s] Having gotten a definition of a serial schedule, let's talk about a definition of two schedules being equivalent. So we'll say the two schedules are equivalent if they satisfy the following three properties. They involve the same transactions, so these two different schedules have the same cost. +[165.26s -> 176.93s] with the same actions in each column. And each individual transaction's actions are ordered the same. So as you go down a column, you see the same sequence of actions in the two different schedules. +[176.93s -> 191.18s] then both schedules leave the database in the same final state so one way or another running these transactions in these two different interleavings leaves the database in the same state if that's true we'll say that the two schedules are equivalent +[191.89s -> 205.23s] Having seen all that, we're now ready to define the property we're looking for, which is called serializability. We'll say that some schedule S is serializable if it is equivalent to some serial schedule. So if S is interleaved on the left, +[205.23s -> 219.28s] and it's two transactions, there's two possible serial schedules, the first transaction before the second, or the second transaction before the first. And if we can show that S is equivalent to one or the other of these, we'll say that S is serializable. +[219.79s -> 232.43s] And when you think about serializability, it's pretty attractive. It says, I don't know what order these transactions happened in, but it's as if they happened in some serial order. And so they make sense in some version of the world. +[232.43s -> 238.64s] Another way I like to think about this is if you think about transactions as people queuing up, say, to use an ATM machine at the bank. +[238.64s -> 250.03s] You don't so much care what order the queue is serviced in. You just want to make sure that somebody doesn't interrupt someone else while they're using the ATM. Each person who uses the ATM uses it in isolation. +[250.03s -> 264.37s] So if you can guarantee that concurrent uses of multiple ATMs give the same effect as some ordering of a queue at a single ATM, well then you know that things basically make sense. So note that serializability doesn't say what order the transactions happen in. +[264.37s -> 270.00s] just that a transaction schedule is serializable if it's equivalent to some serial schedule. +[270.03s -> 282.29s] So let's look at Schedule 1 here. We've got two transactions. T1 is transferring $100 from A to B, and T2 is adding 10% interest to both A and B, multiplying each of them by 1.1. +[282.29s -> 293.46s] So here's a serial schedule in which T1 is followed by T2. And so then the final outcome, we first debit A and then give it a 10% interest. So A equals 1.1 times A minus 100. +[293.46s -> 300.85s] And in B, we first credit B with 100 and then multiply it by 1.1 to give us 1.1 times B plus 100. +[301.55s -> 309.39s] Here's schedule 2, in which T2 is followed by T1. In the final outcome here, first we get interest on A, and then we subtract 100. +[309.39s -> 317.76s] making A equal 1.1 times A minus 100. And for B, we give an interest and then we add 100. So it's 1.1 times B plus 100. +[317.76s -> 331.38s] Note that these two schedules have different outcomes, but each of them is a serial schedule, which means each of them sort of makes sense. We don't so much care whether T1 happened before T2 or T2 happened before T1. They're both valid serial schedules. +[331.73s -> 334.48s] Here's a third schedule that's interleaving. +[334.48s -> 348.82s] T1 and T2's actions. It is not itself a serial schedule, but if you look at it, it is equivalent to the first schedule we looked at, Schedule 1. In this case, A has 100 subtracted before it is multiplied by 1.1, and B has +[348.82s -> 357.04s] 100 added before it's multiplied by 1.1. So you get the same outcome as we got in Schedule 1. Hence Schedule 3 here, it is not serial. +[357.04s -> 364.40s] but it is serializable because it achieves the same outcome database at the end with the same actions of the same transactions. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_4.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2d944f8c06374a3931ed12c39e3eb43a0e726792 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_4.mp4.txt @@ -0,0 +1,30 @@ +[0.05s -> 14.45s] Hello everyone. In this lecture, we will be studying about minimization of DFA. We have already studied about DFA. We have also studied about NFA. And we have also studied how to convert NFA to DFA. +[14.45s -> 26.61s] And in this lecture, we will be studying about minimization of DFA. But what is minimization and why is it required? Minimization of DFA is required to +[26.61s -> 38.32s] to obtain the minimal version of any DFA which consists of the minimum number of states possible. Alright, so what does this mean? +[38.32s -> 52.67s] example to explain this definition. Suppose you are given the task to design a DFA. Any DFA. And then you design this DFA using 5 states. Alright. And your friend +[52.67s -> 56.37s] Design the same DFA using 4 states. +[56.78s -> 71.09s] Both the DFS are correct. Both the DFS perform the exact same task. But one of them is designed using 5 states and another is designed using 4 states. Both of them are correct. +[71.09s -> 84.21s] Here we see that the same DFA can be designed using a lesser number of states. Now which one do you think is more efficient? 5 state DFA or the 4 state DFA? Obviously it will be the one with the +[84.21s -> 96.78s] lesser number of states. So, we want to design the DFA using the minimum number of states possible. That is known as the minimal version of any DFA. +[96.78s -> 110.16s] If you try to design a DFA directly in such a way to get the minimal version, it may be difficult for you. It is not impossible but it may be difficult. It is possible only after you +[110.16s -> 121.65s] practice and practice but there is a way of minimizing a given DFA. Given a DFA you can apply some technique and minimize it and make it +[121.65s -> 127.09s] to the minimal version. And that is what we are going to study in this lecture. +[127.34s -> 141.04s] So, how can we minimize DFA? So, let's say that you use these 5 states 1, 2, 3, 4, 5. You have these 5 states and you want to minimize this DFA. That means you want to reduce the number of +[141.04s -> 155.12s] states but keep the DFA performing the same thing. So how can you do this? What you can do is you can combine two states. Let's say these two states you combine them together and you make this a single state. +[155.15s -> 169.04s] And then now you have 1, 2, 3, 4 states. So, that is how you can minimize it. But how can you simply combine two states? You cannot just simply combine two states. There is a condition when you can combine two states. +[169.04s -> 183.28s] And what is that condition? Two states can be combined only when these two states are equivalent. Now when are two states said to be equivalent? +[183.28s -> 191.70s] Equivalent. What is the meaning of equivalence? Two states A and B are said to be equivalent if +[192.02s -> 206.46s] A on getting a particular input string x. Here x is any input string. So, if the state A on seeing the input string x goes to a final state. +[206.46s -> 220.90s] And at the same time if state B also on getting that same input string goes to any of the final states then A and B are said to be equivalent. +[220.90s -> 223.57s] or if +[224.05s -> 237.71s] a on getting an input string x does not go to the final state and also b on getting the particular input string x does not go to any of the final states then +[237.71s -> 249.49s] also a and b are said to be equivalent okay and this will become more clear to you when we take some examples and now what we have to study is +[249.65s -> 261.55s] Types of equivalents. There are some different kinds of equivalents like 0 equivalents, 1 equivalents, 2 equivalents and so on. So, next we will be seeing what is that. +[262.35s -> 272.90s] So here we see that if modulo x equal to 0 this means that if the length of the string x here we have taken +[272.90s -> 286.67s] x as any input string. If the length of that string x is 0, then a and b are said to be 0 equivalent. Alright. And if the length of x is equal to 1, +[286.67s -> 300.91s] then a and b are said to be 1 equivalent. And if the length of string x is equal to 2, then a and b are said to be 2 equivalent. So, in general we can write that if the +[300.91s -> 314.14s] length of the string x is equal to n then a and b are said to be n equivalent all right so these are the type of equivalences that we have and we already studied +[314.14s -> 327.63s] When are two states a and b set to be equivalent? It is with these conditions. When on seeing a particular input string x, if both a and b either goes to the final state or +[327.63s -> 339.97s] It does not go to any final state. Then they are said to be equivalent. And why do we need this equivalent property? We need it in order to combine the states, in order to reduce the number of states to get the +[339.97s -> 354.24s] minimum number of states possible in order to design the minimal version of any DFA. So, this was the theoretical explanation and in the next lecture we will be seeing an example which will make it. +[354.24s -> 357.97s] very clear to you. So, see you in the next one with an example. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_6.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..261c286698c2554a4c98526614503f2812dce474 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_6.mp4.txt @@ -0,0 +1,33 @@ +[0.08s -> 14.29s] Hurricane Florence came by While I was working on StatQuest Dark clouds filled the sky But that didn't stop StatQuest +[14.29s -> 28.91s] Hello, I'm Josh Starmer and welcome to StatQuest. Today we're going to be talking about some machine learning fundamentals, bias and variance, and they're going to be clearly explained. +[29.23s -> 41.97s] Imagine we measured the weight and height of a bunch of mice and plotted the data on a graph. Light mice tend to be short, and heavier mice tend to be taller. +[42.54s -> 57.26s] But after a certain weight, mice don't get any taller, just more obese. Given this data, we would like to predict mouse height given its weight. For example, if you told me your mouse weighed this much, +[57.58s -> 72.30s] Then we might predict that the mouse is this tall. Ideally, we would know the exact mathematical formula that describes the relationship between weight and height. But, in this case, we don't know the formula. +[72.30s -> 83.12s] so we're going to use two machine learning methods to approximate this relationship. However, I'll leave the true relationship curve in the figure for reference. +[83.54s -> 97.42s] The first thing we do is split the data into two sets, one for training the machine learning algorithms and one for testing them. The blue dots are the training set, and the green dots are the testing set. +[97.87s -> 112.59s] Here's just the training set. The first machine learning algorithm that we will use is linear regression, aka least squares. Linear regression fits a straight line to the training set. +[113.20s -> 125.55s] The straight line doesn't have the flexibility to accurately replicate the arc in the true relationship. No matter how we try to fit the line, it will never curve. +[127.18s -> 135.44s] Thus, the straight line will never capture the true relationship between weight and height no matter how well we fit it to the training set. +[136.18s -> 144.24s] The inability for a machine learning method like linear regression to capture the true relationship is called bias. +[144.91s -> 157.94s] Because the straight line can't be curved like the true relationship, it has a relatively large amount of bias. Another machine learning method might fit a squiggly line to the training set. +[158.38s -> 172.59s] The squiggly line is super flexible and hugs the training set along the arc of the true relationship. Because the squiggly line can handle the arc in the true relationship between weight and height, it has very little bias. +[173.36s -> 181.20s] We can compare how well the straight line and the squiggly line fit the training set by calculating their sums of squares. +[181.55s -> 195.66s] In other words, we measure the distances from the fit lines to the data, square them, and add them up. Psst! They are squared so that negative distances do not cancel out positive distances. +[196.37s -> 204.24s] Notice how the squiggly line fits the data so well that the distances between the line and the data are all zero. +[204.98s -> 213.39s] In the contest to see whether the straight line fits the training set better than the squiggly line, the squiggly line wins. +[214.26s -> 227.50s] But remember, so far we've only calculated the sums of squares for the training set. We also have a testing set. Now let's calculate the sums of squares for the testing set. +[228.08s -> 236.82s] In the contest to see whether the straight line fits the testing set better than the squiggly line, the straight line wins. +[237.90s -> 252.56s] Even though the squiggly line did a great job fitting the training set, it did a terrible job fitting the testing set. In machine learning lingo, the difference in fits between datasets is called variance. +[253.33s -> 261.01s] The squiggly line has low bias since it is flexible and can adapt to the curve in the relationship between weight and height. +[261.55s -> 269.26s] But the squiggly line has high variability because it results in vastly different sums of squares for different data sets. +[270.00s -> 280.59s] In other words, it's hard to predict how well the squiggly line will perform with future datasets. It might do well sometimes, and other times it might do terribly. +[281.49s -> 290.42s] In contrast, the straight line has relatively high bias since it cannot capture the curve in the relationship between weight and height. +[290.83s -> 298.29s] But this straight line has relatively low variance because the sums of squares are very similar for different data sets. +[298.99s -> 309.68s] In other words, the straight line might only give good predictions and not great predictions, but they will be consistently good predictions. Bam! +[310.06s -> 321.90s] Oh no! Terminology alert! Because the squiggly line fits the training set really well, but not the testing set, we say that the squiggly line is overfit. +[322.48s -> 336.59s] In machine learning, the ideal algorithm has low bias and can accurately model the true relationship. And it has low variability by producing consistent predictions across different datasets. +[337.20s -> 343.57s] This is done by finding the sweet spot between a simple model and a complex model. +[344.43s -> 358.29s] Oh no! Another terminology alert! Three commonly used methods for finding the sweet spot between simple and complicated models are regularization, boosting, and bagging. +[358.51s -> 370.93s] The stat quests on a random forest show an example of bagging in action. And we'll talk about regularization and boosting in future stat quests. Double bam! +[371.44s -> 385.28s] Hooray! We've made it to the end of another exciting Stat Quest. If you like this Stat Quest and want to see more, please subscribe. And if you want to support Stat Quest, well, please consider buying one or two of my original songs. +[385.28s -> 388.75s] Alright, until next time, quest on! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_8.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5ddcd8495865846bd081d3214a7fd54c3dbbc236 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_8.mp4.txt @@ -0,0 +1,45 @@ +[0.24s -> 13.95s] In this session, we are discussing a very important algorithm, Ford Fulkerson algorithm for maximum flow problem. Now, what is the maximum flow problem? So, let us discuss the problem at first. +[13.95s -> 27.15s] Then we shall discuss the terminologies and the algorithm as well. See, the problem says that given a graph which represents a flow network where every edge has a capacity. +[27.15s -> 38.88s] So that means one graph will be given and that will be weighted digraph, directed graph and this is the directed graph will be known as the network graph and this particular network. +[38.88s -> 51.97s] will be known as the flow network where each and every edge will have one integer value associated that is the weight of that particular edge or branch and that will be denoting the capacity of that edge that means +[51.97s -> 65.42s] the flow cannot exceed that capacity also given two vertices one is source s and another one is the sink t in the graph that means the flow will be made originated +[65.42s -> 77.68s] from source S and will get terminated at sink T. So, these are the very important two vertices are there, special type of vertices in the graph. +[77.68s -> 91.68s] Find out the maximum possible flow from S to T with following constraints. So this Ford-Falkerson algorithm is nothing but a method which will calculate the maximum flow. +[91.68s -> 105.30s] through our network here the flow can be of anything the flow can be of anything and the maximum possible flow from s to t with the following constraints so while calculating the maximum flow through the network +[105.30s -> 119.02s] when having two constants constant number one flow on an edge does not exceed that given capacity obviously the flow through a certain age should not exceed the respective capacity mentioned +[119.02s -> 124.43s] as an integer value or numeric value associated with that edge. +[124.69s -> 138.45s] Inflow is equal to outflow for every vertex except your source and the sink S and T. So obviously the whatever the flow that will come into a vertex. +[138.45s -> 149.76s] should be equal to the flow out from the vortex. But in case of source only the flow will come out from the source. In case of sink T the flow will go into the +[149.76s -> 162.78s] sink t it will not come out. So except these two vertices where having the flow in and flow out must remain same in all other remaining vertices in this weighted digraph. +[162.78s -> 176.66s] So, while discussing the algorithm we might be facing different terminologies. So, let me go for the terminologies at first, but before going for the terminology let us see the how does one network looks like you see these are network. +[176.66s -> 188.83s] So here A is the source we have written that one and F is the sink or target. So now from A only the flow will come out and to the sink only the flow will go in. +[188.83s -> 199.82s] So, these are the respective flows we are having, these are the respective flows we are having and this is a diagraph you are getting this head and tail for each and every edge. +[199.82s -> 213.94s] the terminology so let me discuss the residual graph it is a graph which indicates additional possible flow if there is such path from source to sink then there is a possibility +[213.94s -> 227.52s] to add flow that means through a certain path we can add flow if there is a possibility possibility means what means the remaining capacity is there and which is non-zero through the path +[227.52s -> 239.33s] that means from the source to the sink all the hs which will be falling on the path they should be having some residual capacity so let me discuss the residual capacity at first +[239.33s -> 252.40s] So, residual capacity, it is the original capacity of the edge minus the flow. Original capacity means these are the original capacities and minus the flow. So, that is known as the residual capacity. +[252.40s -> 257.36s] Next one is the minimal cut also known as bottleneck capacity. +[257.65s -> 269.90s] which decides the maximum possible flow from source to sink through an augmented path. So, I think it will be better if we show that one on this particular diagram what we are trying to +[269.90s -> 281.78s] through this terminologies. Now, see let us consider we are considering one path say AC then D and F. +[282.26s -> 295.04s] So, you are reaching from source to the sink A to F through C and D. Now, see in this particular path, the maximum flow is 11, that means the capacity is 11. +[295.04s -> 300.50s] Here the capacity is 9, here the capacity is 11. So through this path, the maximum flow +[300.78s -> 314.38s] can be 9 because it will decide the maximum flow and that is known as the minimal cut so here i am giving a flow with 9 here 9 and here we are having this +[314.77s -> 316.40s] So now, see. +[318.16s -> 331.95s] Now, see here the residual capacity, here the residual capacity is 2, here the residual capacity is 9 minus 9 that is 0, here the residual capacity is capacity minus current flow +[331.95s -> 343.30s] through that path through that edge will be 2. So, 2 0 2 are the residual capacities for the respective edges. So, we have discussed what is the residual capacity. +[343.30s -> 355.17s] and the graph thus obtained is known as the residual graph and the minimal cut I told you this one that is the minimal cut. So, minimal cut means the maximum flow possible through that particular +[355.17s -> 368.98s] path from the source to the sink is a minimum cut so in this way it is happening now see as it is having some capacity there so if we consider the path say a c b e +[369.26s -> 373.68s] and F. If you consider the path like this. +[375.98s -> 389.50s] So, A, C, B, E and F, here you see, here the residual capacity is 2, here the capacity is 10, here the capacity is 9, here the capacity is 2. +[389.50s -> 403.54s] So that's why we can have the minimal cut here that is the bottleneck. So that is also very important. Bottleneck capacity. This term is very important. So the bottleneck capacity in this particular path is 2. So what I can do? I can make it 11. +[403.86s -> 414.80s] So, I can make it 2 there, I can make 2 here, I can make 2 here. So, here we will be having some residual capacities, but it is quite full. +[415.41s -> 429.22s] In this way, we shall explain in details in the example. Augmenting path can be done in two ways. So, augmenting path can be done in two ways. One is the non-fold forward edges, whatever you have done. It is a non-fold. +[429.22s -> 441.73s] it is a non-full initially it was 9 and the capacity was 11 so it is non-full so non-full forward edges and another one is non-empty backward edges so non-empty backward edges we shall discuss +[441.73s -> 455.15s] in one example for the better understanding. So, let me discuss the algorithm at first. So, Ford-Fulkerson algorithm. The following is a simple idea of the algorithm. We are having three steps. +[455.15s -> 468.16s] Step number 1. Start with the initial flow as 0. So initially I can write here the flow is 0. Initially the flow was 0. Then we made a flow of 9. So flow has become 9. +[468.16s -> 483.06s] Then we made a flow of 2 here. So, the flow has become 11. So, in this way we will be going for incrementing the flow because we are going to calculate the maximum flow through the network. So, initially we will be starting with the initial flow as 0. +[483.50s -> 494.61s] There while there is an augmenting path from source to saying yes, we are getting so many augmenting paths So here you have demonstrated two of them then at this path flow to flow +[494.61s -> 508.30s] So, this path flow should be added with the flow. So, initially it was 0 then I allowed flow of 9. So, it has become 0 plus 9 that is 9 and then I allowed 2 through this. So, 9 plus 2 that is 11. So, now just +[508.30s -> 521.04s] at this path flow to the flow value and in this way you are going to do until there is no augmenting edge paths are possible from source to target source to sync and after doing this +[521.04s -> 534.93s] the value of the current flow will be returned and that is the maximum flow of the network. In this way, the algorithm will work. Please watch the next video where we will be going for one example for the better and crystal clear conception. +[534.93s -> 544.55s] to generate the crystal clear conception and better understanding on this particular algorithm. So that video will be in the continuation of this one. Thanks for watching this video. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_9.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d4fcb6bcd43d2c30bacf5570592053998982e91e --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Computer_Science_9.mp4.txt @@ -0,0 +1,37 @@ +[0.27s -> 11.98s] Hi everyone, in this video we are going to talk about throughput. Now what is the throughput? Throughput is the rate at which bits are transferred from the center to the receiver. So the unit of throughput is bits per unit time. +[12.18s -> 24.93s] So the two concepts here, one is instantaneous throughput and the other is the average throughput. The instantaneous throughput is the rate at any given point in time. And so it can vary over time. +[24.93s -> 38.61s] The average is the rate over long periods of time and by rate once again It's a number of bits that are being transmitted per unit time between the sender and the receiver So let's look at an example here here. There is a server +[38.64s -> 49.07s] Which has a file which is of length F bits and wants to send it to this client here now between the client there are these two links and let's +[49.07s -> 59.90s] Consider that this first link has a capacity of R subscript s bits per second and the second link has a capacity of R subscript c bits per second. So the way to think of +[59.90s -> 73.49s] throughput is via a fluid model. Think about water flowing through a pipe and this is a reservoir or the server is a reservoir where it has F bits to transmit and this +[73.49s -> 81.04s] Those F bits flow through this pipe at the rate of R subscript S bits per second, and they flow through this one. +[81.04s -> 93.39s] and they can flow through this pipe at r subscript c bits per second. So the next question is what is the rate at which water can flow or in this case bits can flow from the server +[93.39s -> 102.53s] to this client provided that these two links or these two pipes in between are of different capacity or they can carry +[102.53s -> 113.10s] and bits at different rates. So let's look at this. Let's consider the first case where the first pipe that is R subscript S is thinner. +[113.10s -> 124.48s] than the second pipe, which has a capacity to R subscript C, which is mathematically to say is that RS is less than RC. Now, what is the average end-to-end throughput in this case? +[124.48s -> 136.29s] note that this particular pipe is has a smaller capacity than this particular pipe here with the result that the amount of fluid that's going to flow through this pipe is going to dictate +[136.29s -> 143.25s] the total amount of fluid that can flow from the server to the to the client so the thickness of +[143.25s -> 156.88s] The first vibe or the value of RS is going to determine the throughput Once again to analyze throughput you have to think of fluid flowing from the server to the receiver So the average end-to-end throughput in this case is good +[156.88s -> 171.04s] R subscript s. Let's consider another scenario where the first pipe is thicker. That is the capacity of the first pipe is R subscript s and that is greater than RC. What happens is +[171.04s -> 182.62s] The amount of fluid or number of bits that can flow through this pipe is much greater than the amount of fluid that can flow through this pipe per second. As a result, the throughput will be determined +[182.62s -> 196.42s] by the capacity of the second pipe or is going to be RC. So the takeaway message from this slide is that the bottleneck link or the link on the end-to-end path which has the least capacity +[196.42s -> 209.28s] constraints the end-to-end throughput. So, depending on the thickness of each of these pipes, the one with the minimum capacity is going to determine the end-to-end throughput. +[209.28s -> 221.34s] So let's look at an example which in the internet, which is slightly more complex. So here what we have is here we have 10 servers +[221.34s -> 226.45s] 10 sending files to 10 clients out here now all these +[226.48s -> 239.66s] These servers are connected by have a different connection to the directly to the internet which is our subscript s you could think of this as Ethernet cable which connects the server to the greater internet and then +[239.79s -> 247.70s] each of these clients also has a dedicated connection to the internet, which once again can be thought of as the +[247.86s -> 261.89s] as Ethernet cable joining this client to the Internet. Now the entire capacity through the Internet, the packet can flow over multiple hubs or multiple routers, but we abstract that notion and we consider that the +[261.89s -> 275.46s] that the entire capacity through the internet is going to be given by this fat pipe of capacity R. Now, this capacity is going to be equally shared between all the +[275.46s -> 279.47s] all the 10 servers. So all these 10 servers are going to use +[279.47s -> 290.67s] this capacity R. Note that there is not a single connection. There may not be a single connection of capacity capital R. It's just an abstract way of saying that the internet can provide. +[290.96s -> 305.41s] a rate of capital R. Now this capital R has to be equally divided among each of these connections and note that there are 10 connections in all so each connection will get its fair share of R over 10. +[305.41s -> 314.54s] now for each connection you can get r over 10 in the middle and then there is rs and rc so the +[314.61s -> 323.76s] The end-to-end throughput for each connection is going to depend on the value of RS, RC and R over 10. +[324.05s -> 338.64s] The way to mathematically represent this is to use this minimum function, which just means that the value of the end-to-end throughput is going to be the minimum of RC, RS, and RO10. That is, whichever is this minimum value. +[338.64s -> 345.71s] that is going to determine the end-to-end throughput so for example if RC is less than RS +[345.71s -> 359.50s] RO10, then the throughput is going to be RC. On the other hand, if RS is less than RC and RO10, then the throughput is going to be RS. And if RO10 is less than both RC and RS, then the +[359.54s -> 369.90s] and throughput is going to be r over 10. In practice mostly it is rs or rc that is a bottleneck and not r so +[370.26s -> 379.55s] So with this, I'd like to end our discussion on throughput and I would conclude by saying that the throughput is the +[379.55s -> 392.30s] the is the rate between the sender and the receiver and is and its units and its units as bits per second to calculate the throughput what you have to determine is consider fluid model and considered +[392.43s -> 399.41s] and the capacity of each of the intermediate links between the sender and the receiver and minimum +[399.41s -> 409.68s] capacity of the minimum link is going to be the bottleneck and that is going to determine the throughput between the sender and the receiver. With this, I'll conclude this lecture. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_1.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..da46c2a34c326c8600ab14f8b8025da5d662f429 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_1.mp4.txt @@ -0,0 +1,37 @@ +[4.85s -> 19.31s] In this lecture I will explain transistor saturation. The transistor is set to be saturated when the collector current Ic is larger than or equal to the maximum collector current for the particular design. Let's say +[19.31s -> 30.86s] the maximum collector current is ICmax and we have the saturation condition when the collector current is greater than or equal to +[30.99s -> 42.80s] ICmax and in this condition the collector current is represented by ICsat representing the collector current in saturation condition +[42.80s -> 56.85s] We try to avoid the saturation conditions because in saturation region the collector base junction is forward biased and there is distortion in the amplified signal. We are trying to amplify the weak input signal +[56.85s -> 70.61s] using transistor and for this purpose transistor must operate in the active region transistor must operate in the active region and in active region the collector base junction +[70.61s -> 83.04s] is reverse biased and the emitter base junction is forward biased but in saturation region the collector base junction +[83.04s -> 94.21s] will forward bias and the ammeter base junction is already forward bias so the resistance offered is nearly equal to zero. +[94.21s -> 108.27s] that we will try to see by the help of this output characteristics this is the output characteristics of common emitter transistor and we already know this region is the active region +[108.34s -> 122.45s] And the region on the left hand side of this green line is saturation region and the region below the base current IB equal to zero is cutoff region. +[122.45s -> 133.94s] and as collector current is larger than or equal to the maximum collector current, the transistor will operate in the saturation region. This means the operating point +[134.06s -> 139.25s] or the cue point is in the saturation region like this. +[139.25s -> 152.40s] And if we consider the approximate curves then it will look something like this. And you can clearly see the collector current IC is relatively high and VCE is zero. +[152.40s -> 160.69s] the collector current Ic that is Ic set is relatively high and Vce +[160.94s -> 172.30s] is equal to 0. Now we will try to find out the resistance and for this I will use the Ohm's law. We know ICsat +[172.66s -> 181.26s] multiplied with RCE is equal to VCE. We want to find out resistance RCE. +[181.26s -> 194.53s] So RCE is equal to 0 volts because VCE is equal to 0 volts by ICsat. So simply the resistance is equal +[194.53s -> 205.82s] to 0 ohms this means there is no resistance between the collector and emitter terminals and we can short circuit we can short circuit +[205.82s -> 214.32s] the two terminals. Now we know what actually happens when transistor operates in the saturation region. The relatively high +[214.32s -> 228.26s] collector current is there and VCE is equal to zero volts and because of this collector and emitter terminals are short-circuited. Now we can easily find out the saturation condition +[228.26s -> 239.70s] for the fixed bias configuration saturation saturation condition for the fixed bias configuration fixed +[240.11s -> 253.28s] bias configuration first we will draw the circuit of fixed bias configuration then we will find out the collector current in saturation region and as the collector current +[253.28s -> 267.31s] the collector current IC is equal to is equal to the maximum collector current ICmax the transistor is operating in the saturation region and the collector +[267.70s -> 281.92s] Ammeter terminals are short circuited. Now we will calculate the value of IC set by applying KVL in the output loop. We have VCC minus ICRC. +[281.92s -> 294.11s] IC, RC, IC is IC set equal to 0 and from this equation you can see IC set +[294.11s -> 308.10s] is equal to VCC divided by resistance RC so this is the condition for saturation in case of fixed bias configuration the next thing is condition for saturation +[308.10s -> 315.31s] in case of emitter bias configuration in case of emitter +[315.92s -> 326.54s] bias configuration and again we will do the same thing the collector current is equal +[326.99s -> 335.46s] to the maximum collector current so we have IC set and we will draw the circuit of emitter bias configuration +[335.46s -> 343.89s] In case of emitter bias configuration, we have emitter resistance Re and the transistor is operating. +[344.50s -> 359.31s] saturation region so the collector emitter terminals are short-circuited and when we apply KVL in the output loop we have the equation VCC minus +[359.34s -> 370.61s] IC set RC minus IE RE equal to 0 and we know +[370.90s -> 383.89s] IE is nearly equal to IC or we can say IE is nearly equal to IC set. We have VCC minus IC set. +[383.89s -> 394.13s] inside the bracket Rc plus Re equal to 0 and from this equation IC set is equal to +[394.48s -> 408.27s] VCC divided by resistance RC plus resistance RE. So this is what you need to do in emitter bias configuration. Now there is one homework problem. In this homework problem +[408.62s -> 421.58s] you need to find out the condition for saturation that is ICSAT for the collector feedback bias for +[421.90s -> 435.73s] the collector feedback bias and for the voltage divider bias for voltage +[436.72s -> 446.69s] divider bias. Once you have your answers, post them in comment section. I will end this lecture here. See you in the next one. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_10.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..32f65d9e143087459850dad2d753254700a4959b --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_10.mp4.txt @@ -0,0 +1,55 @@ +[0.91s -> 12.08s] Hi, welcome to Wiseguys. This video is on complex numbers and it is dealing with applications of complex numbers that have to do with AC circuits. +[13.78s -> 25.90s] So complex numbers are used in AC circuits because the resistors, capacitors, and inductors all react differently to AC current. +[26.64s -> 40.82s] And another piece of information that's important is that the effective resistance of each element is called the reactants. Those elements actually that I'm talking about are the capacitor. +[40.82s -> 46.70s] and the inductor. So resistance is just resistance, and the symbol for it is this. +[47.44s -> 61.20s] The capacitive reactants is a formula that's put together when you have the capacitor in order to get an essential resistance that you can work with in a circuit, and it's called reactants. +[61.58s -> 65.49s] and, as I'm sure you already know, the symbol for capacitors here. +[66.32s -> 77.20s] Symbol for an inductor is this one, and the inductive reactants is XL, and that again is sort of a... +[77.20s -> 86.58s] kind of a resistance, an effective resistance that we use in an AC circuit in order to solve for the information about the inductor. +[89.26s -> 100.05s] Now, in an AC circuit, each of these three elements, capacitor, inductor, resistor, all react differently. +[100.40s -> 111.06s] to current. So here if we have just a graph of current and at this point, so at point +[111.60s -> 124.75s] times zero, okay, we have the current flowing here. In the resistor, what happens is the voltage in the resistor follows +[125.30s -> 136.08s] the current. So when the current here is at its max the voltage here is at its max. +[136.34s -> 145.62s] So what we say is that the voltage across the resistor is in phase with the current. For an inductor, +[145.87s -> 159.66s] the voltage across the inductor legs the current by 90 degrees. So you can see here that it's just behind, alright? It's behind and we know that +[159.66s -> 170.08s] This point here is 90 degrees because this whole piece Is 360 all right? So we're lagging +[170.08s -> 183.44s] the voltage across the inductor lags by 90 degrees and most of this really is just information. You don't have to worry about it too much. And the voltage across the capacitor leads by 90 degrees. +[183.73s -> 194.22s] So, voltage across resistor is in phase, voltage across the inductor legs by 90 degrees, voltage across the capacitor leads by 90 degrees. +[197.01s -> 209.90s] Now, if we have a series AC circuit, which is what we have right here. And again, all I'm concerned about right now is thinking about the complex numbers and what that looks like. +[210.45s -> 223.76s] So we see we have a resistance, we have a capacitive reactance, and an inductive reactance. And what we do is we put them on the x and y axis. +[224.59s -> 236.50s] So the resistor is what we call real, and it goes on the real axis. So whatever amount that resistance would be, let's say it's 12 ohms. +[236.78s -> 240.46s] That 12 ohms would be here. +[241.87s -> 255.50s] Our xc goes on the y-axis and it goes in the negative direction. So whatever amount we have there, that's shown up here, or drawn here. +[256.62s -> 269.62s] Our inductance is on the, or I should say inductive reactance, is on the y-axis as well, and it's in the positive direction. +[269.62s -> 273.36s] So if we had a number there, we'd write it down here. +[277.07s -> 290.85s] Now here we have a circuit. We can't really solve for the circuit because we do not have a current, but I'm just going to talk about what we would do here to solve for the mass of these +[290.85s -> 299.02s] sort of resistant pieces. So we'd think about, okay, so I'm on the x and y axis. +[299.76s -> 313.17s] I have 45 ohms resistance so that goes on the real axis in the positive direction. So there's my resistor which is the 45 ohms. +[314.35s -> 327.70s] My capacitor or my capacitive reactance is 60 ohms and that goes on the y-axis in the negative direction. So I go down here. +[328.24s -> 336.43s] and that's my XC and it is 60 ohms. +[339.09s -> 350.54s] My inductive reactance is 72 ohms and it goes on the positive y-axis. So that's 72 ohms or the inductive +[351.31s -> 359.89s] reactants goes up here. So our XL is here and it's 72 ohms. +[362.06s -> 374.42s] So now what we do is we add up the y-axis because, especially for a circuit like this, a series circuit, you want to find the total effective resistance. +[374.80s -> 382.19s] So we have 72 going up, 60 going down. So we can just redraw this. +[383.31s -> 392.37s] We end up with essentially 12 going up when we add the two together. So the 72 minus the 60 gives us 12. +[393.71s -> 407.76s] going up on this y-axis, alright. So that's the XL minus XC. And we still have our resistance. Oh, and it's 12 ohms. +[410.16s -> 422.29s] And we still have our resistance, which is the 45 ohms, okay? That's supposed to be resistance. +[424.30s -> 438.32s] So now we have 45 ohms here. We have 12 ohms here. So what we can do is solve for what's called the impedance. +[439.12s -> 450.64s] And I need another piece of paper here. So essentially what we have is +[455.73s -> 466.00s] our 45 ohms, which is the resistance, and our +[467.82s -> 476.27s] 12 ohms, which is the sum of XL, so XL minus XC. +[477.20s -> 483.44s] And what we want to solve for is the impedance, which is essentially the total resistance of this circuit. +[484.05s -> 498.64s] And, you can see that it's, in order to add these two together we have to use Pythagoras. So this here, what we're solving for, is called Z. +[499.15s -> 501.65s] And that's impedance. +[506.38s -> 518.83s] So in order to get that we use Pythagoras. So then our impedance equals the square root of 12 squared plus 45 squared. +[520.21s -> 527.98s] and we end up with 46.57 ohms. +[533.14s -> 542.74s] Okay, that's our impedance. The other thing we need to know about the impedance is we need to know that angle. And it's typically the angle +[543.63s -> 557.68s] against the horizontal axis. So we need to know what this is. So what we're doing is coming up with an answer that's in polar form. Alright? In order to find theta, +[559.28s -> 571.50s] We do the inverse tan. So tan to the minus 1 of opposite, which is 12. +[573.33s -> 585.07s] over adjacent, which is 45. Okay, so we end up with +[589.07s -> 601.71s] Second function, what are we doing here, tan 12 divided by 45, close bracket, equals. +[602.45s -> 611.34s] 14.93. I'm just going to round it up to 15, alright? So 15 degrees. +[615.57s -> 622.26s] So, our impedance then for this circuit is +[622.74s -> 632.34s] 46.57 ohms, angle 15 degrees. +[632.78s -> 643.73s] depending on your instructor you might need to have more digits in there I was just being a little bit lazy all right and that's basically solving for your impedance +[643.73s -> 658.63s] If you had more information here, you could solve for other things, but I just wanted to give you an idea of what you'd be looking at in the beginning. So this video has been brought to you by Wiseguys. I hope you have a super day. Take care. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_11.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..25c108c05e1c3576890caea47686eca6f77b8584 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_11.mp4.txt @@ -0,0 +1,53 @@ +[1.71s -> 13.73s] Alright, welcome back. We're doing another example here on nodal analysis, and in this case we have two voltage sources. We have a 3 volt and a 2 volt voltage source, and a couple different resistors that are in no particular order. +[13.73s -> 28.30s] So to solve this problem, we're going to use nodal analysis. And to get started with that, first we have to identify a ground. In the case where there's voltage sources, especially if two voltage sources are connected to the same node, you're probably going to want to ground that node because it'll reduce the number. +[28.30s -> 36.13s] of unknowns that we have. So let's pick this one. Let's draw on a ground and this is going to serve to be our zero volts. +[36.13s -> 48.03s] reference point for the rest of the circuit but because we have voltage sources attached to it that means that across this element basically this node here is going to be three volts higher than the zero ground +[48.03s -> 60.54s] And then, same thing when we cross this voltage source, it's going to jump by 2 volts, so this node up here is going to be equal to 2 volts higher than ground. Then when we look at this, we only have two remaining unknown null voltages, this one and this one. +[60.54s -> 68.61s] So let's give them names. Let's call the voltage of this node, let's call it VA, and let's call the voltage of this node VB. +[68.61s -> 80.51s] Now when we're doing nodal analysis basically all we do is Kirchhoff's current law at each of the nodes that have unknown voltages. So we have two. So we're going to need the current flowing into node A. +[80.51s -> 93.98s] and out of node A, and also B. So we just assume some directions here. It doesn't actually matter if we get them right or wrong. But let's just pick some for the purpose of this problem. So we'll call this I1. Let's call this one I2, going this way. +[93.98s -> 107.41s] And let's say we have I3 and then I4. And let's say I5. Cool. So we just need to write KCL for each of the nodes. So let's do KCLA first. +[107.41s -> 121.81s] and you can either sum up so all of the currents flowing in are on one side of the equation and all of the currents are flowing out on the other side of the equation or if you prefer you can pick a convention where we say like negative is the the sign we assign to a current flowing in and positive +[121.81s -> 134.26s] four out. It means basically the same thing. It's just basically if we sum them up together that we get a net of zero. So let's go with that. Let's say that then because i1 is flowing in, we're going to have negative i1. +[134.32s -> 148.26s] And then we have I2 flowing out, so we have plus I2 and plus I3 is equal to 0. Clearly, if you just brought this I1 to the other side, you would have these two, which are the flows out, equal the flow in. +[148.26s -> 162.61s] And because Ohm's law is V equals IR, we can rearrange that for current. So we have I is equal to V over R. So even though these currents are unknown right now, we can write them in terms of the voltage drop across the element and +[162.61s -> 167.25s] the resistance. So for I1 let's keep the negative sign. +[167.25s -> 179.10s] And the current is equal to voltage over resistance. Now, we've assumed that the current is going from left to right, which means it's flowing from a high voltage to a low voltage. So we're assuming that 3 volts is higher than VA. +[179.10s -> 193.50s] If it turns out that we got this wrong later in the problem, it's fine. We'll just find this current to be negative and we'll switch the direction. But we're going to proceed as we've drawn it. So the voltage across it is going to be 3 volts minus VA. +[193.50s -> 203.47s] So that's the difference. We subtract the smaller one from the bigger one, and that's based on the assumption that we've made. And then we just divide this by the resistance, which is 2 ohms. Okay, for I2. +[203.47s -> 209.06s] we have positive and when we look at i2 that is this one right here +[209.06s -> 223.28s] And so we're assuming the current to be going down, which means we assume that VA is bigger than 0. So the voltage drop across that resistor is going to be VA minus 0 over the resistance, which is 3 ohms. +[224.91s -> 239.36s] And then for the other resistor where I3 is flowing through, the voltage drop here, again we're assuming it's flowing this way, so we assume VA is bigger than VB. So the difference, or the voltage drop across this resistor is going to be VA minus VB. And it's over... +[239.36s -> 252.80s] 4 ohms. All right let's give ourselves a bunch more space here to work with and we'll just go through simplifying this calculation. So we're going to multiply each term here by the lowest common denominator basically which is 12. +[252.80s -> 267.44s] So we multiply by 12 to each term. And in this case, we can simplify a little bit. So 12 divided by 2, we're left with a negative 6 here. 12 divided by 3, we're left with a 4. And 12 divided by 4, we're left with a 3. +[267.44s -> 280.40s] So we can just rewrite this a little bit. So we have negative 6 times. What I'm also going to do, actually, I'm going to drop the units of volts and ohms because it gets a little bit confusing here when you have this unit of volts and then a V also in the name of the variable. +[280.43s -> 292.96s] So we're just going to say that this is 3 minus VA, and we've gotten rid of the ohms as well. So each term here is going to be in units of amps. Okay, so then the next term just becomes 4 VA. +[292.96s -> 304.69s] And the next term just becomes 3 times VA minus VB. So we can just distribute those out and simplify to get 13 VA minus 3 VB is equal to 18. +[304.69s -> 319.12s] Alright, so let's also write the expression for KCL at node B, and we need to scroll up here to just double check what the values actually were. So we have I4 flowing out, so let's give that a positive, and we subtract I3, which is coming in. +[319.12s -> 330.34s] and subtract i5, which is coming in, and set that equal to 0. Again, you could move these negatives to the other side and have everything flowing out equals everything flowing in, if you prefer. +[330.34s -> 344.03s] But let's go through with the same logic as last time so looking at this resistor for I4 we're going to replace I4 with this expression which is the voltage drop divided by the resistance and in this case the voltage drop is VB +[344.03s -> 355.97s] minus zero and again because of the direction that we've picked for the current we're assuming that VB is greater than zero so we subtract zero from VB and that's all over two ohms +[355.97s -> 365.04s] And then for I3, we do the same thing. So the voltage drop, we're assuming the current is going left to right. So the voltage drop is going to be VA minus VB. +[365.36s -> 379.34s] over the resistance, which is 4 ohms. And then we can do the same thing for the other one, for I5. And we're assuming the current is going from right to left, so we're going to say that the voltage drop is 2 volts minus VB. +[380.08s -> 389.68s] all over the resistance which is one ohm and set that equal to zero all right we can give ourself more space again and +[389.68s -> 403.89s] Let's multiply everything by the lowest common denominator, which is 4 in this case. So we'll multiply every term to 4. You can even multiply the 4 to the 0, but it really doesn't matter because nothing will happen there. This 1 will disappear. +[403.89s -> 415.57s] This 4 and this 4 will disappear, so we'll be left with a negative 1 here, and this 4 will cancel with that, so we have a positive 2. So that leaves us with this first term is just 2VB. +[415.95s -> 426.51s] And then we have minus VA minus VB. And this is plus 4 times 2 times VB. +[426.64s -> 439.25s] Again, I'm just dropping the units of volts, because it gets confusing here, and the units of ohms. If you want to carry it through, you might want to do a better job of distinguishing between when it's a unit and when it's a variable name, but I prefer just to drop them. +[439.79s -> 451.31s] So yeah, let's set that equal to 0, and we can just distribute out what we have left. And this just simplifies to VA equals 7VB minus 8. All right, so we just want to take this VA. +[451.31s -> 464.06s] and plug it in right here. So we get 13 times that whole expression which is 7 VB minus 8 minus 3 VB is equal to 18. +[464.06s -> 470.42s] And then we can just simplify this a little bit and we'll just get VB is equal to 122 over 88. +[470.42s -> 479.95s] And then we can just take this and just plug it right back into the other expression. So let's actually take the fraction because it's going to give us less rounding issues. But we have VA. +[479.95s -> 494.06s] is just equal to 7 times 122 over 88 minus 8 and we find that VA is equal to 1.70 volts. +[494.06s -> 503.47s] So let's go and label these onto the original diagram then. So VA is equal to 1.7 and VB is equal to 1.39. +[503.47s -> 517.76s] That means we can find the voltage drop now across every resistor. So V1 here is just going to be 3 volts minus 1.7 volts, which gives us 1.3 volts. We can do the same thing here, 1.7 minus 0. +[517.76s -> 528.54s] that just gives us the voltage here of 1.7 the voltage drop across this resistor is 1.7 minus 1.39 which is +[528.54s -> 541.46s] V3 which is going to be 0.31 volts. The voltage dropped across here is 1.39 minus 0 so that is just V4 is equal to 1.39 volts. +[541.46s -> 549.87s] And then the voltage drop from here, 2 volts minus 1.39, is just V5, which is equal to 0. +[549.87s -> 564.21s] 6 1 volts and then we can just really quickly calculate the current flowing through each resistor using the Ohm's law here because current is again just equal to voltage divided by resistance so we just take the voltage divided by the resistance for each one so I1 is +[564.21s -> 572.34s] going to be 1.3 divided by 2 which gives us a current of 0.65 amps for I2 here +[572.34s -> 586.38s] We just have 1.7 divided by 3 for 0.57 amps. For I3, 0.31 volts divided by 4 ohms, which gives us 0. +[586.38s -> 600.26s] 0.08 amps and then here 1.39 volts divided by 2 gives us 0.7 amps and then lastly for I5 0.61 divided by 1 is just 0.61 +[600.26s -> 614.67s] and then we can just check that the current flowing in equals the current flowing out and 0.65 is equal to 0.57 plus 0.08 and then at this node the current flowing out is 0.7 and the current flowing in is 0.61 plus 0.65 +[614.67s -> 621.07s] And that's just off by a tiny little bit for rounding, but basically we can see that Kirchhoff's current law +[621.07s -> 635.25s] is satisfied for both of these nodes and yeah that's basically the problem if you were asked to find also the power dissipation and stuff like that you could do that but you might just be asked to find the current flowing through each resistor which we've done using nodal analysis in this example diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_12.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..49e29dfc85d17d717a053b30250dad82746646cd --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_12.mp4.txt @@ -0,0 +1,68 @@ +[0.00s -> 12.30s] hello friends welcome to electronic circuit hub so today we will determine the value of vbe vce and vcb so i will explain +[12.30s -> 21.46s] the step-by-step process procedure to calculate the value of VBE, VCE and VCB +[21.84s -> 35.25s] So this is most commonly asked question in the university exam. So you will get this type of circuit which you need to identify the type of circuit. +[35.25s -> 48.64s] then you have to calculate the the value of VB VC the VCB okay so today I will explain the step-by-step calculation +[48.64s -> 50.59s] how will you calculate +[50.59s -> 64.21s] The value of VB, VC, VCB. How will you calculate the base current? How will you calculate the collector current? How will you calculate the VB voltage? How will you calculate the... +[64.21s -> 72.29s] vc voltage so this this i will explain a step by step so after watching this video +[72.29s -> 84.51s] you should able to calculate such kind of circuit okay you should able to understand such kind of circuit you should able to analyze such kind of circuit +[84.51s -> 91.25s] and if you ask to calculate the value of vb the value of vc the value of vc +[91.25s -> 104.69s] you should able to calculate okay so let us understand right so in this circuit first you need to identify what is the type of circuit so what i can see is this is +[104.69s -> 115.07s] this is BJT and PNBJT and which is in the common emitter configuration if I say common emitter +[115.07s -> 127.86s] you can see emitter is common for your input signal and for the output signal so this reference for your input signal is emitter and reference for your here +[127.86s -> 141.33s] a reference for your base signal i would say is emitter and reference for your collector signal is collector signal is emitter so this is common emitter configuration +[141.33s -> 152.74s] and you have got the VB value which is 5 volt you have got the RB value which is 4.7 volt and you have got the VCC value which is 15 volt +[152.74s -> 166.48s] And you have got the collector resistance which is 181. So, I would say this is my first number to find out the value of VBE. +[166.48s -> 172.75s] So, the value of VB is 0. +[173.71s -> 188.24s] 0.71 so if you have studied about the the silicon based transistor transistor you would know okay so you might know +[188.24s -> 201.98s] what is the vbe value for silicon transistor this is for si so this directly we know this for the silicon transistor the vbe value is 0.7 volt so this this +[201.98s -> 215.73s] we know now what we do we will calculate the value of vc okay so in the second step i will calculate the value of vc so to calculate the value of vc +[215.73s -> 225.12s] you should know the value of IB okay once you know the value of IB then you need to calculate the value of IC +[225.12s -> 237.63s] once you know the value of ic you will easily able to calculate the value of vc so let us calculate one by one so to calculate the value of ib +[237.63s -> 250.72s] you need to apply the Kirchhoff voltage law that is called KVL in base to emitter junction okay in this junction okay and the voltage across +[250.72s -> 260.11s] this base here is base to emitter if i would say is vb the voltage across base to emitter is vb +[260.11s -> 273.68s] okay the voltage across base to emitter is vb now let us apply the kvl in this loop let us say this is loop number one and this is loop number two so let us apply +[273.68s -> 283.38s] the kvl in this loop so if you write the equation for loop one so how will you write vb +[284.56s -> 296.72s] minus IB into RB IB into RB minus VB +[298.42s -> 300.69s] equals to 0 +[301.17s -> 314.54s] So here you can see minus then plus and then here you have plus and minus. Okay. And then again here you have plus and minus. So that is how it will become VB. +[314.54s -> 326.70s] minus IB into RB minus VBE equals to zero. Now you need to calculate the value of IB. The value of IB is given by VBE +[327.31s -> 329.68s] minus VB +[330.16s -> 343.90s] Alright, minus VB divide by, divide by RB. This will give you the value of, divide by RB. This will give you the value of IB. +[343.90s -> 356.43s] so 5 volt i would say minus 0.7 volt so this is 0.7 volt divide by 4.7 k +[356.43s -> 368.77s] and if you solve this this 5 volt minus 0.7 volt which you already know from here and divide by 4.7 k let me do some math for you so +[368.77s -> 382.50s] 5 volt minus 0.7 volt right 5 volt minus here 0.7 volt this will give you 4.3 volt and divide by 4 +[382.50s -> 397.26s] point seven K and you will get the value of IB equals to zero point nine one four milliampere so this is very important guys so let me +[398.13s -> 412.37s] do like this your IV value is 0.914 now let us calculate what I said if you know IV you will easily calculate the IC +[412.37s -> 426.08s] So, let us calculate Ic. So, Ic is given by, what is the formula for, what is the relation between Ib and Ic? So, the relation between Ic and Ib equals to +[426.08s -> 439.38s] ic equals to beta iv now you know the value of beta which is given here you can see guys pay more attention now guys you can see the value of beta is 50 +[439.38s -> 451.22s] and you will multiply 50 into 0.914 milliamps okay so let me do math for you +[451.22s -> 465.44s] I will multiply this by 50 and what I will get is 45.74 +[465.44s -> 479.98s] seven seven four milliamps so this is the value of ic 45.74 let me color again it so now you get the value of +[480.27s -> 494.56s] Now you get the value of IC. So your IC value is 45.74 millivolt. So now let us apply the KVL on this loop now, in this loop. +[494.56s -> 508.29s] so 15 volt minus 15 volt minus the IC into RC okay +[508.29s -> 521.62s] So, IC into, I would say IC into RC minus VCE, okay, minus VCE equals to 0. +[521.97s -> 535.57s] so how you can see so the voltage across collector to emitter is given by VCE so I have applied the KVL minus plus +[535.57s -> 549.38s] plus and minus okay for this resistance and plus and minus for this resistance okay so that is how 15 volt minus ic into rc minus vc equals to zero +[549.38s -> 562.21s] and from here you can easily calculate the value of vce and the value of vc what is the value of vc the value of vc is 15 volt minus +[562.21s -> 571.94s] ic into ic into rc okay so i am so sorry guys since i am using syncing tool so i am not much +[571.94s -> 585.17s] comfortable with this tool but is still trying to make you understand so 15 volts minus ic you know the value of ic which is 0.0 +[585.97s -> 591.60s] five zero point zero four five +[592.05s -> 605.81s] 0.057 okay so I write it here in the terms of ampere so this is in milliampere 45.74 milliampere so right I write it here 0.0457 amps into +[605.81s -> 618.45s] 180 ohm this the resistance of RC so let me do math for you quickly so 0.0457 +[618.45s -> 632.56s] into 180 ohm and you will get here 8.2 volt so that means the value of vc is 15 volt minus 8 point +[632.56s -> 645.70s] volt okay and if you solve you will get the value of VCE and the value of VCE is now 15 minus 8.2 okay 15 minus +[645.70s -> 654.90s] and your value of VC is 6.8 volt so this is your second +[656.62s -> 670.96s] question you solve you got now you got the value of vbe you got the value of vce to get the value of vce you need to calculate first the base current ib here ib then +[670.96s -> 684.59s] You need to calculate the collected current IC by using this equation IC equals to beta IV and then you have to apply the KVL on loop number 2, a second loop or collector to emitter loop. +[684.59s -> 696.99s] and by applying the kvl you can solve it for vc now you have arrived your third question what is your third question you need to find out the value of vcb +[696.99s -> 710.00s] So, what is the VCB? VCB stands for VC minus VBE. What is the VCB? VCB equals to VC minus VBE. +[710.00s -> 715.09s] And what is VC? VC equals to VC. +[716.14s -> 729.79s] What is VCE? So you need to tell you have got the value of VCE. So what is VCE? VCE equals to VC minus VEE. So you know. +[729.79s -> 738.58s] This VC minus V so, you know the value of VC, you know the value of you know the value of V so +[738.58s -> 751.17s] the value of VE is 0V since your emitter is tied with the ground so your value of VE is 0V so you can see your VCE equals to VC +[751.17s -> 763.36s] okay your vc equals to vc and what is the vb vb you can see this node is vc this node is vc and this node is vb here so +[763.36s -> 771.62s] your value of vb is 5 volt so you can write it here 6.8 volt right +[771.62s -> 784.26s] 6.8 volt minus 5 volt let me solve it for you 6.8 volt minus 5 volt you will get 1.8 volt so your vcb value is 1 +[784.26s -> 797.10s] 0.8 gold so this is your another answer guys so this is your third answer you have calculated the value of VCB you have now the value of VBE +[797.10s -> 811.02s] you have now the value of VCE and you have now the value of VCB okay so that is how you will analyze this circuit okay if you have any further question feel free to ask me in comment section thanks for watching this video diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_13.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b495ed3370858cf9b811f5d196e46b25370aef10 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_13.mp4.txt @@ -0,0 +1,28 @@ +[0.94s -> 2.35s] 🎵 🎵 +[6.51s -> 16.30s] Hey friends, welcome to the YouTube channel ALL ABOUT ELECTRONICS. So in this question, we have been asked to find the Laplace transform of the given periodic waveform. +[16.66s -> 28.69s] So let's say, for the given periodic signal F , its Laplace transform is equal to F . And this F can be given by this expression. That is Fn . +[28.69s -> 42.67s] And here, this T is the time period of this periodic waveform. So, in this case, as you can see, this time period T is equal to 2. +[42.67s -> 55.41s] this Fn is the Laplace transform of the first period of this periodic function. That means here, this Fn is the first period of this periodic signal. And this Fn +[55.41s -> 66.91s] is the Laplace transform of this F1 . So here, to find this Laplace transform of this periodic signal, first we need to find this F1 . And to find this F1 , +[66.91s -> 81.09s] First of all, let's find the mathematical expression of this f and t. So as you can see this function, at time t is equal to 0, its amplitude is equal to 1. And up to time t is equal to 1, its amplitude remains 1. +[81.09s -> 93.04s] So, initially, it can be represented by this unit step function. That means up to time t is equal to 1, its amplitude is equal to 1. Now as you can see, at time t is equal to 1, +[93.04s -> 107.57s] Its amplitude changes from the plus 1 to minus 1. So to get that, we need to add the time shifted unit step function whose amplitude is equal to minus 2. And this function will start at time t is equal to 1. +[107.57s -> 119.55s] So, if we add these two functions, then we will have this kind of waveform. Now as you can see, at time t is equal to 2, the amplitude of the waveform becomes zero. +[119.55s -> 132.86s] The amplitude of the waveform is equal to minus 1. And to make it 0, we need to add the time-shifted unit step function whose amplitude is equal to 1. And this function will start at time t is equal to 2. +[132.86s -> 146.18s] So, in these two waveforms, if we add this third waveform, then we will get this kind of waveform. That means by adding these three functions, we can achieve our Fn . So, we can say that our Fn +[146.18s -> 158.24s] is equal to u minus 2 times u plus u . So in this way, we got the mathematical expression of the f and t. So now, +[158.24s -> 172.53s] Let's take the Laplace transform of this f and t. And if we take the Laplace transform, then we will get this expression. So as you know, the Laplace transform of this unit step function is equal to 1 divided by s. And here, +[172.53s -> 186.50s] Using the time shifting property of the Laplace transform, we can say that the Laplace transform of this U is equal to e to the power minus s divided by s. And similarly, the Laplace transform of this U +[186.50s -> 200.43s] is equal to e to the power minus 2s divided by s. So we can say that, our F1 is equal to 1 divided by s times, it is 1 minus 2 times e to the power minus s plus e to the power minus 2s. +[200.43s -> 213.90s] So, here if we assume that this e to the power minus s is equal to x, then we can say that this expression is equal to 1 minus 2x plus x square and that is equal to +[213.90s -> 228.03s] 1-x whole square, where this x is equal to e to the power minus s. So from this, we can say that this f1 is equal to 1 divided by s times this 1-e to the power minus s whole square. +[228.03s -> 242.50s] So, now once we got the Fn , then we can easily find the Laplace transform of this periodic waveform. That means this F is equal to Fn divided by 1 minus e to the power minus Ts. So, in this expression, +[242.50s -> 254.74s] If we put the value of F1 and T, then we can write it as 1 divided by S times this 1 minus e to the power minus S whole square divided by 1 minus e to the power minus 2S. +[254.74s -> 269.02s] So, here once again let's assume that this e to the power minus s is equal to x. So, further we can write this expression as 1 divided by s times this whole square divided by 1 minus x square. +[269.02s -> 283.04s] So, in the denominator, if we expand this 1-x square, then we can write it as 1-x times this 1 plus x. So, here this 1-x in the numerator and the denominator will get cancelled out. +[283.04s -> 295.54s] And we will have this 1 divided by x times this 1 minus x divided by 1 plus x. So now, if we put the value of x, then further we can write it as 1 divided by x times +[295.54s -> 307.81s] this 1 minus e to the power minus s divided by 1 plus e to the power minus s. So now further, this e to the power minus s can also be written as this e to the power minus s by 2 +[307.81s -> 321.62s] divided by e to the power s by 2, right. So now, if we multiply both numerator and the denominator by this e to the power s by 2, then further we can write it as this 1 divided by s times this e to the power s by 2. +[321.62s -> 333.82s] minus e to the power minus s by 2, divided by e to the power s by 2 plus e to the power minus s by 2. Now we know that the tan hyperbolic x can be given by this expression. +[333.82s -> 347.94s] So, if you compare these two expressions, then here this x is equal to s by 2. So, we can say that the Laplace transform of this periodic waveform is equal to 1 divided by s times this tan hyperbolic s by 2. +[347.94s -> 353.10s] And therefore, for the given question, this A is the correct answer. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_14.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..afb860db4d3cd0861ee167d02f3b78a0a174a15d --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_14.mp4.txt @@ -0,0 +1,28 @@ +[0.24s -> 10.35s] Hi all, in this video I am going to explain how to represent a signal in terms of unit step and unit ramp function. +[11.02s -> 24.05s] Consider a problem. This signal consists of unit ramp as well as unit step. First of all, we should know what is unit step. So, this is the unit step signal. +[24.72s -> 32.85s] And next this is the unit ramp signal because it is looked like a ramp. So this is the unit ramp signal. +[33.14s -> 41.94s] And next I am going to explain how to write the equation of x of t in terms of unit step and unit ramp. +[42.29s -> 56.27s] So, before that first of all we should know how many changes in the waveform. So, how the changes in the waveform that is corresponding to the number of times in the mathematical equation. +[56.50s -> 68.88s] So this is the change number 1. And next here minus 2 2 minus 1. Next minus 2 2 plus 1. This is the change number 2. +[69.23s -> 81.10s] And next here, here the slope is 0 and this is the change 3. And next, this is rise to amplitude 2 and this is the step signal. +[81.46s -> 89.46s] change number four and see this is the another one step signal change number five +[89.90s -> 103.31s] How many changes in the signal? There are 5 changes in the signal. So, 5 changes that is corresponds to 5 times in the mathematical equation. +[103.73s -> 117.82s] And next I am going to explain how to represent x of t. So x of t is equal to take the change number 1. Here the signal is rise from minus 2. +[117.82s -> 129.49s] to the positive slope. The positive slope is plus 1. So plus 1 is the positive slope and this is looked like a unit ramp function. +[129.52s -> 137.55s] And how to represent the unit RAM that is R of t. The starting point is t is equal to minus 2. +[137.97s -> 146.51s] How to represent this? t plus 2. So, R of t plus 2. This is the first term. +[147.60s -> 159.42s] And next consider the next change, the change number 2. So what is the slope corresponding to the change number 2? That is the slope minus 1. +[159.42s -> 171.60s] Here this is the positive slope then the ramp is in the decreasing order. So you have to put minus and next you have to write already we are having the positive slope. +[171.60s -> 183.07s] What is the change in slope minus of minus 1 into what is the starting point of this ramp that is t is equal to minus 1. +[183.07s -> 195.76s] How to write this t plus 1? So, R of t plus 1. Next, we have to consider the change 3. +[195.76s -> 204.40s] Third change, what about the slope? The slope is equal to 0. Already we are having the slope is equal to minus 1. +[204.40s -> 216.38s] And the minus, how the minus 1 is converted into 0? We have to add another 1 plus 1. Then we get the 0 slope. So, plus. +[216.38s -> 230.58s] Here what is the starting point? The starting point is t is equal to 1. How to represent this? t minus 1. So r of t minus 1. Next change is +[230.58s -> 243.55s] Here there is no slope and the amplitude is rise from this point to this. So total rise in amplitude is 2. Here 1 and the top 1 the total amplitude is 2. +[243.55s -> 254.86s] So, plus it is rising, no? Plus 2 into, this is the unit step signal. This is look like a unit step signal. So, that. +[254.86s -> 267.95s] Unit step signal is represented by u of t, no? So, u of what is the starting point here? That is 3. So, t is equal to 3. So, how to write this? t minus 3. +[267.95s -> 281.41s] So u of t minus 3. Then see up here up to this the change is over. Next the change is amplitude of the signal is reduced. +[281.41s -> 288.72s] 2 minus 1. So, how to write this minus and what is the point here? The point +[289.81s -> 301.49s] The time value is t is equal to 4. So, how to represent this t minus 4? So, u of t minus 4. So, this is the equation. +[301.49s -> 313.62s] So, after rearrange this R of t plus 2 minus 2 into R of t plus 1 plus R of t minus 1. +[313.62s -> 327.37s] plus 2 into u of t minus 3 minus u of t minus 4. This is the equation for x of t. Thank you. Have a nice day. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_2.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..40c2992c7f932d711c4239bb2c554a8e44ad66f2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_2.mp4.txt @@ -0,0 +1,33 @@ +[7.95s -> 21.36s] Hello everybody, and today we're talking about periodic waveforms. And periodic waveforms are simply waveforms that repeat. And we'll be using them a lot. We'll be looking at the voltage in the current waveforms. +[21.36s -> 35.17s] and ultimately at power. But first we're just going to start with simple waveforms. And I've drawn a few periodic waveforms here. The very simple one is a sinusoid. People are very commonly know that waveform. +[35.17s -> 48.74s] And I've drawn a few other ones. This is a type of pulsed waveform. It can have positive and negative. And you can also have waveforms that are all positive or triangular in shape like this. +[48.74s -> 62.51s] The waveform isn't important. What's important is that it repeats. So from 0 to t, t is your period, you have the first period, and then the second, third, fourth, and so on, you're going to have the exact same pattern. +[63.44s -> 77.33s] We're going to talk about two very important values for these periodic waveforms. And one is the average, and the second one is the RMS value, or the root mean square value. Okay, so the average one is more intuitive. So let's look at these. +[77.33s -> 85.74s] examples real quick. And for this sinusoidal waveform, what's the average value? +[86.29s -> 100.83s] Correct. For this one, it would be 0. So here, if you take the average here, it's 0, right? And what about this waveform? Probably close to 0, because we have some positives and some negatives, so the average value would be somewhere around 0. +[100.83s -> 102.77s] And what about for this one? +[103.09s -> 116.24s] Valerie says something's slightly positive. So somewhere in the middle here you'd have an average value. Okay, that's a very simple calculation for the average. So let's write that value out. +[116.69s -> 131.12s] For this class, we'll be using the notation of square brackets to mean the average value. V is actually V , so it's actually going to be this waveform. We're going to use voltage. You could also use current. +[131.31s -> 134.54s] And the average is simply going to be... +[135.06s -> 149.58s] the average value, also the mean value. So you're looking over one period here, and then you're going to take an integral from 0 to t, which is the time of the period, and you're simply going to take your +[149.58s -> 161.68s] value V and dt here. So you finish your integral and you divide by the time. So that's your average or mean value for your waveform. +[162.61s -> 174.27s] The second one is the root mean square. And first we're just going to define it. The name actually defines it. So it's the root of the mean of the square of a waveform. +[174.27s -> 181.36s] So let's start with the root part, the square root. Then we're going to take the mean. Mean and average are the same. +[181.62s -> 191.31s] Oh, and we're going to define this as a capital letter V for voltage. Okay, so now we take the mean, 1 over T. +[192.30s -> 203.18s] Integrate from 0 to t. And we're going to put something inside here. First I'm going to close the integral here. And we're going to do the square of our value. +[203.57s -> 216.02s] So here we're going to do V , and that quantity will be squared. So this is the definition of the root mean square value, the RMS value for a waveform. +[217.84s -> 231.76s] If we go back and look at these waveforms, essentially what you're doing is you're going to square them so all the negatives will become positive, and then you're going to take the average of that and then take the square root of it. +[231.98s -> 245.71s] So the RMS value of this waveform will not be zero. The average is zero, but the RMS value will be positive. Same for this one, it will be a little positive, and same for this as well. +[247.15s -> 252.34s] You can think of the root mean square value as the equivalent voltage +[252.69s -> 266.02s] For if you put this waveform or your waveform of choice over a resistor, so I'm gonna write this out in Equation form so this is the relationship between these two so you can think about power +[266.02s -> 276.69s] to a system over a resistor would be the voltage waveform squared over the resistor and if we were to take the average of these +[277.07s -> 289.01s] we get an average power out. And the root mean square is essentially the equivalent voltage squared here over the same resistor. +[289.30s -> 303.49s] So if we, our resistor is constant, so you can actually take that out of the average, so these would be able to cancel. And what you'd be left with is the average of V squared equals the RMS value +[303.49s -> 309.17s] squared. So there's an important relationship. This is always true. +[310.16s -> 324.27s] V squared here, so this is the time domain value squared, is equal to, average of the square is equal to the RMS value squared. This is true, a true relationship. +[325.10s -> 327.95s] Some students make this mistake. +[328.27s -> 341.62s] They will try to make these things equivalent. This is not true, not true, not true, not true. So this relationship is true based on the definition of the RMS value. +[341.81s -> 350.58s] in relation to the average, and this is not true. So do not try to make this relationship here. +[352.02s -> 365.78s] We talked about periodic waveforms, which are simply waveforms that repeat over multiple periods, and we gave some examples, and we defined the average or mean value using this equation. +[365.78s -> 380.08s] and the root mean square, or RMS value, using this equation. We talked about some relationships. If this isn't quite clear to you yet, don't worry. This is a statement you can rely on. +[380.08s -> 391.86s] This one actually is only true for DC values, but generally not true. And if you get confused, always go back to the original equation and it will help you understand the waveform. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_3.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7278c3dd99c50c86fb9327182409caed82901247 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_3.mp4.txt @@ -0,0 +1,52 @@ +[1.23s -> 15.52s] okay in today's video we're going to go over a circuit analysis for an r l circuit you can see we have an r as our resistor we have an l our inductor so we have an rl circuit and we have a d c voltage source and +[15.52s -> 22.51s] This is the circuit we're going to be using, 12 volts, 10k ohms, and a 100 henry inductor. +[22.80s -> 34.29s] And we're going to look at this circuit at two different time points. One, first of all, immediately after the switch is closed, and then after the switch has been closed. +[34.29s -> 46.61s] for a long time. But immediately after the switch has been closed, which we call time equals zero seconds, right when the switch is closed, not before the switch is closed, but right when the switch is closed, we want to know. +[46.61s -> 59.97s] What is the current through the circuit? What is the voltage across the resistor? And what is the voltage across the inductor? Okay, now you should remember, this is an RL circuit. Inductors resist. +[59.97s -> 74.19s] changes in current that's their job capacitors resist changes in voltage and inductors resist changes in current okay so when we first close the switch because that is the point +[74.19s -> 83.89s] when the inductor can give the most resistance to the current, then the current actually is zero when you close the switch, right when you close the switch. +[84.46s -> 96.32s] The current through the circuit is zero. And that's the current through the battery, through the resistor, through the inductor. It's a series circuit. So that's the current through the entire circuit. The current is zero. +[96.32s -> 110.13s] And we want to know what is the voltage across the resistor. Well, V equals I times our ohm's law. If there's no current, then there's no voltage across the resistor. So the voltage across the resistor is also zero. Not also zero, but is zero volts. +[110.13s -> 124.82s] But the switch is closed, and we have a 12-volt source. Well, if there's no volts across the resistor, then where is that 12 volts? Well, that 12 volts is across the inductor. So the voltage across the inductor, when we first close the circuit, +[125.55s -> 136.30s] is equal to the voltage of the battery and that's going to be 12 volts. Now the magnitude of the voltage is 12 volts. I put a negative sign here because it's self-induction so it's a +[136.30s -> 141.55s] polarity of the voltage is opposite that of the battery so this is not like it's less than zero +[141.81s -> 156.22s] Okay, it's not a vector. It's just 12 volts, but it's the polarity of the voltage is opposite that of the battery. Okay, so 0 amps, 0 volts, and 12 volts across the inductor, all the volts across the inductor. +[156.22s -> 170.18s] None of the voltage is across the resistor. So then, of course, we have the same circuit, but now it says after the switch has been closed for a long time. Now I say T equal infinity. Now it's not necessarily, it could be 10 seconds, could be 20 seconds, a minute. +[170.18s -> 173.58s] after the current has come to steady state. +[173.84s -> 188.05s] And after a long time, what is the current through the circuit? What is the voltage across the resistor? And what is the voltage across the inductor? Now remember, once again, inductors resist changing current. Now they can't resist that changing current forever. They can only do that. +[188.05s -> 202.11s] for a little time so the current increases so after a long time then the current through the circuit is going to be equal to the voltage divided by the resistance the voltage of the circuit divided by the total resistance and we only have one resistor +[202.11s -> 208.14s] So this is Ohm's law again, which is just solve for the current. And we know the voltage is 12 volts. +[208.50s -> 219.42s] the resistance of the resistor is 10k and that gives us 1.2 milliamps so after a long time after the current has come to a steady state then +[219.42s -> 224.21s] We have 1.2 milliamps of current flowing through the entire circuit like that. +[224.69s -> 237.15s] All right, and then so remember with zero now, it's 1.2 milliamps the voltage across the resistor the voltage across resistor is just Ohms law equals I times R so V +[237.15s -> 246.66s] The current is 1.2 milliamps. The resistance is 10k and that gives us 12 volts That means that all of the voltage is now across the resistor +[246.66s -> 259.15s] And because the inductor is no longer resisting the change in the current, basically acting like short, that means the voltage across the inductor is zero. As I said, after a long time, the coil... +[259.41s -> 273.38s] It's just acting like a short, or people say like a long wire, okay? But it's just a short. There's no resistance across, or there's no voltage across the inductor. All right? Now let's just summarize those two things. Summary. +[273.38s -> 287.18s] This is at time equals zero, and this is at time equals long time. Okay, at time equals zero, the current through the circuit is zero. That's when the inductor is offering its greatest resistance to change in the current. And after a long time... +[287.18s -> 300.78s] The current is equal to the voltage of the battery divided by the total resistance of the circuit, which in our case was 1.2 milliamps. So it goes from zero to its maximum. This is the maximum current. But the resistance across the... +[300.78s -> 314.66s] resistor is also zero, excuse me, the voltage across resistor is also zero because there's no current in vehicles. That times our Ohm's law, no current, no voltage. But then... +[314.66s -> 327.31s] At the end, after switching it in close for a long time, then all the voltage is across the resistor. It's the current times the resistance of the resistor. So from 0 to 12. +[327.50s -> 330.38s] And then as far as the inductor is concerned... +[331.22s -> 344.59s] When we first close the switch, all of the voltage is across the inductor. That means the voltage across the inductor is equal to the voltage of the battery. Then after a long time, when the inductor is no longer resisting changes to the current, +[344.59s -> 346.93s] than the voltage across the inductor. +[347.22s -> 360.32s] is zero volts, it should be zero volts, okay? So you can see we go from minimum to maximum, minimum to maximum, and then maximum to minimum. You can see that in these graphs, okay? This is a graph of the current. +[360.32s -> 369.65s] with respect to time. Now, this is time constants, which we're not talking about yet in this video, but I have that in my future videos or in my other videos. So this is basically time. +[369.65s -> 381.89s] and this is the current as a percentage of the eventual maximum so this is increasing current this is increasing time you can see over time the current starts at zero and increases to essentially it approaches a hundred percent +[381.89s -> 392.80s] Now, the same graph, you can show the same graph for the resistance across the resistor, because they're directly proportional to each other through Ohm's Law of V equals I times R. So this graph. +[392.80s -> 406.67s] It's for the current, but it could also be for the voltage across the resistor. Now, this is the graph for the voltage across the inductor. Once again, time and time constants of time increasing this way, and this is the voltage across the inductor. +[406.67s -> 418.94s] as a percentage of the original maximum voltage across the inductor you can see over time it goes to zero and approaches zero all right so the current increases to its maximum +[418.94s -> 425.07s] and the voltage decreases from its maximum to zero all right now we have one more +[425.33s -> 439.28s] Now you can kind of look at this circuit really quick. 24 volts, two resistors this time, one inductor, and we are going to answer all these questions. So you could, if you wanted to, you could stop the video, pause the video right now. +[439.44s -> 448.37s] Try and figure out what the current in the circuit is going to be, the voltage across the 5, the voltage across the 3, and the voltage across the inductor. Do that, answer those questions, and then... +[448.72s -> 462.58s] we'll come back now and i'll give you the answers see if you got them right okay it's kind of like a puzzle it's not a lot of math involved it's supposed to be just kind of a see if you have a conceptual understanding all right so once again when we first close the switch +[462.58s -> 475.89s] the current through the circuit is zero because the inductor is resisting the change in current. And if the current is zero, then the voltage across the five and the voltage across the three are also zero. +[475.89s -> 489.18s] Well, we do have a 24-volt source. If there's no voltage across the resistors, then where is that voltage? Well, that voltage is all across the inductor, and the voltage of the inductor is equal to the voltage of the battery. +[489.18s -> 503.25s] So the next one, after switching to close for a long time, we're going to basically answer the same questions. So you could now pause the video again, answer those questions, and then we'll come back in one second when you're done and show you the answers. +[504.02s -> 516.22s] Okay, now we're at the other end of the spectrum. The switch has been closed for a long time. What is the current through the circuit? Well, we have a 5 and a 3. That's an equivalent resistance of 8, a voltage source of... +[516.22s -> 525.33s] 24 the current is the voltage divided by the resistance and that means the total current the maximum current through the circuit after switching close a long time is three amps +[525.78s -> 540.03s] Well, what's the voltage across the 5? Well, the voltage is the current times resistance. Resistance is 5. The current is 3. That makes 15. What's the voltage across the 3? 3 times 3 is 9. You can see we have 15. +[540.03s -> 553.30s] across the 5, 9 across the 3, 9 plus 15 is 24, we have a 24 volt source and that means that all the volts are across the resistor and we know the inductor is no longer resisting. +[553.39s -> 566.26s] no longer resisting the change in the current after a long time, and therefore now the voltage across the inductor, as it acts like a short, simple wire, there's no voltage across the inductor. All right, so there you go. +[566.26s -> 574.54s] I just wanted to go over kind of a quick circuit analysis for an RL circuit. We'll do some more complicated circuits in the next videos. +[574.54s -> 588.67s] And thank you very much for watching. Hope you found that helpful. If you did, please do all the following three things. Subscribe to my channel, get all my excellent physics, chemistry, and math videos. Give me a thumbs up for this video and leave me a nice positive comment in the comment section below. Thank you very much for watching. We'll see you in the next. +[588.67s -> 589.68s] video. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_4.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..603a2927cacd0c9967c7242acb783835b1241614 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_4.mp4.txt @@ -0,0 +1,84 @@ +[12.30s -> 25.94s] Hey friends, welcome to the YouTube channel ALL ABOUT ELECTRONICS. So, in this video, we will learn about the voltage divider biasing configuration of the BJT. Now, if you have followed the previous videos on the BJT, +[25.94s -> 31.79s] Then we have already discussed about the fixed bias and the emitter bias configuration of the BJT. +[32.05s -> 44.86s] And we had also seen that in the fixed bias configuration, by connecting this emitter resistor, it is possible to stabilize the operating point against the variation in the β. And in fact, +[44.86s -> 58.19s] By properly selecting the values of this base and the emitter resistor, it is possible to make the operating point almost independent of the variation in the β. But in these configurations, we require the two power supplies. +[58.48s -> 72.11s] But instead of using the two power supplies, it is possible to derive this voltage source from this Vcc using the voltage divider circuit. And that is exactly what is done in this voltage divider passing configuration. +[72.37s -> 86.06s] Now, here as we are interested in the DC analysis, so for the DC analysis, all these capacitors will act as an open circuit. And if you see the equivalent circuit, then it can be represented as follows. +[86.06s -> 99.62s] Now, here what we will do, first of all we will do the approximate analysis and using that we will find the operating parameters. That means we will find the expressions for this collector current Ic. +[99.62s -> 101.90s] And the voltage VCE. +[102.70s -> 117.26s] So, during this approximate analysis, we will assume that this base current Ib is almost negligible. That means we will assume that this base current Ib is approximately equal to zero. And in that case, +[117.26s -> 129.84s] Almost entire current will flow through these two resistors, particularly through this branch. And in that case, by applying the voltage divider rule, we can find the voltage at this particular node. +[130.10s -> 142.88s] So, assuming Ib is equal to zero, if we see the equivalent circuit, then it will look like this. I mean, of course, here there will be a Thevenin's equivalent resistance because of this voltage divided circuit. But here, +[142.88s -> 152.88s] As we are assuming this Ib is equal to zero, so it won't make any difference. And we will see in detail about it, once we finish this approximate analysis. +[153.23s -> 166.90s] So, here this voltage VB can be given by this expression. And here voltage VE can be given as voltage VB minus VBE. +[168.50s -> 177.68s] And here this emitter current I can be given as voltage VE divided by RE. +[179.70s -> 189.68s] And here, the value of Ic is approximately equal to emitter current. That means this Ic is approximately equal to emitter current. +[190.16s -> 199.79s] So, once we know the value of this collector current, then we can easily find the voltage Vce. So, let's apply the KVL on this output side. +[200.05s -> 212.91s] So, applying the KVL, we can write voltage Vcc minus Ic times Rc, that means the voltage drop across this resistor minus Vce. +[213.97s -> 217.81s] minus v that is equal to zero. +[218.35s -> 232.88s] Or we can say that voltage Vce is equal to Vcc minus Ic times Rc minus Ie times Re. And here as we are assuming +[232.88s -> 246.90s] This Ic is approximately equal to emitter current. So, we can say that voltage Vce is equal to Vcc minus Ic times Re. +[247.18s -> 258.48s] So, in this way, using this approximate analysis, we can find the operating parameters. And if you notice over here, these expressions are independent of beta. +[258.51s -> 271.12s] That means if we can use this approximate analysis method for this voltage divider biasing configuration, then the operating point is independent of the variation in the β. Now, let's understand +[271.12s -> 279.54s] Under which condition we can use this approximate analysis. And for that, let's do the exact DC analysis of the given circuit. +[280.02s -> 294.18s] Now, if you see this circuit, then the same circuit can also be represented like this. Right? And if we focus on this portion of the circuit, then we can apply the voltage divider rule only if the same current is flowing through. +[294.18s -> 307.82s] both resistors. Or in other words, when these two resistors are connected in series. But if you notice over here at this node, this entire circuit is also connected. So, in that case, +[307.82s -> 318.35s] What we need to do? We need to find the Thevenin's equivalent of this particular circuit at this node. So, the same circuit can also be redrawn like this. +[318.70s -> 331.74s] And now, let's find the Thevenin sequent of this circuit while looking from this side. So, now to find the Thevenin sequent resistance, let's short this voltage source. And in that case, +[331.74s -> 345.33s] The Thevenin sequent resistance is the parallel combination of this R1 and R2. Similarly, the Thevenin sequent voltage can be given as R2 divided by Vcc. +[345.78s -> 359.65s] So, once we find the Thevenin's equivalent voltage and resistance, then the equivalent circuit will look like this. So, in this circuit, now let's find the expressions for the base current, the collector current and the voltage. +[359.65s -> 374.03s] And first of all, to find this base current, let's apply the KVL on this input side. So, applying the KVL, we can write +[374.03s -> 384.53s] Ib times Rth minus Vbe minus Ve that is equal to zero. That means +[384.82s -> 396.11s] Vth minus Vbe that is equal to Ib times Rth plus Ie times Re. +[396.46s -> 403.89s] Now, we know that this emitter current I can be given as β plus 1 times Ib. +[404.30s -> 416.40s] That means from this we can say that this Vth minus Vbe that is equal to Ib times Rth plus +[416.91s -> 430.29s] Or in other words, we can say that this base current Ib is equal to voltage Vth +[430.29s -> 443.44s] So, this will be the expression of the base current. +[443.73s -> 456.72s] And we know that the collector current Ic can be given as β times Ib. And here we are assuming that this emitter current is same as the collector current. +[456.94s -> 470.80s] So, once we know the value of this collector current, then we can easily find the voltage Vce. And the voltage Vce can be given by the same expression. That means voltage Vce is equal to Vcc. +[470.80s -> 483.41s] So, these are the expressions of the operating parameters using the exit analysis. Now here, +[483.41s -> 497.74s] This emitter current I can be given as voltage Vth minus Vbe divided by Rth divided by β plus 1 plus Re. +[498.70s -> 504.30s] So, if we solve this expression for the emitter current, then we will get this expression. +[504.69s -> 519.07s] Now, in this case, if this first term is very small, then the expression of the emitter current is the same as the expression which we have derived using the approximate analysis. And in fact, under this condition, +[519.07s -> 532.94s] The emitter current is almost independent of the value of β. That means whenever this Rth divided by β plus 1 is very small compared to this emitter resistor +[532.94s -> 546.78s] Or in other words, whenever this Rth is much smaller than the β plus 1 times Re, in that case, we can use the approximate analysis. And in fact, in that condition, the operating point +[546.78s -> 550.16s] would be almost independent to the variation in beta. +[550.64s -> 564.37s] Now, practically, the value of this Thevenin's equivalent resistance should be at least 100 times less than this term. That means the value of Rth should be less than or equal to 0.01 times +[564.37s -> 567.18s] beta plus 1 times Re. +[567.47s -> 581.55s] But sometimes, it is not feasible to follow the criteria as with that criteria, the value of R1 and R2 would become very small. So, for relatively stable operating point, the value of this Thevenin sequence resistance +[581.55s -> 590.58s] should be at least 10 times smaller than this term. And if this condition is satisfied, then still we can use the approximate analysis. +[591.02s -> 603.34s] So, let's take one example and let's see in this voltage divider biasing configuration, how the operating point changes if there is a variation in the bit-term. And during the analysis, +[603.34s -> 614.66s] we will use the exact analysis method. So, here first of all let's find the Thevenin's equivalent voltage and the resistance. So, the Thevenin's equivalent voltage Vth can be given as +[614.66s -> 626.96s] R2 divided by R1 plus R2 times Vcc. That means over here, it is equal to +[627.47s -> 641.10s] That is equal to 2V. And if you see the Thevenin's equivalent resistance, then it is equal to R1 parallel R2. That is equal to +[641.78s -> 654.90s] 2 kΩ in parallel with 10 kΩ. That is equal to 1.66 kΩ. So, now if we see the Thevenin's equivalent circuit, then it will look like this. +[655.38s -> 669.36s] Now, here β is equal to 50. That means over here, β plus 1 times Re is equal to 51 kΩ. And here, the value of Rth is equal to 1.5. +[669.36s -> 677.55s] That means here, this value of Rth is almost 30 times less than this term. +[677.84s -> 692.50s] That means even if there is a variation in the β, the operating point should relatively remain stable. But let's find out the exact numbers. So, first of all, using this expression, let's find the base current. +[692.72s -> 706.80s] So, the base current Ib can be given as 2V-0.7V divided by 1.66kΩ plus 51 times 1kΩ. +[707.98s -> 720.88s] That means the value of the base current Ib is equal to 1.3 V divided by 52.6 kΩ. That is equal to 24.6 µA. +[721.07s -> 734.22s] And the collector current Ic can be given as β times Ib. That means this collector current Ic is equal to 50 times 24.68 uA. +[734.35s -> 748.56s] That means the collector current Ic is equal to 1.234 mA. And once we know the value of this collector current, then this voltage Vce can be given by this expression. +[748.94s -> 761.39s] That means voltage VCE is equal to 12V minus 1.234 mA times 3.6kOhm plus 1kOhm. +[762.38s -> 777.04s] That means the voltage we see is equal to 12V minus 1.234 times 4.6kΩ. That means the voltage we see is equal to 6.32V. +[777.36s -> 787.92s] So, if we see the operating point, then it would be somewhere around here. Because here the value of Ic is equal to 1.234 mA. +[789.74s -> 794.80s] While the value of VCE is equal to 6.32V. +[795.06s -> 809.36s] And for this particular case, the maximum value of the collector current would be equal to 12 V divided by 4.6 kΩ. That is roughly equal to 2.6 mA. And the maximum value of the VCE +[809.36s -> 821.71s] is equal to 12V. That means roughly the operating point would be somewhere around here. Now, let's see how the operating point changes when the value of β becomes 100. +[822.00s -> 835.68s] So, here the Thevenin sequent resistance as well as the Thevenin sequent voltage will still remain same. That means voltage Vth is equal to 2V and the value of Rth is equal to 1 point. +[835.68s -> 849.68s] But in this case, as the value of β has changed, so this base current Ib will also change. So, in this case, now the base current Ib can be given as +[850.00s -> 861.74s] 2V minus 0.7V divided by 1.66kΩ plus 101 times 1kΩ. +[862.83s -> 870.54s] So, if we calculate the value, then this base current Ib is equal to 12.66 uA. +[871.31s -> 885.14s] And the collector current Ic is equal to β times Ib. That means this collector current Ic is equal to 100 times 12.66 uA. That is equal to +[885.14s -> 887.09s] 266 mA. +[887.89s -> 902.40s] And from this, we can find the value of the voltage Vce. That means voltage Vce is equal to +[902.40s -> 913.38s] That means voltage Pc is equal to 6.174V. So, now with the value of β is equal to 100, +[913.38s -> 921.90s] The value of VCE is equal to 6.174 V, while the value of this collector current IC is equal to 1.26 mA. +[922.35s -> 936.53s] So, now if we see the operating point, then it would be somewhere around here. Because now, the correct current Ic is equal to 1.266 mA, while the voltage Vce is equal to 6.17 V. +[936.56s -> 949.98s] So, as you can see, there is only marginal change in the operating point when the β has increased by 100%. That means whenever this Thevenin's equivalent resistance is less than or equal to +[949.98s -> 957.87s] 10 times β plus 1 times this emitter resistance, then there is only marginal change in the operating point. +[958.26s -> 971.89s] And here, while considering this condition, we should consider the minimum value of the β for the given transistor. And if this condition is satisfied, then we can even use the approximate analysis for finding the +[971.89s -> 983.31s] operating point. So, for the same example, use the approximate analysis and do let me know the value of voltage Vce and the Ic. And very soon... +[983.31s -> 989.20s] We will also see few more examples on this voltage divider biasing configuration on our second channel. +[989.49s -> 998.53s] But I hope in this video, you understood what is voltage divider biasing configuration of the BJT. So, if you have any question or suggestion, +[998.53s -> 1005.71s] Do let me know here in the comment section below. If you like this video, hit the like button and subscribe to the channel for more such videos. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_5.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..906caa0f7d2e703132ccb0e142691e6429b931b0 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_5.mp4.txt @@ -0,0 +1,52 @@ +[0.24s -> 11.50s] Ok, Assalamualaikum class. Bismillahirrahmanirrahim. So now let's see how we are going to derive the output resistance of the common collector amplifier. Ok. +[11.50s -> 19.47s] Jadi, seperti yang kita lihat di sini, ini adalah ekvivalen AC tanda kecil untuk amplifier kolektor biasa. +[19.76s -> 28.37s] Okay, what is the difference between the common emitter and the common collector? Your equivalent circuit for the common collector will remain. +[28.37s -> 38.82s] anda tidak melakukan perubahan betul, jadi kita mempunyai beberapa elemen di sini kiri dan di bawah tetapi untuk pengumpulan komen anda melakukan perubahan di +[38.82s -> 51.15s] So, during your common emitter, what is your Rout? Your Rout is only until here only. So, whatever you have run. +[51.15s -> 63.79s] semasa derivasi keuntungan, iaitu Rout. Tetapi untuk ampu kolektor biasa anda, sebab sirkul itu dipindahkan, anda akan pindahkan dari C ke E menjadi E ke C. +[63.79s -> 70.10s] semasa real anda keluar, anda perlu mempertimbangkan seluruh segi. +[70.10s -> 81.36s] Okay, so now what we want to do is we want to derive what is the real output resistance for the common collector amplifier. Again, for your common emitter, what is your Rout? +[81.36s -> 94.83s] hanya di antara C dengan E, apa sahaja resistan yang anda ada di sini, anda akan menggabungkannya tetapi berbeza daripada kolektor biasa anda kerana anda melakukan swapping, jadi resistan output kolektor biasa anda akan berbeza +[95.18s -> 108.10s] So, now what you need to do is you need to introduce what we call imaginary voltage source and also you are going to introduce imaginary current source. So, +[108.10s -> 118.90s] Apabila anda mahu memperkenalkan sumber voltage dan sumber current pada output, anda akan menyalakan sumber input di sini, jadi membuatnya pendek. +[118.96s -> 128.45s] Okey dan RS anda akan sentiasa sama dengan 0 untuk memperlembabkan derivasi dan seterusnya anda akan memperkenalkan di sini +[128.45s -> 141.82s] apa yang kita panggil VX IMAGINARY dan di mana IX ialah current yang berjalan melalui VX jadi bagaimana ciri-ciri ini jadi sumber anda di sini akan menjadi ciri-ciri pendek +[141.82s -> 150.61s] Ini adalah pembentukan sumber voltage imaginari. Di sumber voltage imaginari, ada sumber cairan. +[150.96s -> 164.91s] And you're going to assume your RS here will be 0. Means this will be a short circuit. Okay. Next, how you're going to find R out? This is what you want to derive. So, according to the Ohm's law, V equal. +[164.91s -> 174.83s] R equal V over I. So it become R naught equal VX over IX. So what you want to do now. +[174.83s -> 181.20s] We are going to derive the current Ix by using KCL. +[182.03s -> 196.35s] Ok, so let's see the same circuits. So, imagine here this will be I1. Here will be I2. Here will be I3. And here will be I4. Ok, now. +[196.35s -> 207.10s] Oleh kerana kita mempunyai jaringan pendek di sini, sebelumnya kita mempunyai sumber voltage tetapi kita akan menyalakan dan mempunyai jaringan pendek di sini jadi +[207.10s -> 219.33s] Di antara ini dan ini, apa yang akan berlaku? Oleh kerana cahaya akan berjalan melalui kawasan pendek, tidak akan ada cahaya yang berjalan melalui R1 bergantung dengan R2. +[219.33s -> 234.06s] so if you redraw the circuits you move this r pi down so it will be here v pi you become minus and plus okay and r1 r2 will be gone +[234.93s -> 247.31s] So, here is R by. Okay. And next, you have a current source. Next, you have R out. R E. +[248.11s -> 261.73s] Dan yang terakhir, anda mempunyai sumber volta imajinal. Okey. Jadi, apa yang anda perlu lakukan sekarang? Anda lakukan kes ini. Jadi, peluang current di sini adalah sama dengan peluang current keluar. +[261.73s -> 270.42s] Jadi, kita mempunyai berapa banyak garis untuk dikeluarkan? I1, I2, I3 dan I4. +[270.90s -> 284.96s] So, just repeat it here. So, this is the short circuit. So, this one will be ignored. There are no more R1 and R2. So, when I redraw this one, here become V pi. This is minus, right? You move this one down. +[284.96s -> 298.22s] kemudian kemudian kemudian kemudian kemudian kemudian kemudian kemudian +[298.77s -> 300.34s] Re. +[301.04s -> 314.51s] dan kita akan memperkenalkan sumber imajinasi voltas di sini yang dipanggil Vx. Perkembangan sekarang di sini adalah Ix. Sekarang kita mahu mengukur apa adalah Rout yang terlihat dari sini. +[314.51s -> 328.85s] Jadi, kita akan menentukan keadaan. Ini adalah I1, I2, I3 dan I4. Sekarang, berdasarkan KCL, apa adalah peluang keadaan E? Ix. +[329.01s -> 342.78s] Jadi, anda boleh lihat di sini, ini adalah Ix. Colour flowing out adalah I1, I2, I3 dan I4, betul? Jadi, berdasarkan KCL, Ix adalah +[342.78s -> 355.87s] Current entering equal current. Current leaving. So, we have 4 current leaving. Now, let's define Y1. I1. What is I1? Omsler say I equal V over R. +[355.87s -> 367.62s] Jadi, semua 4 elemen ini adalah paralel. Jadi, apabila voltage di sini, di sini juga akan Vx, Vx, Vx dan Vx. +[367.62s -> 379.41s] So, ohm's law say I equal V over R. So, you can VX over RE plus VX over R out plus +[380.46s -> 394.30s] Sekarang, ini adalah sebaliknya, kan? Kita akan mengembalikan, tetapi cahaya mengembalikan. Jadi, ia menjadi minus g dan v pi. Okey. Dan sekali lagi, jika kita katakan di sini vx, +[394.30s -> 402.61s] VX over R. Okay. Now, what is the relation between VX and V pi? +[403.31s -> 415.79s] Semua di sini adalah vx tetapi v pi adalah minus plus dan vx adalah plus minus. Jadi hubungan sebenarnya adalah v pi adalah minus vx. Jadi tujuan anda sekarang. +[415.79s -> 423.63s] You are going to derive R out. Also say R equal V over I. So what is the R out here? +[424.72s -> 438.90s] Okay, so here we have your R out. You want to derive your R out, right? So, now your R out is actually Vx over Ix. Okay, so now you're going to eliminate the V pi here. +[438.90s -> 446.72s] So, we have how many V pi? Only one. So, become Vx over Re plus Vx over Rr. +[446.72s -> 458.38s] So, what is the relation between Vx and Vpi? It's minus. So, when you change it become plus Vx plus Vx over Rpi. So, this is Ix. +[458.38s -> 472.11s] So, if you remove, you take out your VX, VX will become 1 over RE plus 1 over RR plus GM plus 1 over. +[472.11s -> 485.84s] R pi. So, this is Ix. So, now what is R out? R out is Vx over Ix. We can define as 1 over R out is equal Ix over +[485.84s -> 497.70s] Vx. Okay, from this equation, so if you move your Vx down, so it become 1 over Rr is actually Ix over +[497.70s -> 511.44s] Vx. So, you just move this Vx to the other side and then you can get 1 over Re plus 1 over Ru plus Gm plus 1 over Ru. +[511.44s -> 525.46s] Okay, looking at this equation here, what is the parallel equation? If you have two resistor in parallel, you know that the equation of R equivalent, let's say this is R1, this is R2. +[525.55s -> 537.33s] Okey, kita mempunyai 1 over R1 plus 1 over R2. Dari ekwasi paralel ini, kita boleh menjelaskan bahawa RR adalah sebenarnya +[537.33s -> 550.45s] Re, because it's having the same pattern, right? 1 over, 1 over. Parallel to R up. Parallel to 1 over Gm. Parallel to R pi. +[553.46s -> 565.94s] So, the equation will be the same like just now. 1 over gm parallel to re, parallel to r up, parallel to i pi. So, this will be the real output resistor for the common collector amplifier. +[565.94s -> 575.41s] Or you can present it in different way. But if you stop under here, you still can get the same answer. So, for example, the question we see. +[575.41s -> 587.90s] Calculate the output resistance of the emitter follower. So why we call this one emitter follower? For the common collector, this is another name for the common collector that is emitter follower. Okay. +[587.90s -> 600.69s] Kerana penggunaan selalunya hampir satu. Jadi, anda hanya ikut apa-apa input dan berikan output. Jadi, saya berikan semua yang tidak diketahui di sini. R pi, R0 dan Re. Sama ada anda mahu menggunakan formula ini. +[600.69s -> 615.22s] Atau anda gunakan formula yang lain. 1 over gm. Parallel to r pi. Parallel to re. Parallel to r out. Like I show before. Okay. And then you can get the final output. Resistance. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_6.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fb9d599067777660d518b14d011441f0133ab873 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_6.mp4.txt @@ -0,0 +1,32 @@ +[0.00s -> 14.51s] In this video, I'm going to analyze this AC circuit to determine the voltage across and the current through every component. Now this is a circuit with a combination of parallel and series components, so there will be a few more steps in this circuit analysis than there were with a purely series and +[14.51s -> 25.46s] and purely parallel circuits. The general strategy that I'm going to take is to start by combining components to create an equivalent circuit and continue combining components until circuit is one equivalent component. +[25.46s -> 39.73s] Then calculate voltage and current for the circuit with one equivalent component. And then finally, expand the circuit back out, calculating voltage and current for the components or the groups of components as I go until I've done this for every component in the circuit. So more specifically to the circuit. +[39.73s -> 53.94s] that I'm analyzing I'm going to start by determining the impedances of each of the components here then begin combining components to create equivalent circuits. So to start I will take this inductor and capacitor combine them together to create this equivalent circuit then +[53.94s -> 68.14s] Then take these two components, combine them together to create this equivalent circuit. Then combine these two components together to create this equivalent circuit with a single equivalent impedance. Then I can calculate the current in the circuit and use +[68.14s -> 82.35s] that information to go back to the previous equivalent circuit to calculate voltage and currents and continue until I am back to the original circuit and have all the voltages and currents calculated. Now here we are with the circuit and I'll start by calculating the impedances. +[82.35s -> 96.38s] all the components. Now I should note that for some of the calculations I am going to fast forward through them so if you need to see exactly what I'm doing for each step then you can pause the video whenever you need to. Okay let's start with the capacitor. +[96.38s -> 102.03s] The reactance of the capacitor, capacitor 1, is 1 over 2 pi fc. +[106.16s -> 112.78s] The reactance of capacitor 2 has the same equation, but it is a 1.5 microfarad capacitor. +[116.46s -> 125.23s] And the reactance of the inductor is 2 pi FL, frequency of 60 Hz, inductance of 650 mH. +[128.62s -> 137.20s] And now I can take all of these reactances and write them out as impedances. So include the phase shifts that the components will introduce. +[146.42s -> 160.48s] And now I'll do the calculation for the first equivalent circuit. So this is combining these two components together to give me this equivalent component. So that ZL1 or ZL1 plus ZC2. +[160.48s -> 168.66s] That's equal to J245.04 ohms minus J1768.4 ohms. +[175.41s -> 189.31s] So the effect of adding the impedance of the inductor plus the impedance of the capacitor gives us something that looks like a capacitor because it's introducing this phase angle of minus 90 degrees or it's got a negative J component. +[189.31s -> 202.38s] The next thing to do is combine these two components together into this one equivalent component. So we've got R2 in parallel with the series combination of inductor 1 and capacitor 2. +[212.40s -> 226.77s] Now I'll convert this value that's in rectangular coordinates into polar coordinates. I won't go through all the steps, I'm just going to give you the value. And then take the inverse of that number to give me the final impedance. +[230.22s -> 243.28s] Now finally, let's make this third equivalent circuit where we have reduced this circuit down to one equivalent impedance by adding this capacitor 1, the impedance of capacitor 1, to this combined impedance that we've just calculated. +[253.55s -> 266.35s] Okay, now we've got that total impedance calculated, and we've got it shown here in rectangular as well as polar coordinates. And now that we have the total impedance calculated, we can now calculate the total current. +[274.29s -> 283.42s] Now working backwards from this third equivalent circuit to the second equivalent circuit IT goes through both of these components +[283.42s -> 291.22s] So we can use that IT value to calculate the voltage across capacitor 1 as well as the voltage across this combination of components here. +[294.00s -> 306.99s] So that calculation is the current through capacitor 1 times the impedance of capacitor 1. And in rectangular coordinates, that is... +[310.16s -> 316.24s] And we can do the same basic calculation for the voltage across this combination of components. +[326.61s -> 341.09s] The value that I need now, going back a step from this second equivalent circuit to this first equivalent circuit, is the voltage across this combination of components, the combination of R1 in parallel with L1 plus C2. +[341.09s -> 352.46s] Since those components are in parallel, the voltage that I've just calculated here is the same as the voltage across L1 plus C2, as well as the voltage across resistor 2. +[352.46s -> 359.73s] Although I just noticed now that that should be resistor one, shouldn't it? So I can use that voltage to calculate the current through each one of these two components. +[366.10s -> 378.80s] So that is that current there. Next I can calculate this current here. So that, like I said, that should be R1. So it's the same voltage divided by the impedance of the resistor. +[381.52s -> 396.10s] Now the last two values that I need are the voltage across inductor 1 and the voltage across capacitor 2. And I can use this current that I've just calculated along with the impedance of capacitor 2 and inductor 1 to calculate those voltages. +[396.10s -> 410.16s] and then i'm done and the voltage across the capacitor same calculation current times the impedance of the capacitor +[416.02s -> 430.29s] And that's it. That was the last calculation. Now here's the table with all the values. So in the table, we have the voltages, the currents, and the impedances for all of the components, C1, the inductor, C2. +[430.29s -> 440.30s] the resistor, as well as the totals. Now this table and example problem came from a free open source textbook, and you can find the link to the problem in the description. +[440.30s -> 453.68s] That website covers AC circuits, DC circuits, communication systems, and if you're lucky enough to be viewing this video far enough into the future from when I created it, it will also cover electronic circuits and digital electronics too. +[453.90s -> 458.35s] As always, thank you so much for watching. I'll see you in the next video. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_7.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e53d8609995c1eb8bc482908065138b51e73bc7c --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_7.mp4.txt @@ -0,0 +1,113 @@ +[1.17s -> 15.76s] Hello, I'm Jason. Welcome to this lesson of the AC Analysis Tutor. What we're going to do now is pick it up from the last section. We had a general overview of what alternating current is. We said that alternating current literally comes out and in and then out the other way. +[15.76s -> 29.97s] back in literally switches direction so many times per second for a wall socket at 60 Hertz or 60 times per second but we're going to study in our circuits many many different frequencies and so all of the techniques we're going to use +[29.97s -> 42.80s] applicable to any problem that you have. But before you go any further, I want to give a little bit of review of trigonometry. Not a long review. I think you really need to have some skills from back then, but I do want to take a few seconds. +[42.80s -> 54.82s] to show you something because it is going to tie in. So let's look at the plot of sine of theta, right? +[54.82s -> 67.09s] Theta remember is just an angle so you can represent angles in degrees 360 degrees in a circle, right? You can also express an angle in radians. There are two pi radians in a circle +[67.09s -> 76.88s] Right, so it's a conversion factor 360 degrees in a circle 2 pi radians also in a circle. So here is a sign of +[76.88s -> 85.97s] theta plotted against theta. Now, I'm not going to be exact with this. The point of this is not to be exact here. But what I want to do... +[86.26s -> 98.42s] is just kind of show you what it generally looks like because you kind of need to have this in your head a little bit. I think it's helpful. Sine functions, just plain sines, sine waves, however you want to look at it, pretty much... +[98.67s -> 110.83s] look like this. They start at the origin. That's where it starts. It goes up and then down and then up and then down and then up. +[110.83s -> 117.20s] And then down. Notice my little marks. I'm trying to evenly space them out. That's a pretty decent looking sign. +[117.20s -> 129.09s] There and the thing that you need to remember a couple things I want you to remember is that it starts at the origin So the starting point starts at the origin and it goes up to plus one and this goes to minus +[129.09s -> 136.82s] So that's what a sine looks like. Now, what are we plotting against? We're plotting against angles. So all you're doing is you're putting an angle in here. +[136.82s -> 147.28s] In circuit analysis, believe it or not, you deal with degrees sometimes and you deal with radians other times. So it's important that you have some familiarity with degrees and radians. I already talked about that a little bit. +[147.28s -> 161.58s] Basically, you're plotting the angle in here, and you're getting the sine function as a result of that angle. So it goes up, it goes through zero, it goes to negative, it goes through zero, and you can see it's cyclic. It just keeps kind of doing the same thing over and over and over again forever. +[161.58s -> 168.43s] Basically. Now, if we wanted to compare that with cosine of theta. +[168.46s -> 181.42s] it would look similar, but there's an important difference. And the reason I want to show you this, even though you probably already know this a lot of you guys, I want to show you this because it is going to be helpful for you later. So let me put my little... +[181.42s -> 194.45s] Marks here as best I can. I'm not trying to be too terribly exact. Cosines do not start at the origin. Cosines start right here. So if you had to do that, cosine would come down here. +[194.90s -> 199.79s] Like this and then it would be up like that reach a peak like that +[200.78s -> 212.67s] OK? Something like that. All right? So when you look at this here, the maximum that the cosine gets to is plus 1, and the minimum that it gets to over here is minus 1. +[212.67s -> 221.81s] So I want you to stare at these and remember that I'm not an artist, so they don't look exactly perfectly right, but they get the point across for what I'm trying to show. +[222.10s -> 233.98s] First thing is I want you to know that both of these functions sine and cosine have a maximum value of 1 and a minimum value of minus 1. So the extent of the height of the function is always plus or minus 1. +[233.98s -> 248.27s] for sine and cosine. The other thing I want you to remember is that the shape of these guys look identical. If I took away the black axis, right, and just had these red things on the board, they would look the same. The shape of the waves look identical to one. +[248.27s -> 254.38s] and other, sines and cosines. So what's the difference between them? Well, the difference really is the starting point right there. +[254.58s -> 269.17s] Here we start at the origin here we start at the maximum so if you use your imagination If I could like grab this sign if I could just grab the red part leave the axis alone if I could just grab the red part and Pull it this way so that the maximum here +[269.17s -> 281.17s] up here then this would exactly equal a cosine so if I could say that again if I could grab this sine wave here and just literally pull it over a little bit then +[281.17s -> 291.28s] they would match up and overlay exactly with this or you can think of it another way i could grab this cosine because don't forget the cosine even though i've stopped it here it continues on +[291.28s -> 305.76s] on the other side of the origin as well. If I could grab this and pull it this way, like this, so that this ends up here, if you can use your imagination, then this again would look exactly like that. So why am I going through all this trouble to explain? +[305.76s -> 318.03s] The sine and cosine. The thing is, they have the same amplitude, same height. They have the same shape. The only difference between a sine and a cosine is that they're shifted versions of one another. I'm going to say that again. +[318.03s -> 332.02s] Because a lot of people, when they study trig, they just learn that sine and cosine is a button on the calculator. And it is a button on the calculator. But fundamentally, they are the same thing. The exact same thing. They're just shifted versions of each other. +[332.11s -> 347.10s] I'm not going to talk much more about that here, but I just need you to believe me there that they're shifted versions of one another. The reason I'm telling you this is because we said that when we're doing alternating current, we're going to be exclusively really studying sinusoidal stuff. +[347.10s -> 361.46s] Sinusoids, meaning I'm going to have a voltage source that's going to look like a sinusoid, and I want to see what's the current and the voltage in the circuit. I'm going to have a sinusoidal current, and I'm going to want to calculate something else in the circuit. And what we're going to find is if the circuit... +[361.46s -> 375.66s] is driven by a sinusoid, then all the other stuff in the circuit, all the voltages and the currents everywhere else, they're also behaving like sinusoids. They may be shifted with respect to one another, but they're all gonna look like sinusoids. They may have different heights and stuff, but they're gonna have... +[375.66s -> 389.87s] of the same overall basic shape. But whenever we're trying to figure out how to write these things down mathematically, we've got to figure out, do we want to represent our voltages as sines or as cosines? Because they really are the same thing. +[389.87s -> 404.08s] engineering text we're going to use the cosine function to represent and write down all of our voltages currents and everything else so keep that in mind we're going to use the cosine function to represent voltages and currents throughout our circuit but it's really no different +[404.08s -> 417.20s] than using sine. The bath would look a little different because they are very similar except for the shift between them. Just kind of keep that in mind. So if you ever wonder why are we using cosines instead of sines, there's no real reason. It's just we do that by convention. +[417.62s -> 427.84s] All right, so we choose a cosine function. If we had chosen a sine function to represent our voltage, it would look very similar. It would be a shifted version. +[427.84s -> 441.28s] But let me show you what a voltage would look like in terms of mathematical. We've drawn it. That's a cosine over there. But let's write it down. So you might have a voltage that's v of t. +[441.28s -> 455.34s] Notice that voltage is now a function of time because it's changing with time. It might look something like this. Capital V sub m cosine omega, I'll talk about that in a minute, t plus phi. +[455.63s -> 470.13s] This is what a typical voltage is going to look like in electrical engineering. It carries all the information to describe what the sinusoid looks like. So think about the things you need to know. When you're building a circuit or you're analyzing a circuit that's AC, +[470.13s -> 481.04s] You're going to want to know how tall is that sine wave if you're talking about the source I'm talking about the voltage source of driving the circuit You might want to know how tall that thing is the amplitude. We'll talk about that in a minute +[481.04s -> 493.97s] And that's represented up here. You might want to know the frequency. How fast is it oscillating back and forth? We'd say that the wall socket's 60 hertz, but our circuit may be 500 hertz or 1,000 hertz or something like this. +[494.06s -> 508.56s] And we also have something called a phase angle we'll talk about a little bit later. So let's analyze this and just see what the parts of this really looks like, see if we can make some sense of it. The number is called Vm, V maximum, that sits out in front of the cosine. +[509.10s -> 522.83s] That is called the amplitude. That's the amplitude. This is the height of the signal, the height of the cosine. This guy is, of course, cosine, and this varies. +[524.62s -> 538.45s] between Plus and minus 1 because the cosine only goes plus and minus 1 remember that This guy is called the angular frequency +[540.88s -> 552.58s] I'll explain why in a minute, but basically it's, you know, we talk about 60 hertz, that's 60 times per second. This is basically very, very closely related to hertz, and I'll explain. +[552.58s -> 566.93s] what it is in just a second. But basically, it's the frequency of your cosine. It's telling you how fast is it oscillating, how many times per second you can kind of gather by looking at this and converting it to regular old frequency. Don't worry too much about what it says angular frequency. +[566.93s -> 573.62s] explain that a little bit later. This last part is called the phase angle. +[574.74s -> 585.92s] And the phase angle I kind of actually introduced to you a minute ago without you realizing it. You can take these functions and shift them around left and right. And so the phase angle is telling you where you start measuring from. +[585.92s -> 592.98s] basically and i'll draw you a picture and show you that in just a minute but every part of this is in +[592.98s -> 607.57s] equally important to characterize what our voltage source looks like. The cosine, it gives you the shape. It's sinusoid, right? It varies between plus or minus one. So this entire thing inside of the cosine just basically governs how the cosine is going to look. +[607.57s -> 621.84s] frequency here is how fast it's oscillating the phase angle is telling us how we're dragging it left and right right and the VM on the outside because remember the cosine only goes between plus or minus one whatever numbers out here is going to govern the actual amplitude +[621.84s -> 635.47s] you know maybe it's a 50 volt source that means 50 would be out in front and the cosine is making it dive up and down between plus or minus 50 because this goes between plus or minus one if this were 50 that would be driving the overall amplitude +[635.47s -> 644.34s] But enough of that. A picture is worth a thousand words, and so we're going to draw a picture here to try to illustrate what we're talking about here. So here is... +[644.78s -> 653.07s] a plot of time in seconds, like this, seconds. And then we're gonna have volts. +[653.46s -> 660.53s] We want to basically plot the function that we have put on the board here and see if we can get some information out of it. +[660.85s -> 671.63s] First of all, this is a cosine, right? Cosines start at the top, and I'm not going to draw it too perfectly, but basically cosines look like this. +[672.05s -> 679.84s] And they just go on and on and on forever. Equally spaced crossings, equally spaced peaks and troughs, and so on. +[679.84s -> 692.77s] We're looking at just the raw cosine function. We said it varies between plus or minus 1, but we have a coefficient out in front of it. And so that means that this varies between vm and over here minus vm. +[692.77s -> 700.53s] So positive and negative bm. So what we have here, this is called the amplitude. +[701.14s -> 712.42s] Amplitude, when you think of the word amplitude, it means maybe the strength of something or the height of something. That's what amplitude means. High amplitude means something that's tall maybe, something like that, or something that's loud. +[712.42s -> 726.78s] Well, here it means the height of your source. And now I'm talking about volt. I'm treating this as if it were a voltage source. And all the DC analysis is just a steady 5 volt. That's boring. Now everything's going to be changing with a cosine. +[726.78s -> 736.78s] The height of that guy, whether it's 5 volts or 10 volts or 95 volts or 1,000 volts, is going to be governed by this number out in front called the amplitude. That's what that is. +[737.10s -> 750.62s] All right. And the other thing here, when you look here, you can see where the signal here, I should say the source, you can see where it starts to repeat. If you look here. +[750.62s -> 752.43s] Between this point... +[752.94s -> 767.47s] And this point right here, notice everything starts over. Here you go from here to the bottom to the bottom. Everything starts over. So this is called one complete cycle or one complete period. So what we have is T is equal to the period. +[768.43s -> 783.02s] and that means you repeat, right? You repeat. All right, so I want to write a few things down underneath here that we're going to be drawing upon as we learn about this stuff. +[783.28s -> 790.16s] And the first one is, let me kind of draw a little divider line here. First thing we want to talk about is the frequency. +[793.33s -> 805.71s] When you look at the word frequency, it means how much does something oscillate. That's what the word frequency means. In electrical engineering, the frequency is 1 over the period. +[805.71s -> 819.95s] When you talk about the period of this guy, the period is going to be in seconds. So you may plot this and I may say, hey, the period of this wave is half a second. That basically means that it starts to repeat itself after half a second. That's called the period. +[819.95s -> 834.27s] If I take one over the period, then I'm going to end up with another unit called Hertz, which means cycles per second. How many times does the thing do complete oscillation in one single second? So this F here. +[834.27s -> 848.85s] This is the 60 hertz that we're talking about in the wall socket. That's the F. That's the frequency or the amount of cycles per second there. So the unit here for frequency is hertz, which is cycles. +[849.36s -> 853.33s] per second. How many cycles per second is this wave doing? +[854.13s -> 868.30s] Now notice that we did not use this frequency up here. We use something different called Omega It's like a little W here and I called it an angular frequency and I told you yeah, it's kind of a frequency But it's a little different. I'll explain later. Well now I'm going to explain it to you +[868.30s -> 882.98s] What we have here is, I'll write it down here, angular frequency. Omega is directly related to the regular frequency. +[882.98s -> 896.02s] by 2 times pi times f. In fact, this I want you to remember. I don't tell you to memorize too many things in any of my classes, but one of them is this. Omega is 2 pi f. Omega is 2 pi f. Omega is 2 pi f. +[896.02s -> 903.63s] Omega is 2 pi f. I want you to say it because you're going to need to convert back and forth a lot. You need to remember that omega is 2 pi f. +[903.66s -> 917.02s] Right? Now, what would the units of this be? Since this is cycles per second, and here we have kind of an angle in radians, two pi radians in a circle, what you get here, I'll go ahead and use the red here. +[917.02s -> 931.79s] The units is radians per second. That is the unit of angular frequency. So I want to take just a second to kind of make sure everybody understands that. +[932.24s -> 942.27s] I want to make sure everybody understands that. When we talk about things that repeat, there's kind of two ways, especially in terms of sinusoids. There's two ways to look at it. +[942.27s -> 956.05s] One is to go figure out the frequency. That's how many cycles per second the thing is changing. And the other is to talk about the angular frequency, which is how many radians per second the thing is changing, right? They both kind of mean the same thing. +[956.05s -> 958.78s] If you have a higher frequency, it's changing faster. +[958.78s -> 973.07s] If you have a higher angular frequency, the thing is changing faster. In fact, they're actually related directly by just a constant here. So really, f and omega are really the same thing. They're just related by a constant. So why do we even do that? Why don't we just deal with frequency? Because that's the one. +[973.07s -> 977.94s] And it makes sense to me. When you first study this stuff, you're like, frequency, that's something I can wrap my brain around. +[977.94s -> 989.78s] Why are we talking about radians and angular frequency? And the reason is because if you look inside of the cosine function, we have the frequency times time plus some phase angle here. +[990.06s -> 999.25s] All right, this is the angular frequency times time. Don't forget, whenever we take the cosine of something on your calculator, let's say, you're always taking the cosine of an angle. +[999.25s -> 1012.37s] Okay, you're not taking the cosine of cycles per second. You're not taking the cosine of inches You're not taking the cosine of cubic centimeters. You're always for it to make sense taking the cosine of an angle which is +[1012.37s -> 1025.14s] Let's say radians, because radian measure in math is what we typically use in engineering. Radians, right? So at the end of the day, whatever is inside of the sky has got to be an angle, and it typically needs to be in radian measure, right? +[1025.14s -> 1036.83s] So if we just put F here for frequency, then that cycles per second, and then we'd be multiplying times time, which is seconds. So then what we end up getting there is... +[1036.83s -> 1051.15s] cycles. So we'd be taking the cosine of cycles. That makes no physical sense. We have to take the cosine of radians, right? So we introduced this thing called the angular frequency. We say it's directly related to the regular frequency. So instead of talking about how many cycles, we're going to talk +[1051.15s -> 1065.36s] about how many radians per second the thing makes you know in one single second so if you take radians per second which is this unit and you multiply by seconds then you just get radians here so this product gives you radians this is just +[1065.36s -> 1079.57s] an angle. So you just have radians in there, and then you can take the cosine of it. That's one way to look at it in terms of units. Basically, you have to have radians somewhere in there to take cosine of it. And so we're going to be dealing with omega all the time, which is radian. +[1079.57s -> 1092.51s] The other way to look at it is it's just another way of representing cycles per second. Here, if we want to know how many cycles per second, we just look at the graph, look at one second and count how many cycles we have. +[1092.51s -> 1106.93s] and so on. But when we multiply by 2 pi, what we're doing is, think about the unit circle from trigonometry. That's why I said, probably a good idea to review some trig. Think about the unit circle. There are 2 pi radians in one full revolution. +[1106.93s -> 1120.85s] So here we're talking about kind of like one full cycle of this wave, but instead of thinking about the wave, think about it going through the unit circle one time. That's one full revolution. That's two pi radians. Every time we go around, two more pi. +[1120.85s -> 1132.93s] Two more pi radians, two more pi radians. So I can express anything cyclic, especially in terms of cosines. I can express how many times is it going to go around the unit circle in one second. How many... +[1132.93s -> 1140.10s] integer multiples of two pi's are going to go all the way around per second and that ends up boiling down to being radians per second. +[1140.10s -> 1150.26s] So when you take the frequency, multiply by 2 pi, what you're getting is you're basically figuring out how many times does this thing take a full trip around the unit circle of 2 pi. +[1150.26s -> 1156.42s] which would be radians per second. So there's a couple different ways to look at it. I'm trying to give you a little bit of a... +[1156.42s -> 1166.24s] solid foundation there because sometimes you look at it and you're like, why are we using omega? Why are we multiplying by 2 pi? It's just another way of representing a cyclic term. +[1166.24s -> 1179.63s] So instead of saying we're changing, looking at this sinusoid as it goes around, and we're counting how many cycles per second, we multiply by 2 pi, that's how many radians, how many 2 pi times we go around the unicircle per second. +[1180.56s -> 1195.22s] All right, now the next thing we want to do, I think we beat angular frequency into the ground, is amplitude. And amplitude, we already talked about, fundamentally that means the height. +[1197.81s -> 1210.64s] the height, which is V sub m, right? That's the height of the sky. If this were 36, then the amplitude would be 36 volts. And by the way, amplitude is measured from the top. +[1210.64s -> 1217.78s] to the axis here it's not measured from peak to peak like this so if this were 36 +[1218.32s -> 1232.75s] from here to here it would be 36 volts. If this were 150, it would be 150 volts. Basically, whatever number sits in front of the cosine is the amplitude, which tells you the height. And then we've already talked about it, but I'm going to write it down again. The period... +[1235.31s -> 1248.66s] The period is called t, which is the length of time for one oscillation. +[1248.91s -> 1262.37s] So I have some more stuff to talk about here related to this, but I want to stop this lesson here, let you absorb this. In the next lesson, we're going to talk about what we call this phase angle here. I want to draw some more pictures and show you what that means. +[1262.37s -> 1267.70s] But as a really, really quick recap, just kind of keep in mind that every single voltage +[1267.70s -> 1282.03s] or current that we talk about in this class is basically going to look like what we've written up here. So you have to have something to go in each one of these spots. Whatever number you put out here is going to be the amplitude. So if it's voltage, then this would be the amplitude of the volt. +[1282.03s -> 1295.01s] voltage that we're talking about. If this is a current source or something, or a measuring current, the number out here is the amplitude of the current. It's the height of this wave. It's cosine, that basically tells you the shape of the thing. Inside here we have +[1295.01s -> 1300.50s] but it's not expressed as just how many times per second. It's expressed as angular frequency. +[1300.50s -> 1314.77s] How many radians per second is it going around? Keep in mind that 2 pi radians is one time around the unit circle. So this is radians per second. When you multiply by time, you end up with a unit of radians, which matches with what we need. And then we have the phase angle. +[1314.77s -> 1328.98s] here which is going to shift it left and right. So what I like to do is close it down now make sure you understand this and we'll do some examples and solidify it a little bit later. Follow me on to the next section we'll talk about the phase angle in terms of alternating. +[1328.98s -> 1332.08s] alternating current circuits. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_8.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5a48d72bb17fc26d5b84758e9eb193999d681ee9 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_8.mp4.txt @@ -0,0 +1,44 @@ +[0.00s -> 13.94s] What if we were charged with the task of modeling this function mathematically? So we see that this function is periodic and that it's a step function. So that it comes up, over, down, over, up. +[13.94s -> 25.84s] over, right? And so we see that it is in fact periodic. Okay, so we might hypothesize that we could use sinusoidal functions to model this function. +[25.84s -> 31.82s] because let's take a look at some sinusoidal function. Here is the sine function and the cosine function. +[32.34s -> 42.64s] And we see that these are periodic functions, so maybe we can use these to mathematically model this. And we would be right in making that assumption. So Joseph Fourier... +[42.64s -> 53.23s] in the early 1800s hypothesized just that and then proved it. So let's take a look at what he proposed and then later proved. +[54.03s -> 67.07s] So he proposed that this function could be approximate approximated by some constant plus a sum of cosine and sine functions +[67.07s -> 74.38s] a combination of cosine and sine functions and that any function could be modeled with this. +[75.38s -> 88.93s] Given that you could find the coefficients these this ace of n and this beast event to match it up right to to make things fit Okay, and also this constant here a sub 0 +[88.93s -> 101.30s] Okay, so we look at these, and let's look at this sine function, let's look at this cosine function. Which one of these do we think is going to do a better job of modeling this function? Which one do you think will do a better job? +[101.36s -> 113.62s] Well, I would guess that the sinusoidal function would do a better job the sine function that is Because it approximately matches the period well it exactly matches the period look +[113.62s -> 126.00s] This one is coming from negative pi, and negative pi is coming down and over. And negative pi, this is coming down and over. And then from zero, this is zero to pi, it's coming up and over. +[126.00s -> 133.14s] And then this is coming up and over. So if we superimpose this on top of this, it would do like this. +[133.87s -> 147.84s] So this sine function is a better approximation to this than this cosine function is. The cosine is off, right? It's out of phase with the function that we're trying to model. +[147.84s -> 160.94s] So if we were using these terms here in our mathematical model that we're using to model this, these cosine terms would be working against us. +[160.94s -> 169.30s] So we conclude the following. When we use +[172.24s -> 184.42s] for modeling odd functions, let's use the sine terms the sine function and For modeling even functions, let's use the cosine Cosine function makes sense +[184.42s -> 194.70s] Now there will be some functions, remember I said any function, so there will be some functions where you will use a combination of cosine and sine terms. +[194.70s -> 207.98s] But for this one, because it's strictly an odd function, you will only use the sign terms to model this function. And in the next tutorial, in part two of this series, we will show that that's true. Okay. +[207.98s -> 221.44s] Here we go. So let's take a look. The hard part, the brilliance of Joseph Fourier, was identifying what these constants would be. And here they are. +[221.44s -> 233.46s] Joseph Fourier in the early 1800s said what if we let the period be equal to 2l? Then these things would be true, okay, so +[233.68s -> 244.75s] The proof is in your book. We will just do we're going to do an application and zip through this kind of quickly But the application I've done this I've been in your place. I've learned this before +[244.75s -> 258.42s] And the application is where you really see it come together when you graph it. And you see how the, what'll happen when you graph it is the function will come up, you'll watch it on your calculator, and it'll come up and it'll do this number. +[258.58s -> 268.37s] And then when it gets to here, it'll come it'll come it'll zip down like this and I'll do this Like that +[269.90s -> 284.56s] So and the more terms you add if you added an infinite amount of terms then it would match this thing exactly But of course no one can add an infinite amount of terms because infinity is not a reachable thing, but we can add a lot +[284.56s -> 296.83s] And so these squiggly lines, the humps will get smaller and smaller and smaller until it looks like you can't see it with the naked eye. You have to zoom down with your... +[296.83s -> 304.05s] With your zoom function you calculated at the zoom down really tight to see the wiggling right the squiggling lines Okay, so +[304.05s -> 316.82s] You see that for A0, it goes from negative L to L. They're all integrating from negative L to L, so half the period, right? Half the period to the positive of the other period. But notice... +[316.91s -> 327.82s] Of the same period it's all one period notice something that this thing goes from negative L to L So that's one wavelength isn't it that's one period right? because +[327.82s -> 340.74s] This one goes, the period, it goes from negative pi. One cycle is, this is one cycle. Boom, boom, boom, boom, boom. That's one cycle, right? Negative pi to pi. So what's the total period? +[340.74s -> 354.67s] it moves over by pi, and then pi again, so the period is 2 pi. So the period is equal to 2 pi, and so solving for L, L is equal to pi. +[355.18s -> 367.36s] So we would integrate from negative Pi to Pi and then this f of x here is The function itself that you're trying to model but notice that this function. We can't just integrate +[367.36s -> 380.91s] It's not a continuous function. It's a step function. So we can't integrate continuously from here to here. So we have to break it up into pieces. So I'm going to write f of x. I'm going to write a0 right here. Step out the way here. a0. +[381.68s -> 390.42s] will be equal to 1 over L. L is equal to pi. 1 over 2 pi. +[391.92s -> 404.21s] Yeah, 2 times L L is Pi okay times Open bracket the integral from negative Pi to Pi +[404.62s -> 410.74s] And we're going to well no pardon me. We're going to go from negative Pi to zero. We're going to break it up +[412.85s -> 426.64s] And then f of x, from here to here, f of x is equal to what? Negative c. So we put f of x in here. This is negative c dx. +[430.06s -> 442.83s] plus from 0 to pi, and then from 0 to pi, look, the function is c. From 0 to pi it's positive c. +[451.15s -> 457.42s] And if we do this, we will see that a0 is equal to 0. Right? Because look at it. +[458.13s -> 472.75s] You have this area here, which is the negative area and you have the same area which is positive So they cancel and a 0 is going to be 0 for this this example But this is just to show you that how we're going to break this up +[473.33s -> 486.85s] And we're going to do this trick here. We're going to do this trick for a sub n and b sub n. And a sub n, we'll have a1, a2, a3, a4. And for b, we'll have b1, b2, b3, b4. +[486.85s -> 490.35s] But question, what do you think all the a's are going to be equal to? +[491.09s -> 502.74s] Zero. Why? Because this is not helping us. This is not a good model. This guy is the one that's matching up closest. This guy is working against us. +[502.74s -> 515.63s] And Joseph Fourier developed the model, or a mathematical construct, that is very clever and self-correcting, if you will, because all of these terms come out to be zero, and we'll show that in the next tutorial. +[515.63s -> 519.18s] I'm going to step aside and give you a clear screen shot. Part 2 is coming. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Electronics_9.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Electronics_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..200bfa903697cf9d34942612428688233d04a3c8 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Electronics_9.mp4.txt @@ -0,0 +1,34 @@ +[0.59s -> 6.80s] Hello student, I am Mayur Gondalia and you are watching School of Physics. +[18.16s -> 30.35s] Student, today we will learn about Fourier series of a sawtooth wave function. Fourier series of a sawtooth wave signal +[30.83s -> 43.15s] The nature of the short truth wave signal is like this. It is defined as f of x equal to x for minus pi less than x less than pi. +[43.89s -> 57.58s] From the nature of the wave signal, we say that it is an odd function. It is also found from the expression of the wave function that it is an odd function. +[57.58s -> 70.80s] If you can't decide about it, then follow this process. f of x equal to x for minus pi less than x less than pi. Say equation 1. +[71.38s -> 82.67s] Take x equal to minus x. Therefore f of minus x equal to minus x for minus pi less than minus x less than pi. +[83.41s -> 94.56s] We put negative sign with all x. Now we replace less than sign by greater than sign in this interval. That's why +[94.56s -> 106.19s] We have to change signs of minus pi, pi and x. Therefore f of minus x equal to minus x for pi greater than x greater than minus pi. +[106.58s -> 120.40s] Now, rewriting the interval in inverse order, we have f of minus x equal to minus x for minus pi less than x less than pi, say equation 2. +[121.07s -> 131.60s] In this equation fx equal to x. While in this equation f of minus x equal to minus x. It means. +[131.60s -> 139.31s] f of x equal to minus f of minus x. Therefore given function is odd. +[139.57s -> 149.97s] As fx is old, therefore coefficients a0 and an are 0. Now we will calculate bn. +[150.10s -> 164.56s] bn equal to 1 upon pi integral minus pi to pi f of x sin nx dx and which is equal to 1 upon pi integral minus pi to pi x sin nx dx. Here the value of fx +[164.56s -> 176.30s] is x. Now this is odd and this is also odd. Therefore integration of odd into odd that is integration of a1. +[176.30s -> 187.73s] So, by applying property of even function, we have dn equal to 2 upon pi integral 0 to pi x sin nx dx. +[187.73s -> 200.82s] We will simplify it using formula of integration by parts. The formula is integral uvdx equal to uv1 minus u dash v2. +[201.17s -> 211.38s] where u dash equal to du by dx and v1 equal to integral v dx and v2 equal to integral v1 dx. +[211.76s -> 225.71s] In our expression, x equal to u and sin nx equal to v. Therefore, bn equal to 2 upon pi into bracket x minus cos nx upon n limit 0 to pi. +[225.71s -> 237.26s] minus 1 into bracket minus sin nx upon n square limit 0 to pi. Here u that is x so here we put x +[237.26s -> 250.69s] V1 that is integration of sin nx. So here we put minus cos nx upon n minus u dash that is differentiation of x. So which is 1. +[250.69s -> 252.91s] So here we put 1. +[253.17s -> 267.57s] into bracket v2 that is integration of v1 that is integration of minus square nx upon n it is minus sine nx upon n square. Now putting the value of limits +[267.57s -> 278.45s] bn equal to 2 upon pi into bracket minus pi cos n pi plus 0 upon n plus sin n pi minus sin 0 upon n square. +[278.74s -> 292.22s] In these terms, sin n pi equal to 0 and sin 0 equal to 0. Therefore, bn equal to 2 upon pi into bracket minus pi cos n pi upon n. This pi and this pi cancelled. +[292.22s -> 301.07s] and take negative sign out of the bracket. Therefore, bn equal to minus 2 upon n into bracket cos n pi. +[302.64s -> 316.56s] And now Fourier series is f of x equal to a 0 by 2 plus summation n equal to 1 to infinity a n cos n x plus summation n equal to 1 to infinity. +[316.56s -> 328.74s] bn sine nx. Putting the value of coefficients, we have f of x equal to summation n equal to 1 to infinity +[328.74s -> 334.29s] Minus 2 upon n cos n pi into sin nx. +[334.67s -> 346.75s] Which is equal to now take this minus 2 out of the summation sign. Therefore f of x equal to minus 2 summation n equal to 1 to infinity cos n pi. +[346.75s -> 358.88s] into sin nx upon n. Expanding it by taking n equal to 1, 2, 3, so on, we get f of x equal to minus 2 into bracket +[358.88s -> 372.32s] minus sin x upon 1 plus sin 2x upon 2 minus sin 3x upon 3 plus so on. Readjust this negative sign with the sign of the terms into the bracket. +[372.32s -> 386.99s] So f of x equal to 2 into bracket sin x minus sin 2x upon 2 plus sin 3x upon 3 minus so on. This is the Fourier series of short tooth wave function. +[388.88s -> 403.02s] In next video, we will learn about some problems of Fourier series. Please write your suggestion in comment box. Like and share this video. And subscribe my YouTube channel, School of Physics. +[403.02s -> 404.66s] Thanks! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_11.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..577378064d8d08c111cc7eddfb2bea66d3858d12 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_11.mp4.txt @@ -0,0 +1,14 @@ +[0.69s -> 4.34s] Thank you. +[8.66s -> 21.71s] In this video, we are going to discuss about different types of thermodynamic processes like isobaric process where pressure is kept constant, isochloric process where volume is kept constant, isothermal process +[21.71s -> 35.86s] will temperature is kept constant and adiabatic process where heat transfer is zero. So, first we will understand what is the use of thermodynamic processes. Here the state of system can be expressed by various parameters such as pressure, temperature, +[35.86s -> 48.08s] volume and internal energy. If any two parameters are fixed like pressure and volume or fixed mass of gas, the temperature of gas will automatically fix according to equation PV is equal to RT. +[48.34s -> 61.52s] No change can be made to temperature without altering pressure and volume. By changing any of these parameters, the state of system can be changed. So, the state of system can be changed by different thermodynamic processes. +[62.16s -> 66.64s] So, here first is the isobaric process in which pressure is kept constant. +[66.93s -> 79.95s] Since the pressure is constant in this process, the volume of the system changes. And work done can be calculated by the equation W is equal to P multiplied by change in volume. That is V final minus V initial. +[80.53s -> 89.90s] If change in volume is positive, that is expansion, the work done is positive. And for negative change in volume, that is contraction, the work done is negative. +[90.51s -> 103.10s] In isochloric process, the volume remains constant. Therefore, the system does not do any work. Such process in which there is no change in volume can be achieved by placing thermodynamic system in a closed container. +[103.10s -> 110.74s] which neither contracts nor expands. Thus, from the first law of thermodynamics, change in internal energy becomes equal to heat transfer. +[111.41s -> 126.00s] In an isothermal process, the temperature of the system remains constant. This process occurs when the system is in contact with the outside thermal reservoir. And changes in the system will occur slowly to allow the system to continue to adjust to the temperature of the reservoir. +[126.00s -> 139.31s] through heat exchange. And since the internal energy is temperature dependent, and here the temperature is constant, so change in internal energy becomes zero. And thus, from the first law of thermodynamics, we will get Q is equal to W. +[139.76s -> 153.92s] In adiabatic process, no heat exchange between system and surrounding, so Q is equal to zero. So, adiabatic process occurs without transmitting heat and mass between system and surrounding. Since Q is equal to zero for an adiabatic process, +[153.92s -> 164.11s] From the first law of thermodynamics, we will get change in internal energy is equal to negative work done. Thus, internal energy will increase if the work done is negative and vice versa. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_13.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..29857a417a14a3f991ba80f3e0b8330f56b7e2fb --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_13.mp4.txt @@ -0,0 +1,168 @@ +[1.10s -> 3.98s] All right, so this is week 11. +[4.37s -> 18.75s] Problem 11.17. Commercial refrigerator with 134A as a working fluid is used to keep a space at minus 30 degrees Celsius, rejecting its waste heat to cooling water. +[18.75s -> 26.86s] that enters the condenser at 18 Celsius at a rate of 0.25 kilograms per second and leaves at 26 Celsius. +[27.63s -> 41.04s] The refrigerant enters the condenser at 1.2 MPa at 65°C and leaves at 42°C. The inlet state of compressor is 60 kPa at minus 34°C. +[41.74s -> 55.04s] and the compressor is estimated to gain net heat of 450 from the surroundings. So we are to show the cycle on the TS diagram and determine the quality of refrigerant at the +[55.04s -> 62.58s] evaporator inlet, the refrigeration load, the coefficient of performance of the refrigerator. +[63.15s -> 76.88s] And the theoretical maximum refrigeration load for the same power inputs to the compressor So we can actually start by talking about this last one here because we know that we learned that +[76.88s -> 90.86s] For any machine, for any system that we can possibly create, we're going to be limited by our TSource and TSync, right? We talked about that in the past, right? So we're going to have it. +[90.86s -> 95.89s] Then whatever we have in the middle here can be a refrigerator, heat pump, whatever that is. +[96.21s -> 108.74s] we're going to be limited, whether we're going to work like that or work like that, doesn't matter. We're limited by those values, right? So in this case here, we can go ahead and do at least the beginning of the... +[108.74s -> 122.59s] maximum coefficient of performance that we can have, we know that's going to be limited by the T source over our T sink minus one. Okay. So before we do anything else, we can... +[122.59s -> 136.82s] calculate what's the maximum coefficient of performance that this system could have. And notice that this has nothing to do with this guy here in the middle, right? It's only related with these two extreme here, which is our sink and our source. In our case, the... +[136.82s -> 148.93s] um source that's given the it's able to get heat out of the system is this 18 celsius right that's the water that's entering the system +[148.93s -> 162.42s] and being able to carry away this energy right so that's the one that's acting as our sink and then as our uh as our source i should say and the one that's the other extreme on this problem is our +[162.80s -> 173.84s] uh space right we're going to keep it minus 30 so be able to keep this guy minus 30 with a water that can come in at 18 those are the two limits that we have +[173.84s -> 187.81s] within this problem. So whatever this guy in the middle right here does has to work within the boundaries of the minus 30 and the 18 Celsius. So in our case here, the coefficient of performance, maximum I should say, +[187.81s -> 202.70s] will be 1 minus, all in Kelvin, so 273 plus 18, divided by 273 minus 30, plus 1, sorry, minus 1. +[204.37s -> 211.66s] And all this subtraction division minus 1 right so the coefficient of performance the maximum order can have in their system +[212.37s -> 224.66s] regardless of how good or how bad our refrigerator is, is 5.0625, okay? +[225.20s -> 231.15s] And this is the dimensionless, obviously. Okay, so that's the maximum we can possibly have. Okay, so let's... +[231.41s -> 242.26s] Start solving the problem now. Let's have a look at what we have and what's being asked. Okay, so let's look at what's going on It's a little drawing of the system that we have at the moment Let me zoom out a bit. Okay +[242.32s -> 251.73s] So let's start, I'll probably do green, it's probably the easiest color, let's start over here. So over here we have a high pressure, high temperature fluid. +[252.21s -> 266.21s] Okay, and to be able to remove some of this energy some of this temperature to be able to decrease the temperature We're going to put this guy through a condenser. Now the condenser is like before is not going to change the +[266.21s -> 279.17s] Pressure of this guy. So this is isobaric process, right? But we have that water that's coming through this at 18 Absorbing some of that energy leaving 26, right? So we have energy leaving the fluid the working fluid and going to the water +[279.17s -> 288.40s] Okay, so when we get to this other side here, we have fluid that's at the same pressure but at a smaller temperature. Then we're going to reach the expansion valve. +[288.40s -> 302.10s] and when we reach that or throttle also knows the throttle and when we reach that guy it's going to only allow a certain amount of sorry only allow a certain amount of +[302.35s -> 310.38s] steam from the r134 to go through and that's going to mean that we're going to have a big pressure drop so we have a big pressure drop here +[310.67s -> 318.77s] Okay, and that pressure drop means that our temperature also drops because we know that pressure is proportional to temperature right ideal gas law +[319.18s -> 329.82s] and so at the end here when we get to this part here we're going to have a fluid that now has low pressure that's right low pressure and low temperature right so we just dropped +[329.82s -> 343.46s] the pressure greatly and with that we also drop the temperature greatly and that's perfect because now this part here we're inside the space that we want to cool right within that those that we like so this would be inside the refrigerator +[343.46s -> 346.54s] if we're thinking about a fridge in your home. +[347.02s -> 359.34s] So this cold fluid is going to go through this guy here and it's going to go through an evaporator. Now the evaporator, like the name says, the idea is that it's going to evaporate this fluid that's going through it. And the idea is as it's evaporating, what it's doing is... +[359.34s -> 372.22s] Gaining heat because because it's a lower temperature that the chamber or the space we want to cool It's going to take away heat from that space going to take away energy, right? That's what QL is representing right there +[372.22s -> 380.50s] So we have energy going from the space that we want to cool into this fluid that is absorbing energy and that leaves evaporated at the same pressure. +[380.85s -> 394.22s] change in pressure took place, but at a higher temperature. So whatever this temperature over here is, I'm not sure what the temperature is, but I know that this is lower than 34, minus 34 Celsius, right? Small temperature. So we just gained... +[394.22s -> 408.32s] temperature going through the evaporator so after the evaporator note that now we have a low pressure low temperature fluid and the idea is that we want to put this guy compress it again to be able to repeat the process so put it through a compressor and the compressor has to do +[408.32s -> 416.88s] We have to put some work into this guy to work and then this guy is going to compress and then we're going to leave this cycle back with a high pressure, high temperature fluid. +[417.20s -> 430.98s] Now in this case here, we also have the surroundings that's kicking in and if you notice what the surroundings is doing is giving energy to the system, so what that means is if I'm taking my +[430.98s -> 440.24s] My fluid, I'm going from minus 34 on state 1 all the way to 65 on state 2. Okay, I'm increasing the temperature of this fluid, but I have Q in. +[440.24s -> 450.14s] that's giving energy to my system. So that means that my compressor has to work a bit less, right? So whatever the compressor, let's put it like this. Whatever the compressor... +[450.14s -> 459.47s] would have to do before, let's put that, is it just a blank because we don't know that number yet, okay? So if we want to take from minus 34 to 65, it would have to do x work. +[459.73s -> 473.55s] Just leave X for now. X work. But because we have that QN going in, it's going to be X minus the 450, is it? Yeah, 450 right there. Yep, minus 450. +[474.96s -> 478.90s] Watts right because the surrounding is actually helping us out in this case +[479.60s -> 490.22s] All right, so let me get rid of all this stuff that I just drew and let's look at what we're looking have a look about What's the problem is asking from us? +[491.09s -> 504.88s] So it wants the quality of the refrigerant at the evaporator inlet, the refrigerant load, and the coefficient of performance. So quality at the evaporator inlet. So it just wants the... +[504.88s -> 509.33s] quality over here how much liquid how much vapor do we have on state four +[510.19s -> 524.14s] It also wants to know the refrigeration load, and that's precisely this Q with an L down here. That is how much heat is being absorbed by our fluid every time it goes through the evaporator. And then the coefficient of performance, we all know that. +[528.72s -> 538.22s] We all know that it's the desired output that we want divided by the required input that we need to be able to get that output. +[538.77s -> 550.96s] In our case here, the desired output that we want is precisely the QL to be able to keep that guy at minus 30. And the required input is how much energy we need to give to our compressor. +[551.25s -> 555.28s] Which is related to this guy here. +[555.66s -> 568.56s] All right, so how are we going to solve this? We're going to find each of the states. We're going to find state 1, 2, 3, and 4. The expansion involved, the throttling process, it occurs so that... +[568.56s -> 582.45s] U and PV these two guys Compensate each other that is if this guy if this guy increases this guy will decrease So that when we go through the throttling process the enthalpy on state 3 is +[582.45s -> 597.23s] approximately equal to entropy on state 4. Okay, so that makes our lives a bit easier. So what I'm going to do is I'm going to find entropy for 1, 2, 3. Then because I already got to have entropy for 4, I can relate that to find the quality. +[597.33s -> 602.83s] Right. The other thing is that if you guys notice they are asking for the. +[603.57s -> 617.15s] QL the load and kilowatts and Since we don't have the mass flow rate of the refrigerant. We can't really determine that yet So we're gonna have to find the mass flow rate and as you can imagine we're going to use +[617.15s -> 620.37s] the fact that we know the mass flow rate of water to determine that. +[620.78s -> 633.68s] Right, so let's get into it. TS diagram to start with. So starting here down on stake one, and I'm going to go through the compressor on a perfect and nice isentropic process over here. +[633.68s -> 648.35s] I'm going to go now through my condenser, and that's going to be an isobaric. Guys, it's going to go like that until we leave the dome, and then it goes like so, right? Now, the throttling process, which is what occurs from three to four, that... +[648.35s -> 660.75s] is there's no change in entropy but there's a gain in entropy so it's something like this right and then from our state four through the evaporator it's all the same pressure so it just stays like so +[661.07s -> 674.90s] Alright, so we would have 1, 2, 3, 4. Mind you guys that as opposed to when we're trying to extract energy, in this case we're giving energy to remove heat. So we're going in reverse cycle. +[675.28s -> 685.58s] And the dome, if we think about it, number three would be either here or as a compressed one, we're not sure. +[685.87s -> 700.85s] yet we know it's a liquid right after it goes through the condenser then two hopefully is going to be a superheated one after going through the compressor and then one we're not sure either so i'm just going to put the dome like that for now and then we can come back to this if it's not correct +[701.33s -> 715.22s] Okay, we have QH over here and that QH is completely related to, in our case here, completely related to the water that's coming through and grabbing this energy and taking it away. +[715.22s -> 721.84s] And down here we have QL, which is related to the energy we need to remove to keep the guy at minus 30. +[722.38s -> 735.65s] So at this point, it might be easier for you to understand why we have the limitations, right? Because regardless of how this cycle in here operates, and I might just put here that's 134A so that we don't look at wrong tables. +[735.65s -> 750.18s] regardless of how this guy operates we know that the QH is going to be determined by the 18 Celsius coming in right and the QL is going to be determined by the minus 30 that we want to keep the place at right +[750.18s -> 756.91s] So that's why we have those two boundary limits limiting the performance of this cycle in here. +[757.81s -> 767.47s] Okay, so I wrote down what we know. We know 1 and 2, sorry, 3 and 4. Ah, 1 and 2. +[770.90s -> 782.10s] So I wrote down what we know. We know 2 and 3 are the same pressure. We know 1 and 4 are the same pressure as well. They've been both given, and I grabbed the temperatures from the drawing. +[782.70s -> 796.56s] So this is information we have to start with. We also know the mass flow rate of water. So mass flow rate, that's 0.25 kilograms per second. And we know that, like we talked before, the... +[796.85s -> 810.06s] Work done by the compressor. We whatever the work that has to be done Minus the 450 because that's the bonus we get from the surroundings +[810.32s -> 820.08s] Okay, so let's define each of the states so that we can start solving this problem. And as we do that, we're going to find out the quality, which is the first part. Okay, so my state number one. +[823.89s -> 837.78s] we have two things for say number one we know the 60 kilopascals we also know the temperature which is minus 34 celsius okay so what i'm going to do is i'm going to do on the first one with you guys and then the next one will just skip this part +[837.78s -> 843.70s] we're going to do table this is superheated refrigerant table so i'm looking at the right table +[844.40s -> 858.00s] And I have the temperature table here, and I'm going to be looking at my 34 right there, right? And I'm going to note that the saturated pressure at minus 34 is 69. Our pressure is smaller. +[858.00s -> 866.64s] So RP, which is 60, right? So RP is smaller than RP set. And therefore, this is superheated. +[866.96s -> 881.34s] Because this is superheated on the wrong table. So we need to go to the superheated table. It's conveniently down here and I'm going to be looking at 0.06 megapascals at 60 kilopascals +[881.34s -> 895.17s] And I'm looking for minus 34, right? That's my temperature, minus 34 Celsius. And you're going to notice that we have minus 20 over here. And we have T sat, which is right here as minus 36. +[895.17s -> 907.92s] So that means that my enthalpy will fall between 227 and 240 kilojoules per kilogram. So I can interpolate that guy there. +[907.95s -> 921.01s] to find my enthalpy and I did that and what I grabbed by the end of it was my interpolation and I grabbed 230.06 +[921.30s -> 932.02s] Kilojoules per kilograms. Okay, I'm going to repeat that process for two and three. So let me go ahead and write down over here H1 +[934.03s -> 945.65s] 230.06 kilojoules per kilograms. I'm going to do similar processes for state 2 and 3. So state 2. +[951.66s -> 964.26s] We know two things about C2. We know the pressure, which is the high pressure state, 1.2 megapascals. And we also know the temperature, 265 Celsius. So same thing, either by looking at... +[964.26s -> 971.95s] pressure table or temperature table you'll see for instance that C2 is greater than T sat at 1.2 therefore superheated +[977.17s -> 990.93s] Superheated, there you go. And then we're going to be looking at table A6 and we can grab enthalpy 2 the same way that I did, 295.18 kilojoules. +[991.22s -> 1000.37s] per kilograms and state three the similar process but this time it's going to be compressed +[1008.05s -> 1021.04s] know this is 60 kilopascals I'm sorry 1.2 1.2 megapascals and the temperature just 42 +[1025.07s -> 1030.00s] Okay, and then for this guy here, we'll find that this guy is a compressed liquid +[1033.07s -> 1044.85s] So that means I'm going to go to my temperature table. That's more precise. And I'm going to do my H3, which will be approximately equal to my ZSAT liquid. +[1046.58s -> 1050.45s] And that's 111.28. +[1053.94s -> 1066.54s] And that's the interesting part now because this is, as we noted, similar to H4 because of the throttling. So that means that we know the second information that we need for state 4, right? Because now we just know that state 4. +[1067.79s -> 1078.80s] State 4 has two things. We know that it has a low pressure because it just went through the expansion valve. But we know that it has the enthalpy of... +[1083.60s -> 1097.23s] Okay, and knowing that, we can go now to the pressure table, take away 5. We know it's already a saturated mixture, but we can be extra sure by noting that our enthalpy falls between the saturated. +[1097.23s -> 1111.63s] Liquid and saturated vapor. That means we can go ahead and do this. And with this we can grab our quality. And quality ends up being 47.97. +[1115.60s -> 1119.15s] that's the first part right because it's asking us what's the quality +[1119.66s -> 1132.82s] the inlet of the evaporator so we know it's about 50 50 about 50 liquid 50 is fluid and we would expect it that after the evaporator we have more +[1133.71s -> 1148.66s] Did I say fluid? It meant more gas state, right? So we would expect this gas state to increase as we're going through the evaporator, right? That's precisely the idea. Okay, so that's part A. Now, part B. +[1149.94s -> 1160.08s] look here okay so part b we're asked what is the refrigeration load okay the refrigeration load is ql +[1161.87s -> 1172.27s] If you guys recall, it's at 1 in QL in kilowatts or watts. So we need a mass flow rate to be able to solve this in kilowatts. How are we going to do that? Well, we're going to use the... +[1173.20s -> 1186.10s] energy balance principle right because what we have on the condenser is the following let's do in green we have water coming in +[1186.54s -> 1191.15s] At 18 Celsius and leaving at 26 Celsius +[1192.02s -> 1206.26s] At the same time, we have 134a coming in at 65, and obviously decreasing because it can create energy, so it decreases to 42. +[1207.89s -> 1219.95s] Okay, now if we do an energy balance inside this condenser, we know energy cannot be created or destroyed, right? So do an energy balance at the condenser. +[1221.14s -> 1234.91s] We know that Whatever the energy that is being absorbed by the water has to be being given by it's being given by the refrigerant, right? So in other words I do energy rate +[1234.91s -> 1244.78s] It's going to be the mass flow rate of water times Q that's being absorbed by the water has to be equal to the mass flow rate of 134 times the Q of 134. +[1246.10s -> 1258.19s] All right, and now let's break down that equation because check it out. This Q here is the Q when we go from state 2 to 3. So that's just the difference from state 2 to 3. So we have that. +[1258.80s -> 1268.93s] This guy here we don't have yet, but we can find out because we know that water going from 18 to 26 we know that +[1268.93s -> 1279.86s] We know how to calculate the energy it needs, right? To go from 22 to 26. And the mass flow rate of water we do have. So with that, we can find the mass flow rate of the refrigerant. So let's do that. +[1280.21s -> 1292.72s] so the mass flow rate of the refrigerant 134 has to be equal to the mass flow rate of water Q of water +[1295.12s -> 1308.90s] divided by Q over 34. Now, the Q over 34 in this case, right, is precisely the QH. So I could rewrite that as QH if I wanted to just to have less unknowns in this question, right? +[1308.90s -> 1323.12s] That's precisely the amount of energy that's being released. So let's write down what we know about these guys. Oh, and let's write down, before we do that, let's just do, what's the Q of water? If you guys recall, it's going to be mass. +[1323.12s -> 1329.07s] CP delta T. If I want it in kilojoules per kilogram, I can divide by the mass. I'm going to have Q over. +[1330.93s -> 1344.69s] everyone this is going to be cp delta t okay cp for water at 20 celsius you can find um table a3 that's 4.18 and then our delta t we have from 26 to 18. so +[1345.10s -> 1359.57s] My mass flow rate of 134a is going to be 0.25 kW per second times 4.18 times the difference in temperature, which is 8, divided by h. +[1361.04s -> 1371.89s] 2 minus H3, that's 295 minus 111. And this guy turns out to be, well, it's a big number. +[1372.91s -> 1380.30s] 0.04545948. Let's just round it up to 455. +[1385.68s -> 1397.81s] And if we wanted to know QH as well, we could also do that by relating the same thing, right? Because the same principle is, as I just said, we could rewrite this equation here as mass flow rate of water. +[1400.62s -> 1404.72s] H2 and this has to be equal to the mass flow rate of refrigerants. +[1407.44s -> 1416.62s] times QH. So if you wanted to know how much energy is actually being exchanged over there, we could just do the mass flow rate of water. +[1417.14s -> 1431.22s] times a 4.18, which is the left part of the equation, right? Times 8. And that's going to give us 8.36. That's kilojoules per second or kilowatts, right? Don't forget that this guy... +[1433.36s -> 1445.42s] It's kilojoules per kilograms Kelvin. And the difference in Kelvin or Celsius is the same, so that's just going to be kilojoules per second, which is kilowatts. So what is this number here? This is... +[1445.81s -> 1460.05s] Q H how much energy is leaving the rate of Q leaving the system? Okay, and we know also now we know the mass flow rate of Refrigerant. Okay, if we want to load if you want to load there's two ways we can find load +[1460.05s -> 1474.18s] Okay, so if you want to know what's a low QL, here's two ways you can find it. I'm going to do both ways with you guys. If I want to find QL, there's two ways I can go about this. I can do, well, I know QL is the difference when you go from 4 to 1, and I can do that. +[1474.18s -> 1488.75s] We can do that. But I also know that because this is a cycle, right? We can't create or destroy energy. So therefore, as I said, QH is what balances everything, right? QH is what is our limit, right? Because all this energy is being removed. +[1488.94s -> 1502.80s] From this environment and minus 30 is then being tossed to QH So whatever we have going on the cycle and we have QH we have work and we have the surroundings and we have +[1502.83s -> 1512.53s] QL. So QH has to be equal to the sum of all these guys. QH, QL, work, and the Q surroundings. +[1512.85s -> 1521.90s] Right, so I can you can think about this way the amount of energy rejected from the cycle Relates to the condenser, right? That's the QH +[1522.58s -> 1535.50s] And it has to be equal to all the energy that the cycle absorbs, right? And the energy that the cycle absorbs is, because the throttling doesn't have any work, then the energy is the QL. +[1535.50s -> 1545.62s] plus the work of the compressor, plus the energy that the surroundings give us. So either way, we can solve QL by doing either of these methods. +[1545.90s -> 1560.40s] So let's start by doing just the normal way, just probably the straightforward way. Going from 4 to 1 times the mass per weight of refrigerant. +[1560.69s -> 1575.57s] You have all that information that is about four points. So that's four points One point five point four or four And it keeps going for four nine. So let's just stop there +[1575.82s -> 1588.94s] but the answer that we have okay so it could be as easy as that but we're going to have to calculate the work of the compressor to calculate the coefficient of performance anyway so we could have done the other way around so we could do +[1589.65s -> 1600.34s] work of the compressor. We know compressor works when we go from state 1 to 2. That would be state 1 to 2. +[1601.49s -> 1615.06s] And we also have to subtract that for 450, right? Now, this would be incorrect, right? If we just did this math. Why? Because this guy is in kilojoules per kilograms and this guy is in watts. So that doesn't work out well. +[1615.06s -> 1624.14s] So what do we need to do? We need to multiply this guy here by the mass flow rates. +[1624.59s -> 1630.51s] We need to divide this guy here by a thousand because then we're going to have everything in kilowatts +[1632.50s -> 1641.04s] Yeah, so we have H2, we have H1, we have the mass flow rate of refrigerant. So this here is about 2.51. +[1644.18s -> 1658.64s] kilowatts okay and then if we wanted to redo with this information go ahead and do this guy again we could have so it's going to be the ql the 5.404 minus the two +[1659.02s -> 1660.27s] um +[1660.59s -> 1675.02s] Sorry, it'll be the 8.36. If I'm looking for QL, right, it'll be the 8.36 minus the 2.51 minus the 0.45 from the surroundings, which will also give me the 5.4. +[1676.50s -> 1688.59s] Alright, so now we need a coefficient of performance. We know that's the desired output over the required input. +[1688.94s -> 1702.16s] In this case, our desired output is the QL, the removal of energy from our system. And what we need to input is the work of the compressor, right? And that's why the surroundings help us because now we need to put less work. +[1702.22s -> 1711.34s] 450 watts less it's not that much of a difference but it's less work so this guy is 5.4 +[1713.10s -> 1724.56s] and this guy is 2.51 you can do this if you want to but it's not going to change much so 251 is my coefficient of performance and that's dimensionless right +[1725.17s -> 1733.30s] Okay, so we have a B and C now D is the one that asks us for the maximum. Let me reread the question +[1735.25s -> 1743.57s] D is asking us. What's the theoretical maximum refrigeration load for the same power inputs the compressor? Okay +[1743.89s -> 1755.82s] So if we're keeping this compressor at this power here, that is, if we don't want to change this guy here whatsoever, what is the maximum? +[1756.08s -> 1768.83s] Q L that I can have right? What's the maximum of this guy? What's the maximum energy? What's the maximum energy I can extract? From this environment that I want to keep in minus 30. Okay, so +[1768.83s -> 1780.34s] We're after the maximum value for any heat engine for anything operating between two temperatures. These two temperatures are going to limit the efficiency of our +[1780.34s -> 1794.13s] machine right it doesn't matter how good your cycle is or how bad it is it will be limited by these guys and in this case here we have a refrigerated space at minus 30 and we have a water that's coming in to remove that energy at 18. +[1794.13s -> 1808.30s] So in other words, when we look at this cycle here, this QL down here that's being removed from the environment, it's being removed from an environment that is at minus 30 and that will remain at minus 30. That's one of our extremes. +[1808.30s -> 1820.05s] limits this cycle in here. The other limitation is this water over here with 18 Celsius. That's another limit there. And know that these two things, they have nothing to do with the cycle. So let's draw this quickly here. +[1820.82s -> 1835.06s] Remember when we had the machine with the guy that was claiming to have an efficiency and all that, and because of that, we were trying to figure out whether he was full of it or not, and you guys were seeing what the maximum efficiency could have and all that. +[1835.06s -> 1848.85s] So what he had, he had his limits, and then he was developing this machine, right? And this machine is this thing that I drew here in the middle. And it doesn't matter how good this guy is, all right? It can only have an efficiency, maximum efficiencies related by these. +[1848.85s -> 1852.88s] outside guys here right these guys are limited and if you guys recall +[1853.33s -> 1867.09s] The efficiency we had a relationship. I told you guys how to listen between the the source and the sink and all that but This is for the number efficiency if we're looking at for the coefficient of performance The performance will be 1 over +[1868.94s -> 1879.82s] T H or T max if you want T high and T low or T deep or T cold. Like that. One thing that always gets students is this guy has to be in Kelvin, right? +[1882.96s -> 1897.07s] It has to be in Kelvin. Because if it's not in Kelvin, imagine if you have one of the sources, for instance, is if this guy, for instance, is zero, this guy would go to infinity, right? And we can't have zero Celsius quite nearly, but we can have zero Kelvin. +[1897.30s -> 1911.54s] So in our case here, these two guys limit the cycle. And again, it doesn't matter which cycle this is. It can be the best or the worst, right? It's going to be limited to maximum coefficient performance. Maximum coefficient performance possible out of the sky will be 1 over. +[1912.02s -> 1924.94s] T high, so that's R18, the wire that's taking away the energy, plus 273 to have it in Kelvin, divided by the 273, minus 30, and that's minus 1. +[1926.29s -> 1938.99s] that's 5.0625 so we know the maximum coefficient performance we calculate let me do D so this is not confusing let's do D +[1939.41s -> 1949.78s] D all right, so we know the maximum maximum coefficient of Performance is five point. What did we get before five point? +[1950.16s -> 1962.64s] 0625 and this is limited by our water coming in and the environment we want to keep in mind is 30, right? So we have 18 and 1, 18 Celsius, sorry. +[1965.30s -> 1978.51s] 18 Celsius on one extreme, and we have the minus 30 on the other extreme, and then we know that this is going to limit our maximum coefficient of performance. So if the coefficient of performance is +[1979.66s -> 1991.54s] the desired output divided by my required input then that means that my maximum amount of energy I can remove is the 2.51 +[1993.46s -> 2004.77s] kilowatts times the 5.0625 dimension that's right so the maximum amount of energy i could remove from this +[2004.77s -> 2013.81s] Environment given the water coming at 18 and I want to keep it at minus 30 is 12.9 kilowatts +[2014.38s -> 2027.63s] Okay, so that will be the maximum capacity at least if I want to keep giving it 2.51 kilowatts Right. That's the best of the best it can do Right hit me up if you have questions talk soon diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_14.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fe1e731664551c0116f7aabb0fc1cfb9441e5c2b --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_14.mp4.txt @@ -0,0 +1,24 @@ +[0.59s -> 12.78s] Okay, so again we have here an interesting problem. Here we have here for the tank shown in the figure, H1 is known to be 3 meters, H3 is 4 meters. +[12.78s -> 20.11s] The question here, determine the value of H2. So what could be this height of the oil? +[20.50s -> 33.20s] Kung nai-oil di ha, dindiri water, dindiri water. Knowing that H1 is 3 and H3 is 4. So this will just be straight forward. Let's make this short. The solution here is simply... +[33.20s -> 46.14s] You connect points that you want to know. In this case, pressure mo na siya. Ang kabalo ka, sure, is you know that the pressure here at the free surface and this free surface is +[46.14s -> 59.89s] atmospheric okay okay they are exposed to the open to the atmosphere so pa here will be the pressure here is zero right okay we call call this a point a and we call this point b +[60.43s -> 73.41s] Okay, we'll be able to solve for h by relating how do we go through to this height. Ngayon ang idea. From there, as you go down, what happens to the pressure? It will increase, right? +[73.41s -> 84.88s] Yes, it will increase. By how much? So, PA, even if it's 0, we just write it there. Para lang ko. PA, as you go deeper, it will increase. By how much? Well, +[85.20s -> 100.14s] Raw GH. Raw is 840 for oil. G is of course 9.81. Height is of course unknown, H2. And as you go further deeper, +[100.62s -> 111.54s] Oh, kumingunta. Well, as you go down, kaya noon mo ng H2, you go down, then H1 will be... +[111.79s -> 125.79s] You go down by how much? By H1. So, that will be then 1,000 roper water times 9.81 times +[125.79s -> 137.97s] h1, which is 3 meters. So, now, dito pwede mo cross direct sa dana. Baka, well, naman tayo boundary din. So, pwede po ka mo +[137.97s -> 150.85s] Move pa ka horizontally, nothing happens, right? Yes, wala may tembo. But as you move up, what happens to the pressure? Well, it decreases, right? So, it will decrease, but... +[150.85s -> 164.56s] Wala man yung distance. We don't know. We could call that really x for the moment. So, x na for example. And we'll show later nga mag-cancel lang yung nasa. It's not necessary but I'm just trying to show it here para medyo dilit na maglibog. +[164.56s -> 176.08s] Now, as you move up, the pressure decreases by raw GH. Raw, same for water. G is 9.81. H is, well, by X. +[176.08s -> 181.10s] Move up by x, gamma is negative, kaya up man. Move horizontally, +[181.39s -> 195.07s] Well, as you move horizontally, nothing happens, right? Okay, horizontal, there's no change in pressure kung horizontal. Ito, ito, lapas, wait. Ito, ito, lapas, pala itong targeto ng B. Then, now, +[195.07s -> 204.40s] Ang aning nga case, as you move down, gusto mo move down kayo, naman tayong measurement ko dyan. As you move down, by how much do you move down? +[204.69s -> 215.98s] Same, x lang di happen. Okay, so, move down by x. So, therefore, 1000 times 9.81. +[215.98s -> 230.48s] times x. So, simply mag-cancel ang kinasila and it simply tells us that the pressure here and the pressure here is just the same. And now, we go upward towards B. So, the pressure decreases by +[230.48s -> 244.13s] Rho gh, 1000 times 9.81 times height which is h3, in this case which is 4, and the pressure at B, that is now equal to the pressure at point B. +[244.13s -> 254.00s] Pb there. And in this case, Pa and Pb is just, you know, could be set to 0. Or they could just really be equal. Equal man sa atmospheric. +[254.61s -> 265.58s] And therefore, here, H2 could be solved. Therefore, H2 is equal to the value sa H2. 1.19 +[266.48s -> 279.14s] meters. Okay? Yung anak lang, 1.19 meters. There are a lot of ways in solving this one. This is one of the ways that I am familiar with. So that's the idea and I hope +[279.14s -> 281.71s] you get something out of this. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_15.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..24b6c294828ad840050c210e9272ebb91701944d --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_15.mp4.txt @@ -0,0 +1,23 @@ +[0.18s -> 9.46s] Welcome to ElectroOnline. Now let's tackle the situation where we have a junction in the pipe. And so we start from a place where I have a greater... +[9.46s -> 16.62s] diameter and therefore a greater cross sectional area and now the pipe splits up into two or more smaller sections. +[16.62s -> 31.06s] What happens? Well, first, let's explore the idea that the pipe doesn't change. And here we have a cross-sectional area A1, and there we have a cross-sectional area A2, velocity V1 and velocity V2. So nothing changes in the pipe. It stays horizontal. +[31.06s -> 45.42s] it stays at the same altitude or same elevation and therefore if the cross-section areas are the same by necessity the velocities must be the same because a1v1 must equal a2v2. +[45.42s -> 59.70s] Remember that the amount of fluid flowing through the pipe per unit time, delta V delta T, is always going to be equal to the product of the cross-sectional area times the velocity. And if neither one of them changes, the other one cannot change either. +[59.70s -> 73.09s] remains constant even when the pipe changes elevation so that this is at a greater height notice if the cross-sectional areas are the same then by necessity the velocities must be the same +[73.09s -> 86.29s] Then taking a look at the Bernoulli's equation, knowing that the velocities remain the same, but h2 is greater than h1, the only way that can be compensated for then is not by the change in velocity. +[86.29s -> 90.22s] but by the change in the pressure. So since... +[90.96s -> 105.55s] If H2 is greater than H1, the equation then only can remain equal, the left side can only remain equal to the right side. If H2 is bigger than H1, that means that P1 must then be bigger than P2. +[105.55s -> 115.70s] pushing something to a higher elevation or a greater height that will then require a greater amount of pressure here to compensate for that additional height. +[115.79s -> 122.18s] Well splitting up a pipe into two smaller sections has kind of the same connotation, the same meaning. +[122.18s -> 131.94s] Because we now understand that by having a small diameter pipe, the internal friction in the pipe is going to be greater. There's going to be greater opposition. +[131.94s -> 140.10s] to the flow of the fluid and therefore we're going to have what we call frictional head loss as if we're pushing the fluid +[140.10s -> 153.09s] onto a higher elevation now even though this appears to be higher lower elevation this is simply a split in the pipe assuming that they remain at the same elevation but yet it will act as if we're pushing it up to higher elevation again +[153.09s -> 164.99s] the velocities cannot change because of the split. We can still say that the amount of fluid going into the junction must equal the fluid coming out of the junction, and therefore we can say that a1 v1 +[164.99s -> 178.86s] The product of the cross-sectional area times velocity here, which is of course the sum of all the delta V delta T's going into the junction, equals the sum of the delta V delta T's out, A2 V2 plus A3 V3. +[179.66s -> 191.22s] But again, nothing can change except for additional pressure to overcome the additional friction forces here. It's not going to change the velocity. +[191.22s -> 202.74s] unless of course the pressure is not available to push a greater amount of fluid or the fluid through at a greater velocity then of course the velocity will slow down but it'll slow down uniformly throughout the entire pipe +[202.74s -> 213.95s] In other words, if you were for some reason to create a greater frictional force here, then less fluid will flow unless you provide the additional force to push the fluid through. The same would happen here. +[213.95s -> 227.57s] But ultimately, what we're interested here is to say, well, what would be the velocities in these smaller pipes? And the only thing we need to worry about is this equation right here, that a1v1 here must equal the sum. +[227.57s -> 240.03s] of the a times v of all the pipes let's say there's three or four or five pipes from coming from the junction we simply would add up all the products of a2 v2 a3 v3 a4 v4 and so forth +[240.03s -> 252.13s] until the sum of all the ones on the right equal a1 v1 on the left and so that is therefore the only thing that will change we'll need a greater pressure here to push it through the two smaller pipes +[252.13s -> 259.57s] instead of having stayed with the same wide pipe all the way through. That's the only difference and that is how it's done. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_16.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_16.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2e6c74c08f2fd3df700f7766afe6ce81684c7e73 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_16.mp4.txt @@ -0,0 +1,51 @@ +[0.05s -> 14.42s] The rather long example we used for a system in the previous lecture, the power cycle or heat engine, serves to go back to another version of the second law of thermodynamics which states that it's impossible for a device to operate and produce a net amount of work +[14.42s -> 24.22s] if it only receives heat from a single thermal reservoir, without dumping heat into a low temperature reservoir. This is what is known as the Kelvin-Planck statement. +[24.22s -> 34.74s] We know that the second law helps us restrict the conservation of energy by giving it directionality. We know that heat spontaneously moves from a high temperature to a lower temperature. +[34.74s -> 48.70s] But just like it is possible to turn heat into work with a more complex cycle like the power cycle or heat engine, the only way to transfer heat from low temperature to high temperature locations is via a refrigeration or heat pump cycle. +[48.70s -> 59.97s] These cycles operate in a very similar manner to the power cycles or heat engines. We talk about refrigeration or heat pump cycles together because they basically work in the same way to each other. +[59.97s -> 69.98s] The only difference is that in an air conditioning system or refrigeration cycle, we want to keep a volume cool, while heat pumps are usually used to keep a volume warm. +[69.98s -> 83.15s] The system schematic for this refrigeration slash heat pump is very simple. We have a low temperature reservoir from which we are going to extract heat, and we are going to provide heat to a high temperature reservoir. +[83.15s -> 94.96s] Of course, we can only do this if we provide the system with a network in, otherwise this would not be possible. These systems consist of an evaporator, which is similar to the boiler, +[94.96s -> 108.90s] We just call it evaporator because as opposed to the boiler where the temperatures are really really high, evaporators work at normal temperatures, but they both turn liquid into vapor. Then we pass through a compressor to obtain a high pressure vapor. +[108.90s -> 117.23s] which requires work to operate and then the fluid passes through a condenser and then to a throttling device slash expansion valve. +[117.30s -> 129.66s] Just like in the power cycle, both in the evaporator and condenser, the pressure remains mostly the same and any changes are negligible. The evaporator is where we take heat in from a low temperature source. +[129.66s -> 142.08s] And notice that we should be saying source as opposed to reservoir, as depending on if it's a heat pump or a refrigeration cycle, we do want for one of these sources to change temperature as it loses or gains heat. +[142.08s -> 156.74s] It's not an infinite reservoir that remains at the same temperature despite the heat that we add or remove. So we'll still say reservoir, but just know that the low and high temperature locations can still vary in temperature if heat increases or decreases. +[156.74s -> 167.84s] The compressor, which was initially described as the opposite of a turbine in the steady state mechanical devices lecture, link below, brings up the pressure and temperature of the fluid while using work. +[167.84s -> 182.13s] as opposed to letting the fluid lose pressure and temperature while producing work, which is what happens in a turbine. This means that the constant pressure in the evaporator is low, while the constant pressure in the condenser is high. Same with the temperatures. +[182.22s -> 195.81s] At the condenser, heat is rejected into a high temperature reservoir. Now it sounds weird to say that we take heat from a low temperature source and provide heat into a high temperature reservoir or warm reservoir. +[195.81s -> 207.92s] But this is not contradicting any thermodynamics laws because, like you see here, the temperature of the fluid at the condenser is already high. Even higher than that of the quote unquote high temperature source. +[207.92s -> 221.14s] so heat will spontaneously flow from the high temperature of the fluid to the still relatively high but also lower temperature of the warm reservoir. And the opposite is true for the evaporator, since the temperature of the fluid is low, +[221.14s -> 235.38s] lower than the temperature of the low temperature reservoir, or cool reservoir. And finally, from the same lecture linked below, we remember that the throttling device will maintain the enthalpy of the fluid while also dropping its pressure considerably. +[235.50s -> 245.74s] So let's position this cycle schematic inside each of the three most common examples for refrigeration slash heat pump cycles, beginning with an actual refrigerator or fridge. +[245.74s -> 258.27s] In a fridge, the interior volume where we keep all the food and items we want to refrigerate would be the cool reservoir. We are removing heat from it into our fluid, in this case a refrigerant, not water. +[258.27s -> 272.69s] which is even colder than the refrigerated space, and we want that refrigerant fluid to go through the rest of the cycle. Our warm reservoir would be the surrounding volume outside the fridge, usually the back or the bottom of the fridge. +[272.75s -> 283.58s] A freezer would operate on the exact same type of cycle. In the case of an air conditioner, the cool reservoir would be the space that is being cooled, for example a house or a car, +[283.58s -> 294.45s] And the warm reservoir is the exterior, which if you're running the AC at all, is most likely already hot. We take heat out of the cool space to toss it back to the warm exterior. +[294.48s -> 305.65s] And finally we have heat pumps, which are used to bring up the temperature of a space. These are of course used to make spaces warmer, and they are usually used in places that do not get that cold. +[305.68s -> 318.67s] These types of heat pumps are common in coldish weather locations, but not extremely cold regions of the world. If you're interested in what is used in colder places, I'll leave a link to that in the description of this video. +[318.67s -> 328.86s] What's cool about these heat pumps is that it's the exact same unit as your air conditioning system. They just operate in the opposite direction to the refrigeration cycle. +[328.86s -> 341.86s] When you set your house thermostat or a car's AC to heating instead of cooling, all we're doing is changing the direction of this cycle. The cool reservoir is now called warm, a warm car or a warm home. +[341.86s -> 352.48s] The warm reservoir is now called cold, the cold exterior, and the condenser and evaporator just change names. These two are really just heat exchangers. +[352.48s -> 366.96s] Remember that steady state mechanical device we covered in the third of the three series lectures? It's linked in the description below if you need a refresher. So they'll basically allow the exchange of heat between the refrigerant fluid and the surrounding air. +[366.96s -> 380.77s] Of course, a fridge, an AC, or a heat pump doesn't just allow the heat transfer to occur through natural convection, meaning no forced airflow. There is always some sort of fan that forces the air to flow at a certain speed. +[380.77s -> 391.94s] like in a car's AC vents, so that the heat transfer happens at a quicker rate through what we called force convection. You'll learn more about those types of heat transfer in your heat transfer class. +[391.94s -> 406.32s] Link to that course's playlist down in the description of this video if you're interested or plan on taking that in the near future. Now, in cycles like these, we don't talk about efficiency since under the definition of efficiency, we would be getting values greater than 1. +[406.32s -> 416.46s] In these types of cycles where we're adding work so that the cycle happens, we call it coefficients of performance to assess how well the refrigeration or heat pump cycle performs. +[416.56s -> 428.32s] You can still think about the term as how efficient these cycles are, but just not from the thermodynamic meaning of the word efficiency, just how well they perform at a task they are created for. +[428.32s -> 440.64s] The coefficient of performance or COP is therefore dependent on the goal of our system. In general, the coefficient of performance is defined as the desired output over the required input. +[440.64s -> 450.98s] But for example, for a refrigeration cycle, what we want is to get heat out of a cool space, so the desired output is Q in, and the required input is W in. +[450.98s -> 458.03s] Notice that it's heat out of the cool space, but that heat is coming in to the fluid of our cycle. +[458.48s -> 472.00s] And just like we did for the power cycle in the previous lecture, link below, drawing a control volume around the entire cycle, from our energy conservation we see that W net is equal to Q net, or Q in minus Q out. +[472.00s -> 486.19s] And since the net work is the only work which is coming into the control volume at the compressor, and work coming in is by convention negative, W net is minus W in, and therefore work in is Q out minus Q in. +[486.42s -> 498.78s] And this is applicable for total energies W and Q's or energy rates W dot and Q dot. This means that it's applicable with heat and work or heat rates and power. +[498.78s -> 511.31s] In the case of heat pumps, the desired goal is to heat our house, or any space, and therefore the desired output is Qout. For that reason, the coefficient of performance becomes Qout over Wn. +[511.38s -> 518.93s] Everything we learned here agrees with the second version of the second law of thermodynamics, also known as the Clausius statement. +[518.93s -> 529.65s] which states that it is impossible to construct a device that operates on a cycle and produces no effect other than the transfer of heat from a low temperature body to a high temperature body. +[529.65s -> 543.41s] Let's look at a really simple and quick example on coefficient of performance, and if you want to check out other examples on heat pumps and refrigeration cycles, make sure to check out the links in the description below. What is the COP of a heat pump? +[543.41s -> 555.04s] that supplies heat to a house at a rate of 6000 kilojoules per hour for each kilowatt of electric power it draws. What is the rate of energy absorption from the outdoor air? +[555.04s -> 567.89s] From what we learned today, the COP is the desired output, meaning the heat that we're providing the house with, and again out of the device into the house over the energy or work that is being drawn. +[568.05s -> 580.54s] We substitute the values, we do a simple unit conversion, and we find a COP of 1.6 repeating. As for the heat rate being absorbed from the surroundings and from a simple control volume, +[580.54s -> 590.10s] We know that the heat we took plus the energy we added is the heat provided to the house. Therefore, the heat in is equal to the heat out minus the work. +[590.10s -> 599.36s] We substitute the values, again with a simple unit conversion, and find that the heat in is 2400 kJ per hour. And that's it. +[599.36s -> 613.46s] Like I said, if you want to check out other examples on this topic or other lectures of the Thermo course and other engineering courses, make sure to check out the links I left in the description of this video. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_2.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0c22700bfdc0c84e0c0bc372ae21f7d5e8f6078f --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_2.mp4.txt @@ -0,0 +1,77 @@ +[0.69s -> 14.00s] Hey y'all, this is a thermodynamics skill chunk on heat engines and the idea of second law efficiency, which is a way of thinking about efficiency as it relates to the second law of thermodynamics. +[14.96s -> 29.30s] So first of all, what do we mean by a heat engine? A heat engine is a device that converts heat into work or vice versa. We'll find out about the vice versa. It's a really important concept. +[29.30s -> 41.70s] for assessing the efficiency of power plants, refrigeration cycles, and other systems that convert between heat and mechanical power. Let's look at a few examples. The train engine. +[41.70s -> 49.58s] the train engine converts heat to power those are power mechanical power on the wheels a power plant +[49.58s -> 62.77s] also converts heat to power, but in this case we're taking mechanical power and use a generator to turn that into electricity to push on electrical power. An air conditioner is also a heat engine. +[62.77s -> 76.53s] but it's one that does the conversion in the opposite way. In this case we need power and we use that power to generate heat. Now in this case what we're doing is we're taking heat +[76.53s -> 88.30s] out of a house and putting the heat outside. That's how the air conditioner works. It pulls heat out of the air in the house, pushes that heat outdoors. It's essentially concentrating the heat. +[88.30s -> 94.32s] The heat otherwise would be going the other direction. So in this case, we're using power to concentrate heat. +[94.83s -> 109.42s] All of these are heat engines, and the upper limit of efficiency for any heat engine is constrained by the second law of thermodynamics, which tends that systems tend toward less ordered states. +[109.42s -> 113.62s] systems will tend towards disorder and the +[113.62s -> 127.89s] how close we can get to this theoretical best efficiency is what we call the second law efficiency. Now, if you want to see more about the second law and on entropy, which is the formal term for describing the disorder in systems, really +[127.89s -> 141.07s] suggest go to watch some other videos or do some reading to understand the second law of thermodynamics. We're not going to talk about that here. We're just going to presume we have a sort of understanding of that or just breeze past it and just... +[141.07s -> 143.15s] Focus on the equations. +[145.58s -> 160.18s] So a power plant, as we mentioned, is a heat engine. It's a really important one for those of us who are working on energy and environmental systems because fossil fuel power plants are what drives climate change. So we really need to know it's one of the things that drives climate change, not the other. +[160.18s -> 169.22s] only one, but we really need to know how these things work. We've already talked about the first law efficiency and that's shown here. +[169.22s -> 181.46s] So if we talk about the first law efficiency of a power plant, it simply relates the work that we get out divided by the flow of heat, in this case it's coal, coming in. +[181.71s -> 194.86s] So this is a power plant and what we saw in an example previously was that a typical first law efficiency for a power plant like this might be +[194.86s -> 206.96s] 35%. So 35% of all the energy that's contained in coal eventually becomes electricity. The other 65% is waste heat. +[207.63s -> 212.24s] waste heat that comes out the top or goes down into cooling water. +[213.26s -> 226.67s] So the question that we want to ask with the second law and with the sort of analysis of the power plant as a heat engine, we want to know just how good is it to be 35% efficient? +[226.67s -> 232.11s] What is that compared to? What's the theoretical best efficiency and how close are we? +[235.18s -> 246.70s] Before we answer that question, we need to know something about the theoretical best. And the way that we do that is we consider the power plant as a heat engine. +[246.70s -> 259.14s] and this diagram shows the kind of classic diagram for thinking about heat engines instead of looking at a picture of a power plant we're just going to look at this diagram +[259.14s -> 269.97s] Now, it does map on to the power plant. In this case, the engine is the combination of the boiler and the steam turbine. +[270.00s -> 278.66s] And we're going to imagine that we've got one hot reservoir and one cold reservoir. So we've got a hot... +[278.66s -> 292.11s] in a cold heat is flowing from the hot side to the cold side through the engine and the engine does work based on that flow of heat so that's our fundamental concept for the heat engine is that +[292.11s -> 305.78s] temperature goes from hot to cold we've got heat flowing qh qc and that there's work coming out of the engine +[306.64s -> 317.07s] Notice that the work is going to have to equal QH minus QC. +[317.42s -> 330.08s] because of the first law of thermodynamics. We need to be able to draw an energy balance around that heat engine. So we know work is equal to QH minus QC. So that's how we can write this. +[330.08s -> 343.78s] alternative form of the efficiency equation we know that efficiency of the engine is the work divided by the heat that we put in the heat that we put in in this case is the hot +[343.78s -> 358.16s] side work, or the hot side heat, QH, we can also reframe the net work of the system as QH minus QC because of the first law. +[358.67s -> 371.82s] All right, so this is just getting us set. So now we've got our heat engine idea. The source, remember, of QH is burning coal. The work that we get out of our power plant is electricity. +[371.82s -> 374.77s] But we can analyze it as a heat engine. +[379.86s -> 393.87s] we want to know something about the maximum work that would tell us about the maximum efficiency of this heat engine. And it so turns out that the maximum work possible that comes out of a heat engine +[393.87s -> 403.06s] is related to the temperature difference between the hot and the cold side. And it's related this way. +[404.11s -> 418.46s] The maximum efficiency in this case is equal to this formula. So the maximum efficiency for any heat engine +[418.46s -> 428.59s] is equal to the temperature on the hot side, TH, minus the temperature on the cold side divided by the temperature on the hot side. +[428.98s -> 443.06s] And we call this the Carnot efficiency. It looks like Carnut, but Carnot was the name of a person who wrote down and figured out this relationship for heat engines. +[443.79s -> 455.41s] And one thing that we can do is we can also kind of use algebra and rewrite this as one minus the temperature on the cold divided by the temperature on the hot. +[455.41s -> 466.48s] There's a really important note at the bottom here is that these temperatures all have to be in absolute terms on the Kelvin or the Rankine scale. So remember that Kelvin +[466.74s -> 476.06s] degrees are equal to some number of degrees Celsius plus 273.15 +[476.06s -> 489.52s] So zero degrees Celsius is the same as 273.15 Kelvin. And then there's another relationship for Rankine, which is for the absolute temperature that's related to Fahrenheit. +[489.52s -> 502.85s] So we always need to use absolute temperatures when we're making these assessments and figuring out what's the best possible efficiency. Or we sometimes call that the Carnot efficiency. +[502.85s -> 507.66s] that would be the best possible maximum efficiency for our power plant. +[509.26s -> 522.83s] Let's consider that coal-fired power plant. Some temperatures that might be at play might be 200 degrees Celsius, double boiling water, and 10 degrees Celsius. Something like... +[522.83s -> 528.53s] the atmospheric environment. We want to know what's the maximum efficiency here. +[532.72s -> 538.22s] So first of all, we need to convert this to Kelvin. +[540.34s -> 549.26s] So 200 degrees Celsius in Kelvin is going to be 473.15 Kelvin. +[549.74s -> 560.59s] And 10 degrees Celsius is going to be 10 plus 273.15, or 283.15 Kelvin. +[561.62s -> 568.88s] So we're going to compare the hot side to the cold side using this formula. +[579.82s -> 593.81s] Oh, and let me, oh, went one too far. So if we multiply, or I'm sorry, if we plug into our formula here, our maximum efficiency is equal to one minus the... +[593.81s -> 603.78s] cold divided by the hot and that's equal to 40 percent so operating between a 200 degree and 10 degree reservoir +[603.78s -> 617.36s] gives us a maximum theoretical efficiency of 40%. We'll never get better than that. It's just not possible based on those two temperatures. Now what can we notice here? One thing that we can notice is that +[617.74s -> 618.86s] Um. +[619.92s -> 633.95s] is that the ratio of cold to hot is one of these kind of limiting factors. So the closer these two temperatures are together, in other words, +[633.95s -> 648.18s] the closer together the hot and the cold side, TC divided by TH is going to be closer and closer to one, which is going to push down our maximum efficiency. If cold and hot are really far apart, +[648.18s -> 650.45s] our efficiency can be better. +[652.43s -> 665.68s] And so let's see how that plays out. What if our temperature for the high temperature reservoirs increased? And now it's 300 degrees. We still have the same cold reservoir. In this case, +[665.68s -> 679.84s] we have a higher possible efficiency we can get an efficiency up to 50 if we have a hotter temperature on the hot side so this would tend to make us want to build power plants that can be hotter and hotter +[679.84s -> 694.13s] on the inside of the boiler because we have a higher maximum efficiency, but then we become limited by our materials, you know, like maybe the steel that we're using gets brittle at that temperature. So there's always going to be some drawbacks, but this relates... +[694.13s -> 705.42s] shows us something about what we should want. We should want to have a bigger difference between the hot and the cold side if what we're doing is we're trying to extract work from our Carnot engine. +[713.42s -> 723.02s] So here is an example of a power plant, and we're drawing it a little bit differently. I want to describe this diagram because it's one that you'll see a lot. +[723.02s -> 737.36s] We won't necessarily need to analyze all the different parts, but it's important to know a little bit about how these power plants work. This diagram shows how we can provide heat to the boiler, and in this case we're providing heat. +[737.36s -> 751.73s] at 600 degrees Celsius, which is the operating temperature of the boiler. What happens is that the boiler takes liquid water and it creates vapor at 600 degrees. +[752.62s -> 767.01s] That water vapor goes through a turbine Spinning the turbine to generate work So it's like a big fan that the water vapor goes through it comes out at lower pressure +[767.01s -> 779.38s] lower temperature so we've reduced the pressure and the temperature on the outlet and we need to condense the the vapor down to a liquid in order to put it through the pump +[779.44s -> 788.05s] and pump our liquid back into the boiler. And the power that generates that pump comes off the turbine as well. +[788.37s -> 800.75s] And so our condenser is operating at 20 degrees Celsius. So the operating temperatures of our boiler and our condenser define the temperatures for our heat engine, and we've got work coming off. +[805.68s -> 819.95s] Let's remember, what is our equation? What is our maximum efficiency that we could operate at? Remember, the maximum efficiency is equal to 1 minus the cold divided by +[819.95s -> 822.06s] the hot temperature. +[827.12s -> 838.82s] So that's when we work out using 600 degrees and 20 degrees, that maximum efficiency, it turns out that the maximum is 66%. +[838.82s -> 843.63s] And we can compare that to the typical efficiency of a power plant, which is 35. +[844.11s -> 855.47s] And that comparison is what we're going to call second law efficiency. So that has to do with how well we're doing compared to that theoretical maximum. +[859.18s -> 872.48s] So another way of writing this is that we say that the second law efficiency is the actual first law efficiency, so 35% in the case of our power plant. +[872.48s -> 883.25s] divided by the maximum or the Carnot efficiency for a heat engine operating at the same temperature range. In this case, it was 66%. +[889.17s -> 903.12s] So given that, given 35% typical efficiency, actual operating efficiency, and 66% is the maximum, we would say that the second law efficiency of this power plant is 53%. +[903.12s -> 911.18s] In other words, it's operating at 53% of the best it could possibly do given the temperatures that are involved in the power plant. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_21.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_21.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..84a12db041426f53ff21d29ae0bf865587177a7f --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_21.mp4.txt @@ -0,0 +1,63 @@ +[0.98s -> 9.78s] In this video, we're going to go over a few problems associated with absolute pressure and gauge pressure. So let's start with this one. +[10.10s -> 18.67s] The pressure inside a tank is 4.2 atm at sea level. What is the gauge pressure inside the tank? +[19.50s -> 33.14s] So what you need to know is that the gauge pressure is the difference between the total pressure and the atmospheric pressure. Let's call the atmospheric pressure PA. +[33.71s -> 46.48s] The total pressure is the same as the absolute pressure. So the gauge pressure is basically the pressure that's measured relative to the atmospheric pressure. +[47.60s -> 62.06s] Now we have the pressure inside the tank, or the total pressure, and that's 4.2 atm. At sea level, the atmospheric pressure is 1 atm, so the gauge pressure is 3.2 atm. +[65.10s -> 71.25s] That's the pressure above the atmospheric pressure. And so that's the answer for this problem. +[72.69s -> 82.26s] 2. If the pressure inside a storage tank is 0.9 atm at sea level, then what is the gauge pressure inside the tank? +[82.77s -> 95.50s] So this question is very similar to the last problem. And so we could use the same formula. The gauge pressure is the difference between the absolute pressure, or the total pressure, and the atmospheric pressure. +[97.07s -> 109.54s] So the total pressure inside the tank is 0.9 atm. And we know that the atmospheric pressure at sea level is always going to be 1 atm. And keep in mind, 1 atm is... +[109.54s -> 121.39s] 101.3 kilopascals. So the gauge pressure is going to be 0.9 minus 1, which is negative 0.1 atm. +[123.57s -> 137.63s] So a negative gauge pressure means that the absolute pressure inside the tank is less than the atmospheric pressure. A positive gauge pressure means that the pressure in the tank is above. +[137.63s -> 152.05s] the atmospheric pressure. Number three, a tire gauge measures the pressure of a tire to be 325 kilopascals. What is the absolute pressure inside the tire at sea level? +[152.66s -> 163.50s] So the absolute pressure, which is basically the total pressure, is the sum of the atmospheric pressure plus the gauge pressure. +[166.16s -> 173.84s] So we know that the atmospheric pressure at sea level in kilopascals is 101.3 kPa. +[174.96s -> 182.42s] And in this problem, the gauge pressure of the tire is 325 kilopascals. +[183.18s -> 198.16s] So the total pressure is going to be the sum of these values. So it's 101.3 plus 325. And so it's 426.3 kilopascals. +[198.74s -> 206.10s] So that's the total pressure or the atmosphere. I mean the absolute pressure inside this particular tire +[206.90s -> 219.44s] Number four, a diver is currently located at a depth of 50 meters in the ocean. What is the gauge pressure at this point? And what is the absolute pressure? +[223.54s -> 232.88s] So let's say this is the water or the ocean and the diver is somewhere +[235.98s -> 248.46s] right here. So it's 50 meters below the surface of the water. How can we find the pressure at that level? +[250.67s -> 258.64s] now what you need to understand is that the gauge pressure is The pressure due to the fluid due to the water alone +[258.90s -> 267.76s] The absolute pressure is going to be the total pressure due to the weight of the water above him plus the weight of the atmosphere. +[268.62s -> 282.96s] So the weight of the water above the diver will give you the gauge pressure. And the weight of the water plus the weight of the air above him will give you the absolute pressure. So first we've got to find the gauge pressure. +[285.84s -> 293.39s] Now pressure is defined as force divided by area. So we want to find the gauge pressure due to the water. +[293.78s -> 300.85s] So what we need is the force of all of the water molecules above the diver. +[302.51s -> 317.26s] divided by the area of the diver. Now, the force that all of these molecules exert is basically the weight of all of that water above the diver. And the weight force is simply mg. +[319.12s -> 331.28s] Now when dealing with fluids, you don't want to use the mass of the fluid. Rather, you want to use density and volume. Density is mass divided by volume. +[331.66s -> 341.78s] So mass is density times volume. So let's replace M in this equation with PV. +[343.09s -> 353.52s] So this lowercase p is basically rho. That's the density of the fluid times the volume of the fluid times gravitational acceleration divided by the area. +[354.80s -> 362.19s] Now the volume of an object can be described as the area times the height. So for example, let's say if you have a cylinder. +[365.17s -> 379.89s] The volume of this cylinder is the area of the base, which is the circle, times the height. And the area of that circle is pi r squared. So therefore, this is the volume of the cylinder, pi r squared times h. +[382.03s -> 394.03s] But in this example, we're going to replace the volume with the area times the height So we could cancel a on the top and on the bottom +[394.58s -> 408.27s] So this is the formula you need to calculate the gauge pressure due to a fluid. It's the density of the fluid times the gravitational acceleration times the height. So now I can get rid of this other stuff. +[418.10s -> 429.39s] So the gauge pressure is going to be the density of seawater since the diver is in the ocean. So that's 1025 times g, which is 9.8. +[430.19s -> 442.86s] times the height of 50 meters so 1025 times 9.8 times 50 That's going to give us a gauge pressure of 500 2000 +[443.28s -> 456.78s] and 250 pascals. So let's convert that to kilopascals. So let's divide it by 1,000. So we could say we're going to round it. It's about 502. +[457.52s -> 465.68s] kilopascals So that's the gauge pressure due to the water above the diver +[470.45s -> 483.60s] Now what is the absolute pressure? So the absolute pressure is based on the weight of the seawater above the diver, which represents the gauge pressure, plus the pressure of the atmosphere. +[486.58s -> 494.80s] So the gauge pressure is 502 kilopascals. The atmospheric pressure is 101.3 pascals. +[495.95s -> 502.77s] So if you want to get a more exact answer, it's 502 point 25 plus 101 point 3 +[507.44s -> 521.14s] So that's going to be 603.55 kilopascals. So that's the absolute pressure at this point. +[522.93s -> 530.77s] Number 5. In the figure shown below, the height of the water and oil are 15 meters and 8 meters respectively. +[531.38s -> 539.12s] The container is open to the atmosphere. What is the gauge pressure and absolute pressure at the oil-water interface? +[540.34s -> 552.62s] So this is the oil water interface. So the gauge pressure is going to be due to the weight of the oil alone. So let's find the gauge pressure first. +[553.20s -> 567.95s] So the gauge pressure is going to be pgh, the density of the oil, which is 750, times the gravitational acceleration, which is 9.8, and the height in meters is 8 meters. +[568.50s -> 576.43s] 750 times 9.8 times 8 that's going to give us a gauge pressure of 58,000 +[576.69s -> 589.30s] 800 pascals but now let's convert it to kilo pascals let's divide it by a thousand so this is going to be fifty eight point eight kilo pascals +[589.87s -> 596.98s] So that's the gauge pressure at the oil water interface now the total pressure +[598.19s -> 611.22s] is going to be the gauge pressure plus the atmospheric pressure. So it's based on the weight of the oil above the interface and the weight of the air molecules above the oil. +[612.14s -> 617.52s] So it's going to be 58.8 plus 101.3. +[623.02s -> 636.37s] So the total pressure is going to be 160.1 kilopascals. So that's the absolute pressure at the oil water interface. +[643.34s -> 655.15s] Now let's move on to Part B. So what is the gauge pressure and the absolute pressure at the bottom of the container? So let's start with the gauge pressure. +[656.05s -> 664.50s] The gauge pressure, which is the pressure relative to the atmospheric pressure, is going to be due to the weight of the oil and the water. +[666.90s -> 680.82s] So we're going to have the pressure due to the oil plus the pressure due to the water. So we've got to add these two. So it's going to be PGH for the oil plus rho GH for the water. +[683.09s -> 691.54s] So the density of the oil, we know it's 750. G is 9.8. And the height is 8. +[692.98s -> 702.67s] That's for the oil now for the water the density is a thousand. You just need to know that G is 9.8 again and the height of the water is 15 +[704.75s -> 718.03s] So we know that 750 times 9.8 times 8, that's 58,800. And 1,000 times 9.8 times 15. +[718.61s -> 725.94s] That's 147,000 pascals. So if we add these two numbers... +[726.45s -> 740.85s] This will give us a gauge pressure of 205,800 pascals. So if we divide that by 1,000, that's going to be 205.8 kilopascals. +[741.87s -> 755.66s] So that's the gauge pressure at the bottom of the container. Now the absolute pressure is simply the sum of the gauge pressure and the atmospheric pressure. +[758.51s -> 764.72s] So we have the gauge pressure as 205.8, and the atmospheric pressure is 101.3. +[770.19s -> 778.93s] And so the absolute pressure is going to be 307.1 kilopascals. And so that's the answer. +[779.86s -> 788.46s] That's the total pressure at the bottom of the container So that's due to the weight of the water the oil and the air above it diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_22.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_22.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2027c749d4ade9ea7be389865aaefc8e79a5fe94 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_22.mp4.txt @@ -0,0 +1,21 @@ +[0.59s -> 14.90s] Today I will solve one numerical problem based on application of Bernoulli's equation. Here I will calculate gauge pressure in a pipe flow. So here is the problem statement. +[15.31s -> 27.89s] so water is flowing in a circular pipe at one section of the diameter is 0.3 meter and the tatic pressure is 260 kilo pascal gauge and velocity is +[27.89s -> 41.97s] 3 meter per second and the elevation is 10 meter above the ground level so uh this point so i am considered as one point so here v1 is 3 meter per second diameter is 1 3 meter and +[41.97s -> 52.46s] pressure here p is p 1 that is 260 kilo pascal and elevation is z 1 that is 10 meter +[53.07s -> 67.44s] the elevation at a section downstream is 0 meter so z2 is 0 and the pipe diameter is 0.15 meter and find out the gauge pressure at the downstream section so friction +[67.44s -> 75.41s] effect may be neglected assume density of water to be 99 kg meter cube +[76.30s -> 90.21s] Now first given data so diameter is given D1 0.3 meter diameter at section 2 diameter is given 0.15 meter Z1 is 10 meter +[90.21s -> 103.82s] z2 is 0 meter p1 is 160 kilopascal gauge and velocity at section v1 is 3 meter per second and density of water row that is 99 kg per +[103.82s -> 116.66s] meter key now if we apply Bernoulli sorry first we have to apply continuity equation so we know that quantity equation a1 v1 is equal to a2 v2 so a1 that will be +[116.66s -> 131.12s] pi by 4 d 1 square a 2 is pi by 4 d 2 square so a 1 is nothing but pi by 4 0.3 whole square so that is 0.070 meter square and a 2 pi by 4 0.15 +[131.12s -> 135.66s] whole square so that is 0.0177 meter square +[136.88s -> 151.28s] now using coordinate equation so v2 is nothing but a1 v1 by a2 so 0.0707 into 3 divided by a2 a2 will be something +[151.98s -> 161.30s] here that is something 0.177 so that is 11.7 meter per second +[162.38s -> 175.60s] Now after get so here v2 we got so v2 is nothing but 11.7 meter per second so we know v2 we know v1 +[175.60s -> 181.23s] P1 D1 and we have to calculate P2 so for that +[182.54s -> 196.34s] we apply Bernoulli's equation so P 1 plus half Rho V 1 square and then plus Rho g z1 is equal to P 2 plus half Rho V 2 square +[196.34s -> 204.56s] plus rho g z2 so now the rearrange to solve for the p2 so p2 will be p1 +[204.94s -> 218.90s] plus half rho v1 square minus half rho v2 square plus rho g z1 minus z2 so now plug all this value so 260 into 10 to the power 3 plus half 999 +[218.90s -> 230.93s] into 3 square minus half 999 into 11.7 whole square plus 999 plus 9.81 into 10 minus 0 +[231.25s -> 240.66s] so now from here so rho g z1 minus z2 so 10 minus so now if I do the calculation finally I will get p2 is nothing but +[241.20s -> 255.60s] 289503 pascal so 289.5 pascal so gauge pressure at the downstream section is 289.5 kilopascal so that's it thank you diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_28.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_28.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5373d396f7ab6eb3a12577dadaaab8deb672100e --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_28.mp4.txt @@ -0,0 +1,18 @@ +[1.10s -> 11.62s] Okay, this question deals with an important concept from Chapter 3. This one's a little embarrassing for me as an instructor, as I'll explain at the end of the video. +[11.62s -> 25.09s] this question shows liquid water flowing down a steeply inclined pipe the pipe is completely filled with water and has a constant inside diameter the question asks which curve +[25.09s -> 39.22s] represents the average velocity u bar along the length of the pipe and i've shown a sketch here of the average velocity so does the average velocity increase along the pipe stay constant +[39.22s -> 51.76s] decrease linearly along the pipe, or increase nonlinear along the pipe. If you've done some problems involving pipe flow in Chapter 3, you should be able to answer this question. +[54.03s -> 56.94s] You might want to pause the video here and think about it. +[61.58s -> 70.21s] So the answer is curve B. The average velocity of the fluid remains the same along the entire length of the pipe. +[70.21s -> 83.70s] You can understand this by looking at the definition of volume flow rate. We learned in Chapter 3 that the volume flow rate in say cubic meters per second is the average velocity times the cross sectional area of the pipe. +[83.82s -> 92.67s] Now for this problem, we have liquid water, so we have an incompressible flow. And for an incompressible flow, the volume flow rate is a constant. +[92.67s -> 100.50s] So at any cross-section of the pipe, we have the same volume flow rate, the same number of cubic meters per second passing any section. +[100.50s -> 112.93s] And we can rearrange Q equals U bar A, and we can get that the average velocity is the volume flow rate divided by the cross-sectional area of the pipe. And if the flow rate's a constant, +[112.93s -> 123.15s] and clearly the cross-sectional area of the pipe is a constant because the internal diameter is constant, then the average fluid velocity at any x location is a constant. +[123.41s -> 136.40s] Now, this type of pipe flow would normally be driven by a pump, but this answer is the same even for a purely gravity-driven flow. This is not like a ball rolling downhill. The flow doesn't speed up. +[136.53s -> 139.39s] It's even true for an unsteady flow. +[139.39s -> 152.02s] If, for example, the pump increases the flow rate, the instantaneous flow rate will be the same at any cross section in the pipe. So the average velocity of the fluid will be the same at any x location in the pipe. +[154.13s -> 163.47s] I asked this question on a quiz after my students had finished studying Chapter 3, and these are the sad statistics. +[163.47s -> 176.08s] If you picked curve A or curve C and thought that the mean flow velocity increased along the pipe, you're not alone. About 85% of my students thought this too incorrectly. +[176.40s -> 183.38s] So I'm not proud that only 8% of my students got this question correct. This was definitely a failure on my part. +[183.66s -> 191.57s] So I thought it'd be useful to take a few minutes and make this video. I hope this short video helps to correct this common misconception. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_3.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d6814357d9968c3d31b35cd4e285d315667b8113 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_3.mp4.txt @@ -0,0 +1,62 @@ +[1.84s -> 14.83s] Let's start with this question. The volume flow rate in a circular pipe with a diameter of 4 meters is 50 cubic meters per second. What is the speed of water in this pipe? So let's draw a picture. +[15.47s -> 24.94s] And so here's the pipe. If the diameter is 4, that means the radius has to be 2 meters. +[27.41s -> 42.38s] And the volume flow rate, which is the change in volume divided by the change in time, that's 50 cubic meters per second. So how can we use the volume flow rate to calculate the flow speed in the pipe? +[44.59s -> 55.66s] Volume is area times height. In this case, the height could be just the horizontal displacement. So we can say that volume is going to be area times displacement. +[57.33s -> 62.90s] So the change in volume is the area times the change in the horizontal displacement. +[63.28s -> 74.45s] So delta V over delta T, that's going to be A times the displacement divided by the time. Displacement over time is velocity. +[75.60s -> 82.86s] So the volume flow rate is equal to the cross-sectional area times the speed of water. +[89.20s -> 101.62s] So we have a volume flow rate of 50 cubic meters per second. And the cross-sectional area is pi r squared, since we have a circle. +[102.64s -> 117.49s] So that's going to be pi times 2 squared. And that's going to equal the speed. So we have 50 on the left, 4 pi on the right. So it's 50. +[118.00s -> 131.22s] divided by 4 pi so the water is flowing at a speed of 3.98 meters per second +[131.79s -> 144.69s] And so that's the answer to this problem. Number two, water flows through a pipe with a cross-sectional area of 10 square centimeters at 3 meters per second. +[145.36s -> 155.18s] What is the flow speed in the pipe if the cross-sectional area is reduced to 5 square centimeters? So as always, let's draw a picture. +[164.34s -> 175.28s] So the area, let's call it A1, on the left side is 10 square centimeters. And on the right side, let's say A2, that's 5 square centimeters. +[176.14s -> 189.97s] Now we have the speed of the water on the left. We need to find the speed on the right. On the left side, the speed is 3 meters per second. So how fast should it be moving on the right side? +[191.31s -> 201.42s] So if the area decreases, what's going to happen to the speed? Now imagine if you have a water hose in your hand and water is coming out of it. +[201.71s -> 210.54s] What's going to happen if you place your thumb on the tip of the hose to partially block it? What's going to happen to the water coming out of those? +[211.50s -> 222.13s] If you partially block the opening of the hose, water is going to come out at a greater speed. Perhaps you've experienced that. And so anytime you decrease the cross-sectional area... +[223.28s -> 236.34s] the speed of the fluid is going to increase. Now, how can we prove this with an equation? What we need to realize is that the mass flow rate has to be constant. +[238.45s -> 246.58s] The mass of water entering this container has to equal the mass of water leaving that container in a given time period. +[251.15s -> 265.90s] The mass flow rate is delta M divided by delta T. And we know that density is mass over volume, so mass is density times volume. So delta M is going to be the density times the change in volume. +[268.14s -> 280.59s] And volume is area times height, or area times displacement. So the change in volume is going to be the area times the change in height, or the displacement. +[281.36s -> 295.09s] And displacement over time is velocity. So the mass flow rate on the left side is going to be the density of the fluid times the area on the left side times the speed on the left side. +[295.79s -> 306.96s] And because the mass flow rate is constant, that has to equal the density times the area on the right side times the speed on the right side. And so we have the equation of continuity. +[311.34s -> 319.22s] Now, if the fluid is incompressible, which means that the density of the fluid is constant, we can cancel the row. +[319.98s -> 326.38s] So for this particular problem, we can say that a1 times v1 is equal to a2 times v2. +[335.54s -> 348.59s] Now A1 is 10 square centimeters. Now we don't need to convert the units to meters. As long as A1 and A2 have the same units, it's going to work out fine. +[348.98s -> 361.07s] V1 is 3 meters per second. A2 is 5 square centimeters. And now we get to solve for V2. So it's going to be 10 times 3 divided by 5. +[365.94s -> 374.29s] And so that's going to be 6 centimeters. So notice what happened. We decreased the area by a factor of 2. +[374.96s -> 385.14s] And so the velocity increased by a factor of 2. It went from 3 to 6. So as you decrease the cross-sectional area, the flow speed is going to increase. +[386.32s -> 400.46s] 3. Water flows through a circular pipe with a radius of 4 cm at a speed of 5 m per second. If the radius of the pipe increases to 8 cm, what is the new speed of the water in the pipe? +[401.87s -> 409.49s] So let's draw a picture. So that's the left side of the pipe, and it's going to get bigger this time. +[421.84s -> 435.66s] So on the left side the radius is 4 centimeters on the right side The radius is 8 centimeters So if we increase the radius +[435.98s -> 449.58s] of the pipe, what's going to happen to the speed? Well, because it's wider, we know the speed is going to decrease. But we double the radius, so by what factor should the speed decrease? By 2 or 4. +[450.93s -> 464.53s] Now, because the area is proportional to the square of the radius, the speed is inversely related to the square of the radius. So, if we double the radius, 2 squared is 4. +[464.53s -> 474.38s] the speed should decrease by a factor of 4. So it's going to be 5 divided by 4, which is 1.25. But let's go ahead and prove that answer. +[481.07s -> 486.06s] So the speed is 5 on the left side, and we need to calculate V2. +[488.59s -> 496.66s] So we can use this equation, a1 times v1 is equal to a2 times v2. The cross-sectional area is pi r squared. +[502.13s -> 515.89s] So we could cancel pi in the equation. R1 is 4. V1 is 5 meters per second. R2 is 8. +[516.34s -> 526.32s] And let's calculate V2. So it's going to be 4 squared times 5 divided by 8. Actually, divided by 8 squared. +[527.31s -> 539.25s] So 4 squared times 5 is 80, and 80 divided by 8 squared is 1.25. So that's the new speed. It's 1.25 meters per second. +[540.56s -> 554.48s] So if you double the cross-sectional radius, the speed is going to decrease by a factor of 4. If you triple the cross-sectional radius, the speed is going to decrease by a factor of 3 squared, or 9. +[558.38s -> 563.47s] Now let's move on to Part B. What is the volume flow rate in the pipe? +[569.07s -> 579.12s] So as mentioned before, volume flow rate is equal to the area times the velocity. So on the left side, the area is going to be pi r squared. +[582.06s -> 586.93s] So if we use the right side values, pi R2 squared times V2, it should give us the same answer. +[589.30s -> 601.17s] So on the left side, the radius is 4 centimeters, but we need to convert that to meters this time. So 4 centimeters is 0.04 meters. And the speed is 5 meters per second. +[607.86s -> 614.32s] And so the volume flow rate is 0.0251 cubic meters per second. +[615.18s -> 629.62s] Now, if you use the values for the right side of the pipe, you should get the same answer. So, it's going to be pi r2 squared times v2. So, r2 in this case is going to be 0.08. And v2... +[629.62s -> 643.12s] is 1.25 and this will give you the same answer of 0.0251 cubic meters per second +[649.39s -> 659.31s] Now let's move on to Part C. Calculate the mass flow rate. The mass flow rate is equal to the density of the fluid +[659.86s -> 669.62s] times the cross-sectional area times the speed. So let's focus on the values on the left side. The density of water is 1000 kilograms per cubic meter. +[670.77s -> 682.51s] The cross section or area is pi r squared, so that's pi times the square of the radius, which in meters, it's 0.04. You just gotta divide that by 100. +[683.31s -> 696.14s] and the speed on the left side is 5 meters per second. So basically, the mass flow rate is simply the density of the fluid times the volume flow rate. +[699.76s -> 710.48s] A times V represents the volume flowing. So pi times 0.04 squared times 5. +[710.90s -> 721.04s] which is this portion right here, that gave us a volume flow rate of 0.0251. Then if we multiply that by the density of the fluid, that's going to give us the mass flow rate. +[721.33s -> 733.55s] which is 25.1 kilograms per second. So now you know the relationship between the mass flow rate and the volume flow rate. +[733.87s -> 739.98s] The mass flow rate is simply the density times the volume flow rate. So this is the answer to part C. +[741.78s -> 751.92s] So here's the last problem in the video. So we're given the density of alcohol, and our goal is to calculate the mass flow rate of alcohol in the pipe given the volume flow rate. +[752.18s -> 764.62s] So as mentioned before, the mass flow rate is simply the product of the density times the volume flow rate. And it makes sense because mass is density times volume. +[765.42s -> 776.27s] So the mass flow rate is going to be the density times the volume flow rate. So the density of the alcohol is 790 kilograms per cubic meter. +[778.64s -> 788.91s] And the volume flow rate is 0.035 cubic meters per second. So we can see the unit cubic meters will cancel. +[790.13s -> 803.76s] Leaving us with the units mass over time, kilograms per second. So it's going to be 790 times 0.035. +[806.58s -> 818.42s] And so the mass flow rate is 27.65 kilograms per second. And so that's the answer. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_4.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fb816803ad46be5291e8ce30211b5b9f8302b541 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_4.mp4.txt @@ -0,0 +1,28 @@ +[4.37s -> 16.70s] When we carry out adiabatic expansion, we can do it reversibly as represented by the idea that we start out with a certain number of weights and then we slowly. +[16.70s -> 24.56s] Increase the number of weights as the piston moves up so that there's no imbalance of forces. Or we can do it irreversibly where I've shown. +[24.82s -> 35.39s] piston with stops preventing the piston from moving. We remove the stops and it goes to the final external pressure. And then there's a whole range. +[35.39s -> 47.34s] of possibilities we could have no weight on the piston so it expands as irreversibly as it can then we get no work out or it could be some mixture where we have +[47.34s -> 57.63s] maybe remove half the weights initially, we let it expand and remove some more. And so what we want to do is plot what the various temperatures are for the different +[57.63s -> 69.17s] entropy changes to different irreversible processes. And so we're comparing that to the reversible adiabatic process. And so the idea is we're going to start +[69.46s -> 84.02s] where the initial pressure is 10 bar and we're at 300 Kelvin. And so if we use the ideal gas law to determine the +[84.02s -> 95.86s] initial volume for one mole. I'm gonna do it in terms of R. This is 300 Kelvin, and this is 10 bar. +[96.94s -> 109.86s] then initial volume is 30 times the gas constant. Now, if we wanna compare different irreversible processes, we want to keep something similar and that's. +[109.86s -> 121.20s] the ratio of the final volume to initial volume. We could use pressure, we're gonna use volume here. And that means we could calculate for the reversible case. That's where we get the most work out. +[121.46s -> 135.34s] and of course there's no entropy change, and the equations that relate pressure and temperature, I'm just gonna write down here, so this adiabatic reversible, but we're interested in terms of volume. +[135.34s -> 146.93s] and note that Cp is 3.5 times R. So I'm gonna substitute into this equation and calculate what's the +[146.93s -> 160.27s] final temperature if we do it reversibly adiabatic. So note the Cv for an ideal gas is Cp minus R, so it's 2.5 times R, and of course the Rs cancel out in the exponent. +[160.27s -> 173.23s] And we see the temperature will drop from 300 to 119 Kelvin. So what we wanna plot, and let me show the plot and then show you how we get this plot. So I'm plotting temperature versus +[173.23s -> 184.69s] entropy change divided by R to make it dimensionless. This is our starting point. Well, we could do this expansion isothermally and adiabatically. So what that means is, +[184.69s -> 198.19s] We have no weight, no resisting weight, so there's no work done, so there's no temperature change. It's a big entropy change, but we've got no work out. And this corresponds then to p external equals zero. +[198.19s -> 212.06s] We can also, like we just calculated, do it adiabatically and reversibly. This is our 119.4 Kelvin temperature. Notice this corresponds to entropy change to zero. +[212.06s -> 223.84s] For the adiabatic reversible expansion, the final pressure was one bar. Well, we could do the expansion where the pressure's one bar for the entire time, and if we do that, +[223.84s -> 237.22s] we can calculate what that temperature be. So let me pause and write down some things. So here's the first law for the case. We're gonna do it adiabatically. One bar external pressure, so we're gonna put one bar here. The volume change goes from +[237.22s -> 249.97s] 30 to 300 R, and we know Cv, so we can calculate that final temperature. So let me substitute the numbers in, pause and do that. So constant external pressure of one bar. +[249.97s -> 264.18s] into a temperature of 192. So that says we carry out irreversibly with a constant external pressure one bar. We're gonna be somewhere around here. Well now the entropy change I haven't shown yet, so let's. +[264.18s -> 273.62s] Let's derive the equation for this blue line and the entropy. It's a state function, so that means we don't. +[273.62s -> 286.10s] need to know the process, and there's no entropy change for the surroundings because there's no heat transfer with the surroundings, so you can use this equation for an ideal gas. +[286.58s -> 300.27s] where this is 2.5R, T2 over, we start 300 in all cases, then R log, the final volume over the initial volume ratio is 10. +[300.27s -> 314.64s] So this equation, since I'm gonna plot dimensionless, delta S of R, let me just simplify this. So this is the equation for this blue line. This says for any temperature, +[314.64s -> 326.85s] that we reach by some irreversible process, we can calculate the entropy change because of the state function. We don't know how we got to that point. There's more than one way we could do it, but. +[326.85s -> 340.37s] The irreversible process means there's some imbalance of forces between the gas and the pressure exerted on the piston by the weights on it. So then this blue line defines all possible +[340.37s -> 346.54s] irreversible adiabatic expansions if we start from this point. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_5.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6758b3f05daf498095fc07e1cc6d602160503abc --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_5.mp4.txt @@ -0,0 +1,40 @@ +[0.00s -> 14.32s] So far we've been studying this thing called buoyant force and buoyant force is equal to the mass density of the fluid times the volume of the fluid that's been displaced times the gravitational constant. +[14.32s -> 21.10s] So this is kind of our definition of what a buoyant force is up to this point. +[21.10s -> 33.52s] Now, how can we use this buoyant force and the known knowledge of some object that's fully submerged inside of a body of liquid or fluid? +[33.52s -> 40.30s] and determine if that object will sink or float or just stay still where it's put. +[40.30s -> 52.90s] So that's what I want to study in this video. And so far we've been just looking at very simple objects of uniform mass density. So like a block of wood or a block of steel or a block of ice. +[52.90s -> 67.25s] And for most of those objects, the force that that object, or the weight of that object, which I will call F sub g, is equal to the mass density of that object times the volume of that object times the gravitation. +[67.25s -> 81.46s] constant. Now if we know that the object is fully submerged inside of this liquid, we know that the volume of the object is going to equal the volume of the fluid that's displaced. So in other words, +[81.46s -> 87.10s] V naught is going to equal VF, and that's just going to be volume. +[87.10s -> 101.49s] But what about objects that are not uniform? So let's say a scuba diver went inside of a body of water. So you had some body of water here and this is a very poorly drawn body of water. And let's say... +[101.49s -> 112.98s] me i was a scuba diver and i oh dear uh that's my scuba tank of oxygen gas that's me i'm smiling +[112.98s -> 127.25s] and this scuba diver is obviously not a uniform object right the bones inside of my body have one mass density and that mass density is different from my muscle the muscle has different +[127.25s -> 141.46s] mass density than my skin the skin has different mass density than the clothing that i'm wearing plus all the scuba tank and the scuba gear they're all varying in different mass density so how can we +[141.46s -> 156.37s] out what this mass density of me floating in this body of water or submerged in this body of water is and how do we use that value to determine if I sink or swim or I stay where I'm at. +[156.37s -> 165.38s] So for these compound objects like myself, we define something called the average mass density, and that is simply the +[165.38s -> 174.08s] mass of that object divided by the total volume of that object. So this mass right here is going to be +[174.08s -> 185.07s] the total mass of me so that's going to be the mass of my body the mass of my equipment and the mass of whatever oxygen that i'm carrying inside of +[185.07s -> 199.34s] the scuba tank and this v naught value is going to be well it's going to be the total volume that myself my scuba suit my scuba tank all occupy and if we take those two values and we divide them as divided by +[199.34s -> 214.13s] volume, we get this average mass density. And this average mass density is what we can compare to the density of the fluid that we're displacing to figure out if I float to the top or I sink to the bottom or I stay still. +[214.13s -> 228.53s] So in other words, what we're really doing is we're comparing the buoyant force, which is mass of the fluid times the volume of the fluid displaced times gravity. And we're comparing that to, well, the mass density of me, which is this average mass. +[228.53s -> 239.70s] density of all the stuff that I have on me plus myself times the volume of me times the gravitational constant now if I'm fully submerged +[239.70s -> 252.40s] If I am fully submerged in this body of water, then we know that the volume of the fluid displaced is equal to the volume of me, and that's just equal to volume. +[252.40s -> 264.32s] In other words, this V here is going to be equal to this V here, and the gravitational constants are both the same. So what we're really doing is we're comparing this mass density of the fluid. +[264.32s -> 278.24s] to the mass density of me so how do i know what sinks or swims or not sinks or swims but what sinks to the bottom what floats to the top or what just stays still inside of that body of water +[278.24s -> 291.25s] Well, if we kind of drew a simplified container here, and this thing was filled with some fluid, so this is really just a simplified diagram of this. +[291.25s -> 303.02s] then I could just model myself as some object here in the middle. And on this object, I know that there's going to be a buoyant force acting upwards. +[303.02s -> 312.03s] And then the weight of me is going to have a force that's acting downward. So I'll just call that my mass times gravity, my weight. +[312.03s -> 325.65s] And if we look back to this comparison over here, if we see that the mass density of the fluid is greater than the mass density of me, the average mass density. +[325.65s -> 339.30s] then we know that the magnitude of the buoyant force is going to be greater than the mass times gravity, the weight of me. So in this case, if F sub B or FB is greater than... +[339.30s -> 350.80s] compared to this diagram, this f sub b value is going to pull this object up. So I'm actually going to float in this case. Now what happens if I sync? Well, +[350.80s -> 364.67s] If the mass density of the fluid is less than the mass density of the person, which is me, the average mass density of me, then I know that the buoyant force is going to be less. +[364.67s -> 378.37s] than my weight. So I'm actually going to be more dense than the fluid itself and therefore this force right here is going to be greater than the buoyant force acting up. So I'm going to go +[378.37s -> 391.18s] downwards. So in this case, I'm going to sink. So this is the case where I sink, which is not good. This is the case where I float. And the third case... +[391.18s -> 397.44s] is when the mass density of the fluid is equal to the mass density of me. +[397.44s -> 411.92s] If this is true, then I know that the buoyant force is going to equal my weight. So what I'm actually going to do is I'm going to stay exactly where I am at this container, in this container, in this body of water. +[411.92s -> 424.05s] to stay right there. I'm not floating. I'm not sinking. I'm not moving up or down. I'm just staying where I'm at. And this case is what we call neutral buoyancy. +[424.05s -> 434.13s] And this is the cool thing about scuba gear. So scuba divers, if you didn't already know, they can basically adjust the density of themselves +[434.13s -> 446.24s] to match the density of the water and that causes them to stay at a particular level. So they have these special belts that they can basically adjust. +[446.24s -> 457.22s] the density inside of those belts and that essentially allows them to move up or down as they please so remember neutral density is when the +[457.22s -> 468.13s] mass density of the fluid equals the mass density of the object and then if the mass density of the fluid is greater than the object and the object floats +[468.13s -> 473.55s] If the mass density of the fluid is less than the object, then the object sinks. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_7.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0c70b4162819112fd57c955c6f6a2fbff811bc45 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_7.mp4.txt @@ -0,0 +1,33 @@ +[3.79s -> 17.06s] In this example, we're gonna work through calculations for a vapor compression refrigeration cycle. And to make it easier to follow, we've put the data that we're going to need into a table to. +[17.06s -> 24.72s] avoid having to search through tables to understand what's happening and best way to look at the information is to +[24.72s -> 38.21s] look at a pressure enthalpy diagram that tends to be most useful for refrigeration. So we're going to put the data given in the problem statement into this diagram where the phase envelope looks something like this. +[38.21s -> 50.08s] And now the problem states that the upper pressure corresponds to temperature 45 degrees C. It says we reach saturated liquid here. The course going through the throttle is at +[50.08s -> 64.40s] constant enthalpy and then the lower temperature is minus 10 degrees so this is minus 10 degrees c and it says this yields saturated vapor and so then when we go through to compress +[64.40s -> 76.45s] So let me extend this line a little bit. When we go through the compression, if we do it reversibly and adiabatically, then we see an increase in enthalpy because we're putting energy into the system. +[76.45s -> 90.77s] Well, this says efficiency is 80%, which means we're somewhere to the right of this. We have to put more energy in to get the same pressure. So now we're going to do the calculations by first looking at a reversible. +[90.77s -> 104.98s] compressor in order to determine the work for the irreversible compressor and let me label these points one and i'll call this point two reversible and then the actual the irreversible let's call it two prime three and +[104.98s -> 114.70s] So first calculation then is the compressor for the reversible case S1 would equal S2 and +[114.70s -> 124.72s] S1, this is saturated vapor, minus 10 degrees C. So saturated vapor minus 10 degrees C, here's the entropy. +[124.72s -> 133.81s] So S1, which is equal to S2 is 1.73 kilojoules per kilogram degrees Kelvin. So S... +[133.81s -> 145.79s] 2 now has to have that same entropy because S2 is at a higher pressure. Well the pressure is 12 bar because we can see here the 12 bar that that's for +[145.79s -> 156.98s] the case where we have liquid and vapor, so 45 degrees is the saturation temperature. We're at a higher temperature, but the same pressure, so here is the value corresponding to +[156.98s -> 165.74s] our condition s2 so this means we know the enthalpy at 2 and that's 430 kilojoules per kilogram +[165.74s -> 180.02s] Well, enthalpy at 1, the saturated vapor, minus 10 degrees is 393, and so we can calculate delta H then for the reversible compressor, and that's H2 minus... +[180.02s -> 194.22s] H1, so that's 430 minus 393, and that's 37 kilojoules per kilogram. So remember this is reversible. The delta H is equal to the work, so the work reversible. +[194.22s -> 203.12s] is delta H reversible, because it's adiabatic, so we know the work we have to add for the reversible case. Well, what we're interested in... +[203.12s -> 217.57s] is the irreversible case, so the work for the irreversible case when the efficiency is 0.8, the work has to be more, so it's the reversible work over 0.8, 37 over 0.8. +[217.57s -> 231.86s] 40, let's keep the significant figures for now. The work is larger, this is the irreversible work. Well the irreversible work then is the enthalpy change for the irreversible, so that's H two prime minus H. +[231.86s -> 239.41s] which means H2 prime is H1 plus 46.25. Well, we already. +[239.41s -> 250.16s] look used h1 already right h1 393 kilojoules per kilogram 393 plus 46.25 so +[250.16s -> 264.43s] 439 kilojoules per kilogram is the enthalpy at two. Now calculate the heat. We need enthalpy at three. Enthalpy at three is saturated liquid, 45 degrees C. +[264.43s -> 266.53s] So 45 degrees. +[266.53s -> 280.82s] saturated liquid. Here's the enthalpy. So the change as we condense this fluid, we condense it by removing energy. So heat that we remove, and that's at the high temperature, would be H. +[280.82s -> 293.79s] H3 minus H2 prime. Salt at 265 is the saturated liquid and we just calculated that 439 was the entering into that condenser so. +[293.79s -> 303.47s] QH then, minus 174 kilojoules per kilogram. Well this is one of the values we wanted to calculate for the problem statement, so. +[303.47s -> 317.74s] finished one part, and we're going to now calculate QC. So keeping in mind the diagram, we're gonna need H4, but H4 is the same as H3 because we're going through a throttle, so H. +[317.74s -> 332.40s] H4 then is our 265, so this is also 265 kilojoules per kilogram. And H1, we've already calculated 393, so that means if we wanna calculate +[332.40s -> 346.70s] QC, this is the cooling, how much energy we remove from our low temperature refrigeration section of a refrigerator, put in at minus 10 degrees into this cycle, that's H1 minus H4, the final. +[346.70s -> 360.38s] minus initial, and H1 is 393, H4, 265, so this is 128, and it's positive because we're adding energy into our cycle, and this, so this is QC. +[360.38s -> 362.18s] Remember this is cute. +[362.18s -> 376.46s] So last thing we need to calculate is the coefficient of performance. Coefficient of performance is Q C over W, 128. Remember this is irreversible work, 46.2. +[376.46s -> 382.61s] So coefficient of performance is 2.8. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_9.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..967faddef5a5d2d1306dba8a066b87210f27981b --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Energy_and_Power_9.mp4.txt @@ -0,0 +1,79 @@ +[0.59s -> 14.06s] All right, so what's going on, Yelani? We got another Bernoulli equation problem. I need two more of these, so this one and one more. I forgot to print these out the other day. So the problem reads... +[14.06s -> 25.04s] Water flows steadily through the variable area pipe shown with negligible viscous effects. So we got to determine the manometer reading, the H. +[25.04s -> 33.87s] If the flow rate is 0.5 and the density of the manometer fluid is 600. So let's go ahead and get started. +[38.64s -> 49.78s] All right, so let me show you real quick how we'll approach this problem. So we're going to do Bernoulli's right. We're going to do it from this point to this point. +[49.78s -> 63.92s] Now, the reason I chose these two points, right, because you really could, I mean, technically you could choose it here, here, here, anywhere, right? But the thing is, it's not easy getting pressure values and heights. +[63.92s -> 75.58s] at those locations right so technically yes we could do it from here to some point here right but then we got to find heights from this point to this point and kind of makes no sense so +[75.58s -> 88.66s] And these problems, just know that you usually got to do it here when you could find something in terms of pressure. They really don't give us anything to help us except this manometer here. And obviously this point. +[88.66s -> 102.64s] that goes up to this point right here and again we use these points because we have a cross-sectional area they give us flow rate we got this cross-sectional area that means we could get velocity at both points the height +[103.22s -> 108.30s] We can't get height numbers, but we know +[108.88s -> 118.54s] If we draw our datum here, these two heights are the same, so the heights cancel out. In the Bernoulli, you have pressure, velocity, and height. +[118.86s -> 133.22s] these cancel out we could find velocity and then pressures we don't but we could get pressure um a differential a difference in pressure so delta p and that's going to give us some number right +[133.22s -> 142.72s] Then we use manometers to find another delta in pressure in terms of the manometers, right? And set these two equal together. +[142.72s -> 156.56s] you could find height so you'll see what i mean but let's go ahead and get started so first step right always knowns so we're dealing with water and some +[156.56s -> 168.40s] fluid right so we got density of water is equal to a thousand kilograms per meter cubed +[168.75s -> 180.75s] um they give us the density of the fluid right that's 600 right here uh kilograms per meter cubed what else what else +[181.20s -> 194.80s] they give us the areas so area of 0.1 area of 0.2 a1 is equal to 0.05 meters squared +[194.80s -> 208.45s] Area of 2 is equal to 0.07 meters squared. What else? What else? +[208.45s -> 215.38s] oh on the floor right right obviously right here so let's go ahead and put that here now go ahead and do it here +[216.21s -> 228.40s] Q1 is equal to Q2, right? Flow rate's the same everywhere. So that is equal to 0.5 meters cubed per second. +[228.72s -> 240.88s] And we're also dealing with manometers. So let's go ahead and get the gammas for those. Gamma of water, that's 9810 newtons per meter cubed. +[241.04s -> 252.91s] Gamma the fluid. Multiply this number times 9.81. Right gravity. That will give you 5886 newtons per meter cubed. +[253.55s -> 266.03s] okay cool so again we got to do Bernoulli first um in order to do that we need these three variables pressure velocity and height so let's go ahead +[266.03s -> 280.91s] do let's find the velocities so velocity is what we know q1 is equal to a1 v1 right and q2 is equal to a2 v2 +[281.36s -> 293.81s] We have Q, that's 0.5 for both of them, A1 and A2. So we can find V1 and V2. So if you do that, V1 is equal to... +[293.81s -> 303.63s] 10 meters per second v2 is equal to 7.14 meters per second +[307.09s -> 310.42s] That's just flow rate divided by area. +[312.30s -> 322.54s] and then cool so we got velocities we got heights the heights are the same so they cancel out and then pressure so let's go ahead and start that bernoulli +[325.17s -> 334.67s] So it's P1, right, plus 1 half rho, what is this, V1 squared. +[335.47s -> 346.96s] plus rho gh1 is equal to p2 plus 1 half rho v2 squared +[347.18s -> 351.22s] plus rho gh of 2. +[351.89s -> 366.59s] okay cool so we agreed right that they're at the same height so the heights cancel out this whole term cancels out right here uh we got velocities and we don't know the pressures so +[366.59s -> 379.89s] Let's go ahead and do P1, right, plus 1 half rho V1 squared is equal to P2 plus 1 half. +[379.89s -> 392.78s] Row v2 squared and that's pretty much it. So let's go ahead and keep this in mind. It's just a Bubble it up We'll come back to this +[394.38s -> 403.34s] all right so let's go ahead and do the manometers now so from manometers +[407.15s -> 418.90s] All right, so I'm not sure if you remember, but from manometers, we start at this point, go all around, work down to our final point, set it equal to the final point. So we start at P1. +[419.54s -> 432.88s] We're going up so that's negative We're dealing with water from here to here. Let's go ahead and label this a some distance a right +[434.10s -> 447.66s] okay and then um we'll probably um yeah it's fine just a so it's p1 p1 we're going up to this point so it's minus gamma of water right this blue liquid is water +[447.66s -> 455.63s] and then times your height which is uh height a +[456.37s -> 466.93s] okay now from this point to this point is the distance h what we're looking for so we're going up again right from this point to this point you go up +[466.93s -> 481.23s] So it is density, let's put gamma the fluid, times H. Now from this point to this point, that is A plus H. That's all right. +[481.68s -> 487.60s] plus H that's your height right there +[487.86s -> 501.17s] um right it's just this height plus this height so now we're going from this point to this point we're going down so that's positive gamma water h plus ha +[501.94s -> 506.61s] Height a that's all it means Finally we arrive at p2 +[508.85s -> 522.83s] Alright, so we kind of just work our way through, right? P1 minus gamma of water. Well, you know what? Let's simplify first. Gamma of water, HA. +[522.83s -> 535.63s] Minus gamma fluid times H plus gamma water times H plus gamma of water times HA equals P2. +[536.37s -> 541.42s] Okay, here we see this term cancels out with this one, so that's cool. +[541.74s -> 553.68s] uh let's do let's move p1 to this side um and the reason i move p1 to this side and not p2 to this side well the thing is i know the pressure here is higher +[553.68s -> 567.44s] just by thinking logically so if you see this there's a pressure here right and it's pushing up same here it's pushing up but if you notice this one's winning do you see that you see the line all the way up here this one's +[567.44s -> 580.05s] only up to here that's because this one's pushing up with a greater force than this one so i know pressure two is higher than p one if the line was here for point one and the line was here for point two +[580.08s -> 594.06s] Pretty much just the opposite. I'd know p1 is higher because it's pushing on that fluid More than water if they were at the same height from here to here Then I know the pressures are pretty much the same +[594.06s -> 603.02s] does that make sense i hope that makes sense but try to think about it logically um that's all that's going on so that's the reason i'm moving p1 to this side +[603.57s -> 618.18s] even if even if you're not right don't even worry about that at the end the negatives will sort themselves out if you get a negative number that just means you assumed wrong i mean it's nothing crazy it won't mess you up so we have +[618.18s -> 631.31s] gamma of water, I'm going to put this one first, times H minus gamma of fluid times H is equal to P2. +[631.41s -> 645.94s] minus P1. We don't know P2 or P1, but we do know gamma water, gamma fluid. So let's go ahead and do that. Actually, we could factor out the H. +[647.18s -> 658.13s] Gamma of water is 9810 minus 5886 is equal to delta P. +[659.18s -> 672.59s] okay so that just means difference in pressure um that means this is um you know i'll just leave it like that for now it doesn't matter +[673.39s -> 676.56s] I'm too lazy to do the calculation. +[677.49s -> 691.57s] but we got to do it right so now we do the same thing so this delta p right p2 minus p1 we isolate p2 minus p1 on this equation too so now step five that is p2 +[691.57s -> 705.81s] Minus P1, right? I move P1 over here. So that means this stays positive, right? Is equal to 1 half density V1 squared. +[706.29s -> 715.28s] is oh no minus one half density V2 squared +[716.34s -> 729.66s] In other words, this is just delta P. So now we could set this part of the equation equal to this. Does that make sense? All right, so let's go ahead and do that. That means H. +[729.66s -> 734.10s] Times where's my calculator? Hold on +[739.60s -> 749.17s] all right so i didn't do this calculation for some reason this is 3924 cool +[750.67s -> 765.55s] 98 10 minus 5 8 8 6 is 3 9 2 4 is equal to density is a thousand so when you divide it by 2 that's 500 times +[765.84s -> 772.34s] 10 squared right plug-in velocity minus again 500 +[773.42s -> 780.85s] Now we're going to multiply this by 7.14 squared. Yeah, squared, same thing. +[781.30s -> 791.63s] uh cool so we get a number on one side that's cool we're gonna have three nine two four H +[791.92s -> 804.05s] equal parentheses around that H is equal to 10 square that's 100 that's 5,000 +[804.66s -> 814.48s] Is it 5,000? Two zeros? You know what? 10 times 10 times 500. Yeah, when in doubt, just calculator. +[814.77s -> 827.41s] Minus 7.14 squared times 500. That is 25, 490. Rounding it up. 25, yeah, 490. +[829.26s -> 841.55s] Cool, so $50,000 minus $25,490. That is $25,410. +[843.09s -> 853.94s] All right, this is 3, 9, 2, 4, same thing, H. That means H is equal to, divided by 3, 9, 2, 4. +[854.22s -> 865.30s] 6.246 meters cool so that's the answer to this one so +[865.68s -> 876.13s] This one was a little bit trickier, right? Um, I'm not sure if you but this is something you gotta know So obviously they didn't give us anything for pressure except this manometer +[876.13s -> 890.22s] sometimes this side will be straight open to the atmosphere as you see in um you check the other video you'll see a problem where it's open to the atmosphere same here sometimes they'll just give you a straight up pressure gauge reading +[890.22s -> 899.58s] That makes things way easier, right? They just give you 50 kilopascals or whatever. I think I also did an example on that one. And this one. +[899.58s -> 913.42s] uses a manometer so i think that's the only three cases you'll ever come across with a i guess a horizontal tube like this or vertical um i don't think there's anything else other than that +[913.42s -> 928.37s] um we use bernoulli we set the pressure difference here equal to the pressure difference here right p2 minus p1 is equal to p2 minus p1 here and that's pretty much it um just this one +[929.14s -> 932.75s] Yeah, it could be a Mitchell problem. So just keep an eye out diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_11.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..54b1d4d6f3d82c00e5364b3d89cb60c72e696651 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_11.mp4.txt @@ -0,0 +1,11 @@ +[1.42s -> 15.65s] For the beam and external loads shown, what are the reactions at point A and point B? This is the fourth example for the rigid body equilibrium and moments main video. The links to that main video and other examples are in the description below. +[15.65s -> 27.76s] We know from that main video that the only reaction at the type of support at A is a normal or perpendicular reaction. The reactions at B can be both in the horizontal and the vertical direction. +[27.76s -> 39.86s] and we'll assume all unknown forces to be positive. Remember that these supports cannot generate a reaction moment. With this free body diagram, we can write a sum of forces in the x direction +[39.86s -> 49.82s] the y direction, and the sum of moments that all have to be equal to zero since the beam is not accelerating in any translational or rotational direction. +[49.82s -> 60.16s] The horizontal reaction force at B can be found from the sum of forces in X, but the vertical reactions cannot be found from only using the sum of forces in the Y direction. +[60.16s -> 71.62s] For this reason, the point that we select to do the sum of moments should be one where one of these two unknown forces is not present, otherwise we would end up with two equations and two unknowns. +[71.62s -> 84.42s] A process that, although possible, would take more time. In this case, the sum of moments about A or B would result in an equation without Ay or By respectively, so either one of those works. +[84.42s -> 92.02s] But since the sum of moments about B has one fewer term, because the line of action of the 3 kN force passes through B, +[92.02s -> 99.92s] We'll use that sum of moments to solve for Ay and substitute its value in the sum of forces in Y to solve for By. +[99.92s -> 109.87s] Alternatively, if we hadn't written a sum of forces in the y direction, we could have used the sum of moments about A that we wrote before to solve directly for By. +[109.87s -> 121.90s] For more examples on rigid body equilibrium and the links to the main videos for the Lectures of Aesthetics course, make sure to check out the links in the description below. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_12.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..805ac1a41a9802114527b1dff5559f9aca4e1321 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_12.mp4.txt @@ -0,0 +1,7 @@ +[0.59s -> 13.46s] A vibration isolation unit consists of two blocks of hard rubber bonded to a plate AB and two rigid supports as shown. Knowing that a 25 kN force causes plate AB +[13.46s -> 24.51s] to deflect 1.2 millimeters what is the modulus of rigidity or the shear modulus of the rubber blocks this is the fourth example for the shearing stress and strain main video +[24.51s -> 38.61s] Links to previous examples and that main video are in the description below. Just like in example 3, if we look at this setup from the positive z-axis, we see that the vertical displacement of the plate is related to the shear strain gamma. +[38.70s -> 48.18s] With a vertical displacement of 1.2 mm and a 40 mm thickness of the rubber blocks, we find a shearing strain of 0.03. +[48.18s -> 61.04s] And since the modulus of rigidity is defined as the shearing stress over the shear strain gamma, all we need to do is calculate that shearing stress as the load over the area that is parallel to that load. +[61.04s -> 75.20s] The shear force V that affects each rubber block will be equal to P over 2. With the value of P, the shear strain we calculated, and the area parallel to that shear force, using the appropriate units, +[75.20s -> 89.78s] we find that the shear modulus is 21.7 MPa. For a list of all the topics of this course's playlist, you can check out the links in the description below. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_14.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b1615583012457da6ccc798b711190445f05f520 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_14.mp4.txt @@ -0,0 +1,13 @@ +[0.69s -> 14.30s] Two brass rods AB and BC will be braced together at B and subjected to the loads shown while suspended from a support at A. If the diameter of rod AB is 50 millimeters, +[14.30s -> 27.81s] and the diameter of rod BC is 30 mm, what is the average normal stress at the midsection of rod AB and rod BC? This is the first example for the axial loading main video. +[27.81s -> 41.92s] Link below. To calculate these normal stresses, we'll use the expression that we used in that main video. To find the forces FAB and FBC, we'll perform a cut somewhere around the midsection of both rods. +[41.92s -> 51.28s] Completing the free body diagrams with the internal force at the cuts will allow us to write a sum of forces and solve for the force variables we need. +[51.28s -> 60.11s] And notice that the direction of the vectors I used are such that if the value for the forces is positive, the stress will be positive and therefore tensile. +[60.11s -> 72.26s] And if the value for the forces is negative, it means that the vector should have been pointing in the opposite direction, making the stress a compressive stress, which is consistent with the negative numerical value. +[72.26s -> 86.45s] The sum of forces reveals that FcB is equal to positive 60 kilonewtons and that FbA is equal to minus 190 kilonewtons. The cross-section areas are those of a circle, +[86.45s -> 98.96s] and the force values should be substituted in newtons to have consistent units. Notice that rod AB is under compression and rod BC is subjected to tension. Additionally, +[98.96s -> 106.98s] Notice that the cut can be performed from the bottom like we just did or from the top and we would obtain the same values. +[106.98s -> 121.31s] However, to solve for FAB and FBC in this case, we would first need to find the reaction force at A. FAB will still be equal to minus 90 kN, and FBC equal to 60 kN. +[121.31s -> 131.04s] But of course, this requires that extra step and being extra careful about being consistent with the unknown variables to be positive vectors. +[131.04s -> 145.36s] This way, positive values result in tensile stresses and negative values result in compressive stresses, following the convention we need to follow. For additional problems on axial loading, make sure to check out the links in the description below. +[146.54s -> 148.21s] Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_15.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3d8f778ead2c43165e5adfd1fc8a12a087c0a427 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_15.mp4.txt @@ -0,0 +1,41 @@ +[0.08s -> 8.30s] Hello everyone, I am Dr. Vasim Sheikh. Today we will see what is ductile to brittle transition temperature and why it is important. +[10.83s -> 16.96s] Many materials show an abrupt drop in ductility and toughness as the temperature is lowered. +[16.96s -> 31.34s] Body centered cubic material like low carbon steel they become brittle at lower temperature. So what can be done about this? Why the material change their behavior? What happens in the material? And how should we know about the ductile to brittle transition temperature? +[31.34s -> 41.14s] So, we can carry out an impact test also which is known as Charpy V-notch test to look into the ductile to brittle transition temperature. +[41.14s -> 55.09s] Impact testing is carried out to find the impact strength of the material. What is the strength of the material when it has an impact? So in the impact testing you have a standard setup and a standard specimen. +[55.09s -> 64.69s] so here what we see is there is a standard apparatus where you have a hammer the material is located in an anvil and then it is struck with the +[64.69s -> 74.58s] help of a hammer the hammer is raised to a certain level then it is dropped under gravity it falls it hits the specimen and then it goes beyond to a certain height +[74.58s -> 87.02s] most of the time when the material is brittle the hammer is raised to a little bit more height and when the material is more ductile the hammer stays there and there itself and whatever is happening all these readings +[87.02s -> 92.78s] are recorded with the help of a pointer on the scale which is there on the apparatus +[92.78s -> 107.17s] So here we can see there are three impact tested sample and they are tested at different temperature. The first one you see on the top is tested at a liquid nitrogen temperature that is minus 196 degree. +[107.17s -> 118.13s] centigrade the second one which is tested is at room temperature that is 25 degree celsius the third one which is tested is at zero degree celsius that is it has been kept in ice +[118.13s -> 124.88s] and the fourth one is kept in the boiling water and it has been tested at around 100 degree celsius temperature +[124.88s -> 134.90s] so mainly what we see based on these material is that as the temperature of the material is dropping the material is going from ductile to +[134.90s -> 146.34s] brittle transition and easily we can relate to this just by looking at the specimen the specimen which is at 100 degree celsius temperature we can see that the material did not break in two pieces +[146.34s -> 154.11s] so it is more ductile that is why it did not break into two pieces as we go on lowering the temperature from that place to +[154.11s -> 168.43s] 25 degrees celsius to 0 and then minus 195 degrees celsius that is liquid nitrogen temperature the material becomes more and more brittle and to observe this phenomena i did this experiment and i also looked at the +[168.43s -> 177.25s] microstructure of the material just to see what type of failure the material has gone through exactly at the breakage point. +[177.25s -> 188.78s] so this is an SEM image which shows that the material which has failed at room temperature shows a ductile failure that is the place from where it has broken +[188.78s -> 202.98s] is slightly deformed there is some plastic deformation so the circle which you see here basically shows that the material has been plastically deformed at that place and that the second image shows the same thing which has been magnified +[202.98s -> 217.33s] at a very high magnification rate and we can relate to that that at room temperature the material fails because of some certain deformation so still the material is in the ductile state at room temperature now let us compare this image with the next +[217.33s -> 229.79s] which we will see at the liquid nitrogen temperature that what happens when we do the impact testing at that particular temperature so this is an image which has been impact tested at around minus 192 +[229.79s -> 242.13s] degrees celsius that is at liquid nitrogen temperature clearly here we can see that the material has failed because of brittle fracture and brittle nature of the material and if you +[242.13s -> 255.65s] have difficulty in understanding what is brittle fracture and brittle failure i have made a video on this brittle fracture and brittle material you can refer to that video and then you will know that why this image has failed because of the +[255.65s -> 264.43s] brittle fracture again here the material has failed because it has gone through inter granular fracture inter granular +[264.43s -> 276.46s] brittle fracture and here we can relate to that the material does not show any cup and cone failure and it has abruptly catastrophically failed and gone through the failure and this is a +[276.46s -> 289.39s] pure failure because of brittle fracture so this proves our point that as we lower the temperature the material goes from ductility towards brittleness and it becomes more and more brittle +[289.39s -> 296.34s] and we know that when the material is ductile when the material fails because of the nature of ductility +[296.34s -> 309.68s] it will show or it will give us an intimation that it is about to fail but when the material has become completely brittle it will fail catastrophically and we don't want that so we want a material that when we use that material at +[309.68s -> 322.22s] normal room temperature and when we use that material at subzero temperature it should behave properly it should not abruptly change from ductile to brittle nature and it should not suddenly fail that is why +[322.22s -> 331.98s] ductile to brittle transition temperature is very important we should know the ductile to brittle transition temperature so that we know that this material will abruptly become brittle +[331.98s -> 337.86s] at lower temperature so we know the range of temperature where we can work with no material +[337.86s -> 352.43s] Here in this image, we can see that most of the FCC material and high strength material will somewhat lose their ductility at lower temperature. But body centered cubic material will abruptly change from ductile to brittle behavior. +[352.43s -> 357.06s] as soon as the temperature is decreased so that is very dangerous +[357.06s -> 367.90s] that is very catastrophic if the material is drastically changing its mechanical property the material can fail because of brittle nature and we will have very catastrophic effect +[367.90s -> 374.78s] So what should be the design strategy of the material scientist who are preparing the material for any application? +[374.78s -> 384.94s] so the main thing is that you should know the ductile to brittle transition temperature of the material so as soon as you figure out any material for any certain application you should find out +[384.94s -> 397.01s] what is the ductile to brittle transition temperature and you should say that this material will only function in this temperature range as you decrease the temperature the material might change from ductile to brittle nature +[397.01s -> 408.02s] and it can fail so this should be your design strategy in the past we have seen many examples where the material has suddenly changed its nature from ductile to +[408.02s -> 421.26s] brittle behavior and this is a typical example this is a ship which was there the material by which the ship was made was such a material that it changed from ductile to brittleness as soon as the temperature dropped +[421.26s -> 434.13s] and because of that the ship has been torn apart in two pieces and it had a catastrophic effect and it has failed completely so to avoid all these things before we design any material +[434.13s -> 445.00s] We should know what is the ductile to brittle transition temperature and we should always stay above that temperature for a proper functioning of any material. Thanks for watching. All the best. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_16.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_16.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5bebb61d8b46978a82731589a6a3f0a658ed8597 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_16.mp4.txt @@ -0,0 +1,2 @@ +[0.00s -> 10.90s] Welcome to fav mechanics. In this video we will solve the given problem. This video is just short. Read the caption carefully and understand each process. +[178.16s -> 181.78s] Thank you for watching. Click subscribe for more videos. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_17.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_17.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d43e85495ac79219e66230a6ccb5830b398ff25d --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_17.mp4.txt @@ -0,0 +1,65 @@ +[1.42s -> 15.41s] I welcome you all for today's lecture. Today we are going to see how to use stress strain curve to determine Young's modulus, stress at elastic limit, ultimate tensile stress. +[15.41s -> 29.68s] percentage elongation and percentage reduction in area. Let me read the problem. A specimen of steel 20 mm diameter with a gauge length of 200 mm is tested to destruction. +[29.78s -> 43.82s] Here we are going to test the 20 mm diameter using a universal testing machine. We are going to conduct a tensile test using the UTM. And this is the gauge length. +[43.82s -> 49.52s] that means the length which is subjected to the tension. +[49.90s -> 61.89s] While it is being tested using universal testing machine and this is the length. The remaining length will be under the clamping during the testing. +[61.89s -> 71.92s] So we should not consider the entire length, only the length which is subjected to tension is considered as gauge length. +[72.62s -> 83.66s] It has an extension of 0.25 mm under a load of 80 kN. And here we are provided with the load as well as the deflection. +[84.50s -> 96.59s] And the load at elastic limit is 102 kilo Newton. The maximum load is 130 kilo Newton. The total extension at fracture is 56 mm. +[96.72s -> 109.42s] And diameter at neck is 15 mm. Fine inch modulus, stress at elastic limit, ultimate tensile stress, percentage elongation and percentage reduction in area. +[111.25s -> 124.75s] So after conducting the tensile test, the specimen has elongated by 56 mm. So the diameter of the specimen is 20 mm and the diameter +[125.17s -> 139.12s] of the neck is 15 mm. So here is the neck. So after conducting the test, we could visualize that there is a reduction in diameter in this particular region. +[139.12s -> 153.25s] so that diameter is 15 mm okay we can see that the diameter is reduced by 5 mm because initially it was 20 mm now it become 15 mm +[153.25s -> 165.18s] diameter at the neck. So, the elongation length is 56 mm. So, specimen length is measured after conducting the test. +[165.18s -> 175.12s] So, it has increased by 56 mm. That means the difference between the final length to the initial length that is the gauge length is 56 mm. +[175.76s -> 180.53s] So, then we are provided with some data about the load and deflection. +[180.88s -> 193.62s] So, for that we need to draw the stress-strain curve. If you want to know more about stress-strain curve, watch my lecture on basics of stress-strain curve. +[194.22s -> 209.04s] At this point we started testing the specimen and the strain is exactly proportional to strain up to this point proportional limit. So we can see the straight line. +[209.46s -> 223.86s] Within this region we are provided with a load and a deflection that is 0.25 mm at a load of 80 kN. So here is the load. +[223.89s -> 237.06s] when it is applied a deflection of 0.25 mm happened on the specimen. So, how we have taken this is just under the proportion limit means we are given with the another load that is +[237.06s -> 248.78s] during the elastic limit and this point e is given that is 102 kilo newton so obviously this point must be in between +[248.91s -> 259.25s] the O and the proportionality limit. So, we are going to use this 80 kilo Newton and the deflection to find out the Young's modulus because we know that the +[259.25s -> 267.06s] Slope of this line represents Young's modulus. So, we are going to use this slope for finding the Young's modulus value. +[267.34s -> 282.10s] And the elastic limit load is given as 102 kilo Newton, that is 102 into 10 to the power Newton. And finally, we are provided with the maximum load. The maximum load +[282.29s -> 291.76s] is applied on this specimen at this point and this point define the ultimate stress. So, this load is also provided. +[292.08s -> 299.70s] in the problem, so that we can calculate the ultimate tensile stress. +[299.95s -> 313.17s] We know that all the dimension that means gauge length and initial dia and after the failure or after the fracture what is the neck diameter and the extension of that. +[313.17s -> 325.30s] specimen, everything is provided and also we have marked 5 points on the stress strain curve, that means a point within the proportionality limit. +[325.30s -> 332.62s] that will find out the young's modulus value and the load during the elastic limit and the maximum load +[332.94s -> 343.02s] Now we are going to see how to find out TNX modulus and the other unknown values. Let us solve the problem. +[344.30s -> 358.42s] So this is the given specimen. So the diameter of the specimen is 20 mm. So we are going to calculate the cross-sectional area of the specimen. So it is pi by 4 d square and the value is +[358.42s -> 365.65s] 314.16 millimeter square so this represents the cross +[366.03s -> 381.01s] sectional area so we need to remember that it is the cross sectional area because while finding the stress we need to know the cross sectional area so that we can calculate the stress value now let us calculate the +[381.52s -> 385.84s] Young's model is valid. We know that the region +[387.06s -> 400.05s] Under this proportionality limit is to be used for finding the Young's modulus because within this region stress is directly proportional to strength. +[400.59s -> 415.09s] The Young's modulus value is going to be within the region, it is taken as stress over strain. +[415.60s -> 428.48s] We know the points which lies within the proportionality limit. So, we are going to use this value and the corresponding deflection value to find out the Young's modulus value. So, the Young's modulus is +[428.48s -> 442.46s] stress over strain and we know that the stress value can be calculated by using the load and the cross-sectional area that is load divided by area and the strain value represents the +[442.46s -> 455.42s] ratio between change in length to the original length. So, the deflection at this 80 kilo Newton is provided. So, we are going to use that to calculate the +[455.42s -> 465.07s] Young's modulus. So here 80 multiplied by 10 to the power 3 which represents the load at the +[465.39s -> 480.08s] This point that is within the proportionality limit a load is given that is 80 multiplied by 10 to the power 3 Newton divided by area area is calculated that is 314.16 divided by +[480.08s -> 493.23s] This is the change in length. So at 80 kilo Newton the corresponding deflection is 0.25 +[493.78s -> 504.93s] It is given in the problem. So, here we have substituted that as 0.25 and the gauge length that is the initial length of the rod is 200 mm. +[504.93s -> 518.78s] So, we have got all those data to calculate the Young's modulus. So, we have to remember that while applying this lobe, this must be within the proportionality limit that must be ensured while calculating the Young's modulus. +[518.78s -> 527.02s] So, the Young's modulus value is calculated as 203718 Newton per millimeter square. +[528.91s -> 543.22s] Now, we are going to calculate the stress at the elastic limit. So, we are provided with the load at elastic limit and that is 102 kilo Newton, 102 into 20 to the power 3 Newton. +[543.22s -> 548.62s] we are going to calculate the stress at the elastic limit. So, the load is +[548.91s -> 562.32s] 102 multiplied by 23 power 3 Newton and divided by the area and now we got that stress value was 324.675 Newton per millimeter square. +[563.60s -> 575.47s] So, now we are going to see how to calculate the ultimate stress, because we are provided with the maximum load. The maximum load is applied on this specimen. +[575.54s -> 586.13s] at this point of the stress strain curve and it represents the ultimate stress. So, we are going to calculate the ultimate stress with the help of this maximum load. +[586.74s -> 601.50s] So the ultimate tensile stress is equal to ultimate load divided by the cross sectional area. So ultimate load is 130 multiplied by 10 to the power 3 and the area is known. So we have calculated this ultimate. +[601.50s -> 607.22s] tensile stress as 413.80 Newton per mm square. +[607.60s -> 619.46s] Now we are going to see how to find out percentage of increase in length and the percentage of reduction in cross sectional area. +[619.46s -> 632.67s] So, we have got that specimen which is used for tensile test and this is the specimen which represents the specimen after the test is being conducted. +[632.67s -> 644.30s] So, the percentage elongation is equal to final extension divided by original length multiplied by 100, which is the percentage. +[645.10s -> 655.63s] can be found by using the formula that is final length minus initial length of the specimen. So, in our case +[655.63s -> 667.50s] We are directly provided with that value that is final length minus initial length that is 56 mm. So that is why here we have put that as final extension. So if it is not given. +[667.50s -> 681.46s] We need to use this formula that is final length after the fracture happen minus the initial length of the specimen to find out this value divided by the original length or the initial length multiplied by 100. +[681.46s -> 695.20s] So, here the final extension that means the change in length is 56 mm divided by 200 multiplied by 100 which is equal to 28 percentage. +[695.20s -> 708.61s] So, the percentage elongation of the given specimen is calculated as 28. Now, we are going to see how to calculate the percentage of reduction in cross section. +[708.61s -> 721.82s] The percentage production in cross sectional area is equal to initial area minus final area over initial area multiplied by 100. So, initial area is pi by 4 d square that is +[721.82s -> 735.25s] pi by 4, 20 square. The final area is pi by 4, this neck dia square. So, that means it is 15 mm. The initial area is pi by 4, 20 square. +[735.34s -> 750.05s] minus final area is pi by 4 15 square. This is the diameter at the neck over the initial area that is pi by 4 t square that is 20 square multiplied by 100. So here we have got that +[750.05s -> 762.90s] First, the reduction in cross-sectional area as 43.75. So in this problem, we have seen how to use stress-strain curve to calculate the Hengst modulus. +[762.90s -> 776.94s] stress at the elastic limit and ultimate tensile stress and finally we have calculated the percentage in elongation and percentage in reduction in cross-sectional area. +[777.36s -> 778.95s] Thank you for watching. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_18.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_18.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7aa1f3028b267175c1f201c109e72b56c82704f0 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_18.mp4.txt @@ -0,0 +1,21 @@ +[0.00s -> 12.10s] In the previous lecture, we have learned about stress as the first building block of mechanics of materials. This lecture is about strain as the second important physical quantity to study the effect of forces on the object. +[12.10s -> 20.16s] The forces acting on a body distributes internally. The intensity of internal force at any point inside the body is called stress. +[20.16s -> 34.05s] Recall that there are two types of stresses. Normal stress is caused by a force that is perpendicular to its section. If the force is parallel to the section, it is producing shear stress. The external forces acting on a body +[34.05s -> 44.51s] cause the movements of small particles of the body relative to each other that cause the body to deform. So deformation is another effect caused by the forces. +[44.51s -> 57.98s] But not any movement is deformation. The movement or rotation of the entire solid object, like the objects studied in dynamics, is not called deformation. Because in those cases, the body keeps its shape and size +[57.98s -> 71.33s] and the distance of the inner particles of the element remains unchanged during the move. Deformation reflects the relative movement of the internal particles of a continuous body that caused the change in the size +[71.33s -> 84.56s] or the shape of an object. Deformation could happen due to loading or other factors such as temperature change. Similar to stress, there should be a physical quantity to precisely measure the amount of deformation, strain, +[84.56s -> 96.08s] is the physical quantity that measures the intensity of internal deformation within a body. Any change in the size and shape that takes place in small elements like the one that is shown on the left cube +[96.08s -> 109.36s] as a combination of a change in the length of the element and a change in the angle of the element. The change in the length of the element is caused by normal stress, an element that is subjected to a tensile force +[109.36s -> 122.00s] elongates along the direction of the force. But there is no change in the angle of the element. All corners remain intact. On the other hand, a cube element subjected to shear stress will distort. +[122.00s -> 134.51s] All sides of the cube would keep their original length, but the angles of the elements at the corners would change. Similar to stress, two types of strains are defined as normal strain and shear strain. +[134.51s -> 145.68s] Normal strain is produced by normal stress and reflects the change in the length of the element. Shear strain is caused by shear stress and measures the change in the angle of the element. +[145.68s -> 156.22s] This lecture will focus only on normal strain. Shear strain is discussed in details in the next lecture. Now let's define normal strain. Consider a cube element +[156.22s -> 167.47s] with an initial length of L that is subjected to normal stress, and assume that the amount of elongation in the element is delta. Normal strain, which is shown by epsilon, +[167.47s -> 178.29s] is mathematically defined as the change in the length of the element divided by the initial length so epsilon is delta over l strain is a dimensionless quantity +[178.29s -> 192.18s] Because both delta and L have the same unit, which cancels out in the fraction, so it is unnecessary to distinguish between SI units and US customer units, as the parameter is unitless. However, in engineering, +[192.18s -> 205.26s] Strain is usually expressed as inch over inch or millimeter over millimeter or sometimes it is simply shown by epsilon. All have the same meaning. Another note is that normal strains +[205.26s -> 218.26s] in a typical solid structure are very small. So instead of working with very small numbers, they are expressed as microstrain. 1 microstrain is equal to 10 to the negative 6 strain. +[218.26s -> 232.40s] The sign convention for normal strain follows the normal stress. The element that is subjected to a tensile force elongates, and the normal strain associated with that is considered to be positive. On the other hand, +[232.40s -> 244.91s] If the element is subjected to a compressive force, it gets shorter, and the associated normal strain is considered to be negative. Alright, after learning about basics of normal strain, +[244.91s -> 255.69s] It's time to test our understanding with some examples. I will provide a link to the second part of this video that discusses three examples on how to use normal strain in different problems. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_20.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7aa1f3028b267175c1f201c109e72b56c82704f0 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_20.mp4.txt @@ -0,0 +1,21 @@ +[0.00s -> 12.10s] In the previous lecture, we have learned about stress as the first building block of mechanics of materials. This lecture is about strain as the second important physical quantity to study the effect of forces on the object. +[12.10s -> 20.16s] The forces acting on a body distributes internally. The intensity of internal force at any point inside the body is called stress. +[20.16s -> 34.05s] Recall that there are two types of stresses. Normal stress is caused by a force that is perpendicular to its section. If the force is parallel to the section, it is producing shear stress. The external forces acting on a body +[34.05s -> 44.51s] cause the movements of small particles of the body relative to each other that cause the body to deform. So deformation is another effect caused by the forces. +[44.51s -> 57.98s] But not any movement is deformation. The movement or rotation of the entire solid object, like the objects studied in dynamics, is not called deformation. Because in those cases, the body keeps its shape and size +[57.98s -> 71.33s] and the distance of the inner particles of the element remains unchanged during the move. Deformation reflects the relative movement of the internal particles of a continuous body that caused the change in the size +[71.33s -> 84.56s] or the shape of an object. Deformation could happen due to loading or other factors such as temperature change. Similar to stress, there should be a physical quantity to precisely measure the amount of deformation, strain, +[84.56s -> 96.08s] is the physical quantity that measures the intensity of internal deformation within a body. Any change in the size and shape that takes place in small elements like the one that is shown on the left cube +[96.08s -> 109.36s] as a combination of a change in the length of the element and a change in the angle of the element. The change in the length of the element is caused by normal stress, an element that is subjected to a tensile force +[109.36s -> 122.00s] elongates along the direction of the force. But there is no change in the angle of the element. All corners remain intact. On the other hand, a cube element subjected to shear stress will distort. +[122.00s -> 134.51s] All sides of the cube would keep their original length, but the angles of the elements at the corners would change. Similar to stress, two types of strains are defined as normal strain and shear strain. +[134.51s -> 145.68s] Normal strain is produced by normal stress and reflects the change in the length of the element. Shear strain is caused by shear stress and measures the change in the angle of the element. +[145.68s -> 156.22s] This lecture will focus only on normal strain. Shear strain is discussed in details in the next lecture. Now let's define normal strain. Consider a cube element +[156.22s -> 167.47s] with an initial length of L that is subjected to normal stress, and assume that the amount of elongation in the element is delta. Normal strain, which is shown by epsilon, +[167.47s -> 178.29s] is mathematically defined as the change in the length of the element divided by the initial length so epsilon is delta over l strain is a dimensionless quantity +[178.29s -> 192.18s] Because both delta and L have the same unit, which cancels out in the fraction, so it is unnecessary to distinguish between SI units and US customer units, as the parameter is unitless. However, in engineering, +[192.18s -> 205.26s] Strain is usually expressed as inch over inch or millimeter over millimeter or sometimes it is simply shown by epsilon. All have the same meaning. Another note is that normal strains +[205.26s -> 218.26s] in a typical solid structure are very small. So instead of working with very small numbers, they are expressed as microstrain. 1 microstrain is equal to 10 to the negative 6 strain. +[218.26s -> 232.40s] The sign convention for normal strain follows the normal stress. The element that is subjected to a tensile force elongates, and the normal strain associated with that is considered to be positive. On the other hand, +[232.40s -> 244.91s] If the element is subjected to a compressive force, it gets shorter, and the associated normal strain is considered to be negative. Alright, after learning about basics of normal strain, +[244.91s -> 255.69s] It's time to test our understanding with some examples. I will provide a link to the second part of this video that discusses three examples on how to use normal strain in different problems. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_5.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7473b3723cee80db1aa8a588495ce70151049519 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_5.mp4.txt @@ -0,0 +1,43 @@ +[0.14s -> 9.65s] Some of you may have forgotten some of the more basic concepts from a mechanics of materials course, and some of you may have never truly mastered them, despite doing well, at least grade-wise, in the class. +[9.65s -> 19.30s] This video is the first of a small series of videos where we'll recap some of the topics that need to be of second nature to any engineering student taking a mechanical engineering design course. +[19.30s -> 33.65s] just in the same way some of the physics concepts are essential for a static scores like for example force components free body diagrams sum of forces and moments or how mastering shear and bending moment diagrams was essential for easily understanding their utility during mechanics +[33.65s -> 43.44s] of Materials course, these videos will highlight the most basic concepts from previous classes that you need to fully master before covering newer Mech 1 topics. More importantly, +[43.44s -> 52.77s] These videos will help you identify where your gaps are so that you can work on those either by yourself or by checking the additional videos I've recorded and linked in the description below. +[52.77s -> 67.25s] Today we will talk about axial loading, the definition of stress and strain, elastic modulus and yield strength, and we will solve a very simple structure problem, where we use these topics, and more importantly, situate their importance within a MEK1 course. The reason we don't +[67.25s -> 81.46s] just stop at calculating forces like we used to do on physics 1 or statics is because we could have two very similar structures let's say a simply supported beam that is subjected to a point load of five kilonewtons and not break and then have another beam +[81.46s -> 85.23s] subjected to a point load of 1 kN and have it break. +[85.23s -> 99.60s] there might be more than one reason for this the beam on the left might be thicker or it may be made out of a material that can withstand a higher stress so looking at a five kilonewton force versus a one kilonewton force is not enough and that is why we use stress +[99.60s -> 107.02s] which is defined as force per unit area. From previous courses you know that there's a difference between engineering stress and true stress. +[107.02s -> 121.30s] with engineering stress being the load over the initial area and true stress being the load over the instantaneous area at any given point. Of course, as you stretch something, the cross-section area becomes smaller. So even for a simple tensile test, true stress +[121.30s -> 130.24s] engineering stress will be different. Strain is defined as the change of length per unit length. And again, there's a difference between engineering strain and true strain. +[130.24s -> 144.53s] where engineering strain is the change of length over the original length, and where true strain is the integral of dl over l integrated from the initial length. In most engineering applications, we end up using the engineering stress and the engineering strain, and since we don't +[144.53s -> 155.71s] need to make a distinction between initial area or instantaneous area. We just call this axial strain load over area and the engineering strain deflection or displacement over length. +[155.71s -> 170.00s] The relationship between these two concepts is of very high importance for many engineering applications, especially within the elastic range. From previous classes you probably remember the stress-strain curves, where we have stress in the y-axis and strain in the x-axis. +[170.00s -> 184.21s] the stress strain curves will be different for for example polymers metals and ceramics but within the elastic region you would always somehow be able to calculate the slope of that straight line which would be rise over run or the ratio between +[184.21s -> 197.73s] stress and strain that we call the elastic modulus. A brief parenthesis here, if we were looking at the true stress and true strain for metals for example, we would see that both the ultimate stress and its corresponding strain would be higher. +[197.73s -> 211.57s] And I mention this now because a property called the true fracture strength will be important for some of the applications that we'll discuss later in the course. Also worth pointing out now is that the scale for the axes I use is not the same for all three plots. +[211.57s -> 221.33s] A metal stress strain curve would have a much gentler slope on a ceramics plot, and a low density polyethylene curve would probably only be visible in the ceramics plot. +[221.33s -> 235.63s] Now going back to the elastic modulus and using the expressions that I have for stress and strain, I would find that the elastic modulus is equal to PL over A delta, or if I'm solving for that delta, that the displacement or deflection is equal to P. +[235.63s -> 245.57s] Let's take a look at a simple example of a structure that is subjected to a 200 kN load. I know the distances between points A, B, and C. +[245.57s -> 258.24s] And I know that members AB and BC are both made of a material with an elastic modulus of 200 gigapascals, a yield strength of 350 megapascals, and a cross-section area of 1800 millimeters squared. +[258.24s -> 267.15s] I would like to know the stress and the displacement in member BC. I know that to answer these questions I need to find the internal force from member BC. +[267.15s -> 277.34s] To find that force, I use basic statics or physics, and I know that there's multiple options to finding this force. I could do a free body diagram of the whole structure to find reaction forces A and C, +[277.34s -> 289.22s] and then a free body diagram of BC and AB separately to find the interaction forces. But I know that it's all too complicated. I know that in this case, I would just do a sum of forces for joint B. +[289.22s -> 303.90s] Notice that the sub-indices that I'm using start with the letter B because their force is going from B to A and from B to C. And notice that the direction of the vectors are set so that members BA and member BC are assumed to be under tension. +[303.90s -> 318.19s] We do this on purpose so that when we solve for the variable FBA and the variable FBC, positive values will indeed mean that the members are under tension and negative values would mean the opposite, meaning compression, which is anyways the convention that we all +[318.19s -> 332.40s] follow if any of this is not second nature to you make sure to check out the links in the description below where we go over some examples of basic statics analysis from sum of forces in the X direction I find out that FBA is equal to minus FBC +[332.40s -> 340.83s] If finding the components of a vector in the x and the y direction is not completely clear to you, you can check out some of the other links in the description below. +[340.83s -> 355.12s] Using this information and doing a sum of forces in the y direction and knowing that the angle theta is equal to 45 degrees, I find that FBA is equal to 100 square root of 2 kilonewtons and FBC is equal to minus 100 square. +[355.12s -> 367.01s] root of two kilonewtons which like i explained earlier means that member ba is under tension because its internal force is positive and member bc is under compression because its internal load is negative +[367.01s -> 372.94s] And remember this is only true because of the direction I chose for the vectors FBA and FBC. +[372.94s -> 387.22s] If you choose any other combination of directions of the vectors FBA and FBC, you would still get the same answer and get to the same conclusion about tension and compression, but you would just be adding extra steps. Going back to the stress, I find that the stress is equal to +[387.22s -> 401.42s] to minus 100 square root of 2 kilonewtons over 1800 millimeters squared which yields 0.0783 repeating gigapascals or 78.3 megapascals and substituting the values for the display +[401.42s -> 415.63s] BC I would get minus 100 square root of 2 times 2 square root of 2 for the length of member BC which is the hypotenuse of a right triangle of sides 2 and 2 in meters over 1800 millimeters squared times the +[415.63s -> 418.10s] elastic modulus of 200 gigapascals. +[418.10s -> 432.40s] Since the displacement is only 1.1 repeating millimeters and the dimensions of the members are 2 square root of 2 meters, I can assume that even though member BC is compressing and BA is stretching, the dimensions of the triangles remain mostly the same. +[432.40s -> 446.61s] and both angles theta are almost exactly 45 degrees. As for the stress, in your mechanics of materials course you usually had an allowable stress that you would compare to the calculated stress from the structure you were analyzing. One of the first few things that will +[446.61s -> 460.82s] look at in this course is how to compare those calculated stresses, mainly the principal stresses, to the material properties of your material to calculate a more accurate factor of safety. If you take a look at what we did you'll notice that a good portion requires you +[460.82s -> 475.02s] to have a good understanding of physics, statics, and mechanics of materials, and that only a small portion of mechanics of materials will actually overlap with the concepts from a MEK 1 course. So make sure that you truly master the concepts from statics, +[475.02s -> 489.23s] physics, and mechanics of materials so that you're not held back by them when trying to absorb new concepts or trying to solve the portions of the problems that should be very trivial by now. In our next video we will take a look at torsion, specifically the torsional stresses and +[489.23s -> 501.58s] the angle of twist, including some common questions about that polar second moment of area. If you have questions about how this problem was solved, don't forget to check out the questions and the links in the description below. +[502.99s -> 504.59s] Thanks for watching. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_6.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..871725e90a0f29d9efd9b116a43726e5e6beee76 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_6.mp4.txt @@ -0,0 +1,89 @@ +[6.74s -> 20.67s] Hello, today we will start a new topic. Till now we have been discussing Bravais lattices, 14 Bravais lattices and 7 crystal systems. We looked how symmetry helps in +[20.67s -> 34.96s] classification of crystals into these schemes. We will now start a new topic, the Miller indices of directions and planes. These are techniques or tools to specify +[35.82s -> 49.86s] various directions. When we work with crystals, we need to specify or name different directions and planes in a crystal. So, Miller indexing is a standard. +[49.86s -> 63.42s] method which has been which is being used for this purpose. So, let us we will first in this video we will look at Miller indices of directions and in the next one. +[63.42s -> 78.32s] we will take Miller indices of planes. So, let us look at Miller indices of direction. Suppose we have this crystal a unit cell is shown a face centered cubic lattice. +[79.41s -> 94.05s] So, all these large circle are the lattice points and we want to specify a certain direction let us say this blue direction edge of the cube. Now of course, the cube has this edge. +[94.05s -> 106.00s] It has this another edge, two horizontal edges and one vertical edge. So I have picked out one of them, this blue one and I want to give a name to it. +[106.00s -> 120.34s] Of course, in common language, I can say that it is the edge of the cube on its bottom face coming out of the screen, so to say, and this one is an edge lying in the screen. +[120.34s -> 123.38s] and this is a vertical edge and so on. +[126.06s -> 140.74s] However, Miller indexing will give us a specific notation or a specific system to name this blue line. So, let us look at how we do that we will go step by step. +[140.74s -> 147.18s] The first step in Miller indexing is to choose an origin. +[147.95s -> 157.65s] the direction. So, I have chosen this back corner as my origin pointed out in red. +[158.00s -> 171.42s] So, the first step is always to choose the origin and I have highlighted here that on the direction. So, the origin always has to be on the direction, it should lie on the direction or vice versa. +[171.42s -> 184.80s] The direction should pass through the origin or origin should be so chosen that it lies on the direction. This freedom of choice exists in crystallography. In the crystallographic coordinate system, we are free. +[184.80s -> 197.74s] to choose the origin anywhere we wish. So if I want to index this blue direction, I choose the origin on the blue direction and I took this point as the origin. +[199.44s -> 208.69s] The next step is to choose a coordinate system crystallographic coordinate system with axes parallel to the unit cell edges. +[211.02s -> 216.27s] So, in this case I have chosen x, y and z with. +[216.66s -> 230.48s] the 3 x y z directions parallel to the unit cell edges. Here I have read for illustration purpose I have taken a cube even in a non cubic crystal even if the angle between x and y is not 90 degree. +[230.48s -> 245.04s] and even if z is not perpendicular to x and y, we will always choose our x, y and z parallel to the unit cell edges. This is what is called the crystallographic coordinate system. +[245.42s -> 254.86s] So, we will be using the crystallographic coordinate system with unit cell edges as our axes. +[256.27s -> 263.44s] So, we have done that for this direction, now we have taken this red origin and red axis. +[264.98s -> 278.29s] The next step is to find the coordinates of another point on the direction in terms of a, b and c. a, b and c are the three lattice parameters, so in this case they are the edge lengths. +[278.29s -> 290.32s] So, a is the edge length of the unit cell along the x axis, b is the edge length of the unit cell along y axis and c is the edge length along the z axis. +[290.38s -> 304.86s] So, in terms of these 3 vectors the a b and c vectors I will now try to express the blue vector which is the vector of my choice direction of my choice. +[304.86s -> 319.04s] as in terms of these 3 vectors. So, here it is very simple it is 1 times a because the direction is along the x axis and it is of the length equal to a. So, it is 1 times a 0 times b +[319.04s -> 321.33s] and 0 times C. +[323.18s -> 335.71s] So, I just take these coefficients 1, o, o to represent this direction. So, I find the coordinates of another vector in terms of a, b and c. +[335.71s -> 345.52s] So, the first one means 1 times a, the second 0 means 0 times b and then 0 times c. +[348.02s -> 362.03s] The next step which in this case is redundant but we will write it out because we will use it in the next example is to reduce the coordinates to smallest integers and this can be done. +[362.03s -> 375.28s] either by dividing by a common factor or multiplying by common factor. So, suppose we had fractions then we will multiply by some common factor such that the fractions get cancelled. +[375.79s -> 390.42s] Or suppose if we had a common factor in all these three, then we will divide by that common factor to cancel out the common factor. So, this is a step of reducing the coordinates to its smallest integers. In this case. +[390.45s -> 396.75s] nothing is required 1 0 0 is already smallest integer, so we carry on with that. +[397.17s -> 410.72s] Then, the final step is to just put these three numbers in a square bracket. This is an important step. Square bracket is not my choice in this presentation or this slide. +[410.72s -> 424.93s] It is an internationally agreed upon convention that directions will always be represented by numbers inside square bracket. So, we will follow this convention. So, 100 is the +[424.93s -> 434.51s] which is represented by this blue line. So, 1 0 0 there is a slight difference between +[434.96s -> 444.85s] vector terminology and the Miller index of a direction. Although I picked up one vector this blue vector to +[445.52s -> 459.18s] along this line and you use that to calculate my Miller indices. Once I have found the Miller indices 1 0 0, it is not representing just this blue vector. +[459.18s -> 471.89s] but this entire x axis. So, the entire x axis as well as the negative x axis can be represented this full line is represented by the number 100. +[473.17s -> 487.58s] Another peculiarity of convention here when I wrote the components separately I am writing it with commas, but in the Miller indices I am not using any commas. So, this is a useful convention unless and until. +[487.58s -> 500.69s] we have a two digit miller indices for one of the components. If it is only three numbers we write them without any commas and it is understood that the first number is with respect to the x axis. +[500.69s -> 510.26s] the second one with respect to the y and third one with respect to z. So, let us look at some more examples now. +[513.23s -> 523.09s] before looking at those examples one more point. So, Miller indices of a direction represents only the orientation of the line. +[524.21s -> 537.90s] not its particular position in the space or also its sense. So, I already told that not only the positive x axis but the negative x axis will also be represented by 1 0 0. +[538.03s -> 552.69s] We do not really want to distinguish positive and negative that is to say if we are only interested in the line not in the sense and in Miller indices that is usually the case then 1 0 0 represents the entire x axis. +[552.69s -> 554.86s] Not only that. +[555.92s -> 568.94s] Because what we said about freedom of choosing the origin if we had parallel lines somewhere here then I can again choose my origin here and this will become my x axis. +[569.04s -> 578.35s] or I can choose my origin there and this will become my x axis. So, all parallel directions have the same Miller indices. +[581.07s -> 584.21s] Let us now look at some more examples. +[588.88s -> 602.96s] So, again we take this face centered cubic unit cell and we want to index a direction which is starting from this corner and passing through the top face center. +[603.25s -> 610.38s] So this direction is the direction of my choice, so I choose this as a coordinate first step. +[610.77s -> 624.50s] a coordinate origin and a coordinate system. So I chose this point as my origin and axes along the unit cell edges. With respect to this coordinate system. +[624.50s -> 635.79s] I now write the vector OA, so you can see to reach OA I have to go a by 2 steps along x. +[636.24s -> 643.50s] a by 2 steps along y and then c step along z. +[645.20s -> 656.40s] So, OA the vector OA is half a plus half b and 1 times c. So, the coordinates +[657.10s -> 663.82s] which we will use in the Miller indices in terms of a, b and c are half, half and 1. +[664.43s -> 678.42s] Now, I will use the cancelling of fractions step which we did not require in the previous one in the case of 1 0 0 we did not require that but now in the case of half half 1 we will not call this direction half half 1 but. +[678.42s -> 690.77s] will simply multiply by 2 all these 3 numbers to get 1, 1, 2 and of course I put them in the square bracket. +[692.11s -> 705.44s] which we have agreed upon to use as a convention for directions. So, the OA direction not just the OA vector, but the entire OA direction will be represented by this. +[705.44s -> 712.82s] Miller indices 1, 1, 2. One more example, let us look at this black direction. +[713.71s -> 725.26s] Now of course I have to choose the origin on the black line and that freedom is there, so I shift the origin to this point P on the black line. +[726.51s -> 740.91s] you can note that when I have shifted the origin I have kept the axes parallel. So, we have the freedom to choose our origin anyway, but in a given problem once we have a specified the orientation of the axes. +[740.91s -> 755.54s] the that orientation cannot change. So the xyz in the new with the new origin is exactly parallel to the xyz before the black xyz is parallel to the blue xyz. +[755.60s -> 769.55s] So, now let us try to index this direction along P Q which is one of the body diagonals of this Q. So, if we want to look at this P Q we will +[770.35s -> 782.51s] Start with p and you can see that now I have to take a minus 1 step along x, 1 step along y and 1 step along z to reach q. +[782.74s -> 794.80s] So, the p q vector is minus 1 a minus 1 b and 1 c. +[795.76s -> 802.10s] The components are minus 1, minus 1, 1 in terms of a, b and c. +[802.48s -> 816.35s] Now, I write this in a square bracket with one additional convention that the negatives are written as bars over the number instead of on the side as in useful mathematics. +[816.35s -> 830.72s] in the Miller indexing notation a bar above the number represents negative quantity. So, and it is read also as bar instead of minus 1. So, we will call this direction p q. +[830.72s -> 844.14s] as bar 1, bar 1, 1. Let us now take, so the negative steps are shown as bar over the number. +[846.19s -> 848.14s] Let us now look at. +[848.72s -> 862.46s] Another convention which is used many times we are not interested in just one direction because we have talked about the symmetry in the crystal and crystals can have symmetry and symmetry relates. +[862.46s -> 863.98s] many directions. +[864.53s -> 878.32s] So, many directions become equivalent because of the existing symmetry of the crystal. So, for example, if you take a cubic crystal, so all the edges of the cube are equivalent by the cubic symmetry. +[879.34s -> 881.52s] So, if we. +[881.97s -> 896.37s] If we index the edge along x axis, it will be 1 0 0. If we index along the y axis, 0 1 0 and index along z axis, 0 0 1. But suppose I am not interested in the specific direction. +[896.37s -> 909.33s] I just want to talk about the cube edges for all directions along the cube edge which are equivalent by symmetry. Then there is a new notation that you can put the Miller index. +[909.33s -> 912.88s] of any one of them in an angular bracket. +[913.74s -> 927.82s] So, an angular bracket UVW means the specific direction UVW and all other direction related to UVW by the symmetry of the crystal and it is important. +[928.14s -> 942.22s] that when we are using this notation we have to know which crystal system we are talking about because different crystals will have different symmetry and the symbol will mean different things. We will show you this. +[942.29s -> 956.94s] with the help of cubic and tetragonal examples. So let us look at first the cubic. So in the Miller indices of cubic crystal. +[957.87s -> 972.24s] the 1 0 0 direction is equivalent to 0 1 0, 0 0 1 as well as if we take the negatives minus bar 1 0 0, 0 bar 1 0 and 0 0 bar 1. +[972.72s -> 987.20s] So, the all 6 directions are equivalent by the cubic symmetry. So, if we simply write 100 if I pick any one of them I have picked up 100 you could have picked up 010 or 001. +[987.20s -> 992.21s] any of these 6. So, any member of this direction. +[992.75s -> 1006.34s] This is a family of 6 members, this is a family of symmetry related directions and I pick up any member of the family to represent the entire family. +[1006.34s -> 1012.88s] in angular bracket and I know that it is for cubic then I will mean all these 6 directions. +[1014.26s -> 1023.34s] But now let us look at the tetragonal crystal, in tetragonal you know x and y are equivalent by symmetry but not the z. +[1023.98s -> 1038.51s] So, if I say 1 0 0 for tetragonal it will only mean these 4 directions 1 0 0, 0 1 0 and their negative. The third direction 0 0 1. +[1038.67s -> 1048.82s] is absent from here in this list because tetragonal symmetry does not make 0 0 1 equivalent to 1 0 0. +[1050.45s -> 1060.94s] With this we will end this video, in the next video we will take the discussion on Miller indices of planes. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Materials_7.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Materials_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..75a62586ebf8211e50d9f5d1cb048b1b7c4abf43 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Materials_7.mp4.txt @@ -0,0 +1,6 @@ +[0.75s -> 15.01s] A rubber block is bonded to a rigid support into a vertical plate that is subjected to a 60 kip vertical load P. If the modulus of rigidity, or shear modulus, is 120 ksi, +[15.01s -> 27.25s] What is the vertical displacement of the plate? This is the third example for the shearing stress and strain main video. Links to the previous two examples in that main video are in the description below. +[27.31s -> 40.61s] If we look at this setup from the positive z-axis, we'd see that because of the deformation of the rubber block caused by the subjection of the plate to a load P, the plate would have moved vertically a distance h. +[40.61s -> 53.54s] Since the shear strain gamma is directly proportional to H, and we also know that gamma is the shearing stress over the modulus of rigidity, we can solve for the vertical displacement of the plate H. +[53.54s -> 65.52s] What we're missing from this expression is the shearing stress tau. But we know that tau is equal to the shear force V over the area parallel to it. Substituting the given values, +[65.52s -> 78.06s] we find a displacement of 55 thousandths of an inch. For one more problem on shearing stress and strain, make sure to check out the link in the description below. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_10.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a14e3260715b56cca1f5dcba2c9cfe34c3726aad --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_10.mp4.txt @@ -0,0 +1,15 @@ +[1.01s -> 15.57s] This is example number five and we will find an equivalent spring constant for a bar suggested to an actual load. We have three step bar that are fixed to one end and subjected to an actual load at the other end. +[15.57s -> 27.38s] We have three bars, and each bar has a length i, so bar 1 has length 1, bar 2 has length 2, and bar 3 has length 3. +[27.38s -> 37.18s] and they have cross-sectional area A1, A2, and A3. They are all the same material, therefore the Young modulus for +[37.18s -> 43.89s] All of them are the same. So we want to find the equivalent constant in the actual direction. +[45.30s -> 57.15s] Remember that we saw in the theory for a bar subjected to axial load with a length L and a cross-sectional area. +[57.15s -> 67.15s] and the equivalent K will be equal to A times E divided by L. +[68.18s -> 78.83s] Please look at the theory because we did an example to deduct that equation. Since we have three bars, +[79.25s -> 93.01s] one following the next one, we will have a system equivalent as we would have three springs in series. +[93.01s -> 107.02s] and we want to find the equivalent constant for those three springs in series. We will use the formula that we know for equivalent. +[107.02s -> 121.06s] springs in series, which is the inverse of the equivalent constant is equal to the inverse of each of the individual constants. And then we can +[121.06s -> 125.36s] take out the young models because we have the same material. +[125.65s -> 138.46s] And then we have L1 over A1, L2 over A2, and L3 over A3. If we do the algebra and we take the inverse of these three, +[138.46s -> 151.34s] fractions we get the following result. E times the three areas, A1, A2 and A3 divided by the three terms. +[151.73s -> 162.32s] L1A2A3 plus L2A1A3 plus L3A1A2. And this is the equivalent. +[163.22s -> 168.56s] spring constant for a bar suggested to axial load. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_11.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..955d6a2c94113707bf751f3e87c09b658bc2ba26 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_11.mp4.txt @@ -0,0 +1,60 @@ +[1.81s -> 10.43s] Irregularities or discontinuities such as holes and notches effectively increase the nominal or theoretical stress as we move closer and closer to them. +[10.43s -> 24.78s] The theoretical stress we calculated for a part with the stress concentration at a location where the stress concentration is present is the same stress we would normally calculate with our mechanics of materials tools, only multiplied by a stress concentration factor, kT or kTs. +[24.78s -> 37.02s] for normal or shearing stresses respectively. However, these KTs that we often find by looking at stress concentration factor plots that depend on the geometric parameters and stress type only applies to static loading. +[37.02s -> 45.23s] Stress concentration factors still exist for dynamic loading, and we call them fatigue stress concentration factors, KF or KFS. +[45.23s -> 59.41s] Interestingly, the fatigue strength is not affected as much as stresses are by notches or other stress concentrations. The fatigue stress concentration factor is defined as the fatigue strength of a notch-free specimen over the fatigue strength of a notched specimen. +[59.41s -> 70.38s] So even though it's effectively defined as affecting the material property fatigue strength, it can be used as a stress increase in the nominal stress, just like KT or KTS for static loading. +[70.38s -> 84.75s] the fact that the sensitivity is reduced when going from a static to dynamic loading that is from static to fatigue analysis comes mainly from the fact that the notch stress affecting the fatigue life is not the maximum stress at the notch but instead it's the average stress +[84.75s -> 87.68s] over a volume of material close to the notch. +[87.68s -> 101.76s] Adding to this, any crack that is in fact initiated at a notch will be growing into a region with stresses that are much lower than at the stress concentration. However, not everything about why the effective stress concentration being lower for fatigue is fully understood. +[101.76s -> 114.08s] We define notch sensitivity Q as Kf-1 over Kt-1 and Qs for shearing as Kfs-1 over Kts-1. +[114.08s -> 127.89s] Since all Ks are expected to increase the theoretical stress and are therefore 1 or higher, this definition for sensitivity is basically comparing, as a ratio, the percentage of increase for fatigue +[127.89s -> 138.58s] to the percentage of increase kT-100% for static loading. And since the information we have access to based on experimental data is the notch sensitivity Q, +[138.58s -> 151.86s] These expressions are rearranged to find Kf as a function of Kt and Q, or Kfs as a function of Kts and Qs for shearing. Notch sensitivities will depend on the notch radius, x-axis, +[151.86s -> 156.59s] and sometimes the ultimate strength of the material represented by the different curves. +[156.59s -> 168.74s] And since they are the result of experimental measurements, they are also material specific. For example, notice that not only the values but also the behavior of steels is different to that of the aluminum alloys. +[168.74s -> 183.09s] Even though the fatigue stress concentration factor doesn't fully affect the theoretical calculations for cycles in the low cycle region of SN diagrams, that is, for cycles between 1 and 1000, and the actual value of the fatigue stress concentration factor +[183.09s -> 196.00s] is somewhere between 1 and kf for those numbers of cycles, a conservative approach that is commonly used is to just follow the expression to calculate kf, regardless of how many cycles the part is going to be subjected to. +[196.00s -> 210.32s] Let's look at a problem where we put together what we've learned in the past three main videos. A rotating shaft simply supported in ball bearings at A and C is subjected to a non-rotating force F of 500 newtons right in the center between +[210.32s -> 222.88s] A and C. The shaft is machined from a 1035 cold drawn steel and I know that the radius of the notch is 9 eighths of a millimeter. I want to estimate the life of the part. +[222.88s -> 228.50s] Remember that these problems have two very distinct parts that almost have nothing to do with each other. +[228.50s -> 242.21s] one calculating the fatigue strength and one calculating the stress. So let's start with the fatigue strength first. And even though it's not necessary to solve the problem, having an SN diagram will definitely help us to understand it better. +[242.21s -> 251.12s] We know that the part will fail when the stress is equal to the strength of the material, in this case the fatigue strength, and that is why we need the SN diagram. +[251.12s -> 264.30s] because it will give us the fatigue strength for a specific number of cycles, which is what we're looking for. We know that to fully define the SN diagram, we need to find the F coefficient and the endurance limit, so we know where the inflection points occur. +[264.30s -> 278.58s] We also know that the F coefficient will be a function of the ultimate strength, and that we can look it up specifically for steels by looking at the F coefficient plot that we've used before. After looking up the ultimate strength for the 1035 steel, I find that +[278.58s -> 293.01s] the tensile strength is 550 MPa. And for 550 MPa, the F coefficient that I find is 0.875, roughly in the middle between 0.87 and 0.88. +[293.01s -> 307.14s] Having F and therefore the product between F and SUT, I can draw the line for the low cycle region. Now the other value is finding the endurance limit. I know that my first estimate for the endurance limit is going to be half of the ultimate strength. +[307.14s -> 314.43s] as we defined it a couple videos ago. But I also know that I should probably use the Morin factors to get a more accurate estimate. +[314.43s -> 328.72s] Since neither the temperature nor the reliability were defined for this problem, I won't be using KD or KE. However, I know that the surface finish, meaning the surface factor, the size factor, and the loading factor are +[328.72s -> 338.48s] important and I should take them into consideration. From our previous video we know that depending on the surface finish and the ultimate strength value we can calculate the surface factor. +[338.48s -> 348.05s] Since our part was machined and our ultimate strength is in MPa, I use the corresponding values for the factor a and the exponent b to calculate Ka. +[348.05s -> 361.15s] From what we know about the size factor, we can calculate the value for KB if we know the diameter of our part. And in this case, it doesn't need to be an equivalent diameter because the part is in fact a shaft and it is rotating. +[361.15s -> 375.65s] And notice that I'm using the diameter for the smaller section since that is where the maximum stress is going to occur. Finally, for the loading factor, I know that this rotating shaft is going to be subjected to bending, a completely reversed normal stress. +[375.65s -> 390.21s] which results in a Kc of 1. And therefore, my endurance limit, accounting for the Morin factors, is equal to 197.3 MPa, which is the other value I need to know for the second inflection point of the SN diagram. +[390.21s -> 396.21s] With this, I have fully defined the fatigue strength for any number of cycles for this part specifically. +[396.21s -> 410.48s] Now comes in the second part where I look at the stress that the part is subjected to completely independent from the strength analysis. I know that the part is subjected to bending and that to calculate that bending I need to find the moment that is causing the max +[410.48s -> 412.05s] value for the stress. +[412.05s -> 426.32s] That maximum stress may either be where the moment is maximum or where the stress concentration occurs. In this case, it's pretty clear that the maximum normal stress will occur at the notch since the maximum moment happens where the cross-section area has a +[426.32s -> 429.86s] diameter that is three times as big as the smaller diameter. +[429.86s -> 444.14s] In this case, it's pretty obvious that the maximum stress will occur at the notch, since for the maximum moment, even though it's 50% higher than the moment at the notch, the diameter is 3 times as big, and therefore the stress will be 27 times smaller. +[444.14s -> 448.61s] since the diameter is cubed in the denominator of the stress equation. +[448.61s -> 462.61s] for any other case where you don't know if the stress is going to be higher at the maximum moment or at the notch you evaluate the stress for all the candidate locations that you find so let's do that for this example as a practice exercise +[462.61s -> 475.47s] I know that the moment at D is 75 Nm and that the moment at B is 50 Nm. The stress at D where the maximum moment occurs will be equal to 8.35 MPa. +[475.47s -> 487.46s] using a diameter of 45 millimeters. The moment at B, without using the stress concentration factor yet, would already be way higher than that at 151 megapascals. +[487.46s -> 499.39s] So I know that the higher stress will occur at point B where the notch is located. All I need to do now is find the fatigue stress concentration factor Kf and to do that I need the stress concentration factor +[499.39s -> 509.98s] for static loading, KT, and the notch sensitivity, Q. Remember, not KTS or QS since these are normal stresses, not shearing. +[509.98s -> 520.94s] Since the larger diameter capital D is equal to 45 millimeters and the lower case d is equal to 15 millimeters, I know that the d over d ratio is equal to 3. +[520.94s -> 531.44s] Checking the value of the radius of the notch and using it to find the ratio r over d, we find that the value for the x-axis is going to be 0.075. +[531.44s -> 544.45s] exactly between 0.05 and 0.10, which if we're looking at the curve of d over d equal to 3 gives us a kt of 2.0, right between 1.8 and 2.2. +[544.45s -> 552.06s] Looking at the notch sensitivity plot and using an ultimate strength of 550 MPa, which is exactly between +[552.06s -> 563.46s] 400 and 700 megapascals and using the same radius for the notch of 1.125 which is one fourth of the way from 1 to 1.5 millimeters +[563.46s -> 577.74s] I would get a value slightly higher than 0.7. I will assume Q equal to 0.72. Using these two values and the expression we learned in today's video, I can calculate the fatigue stress concentration factor and find that is equal +[577.74s -> 588.37s] to 1.72. I can now go back to my stress at B and multiply that nominal slash theoretical value by the stress concentration factor for fatigue. +[588.37s -> 599.23s] And since I'm sure that that is the maximum normal stress that the part will be subjected to, that's the stress that will make the part fail when it exceeds the decreasing fatigue strength. +[599.23s -> 609.92s] To find the number of cycles for which the constant stress of 260 MPa will be equal to or exceed the fatigue strength and therefore cause the part to fail, +[609.92s -> 617.31s] I used a relationship that we derived a couple videos ago. N would be equal to the stress over A to the 1 over B. +[617.31s -> 629.66s] which means I need to calculate my coefficients A and B. A would be equal to 1174 MPa, and the B exponent would be equal to minus 0.1292. +[629.66s -> 640.56s] and therefore the number of cycles for the fatigue strength to come down to 260, which is the external stress, would be 116,760 cycles. +[640.56s -> 649.23s] If you'd like to check out some other examples where we put together everything we've learned so far about fatigue, make sure to check out the links in the description below. +[649.62s -> 659.10s] So far, we've looked at completely reversed stresses, which means that the mean stress is zero and the alternating stress goes from a negative to a positive value. +[659.10s -> 672.91s] In the next video, we'll look at the fluctuating stress diagrams, which will allow us to calculate a factor of safety for any fluctuating stress that is not centered at zero. Thanks for watching! diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_12.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2cfca42db0596148961dc11284b806dd93c839a2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_12.mp4.txt @@ -0,0 +1,46 @@ +[4.72s -> 12.03s] Orthographic projection. In engineering drawing, we often have to produce 2D and 3D drawings of different parts. +[12.03s -> 24.24s] These 3D objects need to be shown on 2D planes, that is, X and Y planes in such a way that we get to see all the views. That is a front view, side view, top view etc. +[24.24s -> 38.06s] This type of projection system is known as an orthographic projection. In this system of projection, the views have to be drawn by following certain standard projection rules, which are known as the first angle and third angle projection methods. +[38.06s -> 49.82s] These methods are largely used in industries. If you want to know what the first angle and third angle projection method means, you can get the video link in the description of this video or the i button. In this video, +[49.82s -> 54.35s] We will learn how to draw an orthographic view from this isometric view of an object. +[54.67s -> 66.96s] Isometric view is a graphical method of representing a three-dimensional object. An orthographic view is a means of representing a three-dimensional view in two dimensions. It has only two axis. +[66.96s -> 74.90s] let's see how we can represent this three-dimensional object in a two-dimensional view consider this figure +[76.30s -> 89.70s] Here it is told, draw looking from the direction of X. This means we should assume the viewer is viewing the object from this direction. In other words whatever the view from this direction will be the front view of the object in this case. +[89.70s -> 103.41s] Also, in the instructions, they will mention the number of views required to be drawn. If it is not mentioned, then you need to draw at least three views of the object. That is the front view, top view, and side view. +[103.41s -> 117.26s] Also, they will mention which projection method to use, that is, the first angle or third angle method. If it is not mentioned, then you have to draw using the first angle method. Before starting the drawing we need to draw the reference line. +[117.26s -> 129.89s] which is the XY line. Since we are following the first angle method to draw the projection. On the top, the front view will come, and on the bottom, the top view will come. Next, we need to draw a vertical line. +[129.89s -> 142.21s] which we will name X1Y1. The left side view of the object is drawn on the right side, as we are following the first angle method. Let's start drawing. First, we will draw the front view of the object. +[142.21s -> 152.83s] since the direction of viewing is from this side suppose you are standing here and looking at this object this is how it will look only this part of the object is visible therefore +[152.83s -> 165.22s] This is our front view of the object which we need to draw above the XY line. But to do so, we need the dimensions for this view. We can see this total length is made up of three sections of 25 millimeters. +[165.22s -> 179.70s] Which will be equal to 75 millimeters. That means this total length is 75 millimeters. And these sections will be 25 millimeters each. Next, we need this height. We can see this height is given as 12 millimeters in the figure. +[179.70s -> 190.51s] This height is given as 25 millimeters. This width is given as 20 millimeters in the figure. And at last, we need this width, which is given as 20 millimeters. +[190.86s -> 204.27s] This is our front view of the object with all the dimensions. During exams, you can draw such rough figures, which will help you in drawing faster. Take a ruler, and draw a horizontal line of 75 mm. +[206.22s -> 210.42s] Draw a vertical line of 12 millimeters and construct a rectangle. +[214.26s -> 222.38s] After this, we need to divide this into three parts. Take a ruler and mark 25 millimeters length and draw the horizontal lines. +[229.14s -> 237.10s] After this, we need to draw this section. Take a roller scale and draw a vertical line of 25 millimeters. +[239.28s -> 250.16s] Using this line as a reference, draw a horizontal line of 20 mm from here. Next, using a ruler, mark a 20 mm length on this line from the left edge. +[251.57s -> 264.98s] At last, join these points with a line. This is the required front view of the object. Next, we will draw the top view of this. When we view the object from the top, +[265.62s -> 269.94s] This is how it will look from the top, we can see only this part of the object. +[270.77s -> 285.33s] We already know this total length is 75 millimeters. Next, this length is given as 50 millimeters. This length is given as 12 millimeters. And this rectangle's width will be 20 millimeters and its height will be 25 millimeters. +[285.62s -> 296.08s] This distance is given as 20 millimeters. We will draw the projection lines from the front view. Take a ruler and draw the projection lines as shown. +[307.66s -> 321.87s] after this we can use these reference lines to draw the top view take a ruler and draw a horizontal line next draw a vertical line of 50 millimeters in length +[325.20s -> 334.96s] We can see this length as 25 millimeters, which is equal to this length, which means, the horizontal line will be up to this line. Draw a horizontal line. +[337.01s -> 345.81s] This height is 12mm so from here it will be 12mm up. And again a 25mm horizontal line. +[347.47s -> 352.88s] a 12mm vertical line, and at last, a 25mm horizontal line. +[353.14s -> 364.77s] Next, we need to draw this section. We know this width is 20 millimeters, which is equal to this length. This height is 25 millimeters. Using this vertical line as a reference. +[364.77s -> 368.85s] Draw a vertical line of 25 millimeters and construct a rectangle. +[373.49s -> 386.48s] Also, we need to draw this additional rectangle, which represents this inclined portion. We can see this vertical line is 25 mm and it is 20 mm away from this edge, which is equal to this length. +[386.48s -> 401.26s] Using the vertical line as a reference, draw a vertical line of 25 mm in length Next, take a ruler and extend this horizontal line up to this line This is the required top view of the object +[402.35s -> 410.38s] At last, we need to draw the left side view of the object here. When we see the object from the left side, this is how it will look. +[410.83s -> 424.98s] We know this length is 50 millimeters, and we can see this height is 12 millimeters. Next, this height is given as 25 millimeters, and this width is 25 millimeters. We got all the required dimensions for the side view. +[424.98s -> 429.84s] First, we will draw the horizontal projection lines from the front view of the object. +[435.79s -> 444.69s] Also, we can draw the projection lines from the top view. To do so, first draw an inclined line which will be at 45 degrees. +[445.10s -> 451.31s] after this draw the projection lines from the top view extend these lines up to this inclined line +[458.51s -> 462.32s] and draw the vertical lines from each of these intersection points. +[473.74s -> 486.06s] These lines will help us in drawing the side view. Take a roller scale and draw a vertical line of 37 millimeters in length. After this, draw a horizontal line of 50 millimeters in length as shown. +[487.15s -> 496.18s] We need to construct this rectangle, we can see its height is 12 millimeters. Draw a vertical line of 12 millimeters, and construct a rectangle. +[496.78s -> 508.85s] Next, we need to construct this shape, we can see the width of this shape is 25 mm and the height is 25 mm. Take a roller scale and draw a horizontal line of 25 mm. +[509.94s -> 514.13s] and draw a vertical line of 25 millimeters up to this line. +[514.48s -> 528.37s] At last, we need to draw this dotted lines to represent this intersection. We can see the distance of this dotted line is 12 millimeters. Mark a point at a 12 millimeters distance from this edge, and draw a vertical dotted line. +[529.65s -> 543.39s] This is our required side view of the object. This is how we can draw an orthographic view from the isometric view. I hope this video helped you in understanding how to draw an orthographic projection of the object. If you like the video, +[543.39s -> 552.54s] click on the like button and if you are new to my channel adtw learn click on the subscribe button and turn on the notifications to get all my latest videos diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_13.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2cfca42db0596148961dc11284b806dd93c839a2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_13.mp4.txt @@ -0,0 +1,46 @@ +[4.72s -> 12.03s] Orthographic projection. In engineering drawing, we often have to produce 2D and 3D drawings of different parts. +[12.03s -> 24.24s] These 3D objects need to be shown on 2D planes, that is, X and Y planes in such a way that we get to see all the views. That is a front view, side view, top view etc. +[24.24s -> 38.06s] This type of projection system is known as an orthographic projection. In this system of projection, the views have to be drawn by following certain standard projection rules, which are known as the first angle and third angle projection methods. +[38.06s -> 49.82s] These methods are largely used in industries. If you want to know what the first angle and third angle projection method means, you can get the video link in the description of this video or the i button. In this video, +[49.82s -> 54.35s] We will learn how to draw an orthographic view from this isometric view of an object. +[54.67s -> 66.96s] Isometric view is a graphical method of representing a three-dimensional object. An orthographic view is a means of representing a three-dimensional view in two dimensions. It has only two axis. +[66.96s -> 74.90s] let's see how we can represent this three-dimensional object in a two-dimensional view consider this figure +[76.30s -> 89.70s] Here it is told, draw looking from the direction of X. This means we should assume the viewer is viewing the object from this direction. In other words whatever the view from this direction will be the front view of the object in this case. +[89.70s -> 103.41s] Also, in the instructions, they will mention the number of views required to be drawn. If it is not mentioned, then you need to draw at least three views of the object. That is the front view, top view, and side view. +[103.41s -> 117.26s] Also, they will mention which projection method to use, that is, the first angle or third angle method. If it is not mentioned, then you have to draw using the first angle method. Before starting the drawing we need to draw the reference line. +[117.26s -> 129.89s] which is the XY line. Since we are following the first angle method to draw the projection. On the top, the front view will come, and on the bottom, the top view will come. Next, we need to draw a vertical line. +[129.89s -> 142.21s] which we will name X1Y1. The left side view of the object is drawn on the right side, as we are following the first angle method. Let's start drawing. First, we will draw the front view of the object. +[142.21s -> 152.83s] since the direction of viewing is from this side suppose you are standing here and looking at this object this is how it will look only this part of the object is visible therefore +[152.83s -> 165.22s] This is our front view of the object which we need to draw above the XY line. But to do so, we need the dimensions for this view. We can see this total length is made up of three sections of 25 millimeters. +[165.22s -> 179.70s] Which will be equal to 75 millimeters. That means this total length is 75 millimeters. And these sections will be 25 millimeters each. Next, we need this height. We can see this height is given as 12 millimeters in the figure. +[179.70s -> 190.51s] This height is given as 25 millimeters. This width is given as 20 millimeters in the figure. And at last, we need this width, which is given as 20 millimeters. +[190.86s -> 204.27s] This is our front view of the object with all the dimensions. During exams, you can draw such rough figures, which will help you in drawing faster. Take a ruler, and draw a horizontal line of 75 mm. +[206.22s -> 210.42s] Draw a vertical line of 12 millimeters and construct a rectangle. +[214.26s -> 222.38s] After this, we need to divide this into three parts. Take a ruler and mark 25 millimeters length and draw the horizontal lines. +[229.14s -> 237.10s] After this, we need to draw this section. Take a roller scale and draw a vertical line of 25 millimeters. +[239.28s -> 250.16s] Using this line as a reference, draw a horizontal line of 20 mm from here. Next, using a ruler, mark a 20 mm length on this line from the left edge. +[251.57s -> 264.98s] At last, join these points with a line. This is the required front view of the object. Next, we will draw the top view of this. When we view the object from the top, +[265.62s -> 269.94s] This is how it will look from the top, we can see only this part of the object. +[270.77s -> 285.33s] We already know this total length is 75 millimeters. Next, this length is given as 50 millimeters. This length is given as 12 millimeters. And this rectangle's width will be 20 millimeters and its height will be 25 millimeters. +[285.62s -> 296.08s] This distance is given as 20 millimeters. We will draw the projection lines from the front view. Take a ruler and draw the projection lines as shown. +[307.66s -> 321.87s] after this we can use these reference lines to draw the top view take a ruler and draw a horizontal line next draw a vertical line of 50 millimeters in length +[325.20s -> 334.96s] We can see this length as 25 millimeters, which is equal to this length, which means, the horizontal line will be up to this line. Draw a horizontal line. +[337.01s -> 345.81s] This height is 12mm so from here it will be 12mm up. And again a 25mm horizontal line. +[347.47s -> 352.88s] a 12mm vertical line, and at last, a 25mm horizontal line. +[353.14s -> 364.77s] Next, we need to draw this section. We know this width is 20 millimeters, which is equal to this length. This height is 25 millimeters. Using this vertical line as a reference. +[364.77s -> 368.85s] Draw a vertical line of 25 millimeters and construct a rectangle. +[373.49s -> 386.48s] Also, we need to draw this additional rectangle, which represents this inclined portion. We can see this vertical line is 25 mm and it is 20 mm away from this edge, which is equal to this length. +[386.48s -> 401.26s] Using the vertical line as a reference, draw a vertical line of 25 mm in length Next, take a ruler and extend this horizontal line up to this line This is the required top view of the object +[402.35s -> 410.38s] At last, we need to draw the left side view of the object here. When we see the object from the left side, this is how it will look. +[410.83s -> 424.98s] We know this length is 50 millimeters, and we can see this height is 12 millimeters. Next, this height is given as 25 millimeters, and this width is 25 millimeters. We got all the required dimensions for the side view. +[424.98s -> 429.84s] First, we will draw the horizontal projection lines from the front view of the object. +[435.79s -> 444.69s] Also, we can draw the projection lines from the top view. To do so, first draw an inclined line which will be at 45 degrees. +[445.10s -> 451.31s] after this draw the projection lines from the top view extend these lines up to this inclined line +[458.51s -> 462.32s] and draw the vertical lines from each of these intersection points. +[473.74s -> 486.06s] These lines will help us in drawing the side view. Take a roller scale and draw a vertical line of 37 millimeters in length. After this, draw a horizontal line of 50 millimeters in length as shown. +[487.15s -> 496.18s] We need to construct this rectangle, we can see its height is 12 millimeters. Draw a vertical line of 12 millimeters, and construct a rectangle. +[496.78s -> 508.85s] Next, we need to construct this shape, we can see the width of this shape is 25 mm and the height is 25 mm. Take a roller scale and draw a horizontal line of 25 mm. +[509.94s -> 514.13s] and draw a vertical line of 25 millimeters up to this line. +[514.48s -> 528.37s] At last, we need to draw this dotted lines to represent this intersection. We can see the distance of this dotted line is 12 millimeters. Mark a point at a 12 millimeters distance from this edge, and draw a vertical dotted line. +[529.65s -> 543.39s] This is our required side view of the object. This is how we can draw an orthographic view from the isometric view. I hope this video helped you in understanding how to draw an orthographic projection of the object. If you like the video, +[543.39s -> 552.54s] click on the like button and if you are new to my channel adtw learn click on the subscribe button and turn on the notifications to get all my latest videos diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_15.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2cfca42db0596148961dc11284b806dd93c839a2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_15.mp4.txt @@ -0,0 +1,46 @@ +[4.72s -> 12.03s] Orthographic projection. In engineering drawing, we often have to produce 2D and 3D drawings of different parts. +[12.03s -> 24.24s] These 3D objects need to be shown on 2D planes, that is, X and Y planes in such a way that we get to see all the views. That is a front view, side view, top view etc. +[24.24s -> 38.06s] This type of projection system is known as an orthographic projection. In this system of projection, the views have to be drawn by following certain standard projection rules, which are known as the first angle and third angle projection methods. +[38.06s -> 49.82s] These methods are largely used in industries. If you want to know what the first angle and third angle projection method means, you can get the video link in the description of this video or the i button. In this video, +[49.82s -> 54.35s] We will learn how to draw an orthographic view from this isometric view of an object. +[54.67s -> 66.96s] Isometric view is a graphical method of representing a three-dimensional object. An orthographic view is a means of representing a three-dimensional view in two dimensions. It has only two axis. +[66.96s -> 74.90s] let's see how we can represent this three-dimensional object in a two-dimensional view consider this figure +[76.30s -> 89.70s] Here it is told, draw looking from the direction of X. This means we should assume the viewer is viewing the object from this direction. In other words whatever the view from this direction will be the front view of the object in this case. +[89.70s -> 103.41s] Also, in the instructions, they will mention the number of views required to be drawn. If it is not mentioned, then you need to draw at least three views of the object. That is the front view, top view, and side view. +[103.41s -> 117.26s] Also, they will mention which projection method to use, that is, the first angle or third angle method. If it is not mentioned, then you have to draw using the first angle method. Before starting the drawing we need to draw the reference line. +[117.26s -> 129.89s] which is the XY line. Since we are following the first angle method to draw the projection. On the top, the front view will come, and on the bottom, the top view will come. Next, we need to draw a vertical line. +[129.89s -> 142.21s] which we will name X1Y1. The left side view of the object is drawn on the right side, as we are following the first angle method. Let's start drawing. First, we will draw the front view of the object. +[142.21s -> 152.83s] since the direction of viewing is from this side suppose you are standing here and looking at this object this is how it will look only this part of the object is visible therefore +[152.83s -> 165.22s] This is our front view of the object which we need to draw above the XY line. But to do so, we need the dimensions for this view. We can see this total length is made up of three sections of 25 millimeters. +[165.22s -> 179.70s] Which will be equal to 75 millimeters. That means this total length is 75 millimeters. And these sections will be 25 millimeters each. Next, we need this height. We can see this height is given as 12 millimeters in the figure. +[179.70s -> 190.51s] This height is given as 25 millimeters. This width is given as 20 millimeters in the figure. And at last, we need this width, which is given as 20 millimeters. +[190.86s -> 204.27s] This is our front view of the object with all the dimensions. During exams, you can draw such rough figures, which will help you in drawing faster. Take a ruler, and draw a horizontal line of 75 mm. +[206.22s -> 210.42s] Draw a vertical line of 12 millimeters and construct a rectangle. +[214.26s -> 222.38s] After this, we need to divide this into three parts. Take a ruler and mark 25 millimeters length and draw the horizontal lines. +[229.14s -> 237.10s] After this, we need to draw this section. Take a roller scale and draw a vertical line of 25 millimeters. +[239.28s -> 250.16s] Using this line as a reference, draw a horizontal line of 20 mm from here. Next, using a ruler, mark a 20 mm length on this line from the left edge. +[251.57s -> 264.98s] At last, join these points with a line. This is the required front view of the object. Next, we will draw the top view of this. When we view the object from the top, +[265.62s -> 269.94s] This is how it will look from the top, we can see only this part of the object. +[270.77s -> 285.33s] We already know this total length is 75 millimeters. Next, this length is given as 50 millimeters. This length is given as 12 millimeters. And this rectangle's width will be 20 millimeters and its height will be 25 millimeters. +[285.62s -> 296.08s] This distance is given as 20 millimeters. We will draw the projection lines from the front view. Take a ruler and draw the projection lines as shown. +[307.66s -> 321.87s] after this we can use these reference lines to draw the top view take a ruler and draw a horizontal line next draw a vertical line of 50 millimeters in length +[325.20s -> 334.96s] We can see this length as 25 millimeters, which is equal to this length, which means, the horizontal line will be up to this line. Draw a horizontal line. +[337.01s -> 345.81s] This height is 12mm so from here it will be 12mm up. And again a 25mm horizontal line. +[347.47s -> 352.88s] a 12mm vertical line, and at last, a 25mm horizontal line. +[353.14s -> 364.77s] Next, we need to draw this section. We know this width is 20 millimeters, which is equal to this length. This height is 25 millimeters. Using this vertical line as a reference. +[364.77s -> 368.85s] Draw a vertical line of 25 millimeters and construct a rectangle. +[373.49s -> 386.48s] Also, we need to draw this additional rectangle, which represents this inclined portion. We can see this vertical line is 25 mm and it is 20 mm away from this edge, which is equal to this length. +[386.48s -> 401.26s] Using the vertical line as a reference, draw a vertical line of 25 mm in length Next, take a ruler and extend this horizontal line up to this line This is the required top view of the object +[402.35s -> 410.38s] At last, we need to draw the left side view of the object here. When we see the object from the left side, this is how it will look. +[410.83s -> 424.98s] We know this length is 50 millimeters, and we can see this height is 12 millimeters. Next, this height is given as 25 millimeters, and this width is 25 millimeters. We got all the required dimensions for the side view. +[424.98s -> 429.84s] First, we will draw the horizontal projection lines from the front view of the object. +[435.79s -> 444.69s] Also, we can draw the projection lines from the top view. To do so, first draw an inclined line which will be at 45 degrees. +[445.10s -> 451.31s] after this draw the projection lines from the top view extend these lines up to this inclined line +[458.51s -> 462.32s] and draw the vertical lines from each of these intersection points. +[473.74s -> 486.06s] These lines will help us in drawing the side view. Take a roller scale and draw a vertical line of 37 millimeters in length. After this, draw a horizontal line of 50 millimeters in length as shown. +[487.15s -> 496.18s] We need to construct this rectangle, we can see its height is 12 millimeters. Draw a vertical line of 12 millimeters, and construct a rectangle. +[496.78s -> 508.85s] Next, we need to construct this shape, we can see the width of this shape is 25 mm and the height is 25 mm. Take a roller scale and draw a horizontal line of 25 mm. +[509.94s -> 514.13s] and draw a vertical line of 25 millimeters up to this line. +[514.48s -> 528.37s] At last, we need to draw this dotted lines to represent this intersection. We can see the distance of this dotted line is 12 millimeters. Mark a point at a 12 millimeters distance from this edge, and draw a vertical dotted line. +[529.65s -> 543.39s] This is our required side view of the object. This is how we can draw an orthographic view from the isometric view. I hope this video helped you in understanding how to draw an orthographic projection of the object. If you like the video, +[543.39s -> 552.54s] click on the like button and if you are new to my channel adtw learn click on the subscribe button and turn on the notifications to get all my latest videos diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_16.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_16.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cf1783d7f0a96e354e654b29d4072827f8a3932d --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_16.mp4.txt @@ -0,0 +1,27 @@ +[0.00s -> 10.38s] In this example, we're dropping a block of mass 2 kilograms through a height of 5 meters onto the tip of a spring with a constant of 2500 newtons per meter. +[10.38s -> 19.87s] And we're trying to figure out several things here. I want to find the speed of the block right before it impacts the spring. I want to find of course the maximum compression of the spring. +[19.87s -> 32.02s] and then finally i want to find the acceleration of the block when it's at that maximum compression point i know it will be accelerating upward because it's about to bounce back up to the same height that it came from if energy is going to be conserved +[32.02s -> 44.24s] so let's get started with the speed question and i'm i'm going to write down energy conservation but i have to have a reference point for my potential energy so what i'm going to do in this case is put y equals zero +[44.37s -> 55.50s] right here, so at the tip of the uncompressed spring. And that means I had y equals 5 up here. It also means that when I get deeper into the problem, I'm going to have to use a negative y. +[56.24s -> 70.08s] down here. So that should be interesting. So my speed question, I have in my initial state, gravitational potential energy, mg y. In my final state, I have no more gravitational potential energy. I'm right there at y equals zero. +[70.08s -> 75.98s] and all my energy is going to be kinetic. Turns out the mass doesn't matter for this part. +[77.04s -> 89.58s] I get v squared equals 2gy. I square root both sides. And v is the square root of 2gy, which is the square root of 2 times 9.8 times 5. +[90.00s -> 94.06s] And to 3 sig figs, I get 9.90. +[94.64s -> 108.18s] meters per second so that piece is done next i'm looking at the maximum compression part and for that you could use energy conservation going from the middle picture where everything is kinetic down to the third picture +[108.18s -> 119.50s] Or you could use energy conservation going all the way back to the start of the problem. And I think it's actually going to be simpler if I just go all the way back to the start. So I'm going to write down my energy conservation. +[119.50s -> 125.55s] equation. So in the initial state, I had all potential energy. I'll just write mgy initial. +[127.02s -> 141.52s] In my final state, the mass is now below the zero that I created from measuring my y coordinate, and so I have to put that coordinate in. If I'm using x max for the compression, then the y coordinate here is actually negative x max. +[141.52s -> 145.30s] So my final state, I have this negative gravitational potential energy. +[145.97s -> 158.93s] Negative x max is the y coordinate. There's no kinetic energy in the final state because the block is at the maximum compression. That's where it's turning around. But there is spring potential energy. +[158.99s -> 171.89s] So plugging numbers into this, I have 2 times 9.8 times 5 is 2 times 9.8 times negative x max. +[174.03s -> 187.22s] Plus 1 half times 2500 X max Squared and I'm going to clean things up and move it all to one side of the equation Because I'm going to have to use the quadratic formula on this +[187.54s -> 201.20s] And when I do that, I get 1250. Just moving everything to the right-hand side. 1250 X max squared minus 19.6 X max. +[204.34s -> 215.34s] minus 98 equals 0 and at this point I have to either plug into the quadratic formula manually or use technology to do it +[215.82s -> 227.63s] And when I ran this through the quadratic formula I got one positive answer and one negative answer and the positive one is the physical one here And I got X max is equal to 0.288 +[228.75s -> 236.43s] meters or 28.8 centimeters. +[237.07s -> 249.81s] So there's that part. Finally, we're going to get the acceleration of this mass at the maximum compression. So that spring is exerting an upward force on the mass, and gravity is still pulling down, and you don't want to forget about that. +[250.48s -> 260.82s] So there's gravity, mg, 2 kilograms times 9.8 meters per second squared, and I get 19.6 newtons for that. And then I have the spring pushing up. +[261.58s -> 272.30s] And I know the spring force is going to be greater than the force of gravity. This thing is going to bounce up. And my spring force here is going to be kx. +[272.88s -> 286.38s] May as well just calculate that right over here. So I have 2500 for K and then X is 0.288 meters. And when I crunch the numbers on that, I get 720 newtons. +[288.21s -> 300.94s] So I just have a little bit of calculation to do. I'm going to write down Newton's second law. So F net on this thing is equal to MA. And the net force, well, that's 720 up, 19.6 down. +[301.74s -> 315.02s] equals 2 times a combining the numbers on the left and dividing by 2 i end up with a equals 350 meters per second squared and we're done diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_18.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_18.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2efae3b2960dcd129108a02c93d188bc1e191589 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_18.mp4.txt @@ -0,0 +1,61 @@ +[0.00s -> 11.28s] Let's take a look at objects that spin about a fixed axis and how we can solve for unknown forces. Let's say we have a blob like this. We can attach a pin to it at the bottom like this. +[11.28s -> 25.58s] Let's label it O, and while we're at it, let's apply some random forces to our object. The center of mass of this object is right here. We see that when it starts to move, the center of mass is moving in a curvilinear path. +[25.71s -> 39.38s] Since it's going through curvilinear motion, the acceleration at g can be broken into normal and tangential components. Remember, normal acceleration points towards the center of the curve, while tangential acceleration points straight ahead. +[39.38s -> 52.56s] in other words tangent to the path previously we talked about adding forces in the x and y axes this time we can use the normal and tangential axes and write our equations of motion like this +[52.56s -> 61.87s] So to recap, we can find normal acceleration by multiplying the angular velocity squared times the distance from point O to the center of mass. +[61.87s -> 73.55s] and we can find tangential acceleration by multiplying angular acceleration by the distance from point o to the center of mass we can also figure out the moment about the center of mass using this equation +[73.55s -> 86.29s] It says the sum of moments about the center of mass is equal to the mass moment of inertia of the object at the center times the angular acceleration. Let's say, however, we don't want to find the moment about the center of mass. +[86.29s -> 100.05s] Instead, we want to figure it out about a random point. For example, we want to figure out the moment about point O. The equation for it can be written like this, but the easiest way to understand it is to use a kinetic diagram. +[100.05s -> 110.64s] Using our blob as an example, I will explain what a kinetic diagram is. In a kinetic diagram, we draw mass times acceleration vectors at the center of mass. +[110.64s -> 124.21s] In simple terms, we show the mass times acceleration that occurs due to the sum of all the external forces that's affecting the object. We also show the moment created above the center of mass, which is the mass moment of inertia. +[124.21s -> 137.06s] multiplied by the angular acceleration. You can think of it as a visual representation of F equals ma. When we calculate the moment at point O, we use the free body diagram for the left side of the equation. +[137.06s -> 149.95s] and the kinetic diagram for the right side of the equation. All of this will make a lot more sense when we go through examples. We'll cover each question step by step, and by the end, you should be able to solve the problems you will face. +[149.95s -> 164.34s] One last thing, to do some questions, you need to remember the formulas for mass movement of inertia of different objects. I show some here, but you can find many more online by searching for it. Now let's move on to some examples. +[165.04s -> 177.04s] Let's take a look at this problem where we need to find the initial angular acceleration and the reactions at pin A. So we see that when the square plate is released, it falls down and turns clockwise. +[177.04s -> 188.34s] Let's draw a free body diagram along with a kinetic diagram. The center of mass will be at the center of this plate, since it's a uniform square plate. At the center, we have the weight. +[188.34s -> 200.30s] We also have two reactions at the pin which would be Ax and Ay. For the kinetic diagram, we have to think about how this plate moves. We know that the plate moves in a circular path. +[200.30s -> 214.26s] So the acceleration at the center of mass would have two components. We have the normal acceleration, which would be towards the center of the curve, and we have the tangential acceleration, which is straight ahead, tangent to the curve. +[214.26s -> 226.16s] shows each component of acceleration multiplied by the mass of the plate. Lastly, we have the moment created above the center of mass. So first, let's calculate these acceleration forces. +[226.16s -> 240.21s] The normal acceleration is angular velocity squared times the distance from pin A to the center of mass. The plate starts from rest, which means angular velocity will be zero. That means the normal acceleration is also zero. +[240.21s -> 252.45s] For the tangential acceleration, it's the angular acceleration multiplied by the distance from pin A to the center of mass. The distance to the center of mass can be found using the Pythagorean theorem. +[252.45s -> 266.29s] So we can write our tangential acceleration like this. The moment created above the center of mass can be found by multiplying the mass moment of inertia of the plate by the angular acceleration. So let's find the mass moment of inertia. +[266.29s -> 278.90s] This is where the formulas come in handy. So we will use the formula for a uniform square plate. The mass is 24 kilograms and the sides are of equal length which are 0.5 meters. Let's solve. +[278.90s -> 291.34s] To figure out the angular acceleration, all we need to do is write a moment equation about point A. So for that, remember the equation we talked about, which is this. We will pick clockwise to be positive. +[291.34s -> 304.69s] So when we write our moment equation, or an equation of motion, we use both the free body diagram and the kinetic diagram. So let's go through this equation. On the left side, we have the only force creating a moment about point A. +[304.69s -> 318.56s] which is weight multiplied by the perpendicular distance to point A from the center of mass. Remember, since we are writing the moment above point A, Ax and Ay are not considered because they go through the line of action. +[318.56s -> 327.94s] On the other side, we use the kinetic diagram. What we are saying is that each of the mass times acceleration vectors at the center cause a moment about point A. +[327.94s -> 342.42s] So, we have the mass of the plate multiplied by the tangential acceleration multiplied by the perpendicular distance from the center to point A. Notice that we also have a moment about the center of mass in our kinetic diagram. We need to add that as well. +[342.42s -> 353.46s] which is mass moment of inertia times the angular acceleration. We can now solve for angular acceleration. Using this value we can find the tangential acceleration. +[353.46s -> 365.73s] Now we can move on to equations of motion for the x and y axis. First, for the x axis. So on the left side, the only force we have is the x component of the reaction at pin A. +[365.73s -> 379.49s] On the other side, we have mass multiplied by the x component of the tangential acceleration. Remember that we found the normal acceleration to be 0, so we don't need to worry about it. Let's solve, which gives us Ax. +[379.49s -> 393.89s] Notice once again that we used the free body diagram for the left side of the equation while the kinetic diagram was used for the right side. Now we can write another equation for the y-component forces. So we have the y-component of reaction at pin A +[393.89s -> 405.20s] and then we have the weight. On the other side of the equation, we have mass times the y component of the tangential acceleration. Solving gives us Ay. Those are our answers. +[405.90s -> 418.90s] Let's take a look at this question where we need to find the acceleration of block A. The first step is to draw a free body diagram along with the kinetic diagram. So we have the tension at O, the weight of each of the blocks, +[418.90s -> 428.59s] along with the weight of the pulley itself. For the kinetic diagram, we have the moment created about point O and the mass times accelerations of block A and B. +[428.59s -> 442.29s] We know that the acceleration of the pulley is equal to the angular acceleration multiplied by the radius of the pulley. So let's isolate for the angular acceleration. Now we need to find the mass moment of inertia of the pulley above the center. +[442.29s -> 453.71s] Since the pulley can be treated as a disc, the equation to find the mass moment of inertia is this. Let's plug in the mass of the pulley and the radius. Solving gives us the mass moment of inertia. +[453.71s -> 464.99s] Now we can write just one moment equation about point O and figure out the acceleration. We will pick clockwise to be positive. Let's go through this equation. On the left side, +[464.99s -> 478.54s] We have the weight of each of the blocks multiplied by the perpendicular distance from the block to the center of the pulley. Notice how block A creates a negative moment above point O since it would make the pulley spin counterclockwise. +[478.54s -> 492.67s] while block B would create a positive moment. Moving on to the other side, we have the mass times accelerations of each of the blocks multiplied by the perpendicular distance to point O. Don't forget, we also have a moment about point O +[492.67s -> 504.66s] which is the mass moment of inertia multiplied by the angular acceleration. But remember, we already found angular acceleration in terms of acceleration. Let's solve for A, which is our answer. +[505.36s -> 518.13s] Let's take a look at this problem where we have a spinning disc and when we place it on the ground, we need to figure out how long it would take to stop. We also need to figure out the horizontal and vertical forces about point A. +[518.13s -> 529.74s] We will solve for the time to stop first and then proceed to figure out the reactions at point A. Let's draw a free body diagram. Weight would be at the center. The normal force would be at the point of contact. +[529.74s -> 543.44s] and friction would point to the right since the wheel is spinning clockwise. The other force we need to consider is with respect to member AB. At the point where it's connected to the wheel, which is at point B, the force would not be straight down. +[543.44s -> 554.14s] but rather, it would follow a position vector from A to B. In other words, the force vector FAB would point towards point A. Let's also draw the angular acceleration. +[554.14s -> 563.01s] Remember, the wheel is slowing down which means the angular acceleration, or rather angular deceleration would be opposite to the way the wheel is spinning. +[563.01s -> 576.19s] Now that we have our free body diagram, let's figure out the mass moment of inertia of the disc about point B. For that, we can use this equation. So the mass is 30 kg and the radius is 0.3 m. +[576.19s -> 587.06s] Solving gives us the mass moment of inertia. Also, the frictional force is the coefficient of kinetic friction multiplied by the normal force at C, which we can write like this. +[587.06s -> 598.61s] Now, let's start off by writing our equations of motion for the x-axis forces. So on the left side, we have the frictional force and the x-component of force FAB. On the other side, +[598.61s -> 612.13s] We have mass times acceleration in the x direction, but the wheel doesn't translate left or right, so acceleration in the horizontal direction is zero. Now let's write another equation for the vertical forces. We have the normal force, the weight, +[612.13s -> 625.42s] and the y component of force FAB. On the other side, we have mass times the vertical acceleration, but that's zero since the wheel doesn't move up or down. We now have two equations with two unknowns, so let's solve them. +[625.42s -> 637.71s] we get the normal force and force FAB. Now that we have the normal force, we can figure out the frictional force at C. So let's plug in the values. Now we can calculate the moment about point B. +[637.71s -> 651.98s] We don't need a kinetic diagram since we are calculating the moment above the center of mass and the equation is simple. We will pick counterclockwise to be positive. So, we have the frictional force multiplied by the perpendicular distance from point C to B. +[651.98s -> 663.57s] Every other force goes through the line of action and we don't need to worry about them. On the other side, we have the mass moment of inertia we found earlier multiplied by the angular acceleration. Let's solve. +[663.57s -> 676.40s] okay now we need to use this acceleration to find the time for the wheel to stop since it's a constant acceleration we can use this equation to figure out the time for the wheel to stop this equation should be familiar to you +[676.40s -> 690.91s] If not, please see the description for rigid bodies and rotation about a fixed axis. So the final angular velocity is 0 rads per second, the initial angular velocity is 125 rads per second, and we have the acceleration we just found. +[690.91s -> 703.06s] It's negative because we picked clockwise movement to be positive for this equation. Let's solve for t. Now we can move on to the other part of the question, which is to find the reactions at point A. +[703.06s -> 716.66s] Let's draw a free body diagram of pin A. We have the force FB, which is now going towards the center of the wheel, and we have the horizontal and vertical components at A. One thing to note here is that this pin does not move. +[716.66s -> 730.70s] which means instead of writing an equation of motion, we're actually going to write an equation of equilibrium. All it means is that the forces added together at point A would be equal to zero since it's not moving. So let's start with the horizontal forces. +[730.70s -> 743.73s] so we have the x component of force fab and the reaction ax let's solve now for the vertical forces pretty much the same as before we're just considering the y component of force fab +[743.73s -> 757.33s] Solving gives us Ay. Those are our answers. That should cover the types of problems you will face. It's incredibly helpful to draw free body diagrams and kinetic diagrams for all the questions. +[757.33s -> 762.12s] I hope this video helped you. Thanks for watching and best of luck with your studies. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_2.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2cfca42db0596148961dc11284b806dd93c839a2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_2.mp4.txt @@ -0,0 +1,46 @@ +[4.72s -> 12.03s] Orthographic projection. In engineering drawing, we often have to produce 2D and 3D drawings of different parts. +[12.03s -> 24.24s] These 3D objects need to be shown on 2D planes, that is, X and Y planes in such a way that we get to see all the views. That is a front view, side view, top view etc. +[24.24s -> 38.06s] This type of projection system is known as an orthographic projection. In this system of projection, the views have to be drawn by following certain standard projection rules, which are known as the first angle and third angle projection methods. +[38.06s -> 49.82s] These methods are largely used in industries. If you want to know what the first angle and third angle projection method means, you can get the video link in the description of this video or the i button. In this video, +[49.82s -> 54.35s] We will learn how to draw an orthographic view from this isometric view of an object. +[54.67s -> 66.96s] Isometric view is a graphical method of representing a three-dimensional object. An orthographic view is a means of representing a three-dimensional view in two dimensions. It has only two axis. +[66.96s -> 74.90s] let's see how we can represent this three-dimensional object in a two-dimensional view consider this figure +[76.30s -> 89.70s] Here it is told, draw looking from the direction of X. This means we should assume the viewer is viewing the object from this direction. In other words whatever the view from this direction will be the front view of the object in this case. +[89.70s -> 103.41s] Also, in the instructions, they will mention the number of views required to be drawn. If it is not mentioned, then you need to draw at least three views of the object. That is the front view, top view, and side view. +[103.41s -> 117.26s] Also, they will mention which projection method to use, that is, the first angle or third angle method. If it is not mentioned, then you have to draw using the first angle method. Before starting the drawing we need to draw the reference line. +[117.26s -> 129.89s] which is the XY line. Since we are following the first angle method to draw the projection. On the top, the front view will come, and on the bottom, the top view will come. Next, we need to draw a vertical line. +[129.89s -> 142.21s] which we will name X1Y1. The left side view of the object is drawn on the right side, as we are following the first angle method. Let's start drawing. First, we will draw the front view of the object. +[142.21s -> 152.83s] since the direction of viewing is from this side suppose you are standing here and looking at this object this is how it will look only this part of the object is visible therefore +[152.83s -> 165.22s] This is our front view of the object which we need to draw above the XY line. But to do so, we need the dimensions for this view. We can see this total length is made up of three sections of 25 millimeters. +[165.22s -> 179.70s] Which will be equal to 75 millimeters. That means this total length is 75 millimeters. And these sections will be 25 millimeters each. Next, we need this height. We can see this height is given as 12 millimeters in the figure. +[179.70s -> 190.51s] This height is given as 25 millimeters. This width is given as 20 millimeters in the figure. And at last, we need this width, which is given as 20 millimeters. +[190.86s -> 204.27s] This is our front view of the object with all the dimensions. During exams, you can draw such rough figures, which will help you in drawing faster. Take a ruler, and draw a horizontal line of 75 mm. +[206.22s -> 210.42s] Draw a vertical line of 12 millimeters and construct a rectangle. +[214.26s -> 222.38s] After this, we need to divide this into three parts. Take a ruler and mark 25 millimeters length and draw the horizontal lines. +[229.14s -> 237.10s] After this, we need to draw this section. Take a roller scale and draw a vertical line of 25 millimeters. +[239.28s -> 250.16s] Using this line as a reference, draw a horizontal line of 20 mm from here. Next, using a ruler, mark a 20 mm length on this line from the left edge. +[251.57s -> 264.98s] At last, join these points with a line. This is the required front view of the object. Next, we will draw the top view of this. When we view the object from the top, +[265.62s -> 269.94s] This is how it will look from the top, we can see only this part of the object. +[270.77s -> 285.33s] We already know this total length is 75 millimeters. Next, this length is given as 50 millimeters. This length is given as 12 millimeters. And this rectangle's width will be 20 millimeters and its height will be 25 millimeters. +[285.62s -> 296.08s] This distance is given as 20 millimeters. We will draw the projection lines from the front view. Take a ruler and draw the projection lines as shown. +[307.66s -> 321.87s] after this we can use these reference lines to draw the top view take a ruler and draw a horizontal line next draw a vertical line of 50 millimeters in length +[325.20s -> 334.96s] We can see this length as 25 millimeters, which is equal to this length, which means, the horizontal line will be up to this line. Draw a horizontal line. +[337.01s -> 345.81s] This height is 12mm so from here it will be 12mm up. And again a 25mm horizontal line. +[347.47s -> 352.88s] a 12mm vertical line, and at last, a 25mm horizontal line. +[353.14s -> 364.77s] Next, we need to draw this section. We know this width is 20 millimeters, which is equal to this length. This height is 25 millimeters. Using this vertical line as a reference. +[364.77s -> 368.85s] Draw a vertical line of 25 millimeters and construct a rectangle. +[373.49s -> 386.48s] Also, we need to draw this additional rectangle, which represents this inclined portion. We can see this vertical line is 25 mm and it is 20 mm away from this edge, which is equal to this length. +[386.48s -> 401.26s] Using the vertical line as a reference, draw a vertical line of 25 mm in length Next, take a ruler and extend this horizontal line up to this line This is the required top view of the object +[402.35s -> 410.38s] At last, we need to draw the left side view of the object here. When we see the object from the left side, this is how it will look. +[410.83s -> 424.98s] We know this length is 50 millimeters, and we can see this height is 12 millimeters. Next, this height is given as 25 millimeters, and this width is 25 millimeters. We got all the required dimensions for the side view. +[424.98s -> 429.84s] First, we will draw the horizontal projection lines from the front view of the object. +[435.79s -> 444.69s] Also, we can draw the projection lines from the top view. To do so, first draw an inclined line which will be at 45 degrees. +[445.10s -> 451.31s] after this draw the projection lines from the top view extend these lines up to this inclined line +[458.51s -> 462.32s] and draw the vertical lines from each of these intersection points. +[473.74s -> 486.06s] These lines will help us in drawing the side view. Take a roller scale and draw a vertical line of 37 millimeters in length. After this, draw a horizontal line of 50 millimeters in length as shown. +[487.15s -> 496.18s] We need to construct this rectangle, we can see its height is 12 millimeters. Draw a vertical line of 12 millimeters, and construct a rectangle. +[496.78s -> 508.85s] Next, we need to construct this shape, we can see the width of this shape is 25 mm and the height is 25 mm. Take a roller scale and draw a horizontal line of 25 mm. +[509.94s -> 514.13s] and draw a vertical line of 25 millimeters up to this line. +[514.48s -> 528.37s] At last, we need to draw this dotted lines to represent this intersection. We can see the distance of this dotted line is 12 millimeters. Mark a point at a 12 millimeters distance from this edge, and draw a vertical dotted line. +[529.65s -> 543.39s] This is our required side view of the object. This is how we can draw an orthographic view from the isometric view. I hope this video helped you in understanding how to draw an orthographic projection of the object. If you like the video, +[543.39s -> 552.54s] click on the like button and if you are new to my channel adtw learn click on the subscribe button and turn on the notifications to get all my latest videos diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_23.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_23.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..699cb82daaa57abfe4255e03b13448af82065b10 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_23.mp4.txt @@ -0,0 +1,23 @@ +[0.00s -> 13.73s] welcome back to the channel in today's video we will show you how to determine the design weld resistance and the required length of welded connections the electric arc method is now used for the majority of structural welding +[13.73s -> 25.78s] in which a welding rod or electrode is fused to the parent metal by the heat generated by high current electricity there are two basic types of weld fillet welds and butt welds +[25.78s -> 37.73s] Butt welds are simple to deal with in terms of design. A weld which passes through the hole thickness of the parent metal is a full penetration butt weld, and provided the correct electrodes are used. +[37.73s -> 52.08s] It can simply be assumed that the weld is at least as strong as the parent metal. The surface of the weld may subsequently be ground flush. There are two things you should be aware of about the fillet weld. One is the leg length. +[52.08s -> 63.06s] and also the throat thickness the leg length is actually what you specify so if you see six millimeters fillet weld that is actually the leg length not the throat thickness +[63.06s -> 73.90s] The throat thickness is equal to leg length multiplied by 0.7. The design shear strength of a fillet weld in S275 steel is as follows. +[74.19s -> 88.34s] FU is the ultimate tensile strength of the weaker part of the joint. Gamma M2 is the material safety factor, 1.25. Beta W is the correlation factor, 0.85. +[88.66s -> 100.90s] When we input these factors into our equation, the design shear strength, equals 0.54, multiplied by the ultimate tensile strength, fu, newton per millimeter squared. So, +[100.90s -> 111.89s] to get the design weld resistance per unit length just multiply the design shear strength 0.54 ultimate tensile strength by the throat thickness 0.7 leg length +[111.89s -> 120.24s] Therefore, the design weld resistance per unit length is equal to 0.38 times ultimate tensile strength times leg length. +[120.59s -> 131.44s] The table below illustrates typical weld leg lengths, with ultimate tensile strength of 430 N·mm², for S275 steel. +[131.44s -> 145.79s] As a result, the design resistance for a 4 mm leg length, equals 0.38, times the ultimate tensile strength of 430 N·mm², multiplied by the leg length of 4 mm. +[145.79s -> 156.24s] This gives us a designed weld resistance of 650 newtons per millimeter, which we can convert to kilonewtons per millimeter by dividing by 1000. +[156.53s -> 169.68s] Let's now look at a practical example. We have 100 by 100 by 8 equal angle steel welded to a gusset plate. It must resist a tensile design load of 400 kN. +[169.68s -> 175.89s] what is the required length l if it is welded all around using a six millimeters fillet weld +[176.21s -> 189.98s] We will assume that the steel grade will be S275. Remember, it's always a good idea to draw a diagram to ensure that you fully understand what has to be designed, and that the reader understands what you're designing. +[189.98s -> 196.62s] to begin a six millimeters fillet weld has a weld strength of 0.98 kilonewton per millimeter +[196.88s -> 207.87s] So, the total length required, equals a tensile design load of 400 kN, divided by the design weld resistance of 0.98 kN per mm. +[207.87s -> 218.90s] This gives us a total length of 409 millimeters. However, there are four points of contact. As a result, we must ensure that we account for this. +[218.93s -> 226.51s] Hence, the total length equals 2 × 100 mm, plus 2 × L, the required length. +[226.90s -> 238.27s] Consequently, the required length equals open bracket 409 mm minus 2 times 100 mm close bracket divided by 2. +[238.27s -> 251.06s] This gives us a value of 105 millimeters. Thanks for watching. We hope you found some useful tips. Check out our website at structuralengineercalcs.com +[251.54s -> 265.67s] Please like and subscribe, and let us know what would you like to see next. The human footprint is a masterpiece of engineering and a work of art. Stay safe. Goodbye, and see you soon. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_29.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_29.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cb9301c576647e981a15775588debc6f358f90bc --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_29.mp4.txt @@ -0,0 +1,27 @@ +[23.54s -> 34.10s] Alright, welcome to Integral Physics. Today I want to talk about spring combinations. What that means is we're going to talk about springs that are put together in parallel and springs that are combined in series. +[35.60s -> 49.66s] See depending on how you combine springs, whether that be in parallel or series, the overall combination of those springs produces an equivalent spring that can either be stiffer or softer than the individual springs. +[49.66s -> 57.97s] So we're going to use Hooke's Law to find the equivalent spring constant when combining springs in parallel and when combining springs in series. +[59.95s -> 73.89s] See, Hooke's law says that the force produced by a spring is linearly proportional to how far that spring has been stretched. And that constant of proportionality is what we call the spring constant. Now, each individual spring has its own spring constant. +[73.89s -> 83.15s] But when we combine two springs together, the question comes up, which spring constant should we use in Hooke's law to find the total force produced by these springs? +[83.22s -> 97.58s] And the answer actually is both. Now in the case of parallel spring combinations, these two springs produce force which combine in order to support some load. Now we could in fact just replace these two springs with a single stiffer spring. +[97.58s -> 108.21s] And what we're going to do is solve for exactly how stiff that spring would have to be. Now there's a couple of key ideas that we need to grasp in order to understand how springs in parallel work with one another. +[108.21s -> 116.14s] Now the first being if this load or block stretches these springs downward, both springs are going to stretch the same amount. +[122.80s -> 126.83s] So if we were to write out Hooke's law for each of these individual springs, +[131.41s -> 142.42s] we would find these terms x1, x2, and x for our equivalent spring are all going to be the same dimension. And that's going to be key in finding the equivalent spring constant moving forward. +[142.42s -> 152.85s] Now there's one additional idea that we need to recognize here in order to solve for our equivalent spring constant. And that is that both of these springs are acting upward on this block. +[157.20s -> 164.62s] And from a mathematical standpoint, that means the sum of these two forces are going to be equal to the total force on this block. +[165.97s -> 173.52s] So now what we have are a system of equations which we can substitute into one another in order to solve for our equivalent spring constant. +[176.21s -> 188.62s] So subbing these three versions of Hooke's law into this equation, we come up with this function. And you'll see, because our displacements are all the same, they cancel out, as do the negatives. +[193.65s -> 206.67s] And we find the equivalent spring constant is simply the sum of the two individual spring constants. Now realize if we were to add a third spring to this combination, that would simply be adding a third term to this function. +[206.74s -> 209.81s] Now moving on to a serious combination of springs. +[211.02s -> 224.50s] Because these springs are connected end-to-end, things work a little bit differently when springs are combined in series. Now looking at springs in series, Hooke's Law is still going to apply both to individual springs as well as our equivalent spring. +[228.66s -> 240.22s] But because the springs are connected end to end rather than in parallel, these relationships that we came up with for springs in parallel for both displacement and force are going to work a little bit differently here. +[240.22s -> 249.62s] So if we place a load here, the only thing holding this block up is going to be spring 2. Which means the force by spring 2 is equal to the total force. +[250.22s -> 259.12s] And since the only thing holding up spring 2 is in fact spring 1, that means the force by spring 2 is also going to be equal to the force by spring 1. +[263.63s -> 275.06s] Now in placing this load on these springs in series, we're going to see each individual spring stretch a certain amount depending on how stiff it is. But realize those two displacements are not going to be equal to each other. +[275.06s -> 283.82s] And in fact, the total distance which this load moves downward is going to be equal to the sum of these two displacements. +[288.18s -> 298.29s] And again, we're left with a system of equations, much like we were for springs in parallel. And again, we're going to rearrange our functions for Hooke's law and substitute them into one of our terms. +[303.18s -> 310.19s] Now this time we'll see, because all of our forces are equal to one another, they'll cancel out, as will the negatives. +[313.78s -> 321.47s] And we're left with this equation for the equivalent spring constant of springs which have been connected end to end, or in what we call series. +[321.47s -> 335.84s] And just like with parallel springs, if we were to add a third spring to this in series, we'd simply be adding another 1 over k 3 term. So ultimately what these two equations are telling us is when we combine springs in parallel, we effectively form a stiffer spring. +[335.84s -> 346.35s] And when we combine springs in series, they effectively become a softer spring. So I hope you found this helpful in understanding parallel versus series springs. And on that note, that's all for now. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_3.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a87b5bf0ba45c82ce5b9e5018731ba7cbd6448ce --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_3.mp4.txt @@ -0,0 +1,31 @@ +[5.65s -> 19.23s] Orthographic projection. In engineering drawing, we often have to produce 2D and 3D drawings of parts or components. These 3D objects need to be shown on 2D planes, that is, X and Y planes. +[19.23s -> 32.13s] in such a way that we get to see all the views that is front view side view top view etc this projection system is known as orthographic projection and in this system of projection +[32.13s -> 43.84s] the views have to be drawn following certain standard projection rules that is first angle and third angle method the first and third angle methods are largely used in any designing industry +[43.84s -> 56.54s] To understand this, we first need to learn about the quadrant system. In quadrant system, we have got two planes in 2D, that is, X and Y plane, or, horizontal and vertical planes respectively. +[56.54s -> 69.97s] When the axes of the 2D system divide the plane into four infinite regions, these regions are known as quadrants. These quadrants are designated in an anticlockwise direction, starting from the first quadrant. That is, +[69.97s -> 74.74s] upper right corner to the last which is lower right corner fourth quadrant +[75.47s -> 86.06s] Rule of orthographic projection. According to this rule, to draw the projection of a 3D object on the 2D plane, the horizontal plane is rotated in the clockwise direction. +[87.50s -> 95.98s] First angle method. In the first angle method, the object is placed in the first quadrant such that it lies between the viewer and the plane of projection. +[96.27s -> 108.19s] While considering the observer is standing here, view from this point is considered as the front view. When the viewer views the object from the front view its projection is projected on the vertical plane of the first quadrant. +[108.19s -> 112.37s] You can see from the viewer's eye how the front view of this object looks. +[112.85s -> 126.38s] And when the viewer views the object from the top, its top view is projected on the horizontal plane of the first quadrant. This is how the top view looks from the top. For the left-hand side view, we consider another parallel plane. +[126.38s -> 138.22s] which is placed on the right side of the object. And when the viewer views the object from the left-hand side of the object, the left-hand side view is projected onto the profile plane. This is how it looks. +[139.34s -> 154.02s] For the right hand side view, we consider another parallel plane, on the left side of the object, and when the viewer views the object from the right hand side of the object, the right hand side view is projected onto the profile plane, which is placed on the left side of the object. +[154.02s -> 155.92s] This is how it looks. +[156.21s -> 170.50s] For drawing these projections onto the drawing sheets we follow the rule of orthographic projection. According to this rule, to draw the projection of a 3D object on the 2D plane, the horizontal plane is rotated in the clockwise direction. +[170.50s -> 183.36s] and the profile planes are also unfolded. By doing so, we have the following projections. The front view of the object is on top. The top view is on the bottom. The left-hand side view is on the right side of the front view. +[183.36s -> 194.43s] and the right hand side view is on the left side of the front view. This is how we draw on drawing sheets using the first angle method. If you are enjoying this video, please give this video a thumbs up. +[194.43s -> 207.09s] as it helps the YouTube algorithm to recognize good content, and suggest others who want to learn, and if you are new to ADTW Learn, click on the subscribe button and turn on the notification to get more informative videos like this. +[208.50s -> 217.50s] Third angle projection method. In this projection method, the object is placed in the third quadrant and the plane of projection lies between the object and the viewer. +[217.50s -> 232.46s] As the vertical plane of the third quadrant lies between the viewer and the object the viewer cannot see the object. Therefore, we will make the vertical plane transparent and then we can see the front view, which will be projected on the vertical plane lying between the viewer and the object. +[235.73s -> 244.91s] Similarly, while viewing from the top, the horizontal plane will come between the point of view and the object, therefore the top view will be projected on the horizontal plane. +[247.47s -> 261.04s] For the right-hand side and left-hand side view, we will have the two profile planes on either side of the object. Now when the viewer sees from the right side, the right side view will be projected on the right profile plane of the third quadrant. +[261.65s -> 265.52s] and the left side view will be projected on the left profile plane. +[266.42s -> 280.72s] When we unfold the planes according to the orthographic rule, we will get a front view on the bottom of the XY line, a top view on the above XY line, and left side view on the left side of the front view, and a right side view in the right side of the front view. +[280.72s -> 291.66s] This is how first and third angle projection method works. Symbols used to represent. These are the symbols used for representing first angle and third angle method. +[293.71s -> 306.99s] Why don't we use the second angle and fourth angle method? It is not possible to show a 3D view of an object on the 2D plane, therefore we use orthographic projection. According to the rule of orthographic projection, +[306.99s -> 321.49s] The horizontal plane needs to be rotated in the clockwise direction to view the top and front view on the 2D plane. Once the horizontal plane is rotated in the clockwise direction, the projections present on the horizontal plane are also rotated along with the plane. +[322.19s -> 335.39s] Now consider the second angle view in which the object is placed on the second quadrant and the plane lies between the object and the viewer. The top view is projected on the horizontal plane and the front view is projected on the vertical plane. +[335.39s -> 347.95s] and when the horizontal plane is rotated in the clockwise direction, the top view projected on the horizontal plane will overlap with the front view projected on the vertical plane. A similar problem will occur while using the fourth quadrant. +[347.95s -> 359.70s] Therefore, we don't use the second and the fourth angle method. I hope you have understood the first and third angle methods. It takes lots of effort to make such informative videos. You can help a DTW learn. +[359.70s -> 372.80s] to make more videos by joining our channel and contributing to developing more such videos your support will help us make great educational videos other ways of helping us is by sharing our videos with your friends thank you diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_30.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_30.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2cfca42db0596148961dc11284b806dd93c839a2 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_30.mp4.txt @@ -0,0 +1,46 @@ +[4.72s -> 12.03s] Orthographic projection. In engineering drawing, we often have to produce 2D and 3D drawings of different parts. +[12.03s -> 24.24s] These 3D objects need to be shown on 2D planes, that is, X and Y planes in such a way that we get to see all the views. That is a front view, side view, top view etc. +[24.24s -> 38.06s] This type of projection system is known as an orthographic projection. In this system of projection, the views have to be drawn by following certain standard projection rules, which are known as the first angle and third angle projection methods. +[38.06s -> 49.82s] These methods are largely used in industries. If you want to know what the first angle and third angle projection method means, you can get the video link in the description of this video or the i button. In this video, +[49.82s -> 54.35s] We will learn how to draw an orthographic view from this isometric view of an object. +[54.67s -> 66.96s] Isometric view is a graphical method of representing a three-dimensional object. An orthographic view is a means of representing a three-dimensional view in two dimensions. It has only two axis. +[66.96s -> 74.90s] let's see how we can represent this three-dimensional object in a two-dimensional view consider this figure +[76.30s -> 89.70s] Here it is told, draw looking from the direction of X. This means we should assume the viewer is viewing the object from this direction. In other words whatever the view from this direction will be the front view of the object in this case. +[89.70s -> 103.41s] Also, in the instructions, they will mention the number of views required to be drawn. If it is not mentioned, then you need to draw at least three views of the object. That is the front view, top view, and side view. +[103.41s -> 117.26s] Also, they will mention which projection method to use, that is, the first angle or third angle method. If it is not mentioned, then you have to draw using the first angle method. Before starting the drawing we need to draw the reference line. +[117.26s -> 129.89s] which is the XY line. Since we are following the first angle method to draw the projection. On the top, the front view will come, and on the bottom, the top view will come. Next, we need to draw a vertical line. +[129.89s -> 142.21s] which we will name X1Y1. The left side view of the object is drawn on the right side, as we are following the first angle method. Let's start drawing. First, we will draw the front view of the object. +[142.21s -> 152.83s] since the direction of viewing is from this side suppose you are standing here and looking at this object this is how it will look only this part of the object is visible therefore +[152.83s -> 165.22s] This is our front view of the object which we need to draw above the XY line. But to do so, we need the dimensions for this view. We can see this total length is made up of three sections of 25 millimeters. +[165.22s -> 179.70s] Which will be equal to 75 millimeters. That means this total length is 75 millimeters. And these sections will be 25 millimeters each. Next, we need this height. We can see this height is given as 12 millimeters in the figure. +[179.70s -> 190.51s] This height is given as 25 millimeters. This width is given as 20 millimeters in the figure. And at last, we need this width, which is given as 20 millimeters. +[190.86s -> 204.27s] This is our front view of the object with all the dimensions. During exams, you can draw such rough figures, which will help you in drawing faster. Take a ruler, and draw a horizontal line of 75 mm. +[206.22s -> 210.42s] Draw a vertical line of 12 millimeters and construct a rectangle. +[214.26s -> 222.38s] After this, we need to divide this into three parts. Take a ruler and mark 25 millimeters length and draw the horizontal lines. +[229.14s -> 237.10s] After this, we need to draw this section. Take a roller scale and draw a vertical line of 25 millimeters. +[239.28s -> 250.16s] Using this line as a reference, draw a horizontal line of 20 mm from here. Next, using a ruler, mark a 20 mm length on this line from the left edge. +[251.57s -> 264.98s] At last, join these points with a line. This is the required front view of the object. Next, we will draw the top view of this. When we view the object from the top, +[265.62s -> 269.94s] This is how it will look from the top, we can see only this part of the object. +[270.77s -> 285.33s] We already know this total length is 75 millimeters. Next, this length is given as 50 millimeters. This length is given as 12 millimeters. And this rectangle's width will be 20 millimeters and its height will be 25 millimeters. +[285.62s -> 296.08s] This distance is given as 20 millimeters. We will draw the projection lines from the front view. Take a ruler and draw the projection lines as shown. +[307.66s -> 321.87s] after this we can use these reference lines to draw the top view take a ruler and draw a horizontal line next draw a vertical line of 50 millimeters in length +[325.20s -> 334.96s] We can see this length as 25 millimeters, which is equal to this length, which means, the horizontal line will be up to this line. Draw a horizontal line. +[337.01s -> 345.81s] This height is 12mm so from here it will be 12mm up. And again a 25mm horizontal line. +[347.47s -> 352.88s] a 12mm vertical line, and at last, a 25mm horizontal line. +[353.14s -> 364.77s] Next, we need to draw this section. We know this width is 20 millimeters, which is equal to this length. This height is 25 millimeters. Using this vertical line as a reference. +[364.77s -> 368.85s] Draw a vertical line of 25 millimeters and construct a rectangle. +[373.49s -> 386.48s] Also, we need to draw this additional rectangle, which represents this inclined portion. We can see this vertical line is 25 mm and it is 20 mm away from this edge, which is equal to this length. +[386.48s -> 401.26s] Using the vertical line as a reference, draw a vertical line of 25 mm in length Next, take a ruler and extend this horizontal line up to this line This is the required top view of the object +[402.35s -> 410.38s] At last, we need to draw the left side view of the object here. When we see the object from the left side, this is how it will look. +[410.83s -> 424.98s] We know this length is 50 millimeters, and we can see this height is 12 millimeters. Next, this height is given as 25 millimeters, and this width is 25 millimeters. We got all the required dimensions for the side view. +[424.98s -> 429.84s] First, we will draw the horizontal projection lines from the front view of the object. +[435.79s -> 444.69s] Also, we can draw the projection lines from the top view. To do so, first draw an inclined line which will be at 45 degrees. +[445.10s -> 451.31s] after this draw the projection lines from the top view extend these lines up to this inclined line +[458.51s -> 462.32s] and draw the vertical lines from each of these intersection points. +[473.74s -> 486.06s] These lines will help us in drawing the side view. Take a roller scale and draw a vertical line of 37 millimeters in length. After this, draw a horizontal line of 50 millimeters in length as shown. +[487.15s -> 496.18s] We need to construct this rectangle, we can see its height is 12 millimeters. Draw a vertical line of 12 millimeters, and construct a rectangle. +[496.78s -> 508.85s] Next, we need to construct this shape, we can see the width of this shape is 25 mm and the height is 25 mm. Take a roller scale and draw a horizontal line of 25 mm. +[509.94s -> 514.13s] and draw a vertical line of 25 millimeters up to this line. +[514.48s -> 528.37s] At last, we need to draw this dotted lines to represent this intersection. We can see the distance of this dotted line is 12 millimeters. Mark a point at a 12 millimeters distance from this edge, and draw a vertical dotted line. +[529.65s -> 543.39s] This is our required side view of the object. This is how we can draw an orthographic view from the isometric view. I hope this video helped you in understanding how to draw an orthographic projection of the object. If you like the video, +[543.39s -> 552.54s] click on the like button and if you are new to my channel adtw learn click on the subscribe button and turn on the notifications to get all my latest videos diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_5.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d57be055a7e7b122d4285d5929cb3197da2a6709 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_5.mp4.txt @@ -0,0 +1,67 @@ +[0.78s -> 8.91s] Welcome back to Control System Lectures. In this video, I'm going to discuss the Routh-Herwitz criterion and the Routh array. +[9.39s -> 20.05s] And before we just jump right in, I want to give you a little bit of background knowledge so that you understand why this method was developed and how it's used in classical control theory. +[20.08s -> 32.13s] now if you've been following along with my videos or already have a basic understanding of classical control then you should know at least two things right now the first is that in order for a system to be stable +[32.13s -> 38.00s] All of the roots of the characteristic polynomial need to lie in the left half plane. +[38.32s -> 50.26s] And since the characteristic equation is the denominator of the transfer function, then the roots of the characteristic equation are the exact same as the poles of the transfer function. +[50.32s -> 59.95s] And these roots all must lie to the left of this vertical imaginary line, or all negative real components, in order to have a stable system. +[60.02s -> 71.22s] I'll briefly explain why that is right now by looking at a transfer function with a single pole, 1 over s plus a, where a is a variable and it can either be positive or negative. +[71.22s -> 81.22s] And in this case, the root of the characteristic equation is s equals negative a. So when a is positive, s is negative, and when a is negative, s is positive. +[81.22s -> 91.92s] Now we can take the inverse Laplace transform of this transfer function to get the time domain representation. And this is e raised to the root times t. +[91.92s -> 99.31s] And you can either write the root as negative A or S, whichever you prefer. Let's take the case where A is positive. +[99.57s -> 111.38s] And since s is negative, this root exists in the left half plane. And if you plot this in the time domain, you'll see that the signal will tend towards zero as time approaches infinity. +[111.38s -> 118.16s] And this is stable since any signal into this transfer function will ultimately die out and the system will be at rest again. +[118.45s -> 127.25s] However, if a is negative or the root is positive, then the response will blow up into infinity, which is obviously unstable. +[128.75s -> 142.45s] Now we can stack any number of these poles up to produce a transfer function of higher order. I'll write a transfer function here consisting of three separate poles, two in the left half plane and one in the right half plane. +[142.45s -> 157.41s] But we can always simplify a transfer function written like this using partial fraction expansion, which in this case turns multiplication into a summation of three separate single-poled transfer functions all with different constant gains. +[157.41s -> 168.82s] And when we take the inverse Laplace of each of these, we see that the response is the summation of a bunch of different exponentials. And no matter how stable most of them are, +[168.82s -> 181.73s] All it takes is one to blow up to infinity to make the whole transfer function unstable. And this is why even if a single root is in the right half plane, your entire system is unstable. +[181.73s -> 191.84s] So we know that we can determine the stability of a system by solving for the roots of the characteristic equation. But the second thing that we know is that calculating the roots of a system +[191.84s -> 199.89s] for anything larger than a second-order polynomial becomes time-consuming and possibly even impossible in closed form. +[200.18s -> 214.19s] as would be the case if you were given this fifth order polynomial and asked to solve for the roots. So your question might be, how can I determine stability of a higher order polynomial without solving for the roots directly? +[214.54s -> 225.70s] And one of the ways that you can do this is by using the Ralph Hurwitz criterion and the Ralph array. Now going through the proof of the Ralph Hurwitz criterion is beyond the scope of this video. +[225.70s -> 229.97s] but I will cover it in a future lecture if there is enough interest in seeing it. +[230.22s -> 244.53s] the routh herwitz criterion states that all roots of a polynomial lie in the left half-plane if and only if a certain set of algebraic combinations of its coefficients have the same sign +[244.94s -> 255.47s] And this statement, a certain set of algebraic combinations, is really just a cryptic way of saying that you perform the steps to fill out the Routh array. +[255.50s -> 267.47s] The great thing about the Routh Array is that you don't have to actually solve for the roots of the characteristic equation. It allows you to assess stability just by looking at the coefficients of the polynomial. +[268.18s -> 280.02s] Now when you're trying to assess the stability of a large order polynomial, the first thing you should notice about the coefficients is their sign. If all of the signs are not the same, +[280.02s -> 288.27s] then you can state instantly that the system is unstable. In this case the coefficients are both positive and negative, so it's unstable. +[288.56s -> 298.98s] Now if every single sine of each coefficient is negative, then you can always multiply that transfer function by a gain of minus 1 just to get all positive values. +[298.98s -> 311.44s] Remember that in order to solve for the roots, we're setting this equation to zero, and we can always divide out that negative one. Therefore, from a stability point, there is no difference between all positive +[311.44s -> 325.49s] all negative values. So in general, I'll refer to all the same signs as just being all positive. Therefore, I can say that if any coefficient is negative, then the entire system is unstable. +[326.42s -> 339.04s] Let me explain why. If you build up a transfer function with a series of poles, then the only way to get a negative coefficient is to have at least one pole exist in the right half plane. +[339.04s -> 349.09s] If all you have are roots in the left half plane, then you only have positive values in the characteristic equation, and there's no way to get a negative coefficient out of that. +[349.09s -> 359.54s] So if you have a characteristic equation with at least one negative coefficient, then you can instantly state that that system is unstable without having to go through the process of filling out the Routh array. +[359.66s -> 371.89s] However, you can have all positive coefficients and still have either a stable or unstable system. Let's demonstrate with this transfer function. The first part has roots at 1 half +[371.89s -> 385.10s] plus or minus j times the square root of 3.75. The second has a root at minus 2, and the third a root at minus 1. This system is clearly unstable since there are two roots in the right half plane. +[385.10s -> 395.47s] You can see this from the positive 1 half. However, when we multiply all of these out, we get one polynomial with all positive coefficients. +[395.92s -> 408.27s] So this just goes to show that you can have an unstable system with all positive coefficients. And if we were given this system in this form, we could use the Routh-Hurwitz criterion to determine if the system is stable. +[408.27s -> 420.40s] and we would do this by filling out a route array. The route array is a table that can be populated with the coefficients of your polynomial with a few simple rules. The first step is to set up the table structure. +[420.40s -> 432.34s] When completing this table, I'll refer to entries in this direction as rows, and entries in this vertical direction as columns. Now the number of rows depends on the order of the polynomial. +[432.37s -> 445.68s] To start, you need to write the polynomial in powers of s that are descending. So in this case, you would start with s to the fourth, then s cubed, and then s squared, s, and then finally you would just end with the constant. +[446.10s -> 457.17s] And in the route array, the row labels start at the highest order, in this case s to the fourth, and count down to the zeroth order, or five rows total. +[457.17s -> 471.50s] And the number of columns also depends on the order of the polynomial, and it's determined in this manner. Write the first coefficient in the first row and first column. Then write the second coefficient in the second row, first column. +[471.54s -> 485.26s] Proceed filling out the first two rows following this up and down pattern until you reach the end of the polynomial. So in our case, we'd start with a 1, then 2, then 3, 10, and 8. +[485.90s -> 496.30s] And if you've done this correctly, you'll see that you've placed every other coefficient in the top row, starting with the first coefficient, and then the alternates in the second row. +[499.47s -> 511.79s] Now there's a side note that I want to cover real quick. If there's no value for a particular power of s, then that coefficient is zero. And make sure you write a zero in place for it because you need this in the table. +[511.86s -> 524.30s] And in this case, there's no s squared coefficient, so when you're filling out the table, you would just put a zero in that place. And that's because s squared still exists, you just don't typically write it in if it has a coefficient of zero. +[524.98s -> 534.42s] Alright, at this point you've set up the table and you've populated the first two rows. Now to fill out the bottom rows you need to perform a series of repetitive math operations. +[534.42s -> 545.42s] Now there are several great resources on the web explaining in mathematical terms how to go about filling out the rest of the rows, and I highly recommend you check them out. I've left some links in the description below. +[545.42s -> 555.76s] However, I personally like to imagine it as a pattern that I'm filling out rather than an equation. And if you'd like to get the math behind the pattern, then you can just visit one of those links. +[556.37s -> 568.46s] Let's say you're given a sixth order polynomial where each power of s has a different coefficient, a through g. You can set up your table from s to the sixth and go all the way down to s to the zero. +[568.46s -> 582.70s] And if your polynomial is written in descending powers of s, you can write the coefficients in the up-down pattern that we discussed up above. Now at this point, each entry in the table can be calculated from entries above it. +[582.70s -> 597.06s] exactly in this manner. For this red box, it would be b times c minus a times d all over b. And if you think of this as a pattern, it traces the number 8. You start with the b, you multiply by c, +[597.06s -> 602.42s] you subtract A times D, and then finally you divide by B. +[603.02s -> 615.49s] Now you can use this pattern to move to the next column, but you stretch out that 8 and perform the exact same sequence. So for this blue box, you would start with the B, and you'd stretch the 8 out to the E. +[615.49s -> 627.22s] minus a times f, all divided by b. Notice that the left side of the 8 is always the first column and the right side just keeps expanding as you move right through the columns. +[627.22s -> 633.54s] Once you've reached the end of the columns, you can drop to the next row and perform the exact same steps. +[633.54s -> 646.34s] In this case, the fourth row would just be red times D minus B times blue, all divided by red. And then stretch out the 8 to get pink, and then stretch it out again to get the next one, and then just keep repeating this pattern. +[646.34s -> 655.79s] And once you have the entire table filled out, you can count the number of roots in the right half plane by seeing how many times the values in the first column changes sign. +[655.79s -> 670.11s] Remember that any zero in the right half plane means the system is unstable, so all you need is for the value to change sign at least once and you know that the system is unstable. So let's use this pattern to fill out the route array from above and assess stability. +[670.11s -> 684.13s] We take 2, we multiply by 3, and we subtract 1 times 10 and divide by 2. You can see that 8 is minus 2. We stretch it out and get 2 times 8 minus 1 times 0 divided by 2 is 8. +[684.13s -> 696.74s] Of course, these last two entries are both 0. Now we drop down a row and we say minus 2 times 10 minus 2 times 8 divided by minus 2 is 18. Stretch out the 8, you get 0. +[696.74s -> 707.79s] Finally, we go down to the last row, we do our calculation, and we're left with 8. I find this pattern recognition, rather than memorizing a bunch of equations, simpler to fill out the Routh array. +[708.34s -> 720.56s] We can determine the number of roots in the right half plane by looking at this first column. I'll rewrite it here to make it a little clearer. You can see that the first two are positive, then negative, followed by two positive values. +[720.59s -> 731.38s] And you can see that it changes sign between 2 and negative 2, which means that there's a root in the right half plane, but then changes sign again between negative 2 and 18. +[731.86s -> 745.90s] So what we can deduce from this is that there are two roots in the right half plane out of the four roots in this system. And since there's at least one root in the right half plane, we know that this system is unstable. +[745.90s -> 759.92s] And this is exactly what we would have expected since we built this transfer function with two roots in the right half plane and two roots in the left half plane. So the route array worked for us and we never had to solve for the roots directly. +[759.92s -> 772.66s] In the next video I'll go through a couple more examples and I'll also describe two special cases with the Routh array that require just a few extra steps. Don't forget to subscribe and I'll see you guys next week. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_6.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3145ac0bf93fa66749ea1ebffd0f1783b34665b7 --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_6.mp4.txt @@ -0,0 +1,43 @@ +[0.24s -> 13.54s] All right, let's do an example where acceleration is a function of velocity. So we have a plane decelerating. Its acceleration is negative 0.005 v squared meters per second squared. Notice this isn't t squared. +[13.54s -> 24.29s] Let's say it starts at 80 meters per second. It goes down to 10 meters per second. So let's find out how long it takes and how far it's going to go. So our acceleration is given to us in the problem. +[24.29s -> 29.81s] So we have acceleration is equal to, well, first of all, it's also equal to DV. +[30.22s -> 43.02s] dt, right? That's always true about acceleration. But it's given to us in the problem, so we have negative 0.005 v squared, meters per second squared. +[43.22s -> 58.19s] All right, so what we can do now is we'll just rearrange slightly We'll bring the V squared down and we'll bring the T DT up so we can go over here and we'll get DV over V squared +[58.70s -> 73.25s] is equal to negative 0.005 dt. Okay, so now all we have to do is integrate both sides. This is a constant, so we can actually put that on the outside of the integral. +[73.25s -> 86.10s] The left side is from V0 to V. That's kind of in the way. And the right side is with respect to T, so we have T0 to T. +[86.61s -> 99.76s] Okay, so when we integrate this, we can keep going over to the side. We will get the integral of, actually, you know what? We can rewrite this V naught. We know what V naught and T naught is. So let's just do that now. +[99.76s -> 111.87s] t0, we're considering the beginning of this problem to be 0 seconds, and it was going 80 meters per second at the beginning. We'll put in the 10 later. Okay, so the integral of... +[111.87s -> 123.22s] v to the negative 2, or 1 over v squared, is negative 1 over v from, we had 80 and v. +[123.73s -> 131.66s] And this is equal to negative 0.005t. +[132.11s -> 144.37s] from T and 0. Okay, so let's just substitute our values in now. We can come down here, so we'll get negative 1 over V. +[144.37s -> 150.70s] minus negative 1 over 80, so we can say that's plus 1 over 80. +[151.54s -> 162.14s] This is going to be equal to negative 0.005t and minus 0. So that just goes away. +[162.14s -> 170.93s] All right, so let's do something here. Actually, let's multiply this everything by negative 1. And you'll see that that will make us a lot happier. So we can just change that. +[171.86s -> 185.87s] to be like this. All right, so now we divide both sides by 0.005. That's the same as multiplying both sides by 200. So we can come over here, and we will find that t is equal to +[186.29s -> 198.54s] 200 times 1 over V minus 1 over 80. And again, we knew that V was, this is our V final, so we can write this in as +[198.96s -> 211.15s] 110th minus 180th times 200. So if you go and type this into your calculator, you will actually get that the time that this interval takes is actually equal to +[211.28s -> 225.98s] 17.5 seconds. Awesome. So that's actually the first part. That's the answer to the first part of the question. Let's put a box around that. So we found the time. Now we want to find how far it's going to go during this time. +[225.98s -> 234.64s] So again, let's write, let me come down here. Let's write acceleration, again, is equal to dv. +[235.18s -> 248.78s] dt. Now, let's do our favorite trick here. We'll multiply it by 1, or essentially multiply the top and bottom by ds. We'll rearrange this, so we get dv +[248.78s -> 259.54s] over ds. We can do this because it's multiplication times ds over dt. We just switch the order of these and remember +[259.79s -> 274.45s] we keep coming back to this, that ds dt is equal to v, right? v is equal to the change in position over the change in time. So we can use that and we can rewrite acceleration +[275.92s -> 283.44s] is equal to dv and ds times v. +[283.79s -> 297.58s] Okay, so we can use that. Let's rewrite this again. Let's come down here, actually. Well, we knew that acceleration, well, here, acceleration was negative 0.001. +[297.58s -> 307.06s] 5 v squared is equal to v dv over ds. +[307.31s -> 320.62s] All right, so let's put all the Vs on one side and all the Ss on the other. So let's rearrange this again a little bit. So we will get negative 0.005. +[320.91s -> 334.67s] ds is equal to v over v squared dv. Okay, so one of these v's is going to cancel out like that. So we can actually rewrite this as 1 over v. +[335.34s -> 343.66s] So let's go ahead and let's integrate this. So we have negative 0.005. +[343.98s -> 358.77s] The integral of ds, we brought the 0.005 outside because it's a constant from s naught to s and this was equal to the integral of 1 over the +[358.77s -> 368.94s] dv. Okay, so let's come down here. And actually what we can do is, from v0 was 80, +[369.68s -> 382.48s] to v, and we're actually going to consider that s naught is going to be 0, because we're only interested in the distance that it travels during this interval. So at the beginning of the interval, you can imagine that its distance in that interval would be 0. +[382.80s -> 387.86s] Okay, so we're gonna come down we're gonna integrate both sides we will have +[388.37s -> 400.02s] negative 0.005 times s from s and 0. +[400.02s -> 413.81s] And this is equal to the ln of v from we had 80 to v. Okay, so let's plug these in. This we get +[414.06s -> 428.08s] negative 0.005 times s I don't like having s's and 5's together but I guess we can't avoid it in this problem minus 0 so that just goes away we get +[428.08s -> 433.52s] ln minus ln . +[437.74s -> 447.86s] And the first thing we want to do here is multiply everything by negative 1. You'll see why in a second. So this becomes minus ln of v plus ln of 80 is equal to pi. +[447.86s -> 455.79s] positive 0.005s. So the ln of 80 minus ln of v, we can also write this as +[456.27s -> 468.91s] ln of 80 over v. That's by log rules. And we're shown to divide both sides by 0.005. Again, that's the same as multiplying by 200 to both sides. So then we can isolate s. +[469.26s -> 483.41s] Now S is just equal to 200 times ln of 80 over V. And our V, we can write, was 10. That was our final velocity that we were looking at. So 200 times the ln of 8. +[483.41s -> 492.50s] or 80 over 10. And we're going to be able to find that s is just equal to 416. +[492.50s -> 504.06s] little bit of dyslexia 416 meters that is how long our plane traveled during this interval that it was decelerating diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_8.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d17d9bc93ca503de5efd2ebbe6069a4a1520b93c --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_8.mp4.txt @@ -0,0 +1,24 @@ +[0.91s -> 13.84s] YouTube, today I want to walk you through a problem that shows up pretty commonly when we start looking at the forces by gravity acting on an object. See, the problem typically goes like this. There's a spaceship traveling from the earth to the moon. +[13.84s -> 26.03s] And we want to solve for the position between the Earth and the Moon where the net force by gravity is equal to zero. Now, internet, before you just rip me a new one, I know this drawing isn't to scale, so let's be cool about that in the comments, okay? +[26.03s -> 34.83s] You see according to Newton's law of universal gravitation, the force by gravity between two masses is inversely proportional to the distance between them. +[35.12s -> 48.43s] Or in practice, what that means is as our little spaceship here gets farther and farther away from the Earth, the force by gravity from the Earth is going to decrease. But as it gets closer to the moon, that force by gravity from the moon is going to increase. +[48.78s -> 58.61s] Which means at some point between the earth and the moon the force by gravity on our little spaceship From the earth is gonna be cancelled out by the force by gravity from the moon +[58.74s -> 73.30s] Now a lot of people like to dive right into the math of this problem But in order to get a conceptual understanding for what's going on let's graph the force by gravity as a function of position between the earth and the moon and Let's say the direction away from the earth is positive +[73.30s -> 76.59s] You see, applying this equation first to the force by the earth. +[76.59s -> 89.10s] The force by gravity from the Earth is large and towards the Earth, that's the negative direction, when our object, in this case the spaceship, is close to the Earth. But as it gets farther and farther away, that force drops off. +[89.30s -> 93.84s] Now looking at the force by the moon on our ship as it travels from the earth to the moon +[94.90s -> 106.13s] Now kids, realize I've taken a few liberties with how I'm drawing this graph because if I was actually to draw it to scale it would look like this. Which is utterly worthless. But getting back to the concepts and the problem. +[106.61s -> 120.08s] You'll notice when the spaceships close to the earth There's a lot of force by gravity from the earth and very little from the moon But as we move closer and closer toward the moon that force by gravity from the moon increases and the force by the earth decreases +[120.08s -> 134.69s] And it's at this point right here where a little spaceship is in equilibrium, which is sometimes referred to as the neutral point. You see, the net force on our spaceship at any given point is the force by gravity from the Earth plus the force by gravity from the moon. +[134.69s -> 145.46s] But realize they're in opposite directions, so they're competing with each other. And if we were to graph that net force, it looks something like this. And that net force is zero at the point of equilibrium. +[145.46s -> 157.20s] So going back up here to the math, we're simply going to set the force by gravity from the earth equal to the force by gravity from the moon. Now plugging Newton's law of universal gravitation in for both of these forces by gravity. +[157.78s -> 170.72s] We get this equality. And this is really where we have to start being careful in how we solve this problem. You see, these two radii are not the same. This radius right here is telling us the distance between the Earth and the ship. +[170.72s -> 177.81s] Whereas this radius over here is the distance between the moon and the ship. So if this radius is the distance to the earth, +[178.13s -> 189.95s] And this is the distance to the moon. We have another issue, and that is we don't know either of these. But realize, the distance between the earth and the ship, plus the distance between the ship and the moon, +[189.95s -> 199.47s] is equal to the total distance between the Earth and Moon. So I'm just going to say that the distance between the ship and the Moon, that's dm, is equal to... +[199.79s -> 210.77s] The distance between the earth and moon, I'll call it D-E-M minus D-E, the distance between the ship and earth. Now subbing that in right here. +[212.05s -> 218.22s] We get this line. And kids, this is actually where the physics in this problem ends. +[218.22s -> 229.10s] After this, it's just math. Now the first thing is we've got a bit of a cancel party going on here. Our gravitational constant as well as the negatives are going to cancel out. And so is the mass of our spaceship, this little m. +[229.10s -> 242.06s] Now we're trying to solve for DE, and the easiest way to do that is to pull this term over here, and put all our masses on the other side of the equal sign. Then taking the square root of both sides, we can isolate DE. +[248.24s -> 261.65s] leaving us with this expression. And if we plug in the values for the mass of the Earth, Moon, and the Earth-Moon distance, we find the neutral point is actually about 90% of the way between the Earth and the Moon. +[261.65s -> 266.67s] So kids, I hope you found this useful. And on that note, that's all for now. diff --git a/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_9.mp4.txt b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f4df8388da9b62eead249459302e2c3286fc128b --- /dev/null +++ b/VideoMMMU_ASR_large/Engineering/validation_Mechanical_Engineering_9.mp4.txt @@ -0,0 +1,36 @@ +[0.00s -> 14.32s] hello friends welcome to my channel learning electronics we have completed all the topics related to second order control system so from this lecture onwards we are going to solve some numericals related to second order control system +[14.32s -> 28.53s] so before starting the video please subscribe my channel and also press the bell icon so that you can get more updated videos from here in this lecture we are going to solve third numerical related to second order control system in the previous classes we have already solved +[28.53s -> 37.55s] numericals related to second order control system so the question is for the control system shown find the value of K1 and K2 so that +[37.55s -> 49.58s] The maximum overshoot is 25% and peak time TP is equal to 4 seconds. Assume unit step input. So this is the control system given here. +[49.58s -> 61.74s] The forward part transfer function GS will be equal to K1 divided by S square and feedback part transfer function HS will be equal to 1 plus K2 into S. +[61.74s -> 76.05s] We have to find out the closed loop transfer function for this system. The closed loop transfer function CS by RS will be equal to GS divided by 1 plus GS into H. +[76.05s -> 77.38s] Now. +[77.38s -> 91.73s] we put the values of gs and hs in this equation we will get k1 by s square divided by 1 plus k1 by s square into 1 plus k2s when we solve this we will +[91.73s -> 100.46s] get CS by RS is equal to K1 divided by S square plus K1 K2 S. +[100.46s -> 112.13s] plus K1. Let this be equation number 1. Now we have to compare this equation with a standard equation of closed loop transfer function of second order control system. +[112.13s -> 124.32s] which is Cs by Rs is equal to omega n square divided by s square plus 2 zeta omega ns plus omega n square. +[124.32s -> 138.80s] Let this be equation number 2. Now we will compare equation number 1 and 2 and find the value of zeta and omega n. So here we can see that 2 zeta omega n is equal to k1 into k2. +[138.80s -> 142.00s] And omega n square is equal to k1. +[142.00s -> 154.35s] By comparing equation number 1 and 2 we will get omega n square is equal to k1. Therefore omega n will be equal to under root k1. Let this be equation number. +[154.35s -> 165.62s] Again when we compare both the equations we will get 2 zeta omega n is equal to k1 into k2. We know that omega n is equal to under root k1. +[165.62s -> 178.19s] Therefore, zeta will be equal to K1 K2 divided by 2 into under root K1. When we rationalize this equation, we will get zeta is equal to +[178.19s -> 190.62s] 1 by 2 K2 into root of K1. Let this be equation number B. Now it is given in the question that the maximum overshoot MP is equal to 25 percent. +[190.62s -> 204.94s] which is equal to 0.25 and we know the formula for MP which is equal to e to the power minus zeta pi divided by under root 1 minus zeta square. Now we put the value of MP. +[204.94s -> 219.15s] be here we'll get 0.25 is equal to e to the power minus zeta pi divided by under root 1 minus zeta square this will be equal to log of 0.25 is equal to minus of zeta pi divided by under +[219.15s -> 229.17s] root 1 minus zeta square the log of 0.25 will be equal to minus of 1.3863 +[229.17s -> 243.44s] which is equal to minus of zeta pi divided by under root 1 minus zeta square. By squaring both sides, we will get 1.9218 is equal to zeta square pi square divided by 1. +[243.44s -> 257.41s] minus zeta square. Now we cross multiply then we'll get 1.9218 minus 1.9218 zeta square is equal to pi square is +[257.41s -> 271.70s] 9.869 when we solve this we will get zeta square is equal to 0.1629 therefore from this equation zeta will be equal to 0.4037 we will get so this is the +[271.70s -> 273.86s] value of Zeta we are getting +[273.86s -> 288.14s] Again, it is given in the question the peak time TP is equal to 4 seconds and we know the formula of TP is equal to pi upon omega D where omega D is called as damped frequency of oscillations. So when we put the value +[288.14s -> 302.35s] of TP here we will get omega D is equal to pi by 4 radian per seconds we know that omega D is equal to omega n into under root 1 minus zeta square so from this equation +[302.35s -> 316.42s] we can find out the value of omega n which is equal to omega d divided by under root 1 minus zeta square now we put the value of omega d and zeta in this equation omega d is pi by 4 +[316.42s -> 323.04s] divided by under root 1 minus theta square that is 0.4037 +[323.04s -> 334.91s] square when we solve this omega n will be equal to 0.8584 radian per second from the equation a +[334.91s -> 346.05s] we got omega n is equal to under root k1 so k1 will be equal to omega n square now we will put omega n value here omega n was +[346.05s -> 357.01s] 0.8584 square we will get k1 k1 will be equal to 0.7369 so this is the value of +[357.01s -> 371.07s] k1 which we want to find out now we will find out k2 for this we will take equation number b according to equation number b zeta is equal to half into under root k1 into k2 +[371.07s -> 374.19s] From this equation K2 is equal to +[374.19s -> 388.50s] 2 zeta divided by under root k1 under root k1 is omega n so this will be equal to 2 zeta upon omega n now we will put the value of zeta and omega n in this equation therefore k2 will be equal to 2 +[388.50s -> 401.84s] into 0.4037 divided by 0.8584. When we solve this we will get K2 is equal to 0.9406. +[401.84s -> 412.94s] So, this is the value of K2 we are getting. So, hope you have understood the numerical. Thank you very much for watching. In the next lecture, we are going to solve another numerical related to second order control system. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_1.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cf99c6440bcafc7b224f1e0954398a550082f1a8 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_1.mp4.txt @@ -0,0 +1,34 @@ +[0.43s -> 13.01s] When studying history, you'll be frequently asked to analyze historical sources. However, many people don't know what this means or how to do it. In this video, I'll explain what source analysis is, give you a step-by-step guide to follow, +[13.01s -> 16.34s] and show you some examples to help you out. Let's begin. +[28.02s -> 41.84s] Welcome back to another History Skills video. Today we're looking at how to analyse historical sources. Source analysis is one of the most important skills you will need to develop when studying the past, and mastering it will help you achieve your best possible results. +[42.10s -> 51.86s] So what is source analysis? Source analysis is the ability to demonstrate a genuine understanding about why a particular historical source was made. +[52.21s -> 60.96s] It is important to remember that all historical sources were created for a reason. Even though we usually read sources in class to help learn about the past, +[60.96s -> 68.08s] Almost no historical sources were originally made just to be read by students decades or centuries after they were created. +[68.37s -> 79.44s] Therefore, we use source analysis to discover why a specific historical source came into existence, including who originally made it, who they initially wanted to read it, plus more. +[79.60s -> 92.69s] Therefore, source analysis involves much more than just reading a historical source. It also requires you to conduct background research to discover who the author was and find out what was happening at the time the source was made. +[93.58s -> 103.28s] By the way, you are not meant to automatically know all of this information. Most of the time you'll need to do some research about your source to successfully analyse it. +[103.38s -> 109.55s] If you need help, online archives and even Wikipedia can be helpful in conducting your background research. +[110.93s -> 124.21s] To provide a complete analysis of your source, there are six specific source analysis skills you need to use. They are information, origin, perspective, context, audience and motive. +[124.75s -> 137.30s] An easy way to remember these six skills is to use the acronym IOPCAM. I've actually created individual videos about each of these six skills that go into much greater depth about each one. +[137.33s -> 144.50s] So if you're struggling with a specific skill, you can find the links to each of the additional videos in the description section below. +[144.91s -> 153.46s] In order to demonstrate a sufficient knowledge of the six analysis skills, you need to be able to answer the following six questions, one for each skill. +[154.19s -> 165.42s] Firstly, what information is stated in the source about the historical topic you're studying? Remember, a source can either explicitly state information or implicitly mention something. +[165.84s -> 173.81s] Secondly, what was the name of the person or people who created the source? Thirdly, from what perspective was the source created? +[174.45s -> 185.20s] Fourthly, when was the source created, and what was happening at this time? Fifth, who was the intended audience of the source? And finally, for what purpose was this source made? +[185.52s -> 197.65s] Sometimes you may not be able to answer all of these questions, but you want to be able to complete as many as possible. Once you have answered these six questions, you are ready to write your full source analysis. +[198.00s -> 200.69s] So, how do you write a source analysis? +[201.04s -> 214.13s] A source analysis is usually a short paragraph that demonstrates all of the knowledge that you have discovered about the historical source. A simple source analysis can be written in just two sentences using the IOPCAM acronym from before. +[214.48s -> 221.71s] In the first sentence, mention the IOP part of the acronym, which is Information, Origin and Perspective. +[222.22s -> 232.21s] For example, this source is a personal letter that describes what trench warfare was like during World War I and was written by John Smith, an Australian soldier. +[233.01s -> 239.76s] In your second sentence, mention the CAM part of the acronym, that is context, audience and motive. +[240.30s -> 251.82s] For example, Smith wrote the letter on 26 April 1915, the day after the Gallipoli landing, to record his experience of the battle and was to be read by his family in Australia. +[252.40s -> 262.35s] As you can see, you can demonstrate significant knowledge of a source by writing an analysis paragraph like this. Of course, you can use more than two sentences if you need to. +[263.06s -> 276.37s] Now that you know what source analysis is and how to do it, let's look at a full example to increase your confidence in the process. The historical source we're going to analyse in this example is a very famous photograph from the Great Depression. +[276.78s -> 290.58s] After doing some background research online, we were able to go through the six elements of IOP CAM. Information. The image shows a mother and her children who are suffering economic hardship as a result of the Great Depression. +[290.99s -> 302.10s] The photograph was taken by someone called Dorothy Lang. After some background research, we discovered that Dorothy Lang was an American photojournalist. +[302.77s -> 316.02s] Context. The photo was taken in March 1936, which was in the middle of the Great Depression in America. Audience. Lange took the photograph as part of her job working for the Federal Government's Resettlement Administration. +[316.53s -> 331.12s] However, we also discovered that her photographs were intended to be published in newspapers for the general public to see. The reason this photograph was taken was to raise public awareness of the economic toll of the Depression and the need for a solution. +[332.37s -> 339.44s] Now that we have answered each of the six questions, we can tie them all together and write a two-sentence source analysis. Here is the result. +[339.63s -> 347.47s] The photograph by the American photojournalist Dorothy Lane shows the economic struggles caused by the Great Depression on a specific mother and her children. +[347.92s -> 359.60s] This image was taken in 1936 as part of a photographic campaign for the federal government's resettlement administration to raise public awareness through the publication of the photograph in newspapers across America. +[361.23s -> 374.22s] Now that you have a better understanding of what source analysis is, I hope that you feel more confident in your studies. If you need further explanations, examples and advice, head over to the historieskills.com website and I'll see you next time. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_10.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a66fabd7a863688991e6aebc331212847d16bd08 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_10.mp4.txt @@ -0,0 +1,49 @@ +[0.00s -> 9.79s] Why are there so many different religions? Well, it's because different religions are different answers to the biggest questions of life, so that's why people care so much about this. +[9.79s -> 24.30s] Question 1. Is there a God, and if so, how many? Some people don't believe in any gods or any kind of spirituality at all. These people are called atheists. Atheists don't necessarily believe God doesn't exist. Some of them simply lack a belief. +[24.30s -> 33.87s] that God does exist, so some are more agnostic about it. But generally, atheists think we don't have any reason to believe in anything beyond the material universe. +[33.87s -> 48.27s] But some people who don't believe in God still believe in some kind of spirituality, and according to Buddhists, that spirituality should involve denying yourself. Here's why. Buddhism does not teach that Buddha was a god, nor did Buddha teach about any gods, but Buddha did teach- +[48.27s -> 60.88s] about the ultimate red pill, which is that life is basically just suffering. At the root of suffering is desire. Those are the four noble truths. Number one, life sucks. Number two, life sucks because you want stuff. +[60.88s -> 64.35s] Three, if you stop wanting stuff, then your life won't suck. +[64.35s -> 78.67s] Number four, there's a path you can take to not want stuff anymore. It's simple, really. The more you desire something, the more disappointed you're going to be when you don't get it. For example, the more you like a pretty girl, the more disappointed you're going to be when she rejects you. And she will. +[78.67s -> 84.50s] The more you love money, the more disappointed you're gonna be when the economy crashes, and it will. +[84.50s -> 95.09s] You gotta stop being so attached to all these worldly pleasures. So you need to break that attachment by denying yourself. And then you can be spiritually free. Life is a cycle of pain. +[95.09s -> 103.25s] But if you eliminate your desire, you can free yourself from the entire cycle and achieve nirvana, which is true spiritual bliss. +[103.25s -> 117.82s] Now, some people want spiritual freedom but do not want to deny themselves. This kind of spirituality isn't about self-denial at all. It's about the opposite, self-affirmation. It doesn't like the submission involved in traditional religion. +[117.82s -> 126.00s] but still wants to have the spiritual meaning that traditional religion can provide. It's about the freedom to pave your own spiritual path. +[126.00s -> 137.68s] So because it's all about spiritual libertarianism, it's not an organized religion, but it's a decentralized set of practices that are becoming increasingly popular among Westerners, particularly women. +[137.68s -> 144.19s] Now some people believe in many gods like some pagans and Hindus. The difference is that Hindus believe in reincarnation. +[144.19s -> 156.53s] Pagans are usually polytheists, which means they believe in many gods. The gods usually represent forces in nature. The sun? There's a god for that. The moon? There's a god for that. The sky? There's a god for that. +[156.53s -> 160.54s] The sea? There's a god for that. Your crops? There's a god for that. +[160.54s -> 174.93s] So because there's a god for every area of life, if you want to succeed in a certain area of life, you need to win the favor of that particular god. And often different cultures have different versions of the same gods. Another thing is the gods of paganism are a lot more anthropomorphic. +[174.93s -> 189.42s] or human-like than they are in other religions. The gods are a lot more powerful than humans, but they're still both finite. They're not all powerful. Just like humans, gods will fight each other, get drunk, reproduce, and make mistakes. +[189.42s -> 203.92s] Okay, now do Hindus also believe in many gods? Well, it's kind of complicated, because there are indeed many gods in Hinduism, but they're all part of the same ultimate reality. Hindus believe that the one ultimate reality encompasses everything, but it's received in many ways. +[203.92s -> 217.52s] different ways. They believe there can be many incarnations of God or the gods and that's why it's okay to worship idols because the divine expresses itself through the physical. This is why Hinduism has a more pluralistic approach. +[217.52s -> 231.79s] Instead of having a strict canon of what you must believe, the way some religions do, Hinduism is more like a buffet, where you can choose to believe what best suits you, because God can be received in different ways. Hinduism also believes that reality is a cycle. +[231.79s -> 246.00s] That's why they believe in karma and reincarnation. They believe there's a hierarchy of life forms, and if you earn bad karma in this life, you'll move down the hierarchy in the next life. There's also a hierarchy of people, and if you earn good karma- +[246.00s -> 260.77s] this life, you can move up the hierarchy in the next life. So you could say Hindus are monotheists, the difference is they believe God is one with the universe rather than separate from it, which is similar to how Sikhs think of God, the difference is that Hindus worship idols and Sikhs do not. +[260.77s -> 275.09s] Sikhism strictly only believes in one God, but not in the way that Western religions do, because Western religions see God as something outside and external to the universe, whereas Sikhism would agree with Hinduism that God is one with the world, but unlike Hinduism, +[275.09s -> 288.21s] they do not think that that means we can worship idols. They see God as kind of an unknowable mystery, but they also believe that the gurus have been enlightened to teach us how to serve God, and that includes working for equality and justice. +[288.21s -> 302.67s] Western religions, on the other hand, do see God as separate from the universe, and deists don't even think God interacts with the universe at all. According to deism, God is outside the universe, and he sort of set the universe in motion, but doesn't actually intervene in the nat- +[302.67s -> 316.88s] course of events. So deism often compares God to a sort of clockmaker for the universe. Why do they believe this? Well, deists think that from reason alone we can figure out that God exists, but when it comes to divine revelation or supernatural +[316.88s -> 327.34s] miracles, then they're a lot more skeptical. So God exists but doesn't really care. But the Abrahamic religions believe God does care and he does interact with the universe. +[327.34s -> 336.05s] Okay, so how exactly did he do that? Did God become human in Jesus? And if not, is Jesus still the Messiah? Judaism doesn't think so. +[336.05s -> 350.45s] Judaism is about God's relationship with the Jewish people. They believe they're God's chosen people, chosen by God to bless the world by helping people live rightly, and they believe God gave them the Torah to help them accomplish that. Okay, how strictly do they follow- +[350.45s -> 359.74s] the Torah? Well, it depends on who you ask. Some Jews follow the Torah really strictly, some of them follow it kinda strictly, and some of them don't follow it strictly at all. +[359.74s -> 374.16s] They also believe in the coming of the Messiah, a Jewish superhero who's gonna fix the whole world. The reason they don't believe Jesus was Messiah is because the world apparently hasn't been fixed yet, but they still believe it's their job to start fixing the world in preparation for when the- +[374.16s -> 375.73s] Messiah does arrive. +[375.73s -> 390.16s] now islam actually does believe jesus was the messiah but still strictly not god they believe he was a prophet specifically a prophet of islam because they believe the same god gave different revelations to different prophets over the years but these +[390.16s -> 404.37s] gradually got corrupted, so God gave the final and perfect revelation to Muhammad in the Quran. They see Islam as the fulfillment of Christianity and Judaism, so they do believe Jesus was a very important prophet. They believe he +[404.37s -> 416.37s] was the promised messiah and they even believe he was born to a virgin but they do not believe he was god and they do not believe he rose from the dead they believe that he didn't even die god just made it appear that way +[416.37s -> 430.77s] Muslims believe that the Quran is the direct word of God, it's flawless, it's eternal, and it's been perfectly preserved. And it also says how to submit to God, and that's very important because the meaning of Islam is to submit. +[430.77s -> 444.80s] ruler of the entire universe, and all humans are called to submit to God. And eventually, God is going to reward those who do good and punish those who do evil. And if you want to know how to do good by submitting to God, there's five big ways to do so. +[444.80s -> 456.34s] The biggest focus of Islam is the fact that there is only one God. There is nothing like God, and God is so pure and so far above the universe that God couldn't possibly become human. +[456.34s -> 470.70s] Christianity is very different, however, because it teaches God did become human. Christianity is all about Christ. Jesus is truly human, just like the rest of us, but he's also truly God, just like God the Father. And because he's truly human, +[470.70s -> 484.91s] and truly God, he's the only one who can bridge the gap between humans and God. And there is a gap, because God is perfect, almighty, and eternal, whereas we humans are sinful, weak, and corrupted. But still, in his infinite +[484.91s -> 494.86s] love and mercy god came down became human and died for our sins and he rose from the dead and eventually is going to raise the rest of us from the dead as well +[494.86s -> 509.26s] What's unique about Christianity is we don't actually have to be good enough for God because God already did that for us when he became human and died for us. So we just need to be united to Christ and then we can participate in God's eternal life. Okay, but how do we do that? +[509.26s -> 510.03s] that. +[510.03s -> 524.34s] For those who have faith in Christ, the Holy Spirit unites them to Christ, because the Holy Spirit is the Spirit of Christ, and he's also the Spirit of the Father. These three persons have relationships with one another, but they're still all the same being, so Christianity still only believes in Christ. +[524.34s -> 531.87s] in one God. All of this is revealed in the Bible, which is the story about Jesus. Spoiler alert, Jesus wins in the end. +[531.87s -> 545.63s] He defeated death when he rose from the dead, and when he comes back, he's going to destroy all evil in the world and make the world perfect. Just like he united God and man, Jesus is also going to unite heaven and earth. +[545.63s -> 560.08s] So all these religions teach very different things. Some people try and respect all religions by saying they're all basically teaching the same thing, but this actually disrespects all religions by discarding the uniqueness of their claims. The truth is that religion- +[560.08s -> 564.87s] is the biggest questions of life that everyone needs to answer for themselves. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_2.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cf99c6440bcafc7b224f1e0954398a550082f1a8 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_2.mp4.txt @@ -0,0 +1,34 @@ +[0.43s -> 13.01s] When studying history, you'll be frequently asked to analyze historical sources. However, many people don't know what this means or how to do it. In this video, I'll explain what source analysis is, give you a step-by-step guide to follow, +[13.01s -> 16.34s] and show you some examples to help you out. Let's begin. +[28.02s -> 41.84s] Welcome back to another History Skills video. Today we're looking at how to analyse historical sources. Source analysis is one of the most important skills you will need to develop when studying the past, and mastering it will help you achieve your best possible results. +[42.10s -> 51.86s] So what is source analysis? Source analysis is the ability to demonstrate a genuine understanding about why a particular historical source was made. +[52.21s -> 60.96s] It is important to remember that all historical sources were created for a reason. Even though we usually read sources in class to help learn about the past, +[60.96s -> 68.08s] Almost no historical sources were originally made just to be read by students decades or centuries after they were created. +[68.37s -> 79.44s] Therefore, we use source analysis to discover why a specific historical source came into existence, including who originally made it, who they initially wanted to read it, plus more. +[79.60s -> 92.69s] Therefore, source analysis involves much more than just reading a historical source. It also requires you to conduct background research to discover who the author was and find out what was happening at the time the source was made. +[93.58s -> 103.28s] By the way, you are not meant to automatically know all of this information. Most of the time you'll need to do some research about your source to successfully analyse it. +[103.38s -> 109.55s] If you need help, online archives and even Wikipedia can be helpful in conducting your background research. +[110.93s -> 124.21s] To provide a complete analysis of your source, there are six specific source analysis skills you need to use. They are information, origin, perspective, context, audience and motive. +[124.75s -> 137.30s] An easy way to remember these six skills is to use the acronym IOPCAM. I've actually created individual videos about each of these six skills that go into much greater depth about each one. +[137.33s -> 144.50s] So if you're struggling with a specific skill, you can find the links to each of the additional videos in the description section below. +[144.91s -> 153.46s] In order to demonstrate a sufficient knowledge of the six analysis skills, you need to be able to answer the following six questions, one for each skill. +[154.19s -> 165.42s] Firstly, what information is stated in the source about the historical topic you're studying? Remember, a source can either explicitly state information or implicitly mention something. +[165.84s -> 173.81s] Secondly, what was the name of the person or people who created the source? Thirdly, from what perspective was the source created? +[174.45s -> 185.20s] Fourthly, when was the source created, and what was happening at this time? Fifth, who was the intended audience of the source? And finally, for what purpose was this source made? +[185.52s -> 197.65s] Sometimes you may not be able to answer all of these questions, but you want to be able to complete as many as possible. Once you have answered these six questions, you are ready to write your full source analysis. +[198.00s -> 200.69s] So, how do you write a source analysis? +[201.04s -> 214.13s] A source analysis is usually a short paragraph that demonstrates all of the knowledge that you have discovered about the historical source. A simple source analysis can be written in just two sentences using the IOPCAM acronym from before. +[214.48s -> 221.71s] In the first sentence, mention the IOP part of the acronym, which is Information, Origin and Perspective. +[222.22s -> 232.21s] For example, this source is a personal letter that describes what trench warfare was like during World War I and was written by John Smith, an Australian soldier. +[233.01s -> 239.76s] In your second sentence, mention the CAM part of the acronym, that is context, audience and motive. +[240.30s -> 251.82s] For example, Smith wrote the letter on 26 April 1915, the day after the Gallipoli landing, to record his experience of the battle and was to be read by his family in Australia. +[252.40s -> 262.35s] As you can see, you can demonstrate significant knowledge of a source by writing an analysis paragraph like this. Of course, you can use more than two sentences if you need to. +[263.06s -> 276.37s] Now that you know what source analysis is and how to do it, let's look at a full example to increase your confidence in the process. The historical source we're going to analyse in this example is a very famous photograph from the Great Depression. +[276.78s -> 290.58s] After doing some background research online, we were able to go through the six elements of IOP CAM. Information. The image shows a mother and her children who are suffering economic hardship as a result of the Great Depression. +[290.99s -> 302.10s] The photograph was taken by someone called Dorothy Lang. After some background research, we discovered that Dorothy Lang was an American photojournalist. +[302.77s -> 316.02s] Context. The photo was taken in March 1936, which was in the middle of the Great Depression in America. Audience. Lange took the photograph as part of her job working for the Federal Government's Resettlement Administration. +[316.53s -> 331.12s] However, we also discovered that her photographs were intended to be published in newspapers for the general public to see. The reason this photograph was taken was to raise public awareness of the economic toll of the Depression and the need for a solution. +[332.37s -> 339.44s] Now that we have answered each of the six questions, we can tie them all together and write a two-sentence source analysis. Here is the result. +[339.63s -> 347.47s] The photograph by the American photojournalist Dorothy Lane shows the economic struggles caused by the Great Depression on a specific mother and her children. +[347.92s -> 359.60s] This image was taken in 1936 as part of a photographic campaign for the federal government's resettlement administration to raise public awareness through the publication of the photograph in newspapers across America. +[361.23s -> 374.22s] Now that you have a better understanding of what source analysis is, I hope that you feel more confident in your studies. If you need further explanations, examples and advice, head over to the historieskills.com website and I'll see you next time. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_3.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a6f7750f0f44214151d54ef6137354cef2c65170 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_3.mp4.txt @@ -0,0 +1,14 @@ +[0.94s -> 2.54s] Thank you. +[8.37s -> 22.18s] Let's go back to about 200 BC, to around the Qin Dynasty, by which time Hanfu was well established. Designs at the time were based on three key principles. It should have a top and bottom. +[22.18s -> 36.46s] The bottom can be pants or full-length skirt, and the top and bottom meet around waist. Those rules would also be prominent during the subsequent and long-lasting Han Dynasty, around the turn of the millennium. However, +[36.46s -> 48.98s] Sharp cutting edges at the bottom of the top was the signature of the time. As for the ladies, while the design of the skirt is quite effeminate, the top is more about strength and power. +[49.58s -> 62.80s] During the Wei and Jing dynasties, the robe look lost its momentum. It began to put more emphasis on a finished look with a division of upper and lower body from the waist, especially by using a belt. +[63.60s -> 73.46s] By the Sui and Tang dynasties, the three principles are still there, but some new ones have been added. For instance, a long gown is a new norm. +[73.94s -> 85.33s] The guys have an iconic style now and a new element has been added, a hat piece. As for the girls, the dress wraps around and begins from the chest. +[85.33s -> 95.98s] The design wants to create a new look that transforms the body ratio. Accessorizing with some silver and gold embellishments, it creates a cheerful and luxurious look. +[96.91s -> 105.71s] The Song Dynasty innovates based on these four principles. And under these different principles, different styles are born. +[109.52s -> 124.14s] Moving into the Ming Dynasty, from the 14th to the 16th centuries, we see a mood to mix and match. A typical combo is a short top with a Mamian skirt, but it's all very open and easygoing. +[124.53s -> 127.18s] People are encouraged to experiment. +[127.73s -> 141.34s] A long top can also go with a skirt for instance. A major change is on the color however. While keeping the crossover round and symmetric color, the width of the color depends. +[141.34s -> 144.69s] It can almost wrap around the entire neck. +[160.05s -> 169.97s] Hanfu gradually went out of fashion during the Qing Dynasty, and it was largely replaced in the early 20th century. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_4.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..89f67f8afdf5f8f5df51503a25270f22c7b2d3eb --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_4.mp4.txt @@ -0,0 +1,37 @@ +[0.34s -> 10.32s] Hello students and welcome to Global History and Geography video lecture number two, in which we will discuss the first wave of civilizations +[10.32s -> 23.98s] which occurred roughly between 3500 BCE and 600 BCE. You should recall that during the last video lecture, we learned about how human societies developed from the Paleolithic era to the Neolithic era. +[23.98s -> 37.68s] During the Paleolithic age, humans mostly lived in small bands as hunter-gatherers. After the adoption of farming, humans moved into the Neolithic era and began to settle into larger communities. +[37.87s -> 52.18s] Around the year 3500 BCE, we see the first evidence of human societies organizing themselves into larger civilizations. Before we continue, we need to take a longer look at the word civilization. +[52.18s -> 63.60s] What is a civilization and how is it different from other forms of organized society? To understand that, let's take a look at the criteria or characteristics of civilizations. +[63.82s -> 72.37s] In advanced civilizations there is a surplus of food due to agriculture. Therefore, not everyone is needed to produce or gather food. +[72.37s -> 82.06s] This allows some people to focus on doing other specific jobs like making tools or wax making. This allows for job specialization. +[82.51s -> 95.87s] Perhaps because of job specialization, often advanced civilizations are characterized by increased social hierarchy, whereas earlier Paleolithic societies were more egalitarian or equal. +[95.87s -> 101.58s] Advanced civilizations had more social classes based on wealth, power and gender. +[102.10s -> 116.10s] Advanced civilizations also had some form of organized government and systems of law. Early civilizations often had some form of monarchy or king. These governments organized society under a system of rules and regulations. +[116.10s -> 125.39s] and enforce rule with the threat of punishment and the use of force. Advanced civilizations usually have some form of organized religion. +[125.39s -> 139.57s] In early advanced civilizations, organized religion and government were often mixed together. Most advanced civilizations also had areas of higher population density, which leads to the development of urban areas +[139.57s -> 151.90s] or cities. Governments and advanced civilizations also made it possible to finance and organize large-scale public works projects such as irrigation projects and monumental architecture. +[151.90s -> 166.32s] such as the ziggurats of Mesopotamia or the pyramids of ancient Egypt. It makes sense that because water is a necessity for life and agriculture, that the early civilizations all began near major rivers. +[166.42s -> 175.95s] The early first wave civilizations all had some or all of these characteristics. This video lecture will take a brief look at four of them. +[176.50s -> 189.17s] Around 3500 BCE, Mesopotamian civilization began near the Tigris and Euphrates rivers in the Middle East. The term Mesopotamia literally means land between two rivers. +[189.17s -> 193.04s] The region was also referred to as the Fertile Crescent. +[193.49s -> 204.78s] Several kingdoms ruled during this era, beginning with the Sumerians. A notable achievement of the Sumerians was the development of a system of writing known as cuneiform. +[205.10s -> 217.20s] After the Sumerians came the Akkadian Empire, during which one of the earliest examples of literature, the Epic of Gilgamesh, a poem about an ancient Sumerian king, was produced. +[217.36s -> 231.66s] Following the Akkadians were the Assyrian and Babylonian empires. The most well-known Babylonian king, King Hammurabi, developed one of the earliest sets of written laws, known as Hammurabi's Code. +[231.86s -> 246.21s] Another first wave civilization during this time, around 3000 BCE, was ancient Egypt. Ancient Egyptian civilization arose along the Nile River in northern Africa. Like the Mesopotamians, +[246.21s -> 258.62s] They also developed a writing system known as hieroglyphics. They also had a strict social hierarchy and organized religion. At the top of this social pyramid were the pharaohs or kings. +[258.62s -> 271.73s] followed by priests, scribes, or record keepers, and at the bottom of the hierarchy were peasants. Egyptian pharaohs organized the construction of pyramids and large-scale irrigation systems. +[271.76s -> 283.18s] Heading east into present-day Pakistan along the Indus River, the Indus River civilization arose between 3300 BCE and 1800 BCE. +[283.18s -> 295.57s] Not a lot is known about the Indus Valley civilization, but archaeologists have discovered the remains of two major urban areas, the ancient cities of Harappa and Mohenjo-daro. +[295.63s -> 302.13s] These cities showed evidence of extensive urban planning, even including indoor plumbing. +[302.45s -> 316.66s] Mysteriously the civilization appears to have abruptly disappeared around the year 1800 BCE. The cultural and religious practice of Hinduism began to emerge in this region during this period. +[316.72s -> 326.74s] Hinduism has continued to be a part of life in the region of South Asia even to this day. Hinduism will be discussed in more detail in a later lecture. +[327.15s -> 340.00s] The last of the first wave river valley civilizations we will discuss is ancient China. Civilizations began to emerge along the Yellow or Huanghe River and the Yangtze Rivers +[340.00s -> 353.14s] around 2000 BCE. Three kingdoms, the Jia, Shang, and Zhou established ruling dynasties. These civilizations established long-standing traditions in Chinese society. +[353.14s -> 356.30s] One of these was the Mandate of Heaven. +[356.85s -> 368.72s] Chinese kings stayed in power as long as they had the approval of the gods. A famine, natural disaster, or other problems indicated that the ruler lost favor with the gods. +[368.72s -> 372.08s] which justified his overthrow and replacement. +[372.37s -> 386.48s] Chinese civilization had a strict social hierarchy. Bones, with writing called oracle bones, indicated that they developed writing systems as well, and they developed advanced bronze tools and weapons. +[387.25s -> 396.59s] In summary, each of these civilizations, Mesopotamia, ancient Egypt, Indus, and ancient China, developed along major rivers, +[396.62s -> 410.69s] and demonstrated various characteristics of advanced civilization including organized governments and religions, urbanization, advanced tools and knowledge, large construction projects, +[410.69s -> 418.32s] and systems of writing thanks for your time i hope you learn a little bit more today enjoy yourself diff --git a/VideoMMMU_ASR_large/Humanities/new_History_5.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c48ea321014ef5010e8806da1a40da9090d0c04a --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_5.mp4.txt @@ -0,0 +1,53 @@ +[0.00s -> 13.46s] Ancient Egyptian architecture, characterized by monumental stone structures made of mud brick and limestone, as well as intricate hieroglyphs, exudes grandeur and symmetry. Notable examples include the awe-inspiring Pyramids of Giza, +[13.46s -> 27.39s] the majestic Temple of Karnak, and the captivating Luxor Temple. Flourishing from the Old Kingdom to the Ptolemaic period around 3100 BCE to 30 BCE, it reflected the religious beliefs and societal hierarchy of ancient Egypt. +[27.39s -> 37.49s] showcasing a harmonious blend of spirituality and architectural prowess. Ancient Greek architecture, renowned for its emphasis on symmetry, harmony, and proportion. +[37.49s -> 51.39s] showcased a mastery of columnar forms including Doric, Ionic, and Corinthian styles. It features meticulously designed temples crafted from stone and marble, often elevated for optimal viewing of their elegant proportions and light effects. +[51.39s -> 62.29s] Iconic examples such as the Parthenon, Temple of Hephaestus, and Erechtheion epitomize the classical period between 800 BCE and 323 BCE. +[62.29s -> 72.96s] embodying the democratic, philosophical, and athletic ideals of ancient Greece. Byzantine architecture, spanning from 330 AD to 1453 AD, +[72.96s -> 78.19s] blends Roman and Byzantine styles, featuring arches, vaults, and domes. +[78.19s -> 90.21s] It's known for lavish interiors with marble, stone, and mosaic decorations, reflecting the empire's opulence. Furniture made of precious wood adorned Byzantine interiors, showcasing luxury and craftsmanship. +[90.21s -> 97.07s] The Hagia Sophia in Turkey and the Basilica of San Vitali in Italy are perfect examples for this architecture style. +[97.07s -> 110.90s] Romanesque architecture blends Roman, Byzantine, and local influences, featuring massive structures with thick walls, rounded arches, sturdy pillars, and decorative arcading. Buildings exhibit clear, symmetrical forms and simplicity. +[110.90s -> 118.54s] compared to later Gothic styles. Despite regional variations in materials, Romanesque architecture is identifiable across Europe. +[118.54s -> 127.76s] primarily constructed using stone, with occasional brick and timber elements. Notable examples include Durham Cathedral, Spire Cathedral, and Santiago de Compostela. +[127.76s -> 137.73s] Flourishing from the 10th to the 12th centuries in Europe, Romanesque architecture reflects the dominant influence of the Roman Catholic Church during the European medieval era. Gothic Architecture +[137.73s -> 152.02s] Originating in 12th century France, is characterized by pointed arches, ribbed vaults, and flying buttresses, allowing for taller and more open interior spaces. Its hallmark includes intricate decorations like stained glass windows and detailed +[152.02s -> 159.10s] Notable examples such as Notre Dame and Chartres Cathedral showcase the style's grandeur and craftsmanship. +[159.10s -> 167.66s] reflecting the flourishing of medieval European culture during the High and Late Middle Ages. The Renaissance period, originating in 14th century Italy, +[167.66s -> 174.80s] succeeded Gothic, and preceded Baroque styles. It emphasizes symmetry, proportion, and geometric regularity. +[174.80s -> 182.67s] drawing inspiration from classical antiquity, especially ancient Roman architecture. Renaissance buildings feature orderly arrangements of columns, +[182.67s -> 195.09s] pilasters, and lintels, alongside semicircular arches, domes, niches, and aediculae, replacing the complexity of medieval structures. Notable examples include St. Peter's Basilica and Florence Cathedral. +[195.09s -> 203.44s] The Renaissance spread across Europe during the 15th and 16th centuries, marking a cultural renaissance after the Middle Ages. Tudor Architecture +[203.44s -> 217.84s] prevalent in England during the late 15th to early 17th centuries, features timber framing, steeply pitched roofs, and decorative half-timbering infilled with plaster or brick. Notable examples include Hampton Court Palace and Anne Hathaway's Cottage. +[217.84s -> 226.54s] This style reflects a blend of medieval English traditions with Renaissance influences. Baroque architecture, flourishing in 17th century Europe, +[226.54s -> 240.05s] is characterized by its dramatic and ornate features evoking grandeur, movement, and emotion. Notable examples like St. Peter's Basilica and the Palace of Versailles showcase its elaborate decoration and use of materials like marble, +[240.05s -> 253.58s] and gilded elements. Baroque style reflects the power and grandeur of monarchies and the Catholic Church during the period of absolutism, leaving a lasting legacy in architectural history. Rococo architecture, emerging in the 18th century, +[253.58s -> 267.89s] embraces exuberant, asymmetrical designs adorned with intricate ornamentation and playful motifs like shells, frescoes, and scrolls. This dramatic style creates an illusion of motion and surprise. Notable examples such as the Palace of Versailles +[267.89s -> 282.10s] and Schönbrunn Palace show off its pastel colors and lavish use of materials like wood and stucco embellished with gold leaf. Rococo style symbolizes the elegance and refinement of European aristocracy, particularly flourishing in France. +[282.10s -> 293.89s] France, and Germany. Neoclassical architecture, prevalent in the late 18th and early 19th centuries, draws inspiration from classical Greek and Roman architecture, characterized by grandeur, +[293.89s -> 308.18s] Symmetry and simplicity, it emphasizes straight lines, columns, and domes. Notable examples include the Brandenburger Gate, Arc de Triomphe, United States Capitol, and the Parthenon in Nashville, reflecting a revival of classical ideals during the Enlightenment. +[308.18s -> 309.07s] Enlightenment era. +[309.07s -> 323.38s] This style became prominent across Europe and the Western world, influencing iconic structures. Victorian architecture, predominant during the reign of Queen Victoria between 1837 and 1901, is characterized by elaborate ornamentation, +[323.38s -> 337.70s] mixing different architectural ideas and attention to detail. It encompasses various sub-styles such as Gothic Revival, Italianate, and Queen Anne. Notable features include steep gable roofs, bay windows, and intricate woodwork. +[337.70s -> 350.53s] This style reflects the prosperity and innovation of the Victorian era, with notable examples including the Houses of Parliament in London and the Biltmore Estate in the United States. Art Nouveau, also known as Eugen Steele, +[350.53s -> 362.30s] or new art, was popular from the late 19th to early 20th centuries. It's characterized by flowing lines, dynamic movement, organic shapes, and intricate decorative motifs inspired by nature. +[362.30s -> 375.82s] Using modern materials like iron and glass, it aimed to break traditional distinctions between fine and applied arts. Originating in Britain, Belgium, and France, Art Nouveau spread across Europe, adapting to different names and styles in each country. +[375.82s -> 385.28s] Notable examples include the Paris Metro entrances and the works of architect Antoni Godi in Barcelona. Art Nouveau emerged as a reaction against historicism. +[385.28s -> 398.16s] embracing innovation and modernity in architecture and design. Arts and crafts architecture, prominent between 1880 and 1910, emphasized craftsmanship, simplicity, and the use of natural materials. +[398.16s -> 411.97s] It sought to revive traditional craftsmanship in response to industrialization, favoring handcrafted details and functional design, often considered to be in opposition to art nouveau. Notable examples include the Red House in England, +[411.97s -> 420.96s] and the Gamble House in the United States. The movement influenced various aspects of design, including architecture, furniture, and decorative arts. Art Deco +[420.96s -> 432.98s] originating in Paris in the 1910s, reached its peak in the 1920s and early 1930s in the United States and Europe, influencing a wide range of designs from buildings to everyday objects. +[432.98s -> 447.25s] It combines modernist avant-garde styles with rich materials and motifs from various cultures. Characterized by sleek lines, geometric shapes, and luxurious materials, notable features include stepped forms, zigzag patterns, and stylish designs. +[447.25s -> 460.37s] motifs. Examples include the Chrysler Building in New York City and the Palais de Chaillot in Paris. Art Deco represents a celebration of modernity, glamour, and sophistication during the interwar period. Modernism +[460.37s -> 474.70s] Emerging in the late 19th and early 20th centuries is characterized by a rejection of traditional ornamentation and a focus on functionality and minimalism. It emphasizes clean lines, plain or shiny surfaces, geometric forms, and the use of new materials. +[474.70s -> 482.10s] like steel, concrete, and glass. Notable examples include the Bauhaus School in Germany and the Villa Savoy in France. +[482.10s -> 496.40s] Modernism represents a break from historical styles, embracing technological advancements and a forward-thinking approach to design. Brutalism, popular from the 1950s to the 1970s, is characterized by its raw, exposed concrete surfaces, +[496.40s -> 499.39s] geometric forms, and minimal ornamentation. +[499.39s -> 513.68s] Brutalism typically uses exposed concrete or brick, angular shapes, and a limited color palette. Other materials like steel, timber, and glass may also be incorporated. It emerged as a response to the modernist movement, emphasizing +[513.68s -> 528.18s] functionality, and honesty in design. Notable examples include the Barbican Estate in London and the Boston City Hall. Postmodernism architecture, emerging in the late 20th century, rejects the strict rules of modernism in favor of experimentation. +[528.18s -> 542.19s] It often combines elements from different styles and historical periods, incorporating irony, humor, and symbolism. Postmodern architecture often features exaggerated shapes, mixes different styles together, and considers the surrounding context. +[542.19s -> 549.70s] Notable examples include the AT&T building in New York City, the Wisma 46 in Jakarta, and the Piazza d'Italia in New Orleans. +[549.70s -> 557.78s] Contemporary or modern architecture, prevalent from the late 20th century to the present day, emphasizes innovation, sustainability, +[557.78s -> 570.10s] and functionality. It often features clean lines, open spaces, and the use of advanced materials and technology. Notable examples include the Burj Khalifa in Dubai and the Guggenheim Museum Bilbao. +[570.10s -> 583.86s] Contemporary architecture reflects the evolving needs of society and the integration of global influences, shaping the skylines of cities worldwide. Don't forget to like the video and subscribe to our channel so you don't miss out on any future videos. +[583.86s -> 587.34s] check out the other videos of our channel, you might like them. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_6.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c48ea321014ef5010e8806da1a40da9090d0c04a --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_6.mp4.txt @@ -0,0 +1,53 @@ +[0.00s -> 13.46s] Ancient Egyptian architecture, characterized by monumental stone structures made of mud brick and limestone, as well as intricate hieroglyphs, exudes grandeur and symmetry. Notable examples include the awe-inspiring Pyramids of Giza, +[13.46s -> 27.39s] the majestic Temple of Karnak, and the captivating Luxor Temple. Flourishing from the Old Kingdom to the Ptolemaic period around 3100 BCE to 30 BCE, it reflected the religious beliefs and societal hierarchy of ancient Egypt. +[27.39s -> 37.49s] showcasing a harmonious blend of spirituality and architectural prowess. Ancient Greek architecture, renowned for its emphasis on symmetry, harmony, and proportion. +[37.49s -> 51.39s] showcased a mastery of columnar forms including Doric, Ionic, and Corinthian styles. It features meticulously designed temples crafted from stone and marble, often elevated for optimal viewing of their elegant proportions and light effects. +[51.39s -> 62.29s] Iconic examples such as the Parthenon, Temple of Hephaestus, and Erechtheion epitomize the classical period between 800 BCE and 323 BCE. +[62.29s -> 72.96s] embodying the democratic, philosophical, and athletic ideals of ancient Greece. Byzantine architecture, spanning from 330 AD to 1453 AD, +[72.96s -> 78.19s] blends Roman and Byzantine styles, featuring arches, vaults, and domes. +[78.19s -> 90.21s] It's known for lavish interiors with marble, stone, and mosaic decorations, reflecting the empire's opulence. Furniture made of precious wood adorned Byzantine interiors, showcasing luxury and craftsmanship. +[90.21s -> 97.07s] The Hagia Sophia in Turkey and the Basilica of San Vitali in Italy are perfect examples for this architecture style. +[97.07s -> 110.90s] Romanesque architecture blends Roman, Byzantine, and local influences, featuring massive structures with thick walls, rounded arches, sturdy pillars, and decorative arcading. Buildings exhibit clear, symmetrical forms and simplicity. +[110.90s -> 118.54s] compared to later Gothic styles. Despite regional variations in materials, Romanesque architecture is identifiable across Europe. +[118.54s -> 127.76s] primarily constructed using stone, with occasional brick and timber elements. Notable examples include Durham Cathedral, Spire Cathedral, and Santiago de Compostela. +[127.76s -> 137.73s] Flourishing from the 10th to the 12th centuries in Europe, Romanesque architecture reflects the dominant influence of the Roman Catholic Church during the European medieval era. Gothic Architecture +[137.73s -> 152.02s] Originating in 12th century France, is characterized by pointed arches, ribbed vaults, and flying buttresses, allowing for taller and more open interior spaces. Its hallmark includes intricate decorations like stained glass windows and detailed +[152.02s -> 159.10s] Notable examples such as Notre Dame and Chartres Cathedral showcase the style's grandeur and craftsmanship. +[159.10s -> 167.66s] reflecting the flourishing of medieval European culture during the High and Late Middle Ages. The Renaissance period, originating in 14th century Italy, +[167.66s -> 174.80s] succeeded Gothic, and preceded Baroque styles. It emphasizes symmetry, proportion, and geometric regularity. +[174.80s -> 182.67s] drawing inspiration from classical antiquity, especially ancient Roman architecture. Renaissance buildings feature orderly arrangements of columns, +[182.67s -> 195.09s] pilasters, and lintels, alongside semicircular arches, domes, niches, and aediculae, replacing the complexity of medieval structures. Notable examples include St. Peter's Basilica and Florence Cathedral. +[195.09s -> 203.44s] The Renaissance spread across Europe during the 15th and 16th centuries, marking a cultural renaissance after the Middle Ages. Tudor Architecture +[203.44s -> 217.84s] prevalent in England during the late 15th to early 17th centuries, features timber framing, steeply pitched roofs, and decorative half-timbering infilled with plaster or brick. Notable examples include Hampton Court Palace and Anne Hathaway's Cottage. +[217.84s -> 226.54s] This style reflects a blend of medieval English traditions with Renaissance influences. Baroque architecture, flourishing in 17th century Europe, +[226.54s -> 240.05s] is characterized by its dramatic and ornate features evoking grandeur, movement, and emotion. Notable examples like St. Peter's Basilica and the Palace of Versailles showcase its elaborate decoration and use of materials like marble, +[240.05s -> 253.58s] and gilded elements. Baroque style reflects the power and grandeur of monarchies and the Catholic Church during the period of absolutism, leaving a lasting legacy in architectural history. Rococo architecture, emerging in the 18th century, +[253.58s -> 267.89s] embraces exuberant, asymmetrical designs adorned with intricate ornamentation and playful motifs like shells, frescoes, and scrolls. This dramatic style creates an illusion of motion and surprise. Notable examples such as the Palace of Versailles +[267.89s -> 282.10s] and Schönbrunn Palace show off its pastel colors and lavish use of materials like wood and stucco embellished with gold leaf. Rococo style symbolizes the elegance and refinement of European aristocracy, particularly flourishing in France. +[282.10s -> 293.89s] France, and Germany. Neoclassical architecture, prevalent in the late 18th and early 19th centuries, draws inspiration from classical Greek and Roman architecture, characterized by grandeur, +[293.89s -> 308.18s] Symmetry and simplicity, it emphasizes straight lines, columns, and domes. Notable examples include the Brandenburger Gate, Arc de Triomphe, United States Capitol, and the Parthenon in Nashville, reflecting a revival of classical ideals during the Enlightenment. +[308.18s -> 309.07s] Enlightenment era. +[309.07s -> 323.38s] This style became prominent across Europe and the Western world, influencing iconic structures. Victorian architecture, predominant during the reign of Queen Victoria between 1837 and 1901, is characterized by elaborate ornamentation, +[323.38s -> 337.70s] mixing different architectural ideas and attention to detail. It encompasses various sub-styles such as Gothic Revival, Italianate, and Queen Anne. Notable features include steep gable roofs, bay windows, and intricate woodwork. +[337.70s -> 350.53s] This style reflects the prosperity and innovation of the Victorian era, with notable examples including the Houses of Parliament in London and the Biltmore Estate in the United States. Art Nouveau, also known as Eugen Steele, +[350.53s -> 362.30s] or new art, was popular from the late 19th to early 20th centuries. It's characterized by flowing lines, dynamic movement, organic shapes, and intricate decorative motifs inspired by nature. +[362.30s -> 375.82s] Using modern materials like iron and glass, it aimed to break traditional distinctions between fine and applied arts. Originating in Britain, Belgium, and France, Art Nouveau spread across Europe, adapting to different names and styles in each country. +[375.82s -> 385.28s] Notable examples include the Paris Metro entrances and the works of architect Antoni Godi in Barcelona. Art Nouveau emerged as a reaction against historicism. +[385.28s -> 398.16s] embracing innovation and modernity in architecture and design. Arts and crafts architecture, prominent between 1880 and 1910, emphasized craftsmanship, simplicity, and the use of natural materials. +[398.16s -> 411.97s] It sought to revive traditional craftsmanship in response to industrialization, favoring handcrafted details and functional design, often considered to be in opposition to art nouveau. Notable examples include the Red House in England, +[411.97s -> 420.96s] and the Gamble House in the United States. The movement influenced various aspects of design, including architecture, furniture, and decorative arts. Art Deco +[420.96s -> 432.98s] originating in Paris in the 1910s, reached its peak in the 1920s and early 1930s in the United States and Europe, influencing a wide range of designs from buildings to everyday objects. +[432.98s -> 447.25s] It combines modernist avant-garde styles with rich materials and motifs from various cultures. Characterized by sleek lines, geometric shapes, and luxurious materials, notable features include stepped forms, zigzag patterns, and stylish designs. +[447.25s -> 460.37s] motifs. Examples include the Chrysler Building in New York City and the Palais de Chaillot in Paris. Art Deco represents a celebration of modernity, glamour, and sophistication during the interwar period. Modernism +[460.37s -> 474.70s] Emerging in the late 19th and early 20th centuries is characterized by a rejection of traditional ornamentation and a focus on functionality and minimalism. It emphasizes clean lines, plain or shiny surfaces, geometric forms, and the use of new materials. +[474.70s -> 482.10s] like steel, concrete, and glass. Notable examples include the Bauhaus School in Germany and the Villa Savoy in France. +[482.10s -> 496.40s] Modernism represents a break from historical styles, embracing technological advancements and a forward-thinking approach to design. Brutalism, popular from the 1950s to the 1970s, is characterized by its raw, exposed concrete surfaces, +[496.40s -> 499.39s] geometric forms, and minimal ornamentation. +[499.39s -> 513.68s] Brutalism typically uses exposed concrete or brick, angular shapes, and a limited color palette. Other materials like steel, timber, and glass may also be incorporated. It emerged as a response to the modernist movement, emphasizing +[513.68s -> 528.18s] functionality, and honesty in design. Notable examples include the Barbican Estate in London and the Boston City Hall. Postmodernism architecture, emerging in the late 20th century, rejects the strict rules of modernism in favor of experimentation. +[528.18s -> 542.19s] It often combines elements from different styles and historical periods, incorporating irony, humor, and symbolism. Postmodern architecture often features exaggerated shapes, mixes different styles together, and considers the surrounding context. +[542.19s -> 549.70s] Notable examples include the AT&T building in New York City, the Wisma 46 in Jakarta, and the Piazza d'Italia in New Orleans. +[549.70s -> 557.78s] Contemporary or modern architecture, prevalent from the late 20th century to the present day, emphasizes innovation, sustainability, +[557.78s -> 570.10s] and functionality. It often features clean lines, open spaces, and the use of advanced materials and technology. Notable examples include the Burj Khalifa in Dubai and the Guggenheim Museum Bilbao. +[570.10s -> 583.86s] Contemporary architecture reflects the evolving needs of society and the integration of global influences, shaping the skylines of cities worldwide. Don't forget to like the video and subscribe to our channel so you don't miss out on any future videos. +[583.86s -> 587.34s] check out the other videos of our channel, you might like them. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_7.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e79039181fe5965a7fbcc931b22815c9588b022a --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_7.mp4.txt @@ -0,0 +1,15 @@ +[9.84s -> 21.97s] The Stone Age lasted a long time. Archaeologists and historians divide this time period into three ages. +[22.35s -> 36.14s] The Paleolithic, Old Stone Age, Mesolithic, Middle Stone Age and the Neolithic, New Stone Age. Paleolithic +[36.82s -> 51.25s] This age started when humans began to use stones as tools. They mainly used a type of stone called flint, which could easily be shaped into sharp pointed tools that didn't go blunt. +[51.98s -> 64.91s] bones, antlers, shells, amber, animal teeth and mammoth ivory were also used to make tools as well as jewellery. +[65.68s -> 78.58s] During this time, people were nomadic. They moved around from place to place, hunting animals, especially wild horse and red deer to eat. +[79.22s -> 90.42s] people lived in caves or temporary shelters and many cave paintings date back to this time mesolithic +[91.76s -> 104.82s] After the last ice age, the climate in Britain grew warmer. Forests and woodland began to grow, rivers and lakes appeared, and fish and wild birds became plentiful. +[105.52s -> 113.65s] Herds of reindeer and wild horses were less common, so hunters mostly hunted deer and wild boar. +[114.64s -> 123.66s] New hunting tools were developed such as harpoons and spears with small sharp pieces of flint attached to the end. +[126.54s -> 136.78s] Most people at this time were hunter-gatherers. Towards the end of the Mesolithic period, people began to set up farms and villages. +[137.33s -> 148.98s] Now that people were settling in one place rather than moving around, they could own more possessions such as pottery. +[150.42s -> 161.71s] As more and more people turned to farming for food rather than hunting and gathering, forests had to be cleared to make enough space for these permanent settlements. +[163.50s -> 173.94s] Pigs, sheep, goats and cattle were common farmyard animals at this time, and farmers also grew wheat and barley. +[174.54s -> 187.79s] During the Neolithic period people began to build long barrows, mounds of earth with a ditch around them to bury their dead. Henges and stone circles date back to this time. +[188.37s -> 198.86s] Until now, communal burials were normal but by the late Neolithic period, individual burials were becoming much more common. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_8.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..725c6ae5b7b5253d3556f775f95ca8cd50c40d34 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_8.mp4.txt @@ -0,0 +1,51 @@ +[0.00s -> 1.26s] Stone Age +[1.26s -> 15.76s] The Stone Age is divided into three periods, the Paleolithic, the Mesolithic, and the Neolithic. The Paleolithic is the oldest and longest one out of the three, and it's the first one to have seen the Homo habilis, the first true human species. The Homo habilis were able to +[15.76s -> 29.97s] primitive tools such as chipped stones with a sharp edge, and they were also able to build basic shelters. After the Homo habilis, the Homo erectus appeared, which was the first one to learn to control fire for cooking and defense against large beasts and the cold. Homo erectus was able to +[29.97s -> 44.18s] to walk from Africa into Europe and Asia, making it the first intercontinental human species. He also improved his tool crafting skills, making him able to hunt larger beasts using spears. He often used animals' fur to protect himself from the cold, and he started building huts. +[44.18s -> 58.38s] After Homo erectus, the Neanderthals appeared, which were the most commonly found extinct human species. They were the first ones to make tools out of bones instead of stones, and they started wearing clothes and making ornaments. They even buried the dead with flowers. Even though they were very advanced, they +[58.38s -> 72.59s] when extinct, and they were replaced by modern humans, the Homo sapiens. The Homo sapiens is the only remaining human species, as all of the other ones went extinct. So you and I are Homo sapiens. The Paleolithic people formed tribes and used shelters just for the night. +[72.59s -> 86.80s] since they were still nomadic. During the Mesolithic period, some humans started building camps around rivers, which made them more sedentary. The bow and arrow was invented, being the first long-range weapon, and the refining of tool crafting skills made it possible to craft tools for fishing and +[86.80s -> 101.01s] The Neolithic period ended the hunter-gatherer lifestyle completely as they discovered agriculture and developed numerous farming tools. Cattle breeding also began, and sheep, goats, and pigs were domesticated. All of these discoveries caused humans to stay in the same place. +[101.01s -> 112.45s] for longer periods of time, thus enabling them to create villages. Pottery, basketry, weaving, and the wheel appeared. The Stone Age lasted so long that it represents 99% of humans' history. +[112.45s -> 124.14s] The discovery of metalworking, more specifically the melting and smelting of copper, put an end to the Stone Age, even though some basic forms of metalworking were already known, like the use of gold for ornamentation. Bronze Age +[124.14s -> 129.70s] When people noticed that putting copper on fire made it softer and easier to shape, they started using it. +[129.70s -> 143.98s] since it was a more durable material. But copper was too soft to be used as a weapon until they discovered that adding other stuff like arsenic or zinc created bronze, a much harder metal. Bronze enabled humans to create the first swords, helmets, armors, and shields. +[143.98s -> 158.19s] Farming was also much quicker and more efficient, thanks to bronze sickles and irrigation. Food was much easier to produce, which made the population grow and cities expand, becoming more and more complex. Big, majestic buildings such as the ziggurats, the pyramids, +[158.19s -> 172.40s] and multiple temples were made in the Bronze Age. Bronze also made it possible to upgrade ships, which enabled humans to trade. The first forms of writing developed in Mesopotamia and Egypt. After all of these positive discoveries, though, the Bronze Age ended with a societal collapse +[172.40s -> 186.61s] where many large civilizations disappeared off the face of the earth almost instantaneously and many technological inventions were lost. The most acclaimed theories suggest that these civilizations may have been wiped off by volcanic eruptions, droughts, disease, invasions, +[186.61s -> 189.01s] and earthquakes. Iron Age. +[189.01s -> 203.47s] After the Bronze Age collapse, humans discovered that they could also smelt iron, even though they already knew this material thanks to meteoric iron, which didn't require smelting and was more rare and valuable than gold. The initial forms of iron smelting didn't provide any advantage if compared with the +[203.47s -> 217.68s] bronze smelting. But since iron was much less rare, they could mass-produce tools and weapons. During this age, a lot of construction and farming tools were discovered, such as forks and sewing needles. Coins became a widespread currency for trade, and the famous Great Silk Road trade route was created. +[217.68s -> 222.05s] The Iron Age was the last age of prehistory. Classical antiquity. +[222.05s -> 236.53s] The first period of classical antiquity, called the Archaic Period, is the first one in which we start to have historic written books. The first one is considered to have been made by Herodotus, who is known as the father of history. In the western part of the world, the Greeks and Romans laid the foundation +[236.53s -> 242.48s] foundation for what would become known as Western civilization, while the eastern part had the first Chinese imperial dynasty. +[242.48s -> 251.76s] The moral and philosophical foundations of today's Western and Eastern world belong to this period, as Greek philosophers such as Socrates, Plato, and Aristotle lived in it. +[251.76s -> 266.03s] The Bible, the Hindu scriptures, and the writings of Confucius also belonged to this era. Art played a huge role, as classical art pieces are still considered to be some of the best ones in history and have inspired future artistic currents. The ancient Greeks experimented +[266.03s -> 280.24s] with the first democracy, and there was evidence of the first truly scientific thinking. The father of medicine, Hippocrates, also lived in ancient Greece. A lot of the most famous leaders ruled in this period, such as Alexander the Great and Julius Caesar. Classical antiquity +[280.24s -> 283.94s] ended with the fall of the Western Roman Empire. Middle Ages. +[283.94s -> 298.38s] The Middle Ages are divided into three parts, the Early Middle Ages, the High Middle Ages, and the Late Middle Ages. The Early Middle Ages, also called the Dark Ages, represent the period after the fall of the Western Roman Empire, which had a great economic, intellectual, and cultural decline. +[298.38s -> 308.19s] Some also use the term Dark Ages because of the scarcity of records regarding this period. In this era, central states in Europe started losing their power, and Islam began emerging. +[308.19s -> 321.97s] The High Middle Ages were characterized by feudalism, which was a societal system where one party granted property, typically land, to the other in return for services, mostly of military nature that the recipient, or vassal, had to render to the grantor, or lord. +[321.97s -> 336.27s] The Catholic Church also started militarizing after clashes with other powers and the schism with the Eastern Church, which became the Orthodox Eastern Church, and they conducted the Crusades. The state power started to rebuild its legitimacy and strength, and the famous Gothic architecture +[336.27s -> 350.48s] style emerged. The late Middle Ages started with some pretty negative events, with the Little Ice Age which caused the Great Famine, the Hundred Years' War between France and England, and the Black Death, which killed one-third of Europe's population. It wasn't all bad, though. The printing press was invented. +[350.48s -> 354.64s] the creation of mass-produced newsletters, which, however, had a big problem. +[354.64s -> 368.91s] There wasn't a good enough variety of sources to get an idea of what the objective facts about news were. We do have more variety nowadays, but because using multiple sources is a timely and costly process, many prefer to get their news from one source, resulting in a biased and filtered +[368.91s -> 383.12s] That's why Ground News, which is actually today's sponsor, gives a solution to this problem. You can get a 40% discount on their Vantage plan using my link, ground.news.tpe, or by scanning the QR code on screen with your phone's camera, enabling... +[383.12s -> 397.33s] you to see the story from different sources and the political bias for each source based on ratings from three independent news monitoring organizations. For example, we're able to see that the total number of articles published on this story about the Egyptian pyramid's construction mystery is 100. +[397.33s -> 411.54s] We can compare the headlines from different sources and see who owns each publication, like this article, which is written by a source owned by the Turkish government. We can also see how reliable a source's reporting practices are based on ratings from the three independent news monitoring organizations. +[411.54s -> 425.74s] Thank you for watching. +[425.74s -> 439.95s] spectrum that you might have missed and the my news bias page which lets you get insight into your reading habits to see where you're getting your news from and if you have blind spots i really think what they're doing is important and i encourage you to check them out if you go to ground.news slash tp +[439.95s -> 452.94s] You'll get 40% off of their Vantage plan, which includes unlimited access to every feature. Your subscription will not only help this channel, you'll also be supporting an independent platform working to make the media landscape more transparent. +[452.94s -> 455.97s] Thanks again Ground News for sponsoring today's video. +[455.97s -> 470.32s] But going back to the Middle Ages, European exploration for new trade routes started, which eventually led to the Age of Discovery. Also, West Africa had several major empires, including the Mali Empire with Mansa Musa, who is the richest person that ever lived, while Asia saw +[470.32s -> 474.37s] the rise of the Mongol Empire with Genghis Khan. Modern Age +[474.37s -> 488.72s] The early period of the modern age was characterized by the most important cultural and scientific changes, such as humanism, which is the philosophical focus on humans, their agency, and their potential. The Renaissance started flourishing with the goal of reviving classical antiquity +[488.72s -> 502.93s] with figures like da Vinci, Michelangelo, Machiavelli, Donatello, +[502.93s -> 517.14s] Botticelli, Galileo Galilei, Shakespeare, Caravaggio, Christopher Columbus, etc. After the Renaissance, Protestantism started with Martin Luther and his 95 Theses. The Scientific Revolution also happened, where the basis for modern science has been laid thanks to the +[517.14s -> 531.34s] works of figures like Isaac Newton, Copernicus, and Descartes. After the scientific revolution, the age of enlightenment came, which was an intellectual and philosophical movement that featured a range of social ideas centered on the value of knowledge learned by way of rationalism and political ideas. +[531.34s -> 545.55s] deals, such as natural law, liberty and progress, toleration and fraternity, constitutional government, and the formal separation of church and state. The early modern age also saw the age of discovery, where the Europeans, mainly the Spanish and Portuguese, started trying to find +[545.55s -> 559.76s] new trade routes, ending up with the discovery of the Americas and its subsequent colonization. We had the first industrial revolution, which was a period of global transition of the human economy towards more widespread, efficient, and stable manufacturing processes thanks to +[559.76s -> 573.97s] use of automated machines and the spread of steam and water power. Inspired by the American Revolution and the French Revolution, the Age of Revolution started, which is a period where most of the nations revolted and passed from absolutist monarchies to representative governments with a constitution. +[573.97s -> 588.18s] A second industrial revolution happened, since previously there was a slowdown in important innovations. This time we discovered things like standardization, mass production, telegraph and railroad networks, gas and water supply, sewage systems, which had earlier been limited to a few. +[588.18s -> 602.38s] select cities electrical power and telephones after that the two world wars happened and we entered the information age which some refer to as the third industrial revolution with the computer internet artificial intelligence robots etc the period after world war ii is called +[602.38s -> 607.37s] contemporary history. Shout out to these guys who are the first patrons that support my channel. diff --git a/VideoMMMU_ASR_large/Humanities/new_History_9.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_History_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..41a4ae3c853a69f065da69f8f42dd707125e5848 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_History_9.mp4.txt @@ -0,0 +1,70 @@ +[0.00s -> 14.11s] Monarchy A monarchy is a type of government ruled by a monarch, which is often a king or a queen. The monarch's role is passed down through the same family, from generation to generation, often going to the oldest child. +[14.11s -> 21.30s] Major countries operating under a monarchy include the United Kingdom, Japan, Spain, Sweden, and Saudi Arabia. +[21.30s -> 35.46s] There are multiple forms of monarchies, for example, symbolic monarchy, where the monarch has no political or economic power, like the United Kingdom. Instead, the country is run by a parliamentary government led by a prime minister. +[35.46s -> 49.97s] On the other hand, an absolute monarchy is where the king or queen has the power to make all the important decisions in a country. The disadvantage of a monarchy is that it can lead to unsuitable leaders who came to power because they were the heirs. +[49.97s -> 57.04s] This often leads to a lack of democratic governance and the potential for abuse of power. Socialism +[57.04s -> 67.49s] Socialism is a form of government wherein the workers or laborers are allowed to own property, but the distribution of goods and services is controlled by a central government. +[67.49s -> 76.42s] The government's goal is to distribute all of the goods and services equally to ensure everyone in the country has the same opportunities as everyone else. +[76.42s -> 82.91s] Some of the more common examples of socialist states are the People's Republic of China and the Republic of Cuba. +[82.91s -> 95.01s] While most socialist states call themselves republics, they usually follow the fundamentals of socialism, where labor and property are equitably distributed and there are no social classes or hierarchies. +[95.01s -> 105.79s] The reason why socialism is not as popular as some forms of government is the lack of incentives. If someone gets the same resources as someone who didn't work as hard, there's no point in working harder. +[105.79s -> 118.86s] This can potentially lead to the nation's failure, especially if no one is willing to work hard to get better incentives. Democracy A democracy is when a country believes that the citizens are the supreme rulers of the nation. +[118.86s -> 128.13s] Democracy is as old as human civilization itself, but first appeared in the ancient political and philosophical teachings of the people of Athens. +[128.13s -> 142.50s] In a democracy, the people are the ones who determine the leaders and the laws of the land through a majority vote. It also provides an environment wherein fundamental human rights are respected and the people are allowed to exercise their free will. +[142.50s -> 155.57s] Some of the most democratic countries in the world include Norway, Sweden, and New Zealand. However, the problem in a democratic country is that it can be too unstable due to constant leadership changes. +[155.57s -> 168.37s] An autocracy is when only one person or ruling party holds supreme power over an entire nation. Every decision that the autocratic ruler makes cannot be limited by external factors. +[168.37s -> 178.61s] These decisions are absolute and should be followed by the country. The autocrat also has total control over what the people can do when it comes to their civil liberties. +[178.61s -> 192.26s] In an autocracy, the people have no say in the nation's affairs, contrasting it to democracy. Autocracies have existed since ancient times, usually in absolute monarchies, where the king's word is the law. +[192.26s -> 206.38s] The Soviet Union, once ruled by Joseph Stalin, is one of the more recent examples of an autocracy. The biggest disadvantage of an autocracy is the potential abuse of power by the autocrat, who may become a dictator. Federal +[206.38s -> 213.52s] Federal governments formally divide the sovereign power between a central government and the regions that form part of the country. +[213.52s -> 226.82s] The central government is still the leader of the whole nation but allows the different regions or states to have control over their internal affairs. These states can have their leaders and laws but are not independent nations. +[226.82s -> 233.01s] The reason why federalism wants to decentralize some of the functions of the government is to promote efficiency. +[233.01s -> 242.40s] This is usually the case for bigger countries, because it's easier for smaller territories to govern themselves than allowing a central government to govern an entire nation. +[242.40s -> 255.41s] It's similar to how the head coach of a sports team needs to delegate roles to his assistant coaches. The assistant coaches have a sense of independence in their roles, but they are still under the overall leadership of the head coach. +[255.41s -> 266.56s] The most common example of a federal government is the United States of America, which is under the leadership of a president but has different state senators that manage their territories and constituents. +[266.56s -> 280.21s] One of the biggest drawbacks of a federal form of government is the possible economic inequality between different regions because some territories have better access to certain resources that other territories can't have access to. Oligarchy +[280.21s -> 289.65s] Oligarchy, which can be translated to rule of the few, is a form of government wherein only a few oligarchs have power over the entire nation. +[289.65s -> 303.30s] These oligarchs come from different groups or families that usually rise to power through financial or military means. The country's political, social, and economic affairs are settled through the decisions made by the oligarchs. +[303.30s -> 316.83s] Oligarchies, unlike monarchies, don't formally pass their leadership roles to the next generation but can still stay in power for multiple generations as long as they maintain their financial or military status within the nation. +[316.83s -> 327.58s] The USA is formerly a federal government but is often seen as an oligarchy by most people because of the influence that large corporations have on the decisions of politicians. +[327.58s -> 340.82s] Modern-day oligarchies often arise when large firms and businesses become too financially powerful. The worst part about oligarchies is the potential economic and social inequalities between different classes. +[340.82s -> 355.71s] Only the rich and powerful benefit from decisions made by their fellow oligarchs. Republic The concept of the Republic results from the ancient Greek philosopher Plato's teachings and has become the foundation of many modern forms of government. +[355.71s -> 367.73s] In a republic, the people have the right to the affairs of the country because it is believed that the state belongs to the people, and everyone in the state has an equal opportunity to take part in the country's decisions. +[367.73s -> 379.47s] It is only through the will of the people that the leaders of a country are elected into office. The leaders of a republic are representatives of the people and should be making decisions that favor everyone in the state. +[379.47s -> 392.93s] There are notable differences between a republic and a democracy. In a republic, the people own the state. On the other hand, in a pure democracy, the people don't own the state but are the sovereign leaders of the nation. +[392.93s -> 405.09s] A country can be both a republic and a democracy simultaneously. For example, the Philippines is both a republic and a democracy, but not all countries are republics and democracies at the same time. +[405.09s -> 409.41s] Canada is a democracy but is constitutionally a monarchy. +[409.41s -> 422.62s] Republics also have their drawbacks because not all nations are culturally and socially suited for a republic form of government, especially if corruption and abuses are common among the leaders. Communist +[422.62s -> 432.10s] A communist government believes in the concept of a classless society and aims to achieve it through the state's absolute control over the country's resources. +[432.10s -> 441.28s] The ruling party, often led by an authoritarian figure, controls all of the social, political, and economic decision-making in a communist nation. +[441.28s -> 448.62s] Communist countries believe in Karl Marx's teachings that a capitalist form of government would eventually destroy itself. +[448.62s -> 460.43s] As a result, the goal of communism is to achieve a classless society through the elimination of private ownership of property so that all goods and services within the state are equally shared by the people. +[460.43s -> 469.42s] There are currently five countries that practice communism in today's modern world, namely China, Cuba, Laos, North Korea, and Vietnam. +[469.42s -> 478.08s] One of the reasons why communism often fails is that it is prone to abuses and the restriction of human rights. +[478.08s -> 490.99s] Anarchies are often called non-governance because the key aspect of this form of government is the absence of a central government. The goal of an anarchist system is to not only decentralize the power of the government, +[490.99s -> 499.98s] but to eliminate the government itself, to allow the people to self-govern. The popular belief is that an anarchist government tends to be chaotic. +[499.98s -> 510.72s] But that's not the case, because one of the most important goals of anarchism is to allow people to volunteer willingly and freely to help one another for the improvement of the community. +[510.72s -> 521.33s] It is different from socialism or communism because there is no equitable distribution of labor and resources, but there exists an equitable right to self-governance. +[521.33s -> 528.24s] In most cases, anarchies rise from destroying a previous government just before establishing a new form of government. +[528.24s -> 536.62s] There is no true anarchist government today, but Somalia was an anarchy before 2006, when it had no national government. +[536.62s -> 546.29s] The problem with anarchism is that it can lead to chaos when everyone is only looking after their self-interests instead of helping one another. Presidential +[546.29s -> 555.38s] In a presidential form of government, there is a separation between the different branches of the government, allowing the executive branch to have separate roles from the legislature. +[555.38s -> 566.05s] The president is the head of the executive branch and is tasked with the execution of the laws. Meanwhile, the legislature is the branch that's responsible for the enactment of the laws. +[566.05s -> 580.06s] Presidential governments can arise from republics and democracies. Most democratic republics have a presidential form of government. Some of the best examples of presidential governments are South Korea, the Philippines, Nigeria, and Indonesia. +[580.06s -> 589.25s] A presidential form of government's major downside is that too much executive power in one person can lead to abuse of power. PARLIAMENTARY +[589.25s -> 596.98s] In a parliamentary system of government, the party with the greatest representation in the legislature is nominated to the executive branch. +[596.98s -> 606.02s] The party's leader becomes the prime minister, or the chancellor, who appoints members of the party to the cabinet to have their tasks as members of the executive branch. +[606.02s -> 614.11s] However, the ruling party does not hold absolute executive powers because the opposing party must challenge the ruling party regularly. +[614.11s -> 628.50s] The Prime Minister can also be removed from power at the will of the legislature or the ruling party through a vote of no confidence if the Prime Minister fails to uphold their duties. Parliamentary systems can also exist alongside different forms of government. +[628.50s -> 639.10s] government, such as a monarchy. Japan is a constitutional monarchy with a royal family acting as symbolic leaders but has a parliamentary government led by a prime minister. +[639.10s -> 652.05s] The problem with a parliamentary form of government is that it fails to provide a stable government because the opposing party will always try to challenge the ruling party, leading to never-ending conflicts. Constitutional +[652.05s -> 663.62s] A constitutional form of government is when a constitution acts as the foundation of the country's laws and systems. It is the constitution that defines the limits and functions of a government. +[663.62s -> 668.46s] In most cases, the Constitution is enacted to extend the people's will. +[668.46s -> 682.86s] Constitutional governments come in many forms. For example, the United Kingdom is a constitutional monarchy that defines the limits of the monarch's powers. The United States is also a constitutional government but is a presidential form of constitutional democracy. +[682.86s -> 692.70s] democracy. However, the major weakness of a constitutional form of government is that every system or law in place has to be consistent with the constitution. +[692.70s -> 701.26s] The Constitution has to be amended if vital laws need to be passed but are inconsistent with the Constitution. Totalitarian +[701.26s -> 711.07s] The term totalitarian was originally coined by Benito Mussolini, who led the fascist state of Italy during his reign from the 1920s to the 1940s. +[711.07s -> 724.96s] A totalitarian system of government is when the government seeks to control everything within the country. This does not only include the political and economic matters of the country, but also the beliefs and values of the citizens. +[724.96s -> 737.14s] Theoretically, the freedom of the citizens in a totalitarian regime is suppressed. Totalitarian government abides by the belief that everything within the state should fall under the control of the state. +[737.14s -> 751.73s] and that no one in the state should ever go against the state. One of the best examples of a totalitarian regime in modern times is North Korea, which follows a totalitarian republic ruled by the Kim family for three generations already. +[751.73s -> 759.93s] Like socialist, autocratic, and communist governments, a totalitarian regime is prone to human rights suppression and abuses. diff --git a/VideoMMMU_ASR_large/Humanities/new_Literature_1.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Literature_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5f2664a49194a8dedb4a29a59a4da169326cb1c9 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Literature_1.mp4.txt @@ -0,0 +1,59 @@ +[0.02s -> 12.27s] To access free topic sheets, worksheets or to book an online class visit ilearneasy.co.uk Metaphor +[13.26s -> 24.14s] A metaphor compares two different things. This includes objects, ideas, feelings or thoughts. +[24.43s -> 28.53s] We say that something is something else. +[29.10s -> 40.53s] Remember that we can also use other forms of the verb to be. For example, am, are, was, and were. +[41.23s -> 54.19s] For example, Jim is a giraffe. So this doesn't literally mean that Jim is a giraffe. Instead this metaphor compares Jim with a giraffe. +[55.02s -> 68.46s] Although they are two different things, they're being compared due to their common characteristic, which is their height. So essentially I'm saying that Jim is very tall. +[69.30s -> 82.58s] Metaphors make sentences more interesting and create an image in the reader's mind. So rather than just saying Jim is tall, I use the metaphor +[82.58s -> 96.94s] Jim is a giraffe. Another example is, life is a roller coaster. Again, I'm comparing two different things, life and a roller coaster. +[96.94s -> 110.19s] I'm comparing them due to their common characteristic, which is that they both have highs and lows. Remember that a metaphor is a figure of speech. This means +[110.19s -> 123.31s] that it shouldn't be taken literally as the words in the sentence convey a different meaning +[123.86s -> 138.03s] A simile compares two different things. We say that something is like or as something else. For example, +[138.74s -> 149.33s] In this example the simile compares two different things that are compared due to their common characteristic which is their height. +[150.16s -> 164.19s] So essentially I'm saying that Jim is very tall. The simile makes the sentence more interesting and creates an image in the reader's mind. Rather than simply just saying +[164.19s -> 176.27s] Another example is, Again, this simile compares two different things due to their common characteristic. +[176.27s -> 189.06s] which is that they can both swim very well. Remember that a simile is a figure of speech. This means that it shouldn't be taken literally as the words in the sentence +[189.06s -> 199.02s] convey a different meaning lastly remember that similes always includes the words like or as +[203.79s -> 211.95s] Onomatopoeia is a word that sounds like what it describes. +[212.30s -> 222.19s] It's a language technique used to make writing more interesting and helps the reader to hear the sounds in their minds. +[222.83s -> 233.26s] For example the water went splash when I jumped into it. The emphasis is on the sound the water makes. +[233.62s -> 244.02s] Splash! This is the onomatopoeia. The lion roared loudly. The onomatopoeia is roared. +[244.72s -> 253.42s] This emphasizes the sound the lion makes. Another example is the balloon popped. +[254.22s -> 264.75s] The onomatopoeia in this sentence emphasizes the sound the balloon makes. +[265.10s -> 272.46s] Personification is when we assign human qualities to something that isn't human. +[272.94s -> 284.38s] These can be movements, emotions or senses. For example, the tree is dancing in the wind. So... +[284.38s -> 297.46s] We know that trees don't have the human quality of dancing. However, this language technique makes the sentence more interesting and creates an image in the reader's mind. +[298.03s -> 309.71s] It sounds more interesting than just saying the tree is moving in the wind. Another example is the stars winked in the night sky. +[310.83s -> 323.54s] Remember that personification is a figure of speech. Therefore, it shouldn't be taken literally as the words in the sentence convey a different meaning. +[324.56s -> 333.07s] An idiom is a group of words that have a different meaning from the literal meaning. +[333.58s -> 342.16s] They're interesting ways to get a point across. Idioms are commonly used in spoken English. +[342.64s -> 355.94s] for example break a leg So this doesn't literally mean break a leg Rather it means good luck for example I could say +[355.94s -> 365.33s] I know you can do well on your exam. Break a leg. Another example is The exam was a piece of cake. +[366.26s -> 380.67s] So this means that the exam was very easy. It's important to learn the meanings of different idioms as they're commonly used in everyday spoken English. Remember... +[380.67s -> 394.74s] that an idiom is a figure of speech this means that it shouldn't be taken literally as the words in the sentence convey a different meaning alliteration +[395.18s -> 403.38s] Alliteration is the repetition of the same letter or sound at the beginning of words. +[403.89s -> 417.95s] alliteration is used to make writing more interesting for the reader usually in poems it also creates rhythm and sets the mood it's important to note +[417.95s -> 429.58s] that different repeated sounds will have a different effect on the reader. For example, +[429.97s -> 440.69s] The repeated S sound in the sentence suggests snake-like qualities such as the movement of the snake or danger. +[442.19s -> 454.38s] Another example is, fair is foul and foul is fair. +[454.74s -> 458.93s] Hyperbole is an exaggerated statement. +[459.25s -> 472.14s] It describes something to be worse or better than it actually is. It's a way to catch the reader's attention and to make writing more interesting. +[472.91s -> 484.62s] For example, they were dying of laughter. This is an exaggerated statement to emphasize that they were laughing so much. +[484.91s -> 494.51s] It doesn't literally mean that they were dying. +[495.12s -> 502.38s] Again, this is an exaggerated statement to emphasize how heavy my suitcase is. +[502.77s -> 515.06s] Remember that hyperbole is a figure of speech. This means that it shouldn't be taken literally as the words in the sentence convey a different meaning. +[518.13s -> 532.94s] Assonance. Assonance is the repetition of the same vowel sound in a sentence. This language device is used to make writing more interesting and fun for the reader. +[533.14s -> 548.08s] Assonance is usually used in poems. It also creates rhythm, sets the mood and allows the sentences to flow. The vowels are A, E, I, O, U. +[548.78s -> 563.41s] Each vowel has two sounds a short vowel sound and a long vowel sound For example Sam claps his hands and stamps his feet +[564.05s -> 578.03s] In this example, the short vowel a is repeated. Another example is In this example, +[578.03s -> 592.88s] The long vowel sound A is repeated. An oxymoron is a sentence or phrase with two opposite or contradicting words. +[593.20s -> 601.23s] Oxymorons are used to interest the reader and causes the reader to pay attention to what they're reading. +[601.55s -> 614.51s] It also adds some playfulness in the sentence. For example, Pretty and ugly are opposites. +[615.38s -> 625.46s] Another example is Alex is seriously funny. Serious and funny are opposites. +[625.84s -> 638.70s] Remember that an oxymoron is a figure of speech. This means that it shouldn't be taken literally as the words in the sentence convey a different meaning. +[641.30s -> 654.51s] A pun is a humorous use of words that convey another meaning. Puns are commonly used in everyday spoken English. +[654.83s -> 667.74s] We can also use puns in writing to make our writing more interesting to the reader and to create a humorous effect For example, I like kids +[667.74s -> 681.01s] but I don't think I could eat a whole one. In this example, the word kid has two meanings. It can refer to a child or a young goat. +[681.17s -> 686.00s] So this pun adds a humorous effect to the sentence. +[686.70s -> 698.26s] Another example is In this example, the word beat has two meanings. +[699.28s -> 711.54s] Remember that a pun is a figure of speech. This means that it shouldn't be taken literally as the words in the sentence convey a different meaning. diff --git a/VideoMMMU_ASR_large/Humanities/new_Literature_10.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Literature_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..45021583ee13101d4bc0438db5dc49174577e64c --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Literature_10.mp4.txt @@ -0,0 +1,55 @@ +[0.00s -> 12.27s] Hi everyone, my name is Mr Watson and in this video I'm going to be talking you through some of the most common poetic techniques to hopefully help you identify them in your analysis of poetry. +[14.42s -> 24.37s] So we start with alliteration Alliteration is a series of words in a sequence that contain the same consonant sound +[24.98s -> 38.58s] so an example would be Bob bit into the banana that he bought from Bumble there we have the repetition of the B sound and obviously B is a consonant sound and so +[38.58s -> 41.17s] that is why this is alliteration +[42.80s -> 55.98s] Next we have assonance. Now assonance is very similar to alliteration, except this time it uses the vowel sound. So it's a series of words in a sequence that contain the same vowel sound. +[57.78s -> 71.68s] an example would be the rain in Spain falls mainly on the plane the repetition of that a sound in rain, Spain, mainly and plane is a vowel sound and that is why +[71.68s -> 79.41s] It's assonance. Sibilance also fits in with the previous two techniques. +[81.07s -> 91.70s] so sibilance is a series of words in a sequence that contain the same soft consonant sounds sounds that often create something of a hissing sound +[93.55s -> 106.46s] We can clearly see this in the example. The slimy snake slithered through the sharp spiky grass. So if you were to read that out loud, you would hear a lot of ss sounds and th. +[106.46s -> 118.03s] sounds, okay? Quite aggressive hissing type sounds and that is what makes it sibilant. Moving on to imagery. +[119.12s -> 127.86s] Imagery is the use of descriptive language that appeals to the five senses, helping to create a vivid image in the reader's mind. +[129.23s -> 142.69s] So the example here is the bright glowing moon stood out against the deep black of the late night sky. So I've underlined the adjectives there that really help describe this scene and help +[142.69s -> 155.17s] create a very clear image in our minds. If there had been any adjectives describing the sounds that could be heard or the smells or the taste or anything like that +[155.17s -> 167.79s] that would also be imagery because it's helping us create that picture, create that image, that scene in our minds. Next we have metaphor. +[168.14s -> 173.94s] So a metaphor is when one object is described as being another unrelated object. +[174.32s -> 188.42s] So an example would be, life is a roller coaster. So life isn't literally a roller coaster, but what this metaphor does is it takes the qualities of the roller coaster and applies it to life. So... +[188.42s -> 201.74s] For example, a roller coaster can be exciting, thrilling, terrifying, nauseating. And all of these qualities are being applied to life in this example. +[203.41s -> 217.90s] A simile is a technique that is very similar to a metaphor. So a simile is when one object is compared to another unrelated object only this time using the word like or as. +[219.02s -> 233.22s] So a couple of examples here using both those terms, we've got she moved as quietly as a mouse, and we've also got she moved like a mouse. So just like with the metaphor, the second object, in this case it's the mouse and how they move, +[233.22s -> 242.30s] are having their qualities taken and applied to the first object which in this case is the she, the person, the character. So we have the mouse moving +[242.30s -> 254.96s] really really quietly and really kind of stealthily and those qualities are being taken and applied to the character and how she is moving in this moment it is important though to be aware +[254.96s -> 268.80s] when using similes and when looking for similes in other pieces of writing that just because the word like or the word as is used it doesn't always mean that it's a simile there has to be some form of comparison there +[268.80s -> 282.35s] for it to be a simile. So just bear that in mind. Okay next we have personification. Personification is when non-human objects or creatures are given human qualities. +[283.31s -> 292.70s] For example the camera watched over the street so the fact that the camera is being described as watching as an action their cameras +[292.70s -> 305.92s] I mean, yeah, you could say that that's kind of what they do. But in this sense, it's almost as if they're kind of keeping an eye on things. Yeah, surveilling it. And that is what makes it personification. And in the second example there, we've got each of the leaves were dancers. +[305.92s -> 318.03s] twirling without a care in the world so if we look at the leaves were dancers part you could say that that's a metaphor but it's the twirling without a care in the world section of +[318.03s -> 331.25s] that sentence that i would say is the personification because it is applying emotion to it leaves don't have emotions as far as we know so it's a real it's a human quality to have cares about the world +[331.25s -> 342.80s] because we have those emotions. In this case, the fact that the leaves are being described as not having a care in the world shows that they are capable of caring and therefore they're being personified. +[344.24s -> 351.95s] Okay, now we have rhyme. So rhyme is the repetition of syllables, typically at the end of a line. +[352.82s -> 366.82s] So there are three different kinds of rhyme that you can find in poetry. The first of all is probably the most common and the most recognisable, and that's the full rhyme. So, for example, cat and fat, bean and mean. +[366.82s -> 379.39s] kite and fight they are all full rhymes we also have something called a half rhyme which is a bit less obvious than a full rhyme so we see this with words like escaped and scooped +[379.39s -> 393.07s] So with those two words, we've got the pt bit at the end, which rhymes, which is a half rhyme. And we have milk and walk. So it's the k sound at the end, which makes it a half rhyme. +[393.30s -> 407.06s] There's also something called an internal rhyme and that's when the rhyme takes place within a single line Rather than starting on one and ending on another for example the stars never rise +[407.06s -> 416.11s] but I feel the bright eyes. So that is just one line of poetry and yet we have a rhyme within it with rise and eyes. +[416.11s -> 427.98s] internal rhyme is something that's very common in hip-hop and rap music because it creates a flow and it creates momentum which a lot of musical artists use in their work +[429.65s -> 438.13s] Next we have repetition. Repetition is fairly straightforward. It's when you use a word or phrase multiple times for emphasis. +[439.15s -> 452.69s] In this example, we must continue to fight the good fight. The word here that obviously the writer wants to emphasize is the word fight. Next we have rhythm. +[453.65s -> 460.14s] So rhythm is the pattern of sounds and syllables used to create a sense of flow and momentum. +[461.84s -> 474.93s] So there are different kinds of rhythms and I don't want to make this too complicated so what I'll do is I'll stick to a very popular common type of rhythm and that is called iambic pentameter. +[475.15s -> 488.50s] and what that means is it's basically a line of poetry that has 10 syllables which follows an unstressed stressed rhythm so what I've done there is I've colour coded this line +[488.50s -> 500.96s] with orange on the unstressed syllables and the blue on the stressed syllables so it would sound something like shall i compare thee to a summer's day +[500.96s -> 514.78s] so with that unstressed and stressed emphasis on those different words that creates a particular kind of rhythm something like a and that is a rhythm of iambic pentameter +[514.78s -> 528.88s] like i said there are many different kinds of rhythms with different numbers of syllables and different stress patterns and things like that so if you're interested by all means have a have a look online and do a bit of research into it but for now we'll just leave it with +[528.88s -> 533.52s] this one. Next we have couplets. +[534.19s -> 546.06s] So couplets are a pair of successive lines of verse, typically rhyming and of the same length. A good way to remember what a couplet is is to think of couple, meaning two. +[547.34s -> 561.26s] So an example would be I really wish the seagulls would just fly away and not ambush my garden every single day. So of course there we have two successive lines with away and day rhyming. +[562.74s -> 577.30s] Next we have enjambment or enjambment. I've heard it pronounced so many different ways but basically what this is is when one thought or idea in a line of poetry continues onto the next one without any punctuation. +[577.30s -> 586.86s] So this is often used to create flow and pace. For example, I'm feeling rather sleepy but I'm really not sure why. +[587.22s -> 599.28s] Okay, so there we have two lines, but if you notice after sleepy there is no punctuation And so the idea just carries on into the next line and that is enjambment or enjambment +[601.33s -> 606.16s] In contrast to Enjambment, or Enjambment, is Scizora. +[606.77s -> 620.75s] caesura is the use of punctuation in the middle of a line of poetry to create a deliberate pause so this is often used to slow down momentum to create more disjointed +[620.75s -> 634.06s] rhythms. So for example, to be or not to be. So that comma there in blue is there to break the line up, to slow it down. +[634.35s -> 636.94s] And that is Scizora. +[637.33s -> 651.92s] Okay, that's all for this video. I really hope you found it useful. If you did, please feel free to leave a like or leave a comment. If you have any questions, again, leave those in the comment section below and I will try and answer them as soon as I possibly can. If you're not subscribed, please feel free to... +[651.92s -> 661.97s] so you don't miss any future videos from me on this channel. Thank you very much for watching and I hope to see you next time. Bye for now! diff --git a/VideoMMMU_ASR_large/Humanities/new_Literature_3.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Literature_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3adeccb69cbbd20cca58f7e40da90632a96c1a81 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Literature_3.mp4.txt @@ -0,0 +1,51 @@ +[10.35s -> 19.60s] Hello! It's nice to see you again. For today's lesson, we will learn how to analyze the elements of the plot in a story. +[19.92s -> 30.06s] But before we begin, let's find out what you already knew in our lesson. You'll just choose the letter of the correct answer. +[30.51s -> 44.16s] It shows the highest point of interest, suspense, and turning point of the story. +[44.16s -> 57.62s] Resolution Letter B, Climax 2. It provides information about the characters and the setting. +[58.00s -> 71.60s] A. Climax. B. Rising Action. C. Exposition. D. Resolution. Letter C. Exposition. +[72.94s -> 86.64s] 3. It shows how things end up in the story. A. Climax B. Exposition C. Resolution D. Rising Action +[88.21s -> 90.90s] Letter C, resolution. +[92.24s -> 106.72s] 4. It introduces and develops conflict, or the main problem faced by the character. a. Exposition b. Falling action c. Resolution +[106.72s -> 120.75s] D. Rising Action Letter D, Rising Action 5. It shows how the character solved the conflict or the problem. +[121.87s -> 135.02s] Climax. B. Falling Action. C. Exposition. D. Rising Action. Letter B. Falling Action. +[136.88s -> 149.36s] Now, let's talk about plot. Plot is the chain of events that make up a story. In that sequence of events, we learn more about the characters, the setting, +[150.06s -> 164.11s] and how the story develops from beginning to end. Plots are typically made up of five main elements, namely Exposition Rising Action +[164.50s -> 177.78s] climax, falling action, and resolution. This is a map of the plot of a story. The first part of the plot is the exposition. +[178.22s -> 190.61s] It provides information about the character and the setting Character is a person, an animal, or an imaginary creature that appears in a story +[193.07s -> 203.31s] Like Elsa in Frozen, Simba in The Lion King, and Ariel in The Little Mermaid. Setting is the time and place in which the story unfolds. +[205.33s -> 209.23s] The place or scene may be imaginary or real. +[209.62s -> 222.03s] Now, after the characters and setting are introduced, the events of the story begin to create suspense as the character faces conflict. This part is the rising action. +[222.51s -> 233.33s] It introduces and develops conflict, or the main problem faced by the character. It includes the events that help to build toward the climax of the story. +[237.71s -> 249.62s] Climax shows the highest point of interest, suspense, and turning point of the story. This is the moment where the main character reaches their goal. +[250.26s -> 260.21s] Falling action occurs right after the climax, when the main problem of the story resolves. It shows how the character solved the conflict or the problem. +[260.94s -> 270.42s] It winds the story down from the climax to the story's end. We are now in the last part of the story plot. The Resolution +[270.93s -> 279.89s] Resolution shows how things end up in the story. Now let us analyze the plot of the story, Three Little Pigs. +[281.90s -> 296.72s] Once upon a time there were three little pigs. One pig built a house of straw while the second pig built his house with sticks. They built their houses very quickly and then sang and danced all day because they were lazy. +[296.72s -> 301.81s] The third little pig worked hard all day and built his house with bricks. +[302.51s -> 314.29s] A big bad wolf saw the two little pigs while they danced and played and thought what juicy tender meals they will make. He chased the two pigs and they ran and hid in their houses. +[314.29s -> 325.49s] The big bad wolf went to the first house and huffed and puffed and blew the house down in minutes. The frightened little pig ran to the second pig's house that was made of sticks. +[325.49s -> 338.82s] The big bad wolf now came to this house and huffed and puffed and blew the house down in hardly any time. Now, the two little pigs were terrified and ran to the third pig's house that was made of bricks. +[338.82s -> 353.17s] The big bad wolf tried to huff and puff and blow the house down, but he could not. He kept trying for hours but the house was very strong, and the little pigs were safe inside. He tried to enter through the chimney, +[353.17s -> 360.88s] But the third little pig boiled a big pot of water and kept it below the chimney. The wolf fell into it and died. +[361.17s -> 374.13s] The two little pigs now felt sorry for having been so lazy. They too built their houses with bricks and lived happily ever after. Let us now do the plot diagram of the story. +[374.64s -> 388.98s] the exposition is this once upon a time there were three little pigs one pig built a house of straw while the second pig built his house with sticks then the third little pig built his house with bricks +[389.33s -> 402.16s] In rising action. This is the conflict. A big bad wolf saw the two little pigs and chased them. Then, the big bad wolf went to the first house and blew the house down. +[403.06s -> 417.07s] And then, the big bad wolf went to the second house and blew the house down. The next event, the big bad wolf tried to huff and puff and blow the brick house down, but he could not. +[417.81s -> 429.39s] The turning point of the story, or the climax, is when the big bad wolf tried to enter through the chimney, but the third little pig boiled a big pot of water and kept it below the chimney. +[432.11s -> 443.12s] We are now in the falling action. The wolf fell into the big pot and died. Finally, we are in the end part of the story, which is the resolution. +[443.50s -> 455.63s] The two little pigs now felt sorry for having been so lazy The two little pigs built their houses with bricks too and lived happily ever after We made it +[456.43s -> 467.44s] Now, let's see if you could still remember the lesson by playing the word jumble. Rearrange the letters to find out what elements of the plot are being shown and described. +[469.90s -> 483.70s] 1. It introduces and develops conflict, or the main problem faced by the character. Rising Action +[485.49s -> 499.02s] 2. It provides information about the character and the setting. Exposition +[501.01s -> 514.93s] 3. It shows the highest point of interest, suspense, and turning point of the story. +[518.26s -> 528.91s] It shows how things end up in the story. +[530.70s -> 543.98s] 5. It shows how the character solved the conflict or the problem. Falling Action +[548.05s -> 558.45s] Are you ready for a short quiz? Analyze what element of the plot each event represents in the story of Cinderella. Write your answer on a piece of paper. +[560.14s -> 567.95s] 1. The prince had found the girl he was looking for. And so, Cinderella and the prince got married. +[571.31s -> 582.19s] 2. Once upon a time there was a kind and beautiful girl, whose name was Cinderella. She lived with her cruel stepmother and stepsisters. +[587.18s -> 597.62s] 3. Cinderella's stepmother would not let her try the slipper on, but the prince let her try it on. Her foot fit perfectly into it. +[598.35s -> 612.78s] Then, she took out the other glass slipper from her pocket. 4. The prince realized that she was the beautiful girl he had danced with at the ball. +[618.19s -> 626.29s] As she ran down the stairs, one glass slipper fell off, but Cinderella did not stop to pick it up. +[630.45s -> 643.98s] here are the answers number one is resolution number two is exposition number three is climax number four is falling action number five is the rising action +[645.04s -> 657.04s] Congratulations! You can now analyze the plot in a story. See you in our next lesson. +[660.75s -> 670.58s] thank you for watching do not forget to click the like button share this video to your friends and subscribe to my channel diff --git a/VideoMMMU_ASR_large/Humanities/new_Literature_4.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Literature_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3adeccb69cbbd20cca58f7e40da90632a96c1a81 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Literature_4.mp4.txt @@ -0,0 +1,51 @@ +[10.35s -> 19.60s] Hello! It's nice to see you again. For today's lesson, we will learn how to analyze the elements of the plot in a story. +[19.92s -> 30.06s] But before we begin, let's find out what you already knew in our lesson. You'll just choose the letter of the correct answer. +[30.51s -> 44.16s] It shows the highest point of interest, suspense, and turning point of the story. +[44.16s -> 57.62s] Resolution Letter B, Climax 2. It provides information about the characters and the setting. +[58.00s -> 71.60s] A. Climax. B. Rising Action. C. Exposition. D. Resolution. Letter C. Exposition. +[72.94s -> 86.64s] 3. It shows how things end up in the story. A. Climax B. Exposition C. Resolution D. Rising Action +[88.21s -> 90.90s] Letter C, resolution. +[92.24s -> 106.72s] 4. It introduces and develops conflict, or the main problem faced by the character. a. Exposition b. Falling action c. Resolution +[106.72s -> 120.75s] D. Rising Action Letter D, Rising Action 5. It shows how the character solved the conflict or the problem. +[121.87s -> 135.02s] Climax. B. Falling Action. C. Exposition. D. Rising Action. Letter B. Falling Action. +[136.88s -> 149.36s] Now, let's talk about plot. Plot is the chain of events that make up a story. In that sequence of events, we learn more about the characters, the setting, +[150.06s -> 164.11s] and how the story develops from beginning to end. Plots are typically made up of five main elements, namely Exposition Rising Action +[164.50s -> 177.78s] climax, falling action, and resolution. This is a map of the plot of a story. The first part of the plot is the exposition. +[178.22s -> 190.61s] It provides information about the character and the setting Character is a person, an animal, or an imaginary creature that appears in a story +[193.07s -> 203.31s] Like Elsa in Frozen, Simba in The Lion King, and Ariel in The Little Mermaid. Setting is the time and place in which the story unfolds. +[205.33s -> 209.23s] The place or scene may be imaginary or real. +[209.62s -> 222.03s] Now, after the characters and setting are introduced, the events of the story begin to create suspense as the character faces conflict. This part is the rising action. +[222.51s -> 233.33s] It introduces and develops conflict, or the main problem faced by the character. It includes the events that help to build toward the climax of the story. +[237.71s -> 249.62s] Climax shows the highest point of interest, suspense, and turning point of the story. This is the moment where the main character reaches their goal. +[250.26s -> 260.21s] Falling action occurs right after the climax, when the main problem of the story resolves. It shows how the character solved the conflict or the problem. +[260.94s -> 270.42s] It winds the story down from the climax to the story's end. We are now in the last part of the story plot. The Resolution +[270.93s -> 279.89s] Resolution shows how things end up in the story. Now let us analyze the plot of the story, Three Little Pigs. +[281.90s -> 296.72s] Once upon a time there were three little pigs. One pig built a house of straw while the second pig built his house with sticks. They built their houses very quickly and then sang and danced all day because they were lazy. +[296.72s -> 301.81s] The third little pig worked hard all day and built his house with bricks. +[302.51s -> 314.29s] A big bad wolf saw the two little pigs while they danced and played and thought what juicy tender meals they will make. He chased the two pigs and they ran and hid in their houses. +[314.29s -> 325.49s] The big bad wolf went to the first house and huffed and puffed and blew the house down in minutes. The frightened little pig ran to the second pig's house that was made of sticks. +[325.49s -> 338.82s] The big bad wolf now came to this house and huffed and puffed and blew the house down in hardly any time. Now, the two little pigs were terrified and ran to the third pig's house that was made of bricks. +[338.82s -> 353.17s] The big bad wolf tried to huff and puff and blow the house down, but he could not. He kept trying for hours but the house was very strong, and the little pigs were safe inside. He tried to enter through the chimney, +[353.17s -> 360.88s] But the third little pig boiled a big pot of water and kept it below the chimney. The wolf fell into it and died. +[361.17s -> 374.13s] The two little pigs now felt sorry for having been so lazy. They too built their houses with bricks and lived happily ever after. Let us now do the plot diagram of the story. +[374.64s -> 388.98s] the exposition is this once upon a time there were three little pigs one pig built a house of straw while the second pig built his house with sticks then the third little pig built his house with bricks +[389.33s -> 402.16s] In rising action. This is the conflict. A big bad wolf saw the two little pigs and chased them. Then, the big bad wolf went to the first house and blew the house down. +[403.06s -> 417.07s] And then, the big bad wolf went to the second house and blew the house down. The next event, the big bad wolf tried to huff and puff and blow the brick house down, but he could not. +[417.81s -> 429.39s] The turning point of the story, or the climax, is when the big bad wolf tried to enter through the chimney, but the third little pig boiled a big pot of water and kept it below the chimney. +[432.11s -> 443.12s] We are now in the falling action. The wolf fell into the big pot and died. Finally, we are in the end part of the story, which is the resolution. +[443.50s -> 455.63s] The two little pigs now felt sorry for having been so lazy The two little pigs built their houses with bricks too and lived happily ever after We made it +[456.43s -> 467.44s] Now, let's see if you could still remember the lesson by playing the word jumble. Rearrange the letters to find out what elements of the plot are being shown and described. +[469.90s -> 483.70s] 1. It introduces and develops conflict, or the main problem faced by the character. Rising Action +[485.49s -> 499.02s] 2. It provides information about the character and the setting. Exposition +[501.01s -> 514.93s] 3. It shows the highest point of interest, suspense, and turning point of the story. +[518.26s -> 528.91s] It shows how things end up in the story. +[530.70s -> 543.98s] 5. It shows how the character solved the conflict or the problem. Falling Action +[548.05s -> 558.45s] Are you ready for a short quiz? Analyze what element of the plot each event represents in the story of Cinderella. Write your answer on a piece of paper. +[560.14s -> 567.95s] 1. The prince had found the girl he was looking for. And so, Cinderella and the prince got married. +[571.31s -> 582.19s] 2. Once upon a time there was a kind and beautiful girl, whose name was Cinderella. She lived with her cruel stepmother and stepsisters. +[587.18s -> 597.62s] 3. Cinderella's stepmother would not let her try the slipper on, but the prince let her try it on. Her foot fit perfectly into it. +[598.35s -> 612.78s] Then, she took out the other glass slipper from her pocket. 4. The prince realized that she was the beautiful girl he had danced with at the ball. +[618.19s -> 626.29s] As she ran down the stairs, one glass slipper fell off, but Cinderella did not stop to pick it up. +[630.45s -> 643.98s] here are the answers number one is resolution number two is exposition number three is climax number four is falling action number five is the rising action +[645.04s -> 657.04s] Congratulations! You can now analyze the plot in a story. See you in our next lesson. +[660.75s -> 670.58s] thank you for watching do not forget to click the like button share this video to your friends and subscribe to my channel diff --git a/VideoMMMU_ASR_large/Humanities/new_Literature_5.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Literature_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..473e391537d27732d10d35106832ebac4ac05f76 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Literature_5.mp4.txt @@ -0,0 +1,76 @@ +[0.00s -> 8.27s] So in college we had a nickname for our literary theory and criticism class, Boot Camp. And that's because, well, it was really difficult. +[8.27s -> 22.10s] but also because it equipped us with everything we needed to be successful English majors. In this video, I'm going to introduce you to those same core skills so that you can analyze just about anything. +[32.56s -> 43.38s] So first off, what is literary theory, and how do you use it? Well, it's hard to talk about theory without having something to theorize about, so let's take a movie, 2017's Wonder Woman. +[43.38s -> 56.35s] now you could watch this movie and not do any analysis of it and really enjoy it from an entertainment perspective however if you want to dive deeper into the movie and maybe try and pull out some additional meaning +[56.35s -> 61.15s] you have to turn to analysis, and the easiest way to analyze something is through theory. +[61.15s -> 75.54s] for instance you could look at the mythology that went into the lore of the characters and the world you could look at the history of world war one you could look at gender studies and how in a certain scene the sexualization is actually of the male lead not the female +[75.54s -> 82.37s] You could compare it to other superhero movies and how they've performed accordingly. You could look at past Wonder Woman films. +[82.37s -> 94.62s] or future Wonder Woman films one day and see how it lines up, how things have changed, and does that reflect how our society has changed and our tastes have changed. Again, you don't need any of this to watch Wonder Woman. +[94.62s -> 106.35s] That's the idea of literary theory, is you dive beneath the surface, you dive deeper into it, to examine more than just what you see on perhaps a first viewing. Usually to do literary theory, you have to reread some things. +[106.35s -> 117.04s] So first off, as we just talked about, you have concentrated analysis. The other thing that literary theory allows you to do is join the conversation. When you're theorizing, you turn to other theorists as well. +[117.04s -> 125.36s] So you can see, for instance, that people have written about William Shakespeare for hundreds of years. And when you write your paper on Romeo and Juliet +[125.36s -> 134.45s] You're joining a conversation that spans time and cultures as many, many scholars have written about that play. And finally, everyone has a bias. +[134.45s -> 140.75s] And literary theory can help us identify bias, and instead of being completely turned off by them, we can +[140.75s -> 154.53s] look at something from another person's perspective and take from it what we want and leave what we don't want, or respond to it, or perhaps even ignore it completely. But either way, knowing that all of us have a bias because we're humans, +[154.53s -> 160.40s] it's good to try and identify those the first theory we're going to talk about is called new criticism +[160.40s -> 172.46s] Now, New Criticism is a little confusing because it's actually one of the older types of literary theory, but it was new at the time and it's kind of always been called New Criticism. New Criticism became most popular at the turn of the 20th century. +[172.46s -> 179.15s] It's partly a product of what's called Beaker Envy, where the literary types were envious of the scientists. +[179.15s -> 188.62s] And they wanted to find a way to examine things much like how you would conduct an experiment. So what did they do? They focused solely on the text. +[188.62s -> 202.70s] They don't look at anything about the author's life, or what year it was written, or if you were practicing new criticism today, you wouldn't do any googling whatsoever. You would only look at the words in front of you in the poem, short story, novel, or play. +[202.70s -> 215.54s] Now this can be very challenging, and certainly it can be very limiting. However, there's some tricks to try and find some things to write about, because this is still a pretty common assignment. Usually it's called an explication with poetry. New critics love looking at +[215.54s -> 225.63s] Tension in the text usually this is defined as binaries or opposites light and dark life and death savage and civil rich and poor +[225.63s -> 234.62s] whatever it might be, trying to find those opposites and where's the tension in the texts. Likewise, they'll look at parallels in the text, what things run together. +[234.62s -> 241.76s] foreshadowing or callbacks to previous instances in the text. So as I said earlier and as I'm sure as you can imagine +[241.76s -> 255.86s] This is a very limited way to look at something. However, it was very popular for a while and it's still a very useful exercise today when we want to practice close reading. Next up we have psychoanalytical criticism. Psychoanalytical criticism is highly influenced by Sigmund Freud. +[255.86s -> 267.79s] And while Freud has fallen out of fashion in the psychology realm, he's still very alive and well in the literary realm. And that's because Freud used literature and art to back up a number of his theories. +[267.79s -> 276.21s] Perhaps his most infamous theory of all time is the Oedipus Complex, which is of course named after Oedipus from Sophocles' play Oedipus Rex. +[276.21s -> 287.54s] When doing psychoanalytical criticism, it's important to look at the subconscious thoughts of the characters. Not just what they say, but what they might project. What sort of things they're holding back in remission. +[287.54s -> 297.07s] and maybe some cognitive dissonance going on in their lives. This can be a very useful study for those who perhaps are interested in going into psychology one day. +[297.07s -> 307.58s] After all, it's quite rude to just willy-nilly try and psychoanalyze your friends or family. However, literary characters aren't real so it's perfectly okay to psychoanalyze them. +[307.58s -> 314.48s] as long as what you're arguing is backed up by the text. This can be a really fun type of criticism for students because Shakespeare +[314.48s -> 328.82s] writes characters who are depressed, perhaps characters who have PTSD, but he doesn't use those words. Those terms didn't really have the same meaning or even exist in his times. But just because he didn't have those terms didn't mean he didn't recognize them. +[328.82s -> 338.22s] that in people and in his characters so it can really be a way to bridge the gap between older writers and a modern audience next up historical criticism +[338.22s -> 352.53s] While this criticism looks at what is old, it is very much a newer type of criticism and very popular still to this day. There's a couple different ways you can do it. You can look at the author's historical context, but you could also examine the historical context of the story. +[352.53s -> 365.34s] let me give you two examples of this if you're looking at the great gadsby the author's historical context would be the 1920s the setting of the story the 1920s because he wrote it as a contemporary novel however +[365.34s -> 379.22s] If you are looking at Julius Caesar by William Shakespeare, your author's historical context would be the late 1500s, early 1600s, but the character's and the setting's historical context is ancient Rome. +[379.22s -> 387.34s] And really, if you wanted to do it properly, you would want to look at what did Elizabethan England know about ancient Rome at that time. +[387.34s -> 400.70s] There's also a real focus with historical criticism on multiculturalism, looking at things from different perspectives. So let's say you were reading The Scarlet Letter and you took some time to examine the perspective of the Native Americans in the novel. +[400.70s -> 413.15s] as opposed to just the Puritan settlers. This would require you to dive into some history, which would lead you into historical criticism. Biographical Criticism Biographical criticism focuses on the author of the text. +[413.15s -> 423.52s] However, it's not as easy as it necessarily sounds. It's really really important not to draw one-to-one comparisons between the author's life and his or her works. This is what's called a +[423.52s -> 433.78s] biographical fallacy. And I have a video explaining some biographical fallacies in a W.H. Auden poem if you're more interested in that, but basically it's really important to remember that +[433.78s -> 447.41s] No one knows the author better than the author knows themself. So it's important not to just come out and say, oh, this character is written like the author's father or the author's mother or wife or husband or whatever it might be. +[447.41s -> 459.92s] Or, oh, they're writing it this way because of what happened in their life at this time. You have to be really, really careful about drawing those one-to-one comparisons because oftentimes we find out they're not really correct or very well supported. +[459.92s -> 470.06s] So Ben Johnson's On My First Son is about the death of his first son, and biographical criticism would say, well, he wrote this because his son died. +[470.06s -> 481.90s] But if you read that poem, it's very tempting to think that he's writing it in the throes of grief, that his son has just passed away and so he sat down to write this poem, when really he wrote it many, many years later. +[481.90s -> 494.61s] And it's only through careful research that you would figure out that this is long after his son has passed away, and that this is a grief that never goes away. A deep, unhealing grief in his life. +[494.61s -> 507.31s] So the opposite of biographical criticism would be reader response criticism. So instead of focusing on the author, we're focusing on the reader. And this partly came about in the postmodern era with the famous theory about the death of the author. +[507.31s -> 520.75s] And instead of focusing on what the author thinks of the text or what we think the author thinks of the text, we focus on what the text does for the reader. And this is a very useful type of criticism. After all, a poem isn't really complete until it's been read. +[520.75s -> 523.26s] I can write a poem, but if I never share it with anyone... +[523.26s -> 536.85s] it's really only half of the agreement now there's a lot of use for writing just for your own sake and never sharing it with people it can be incredibly therapeutic and helpful but since most of what we're talking about in school has been read since you know +[536.85s -> 549.62s] you're there reading it, it's important to think, what does the reader contribute to this? However, this isn't just what you think of the text, or if it reminds you of your own life, it's what does the text invoke in you? +[549.62s -> 562.37s] so you could examine how other cultures read the text so for instance you might look at how in 2020 a reader sitting in london might not really be able to connect with charles dickens london setting +[562.37s -> 574.51s] However, a reader sitting in another city might very well because that city nowadays might have more in common with Dickinsonian London than current London does. You could also look at original readers. +[574.51s -> 588.45s] What were the first reviews of novels that have big plot twists such as Dr. Jekyll and Mr. Hyde? And finally, you could look at how different age groups respond to a text. Think about when you watch a movie, how your parents see the movie. +[588.45s -> 601.63s] compared to how you see the movie, or your children compared to you. Or think of your favorite movie growing up, how it appeared when you were a child as opposed to when you watch it now, and how things change. All of this can fall under reader response criticism. +[601.63s -> 615.28s] And then we have deconstructionism. So deconstruction is way too complicated for me to explain in a couple of minutes here, but basically it is the opposite of new criticism. It's seeking to destroy binaries in the name of fairness. +[615.28s -> 620.99s] and invert situations for instance when we talk about binaries there's always +[620.99s -> 634.19s] one word that has a positive connotation as opposed to a negative connotation and it changes depending on who's thinking of these words but if you think up and down up positive down negative right and left +[634.19s -> 646.64s] Right positive, left negative. Why is that? Most people are right-handed. Rich and poor. We think of being rich as a positive, poor being a negative. How about black and white? +[647.28s -> 659.52s] That one might make you a little uncomfortable. And that is why deconstructionism exists. Not just that, but that's a really useful purpose of it. To try and take away the structure built into our language. Because... +[659.52s -> 671.76s] There is no denying that there are many, many works out there that use white imagery as a positive and darker imagery as a negative. And that has some real... +[671.76s -> 685.25s] powerful and dangerous implications. So deconstruction is all about breaking that apart. However, it goes a lot further than just that. Basically, it doesn't matter what the structure of the work is exactly. +[685.25s -> 699.57s] And it's very easy if you're not careful with deconstructionism to fall into conspiracy theory that SpongeBob isn't actually just a kid's show. It's a commentary on the dangers of Cold War nuclear testing. +[699.57s -> 713.87s] because bikini bottom is a real location where they were once setting off nukes and that's why all the creatures down there are so messed up and why the snails are meowing and the sponges are talking and the squids are playing clarinet now that's not what +[713.87s -> 726.62s] Spongebob is about. But a deconstructionist doesn't care what the actual meaning of the work is. They want to turn it around and look at it from a different perspective. Now deconstructionism can be a lot of fun, but really it's not. +[726.62s -> 738.05s] in fashion anymore. However, I think it's a good tool to add to your examination belt when it comes to approaching a text. And all of these can be used in combination. Sometimes +[738.05s -> 751.92s] a professor or teacher might want you to only use one type of theory but oftentimes when i'm writing i try and combine many different theories to try and figure out more about the text some other theories you can dive into +[751.92s -> 761.79s] There's theological, which is looking at it from a religious perspective. There's Marxist, which is usually looking at it from an economic perspective. There's feminist and gender studies. +[761.79s -> 776.14s] So there's all sorts of different ways to look at a text and all of these are just different tools. So when your teacher or professor hands you a poem and says, write two pages about this, you have an idea of where to start. You have a way to generate ideas that you could write about and defend. +[776.14s -> 778.43s] because far too often we just +[778.43s -> 792.82s] go into the internet and try and figure out what someone else has to say about this poem or short story. I mean, I make videos about poems and short stories. I know this happens. And there's nothing wrong with having someone else explain their perspective to you. But your... +[792.82s -> 802.35s] view should never stop with their perspective. When I analyze Araby, that's my analysis of Araby. I've derived this analysis from many different places. +[802.35s -> 816.66s] but it's still my analysis. And it would be very wrong for someone to just take my analysis and use it as their own. And I'm not even talking about plagiarism wrong. It'd be wrong because they're not completing the thought experiment that comes with reading and analyzing. +[816.66s -> 829.33s] Because if you can analyze literature, you're going to be better at analyzing other things, including difficult family situations, who to vote for when elections come around. +[829.33s -> 840.62s] whether or not a company is good to work for all of these things require deep thought and they don't necessarily have one correct answer so by all means please continue to watch my videos if you're watching them +[840.62s -> 854.11s] to try and learn more about literature, but you should never stop with my videos. Instead use some of these literary tools to try and figure out the best way that you can approach a text and practice that analysis. +[854.11s -> 863.70s] and hopefully get an A on that paper if that's what you're after. Alright, if you have questions, leave them in the comments, and I'll see you next video. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Literature_8.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Literature_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..19f076d9308640882de9fde9ff749db339e41612 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Literature_8.mp4.txt @@ -0,0 +1,121 @@ +[0.94s -> 11.98s] Today we're going to talk about literary genres and sub-genres. While you watch the video, you can print out the worksheet to take notes and practice while you listen. +[13.01s -> 23.09s] To understand literary genres, the first thing we need is a definition of the word literature. So, what is literature? +[25.20s -> 31.73s] Literature means books and other writing usually by expert authors. +[33.36s -> 45.55s] Now let's talk about the definition of literary genre. So what is a literary genre? Well, a genre is a type or category. +[45.94s -> 59.47s] literary means of literature. So a literary genre is a type or category of literature. There are four main literary genres. +[60.50s -> 70.16s] drama, fiction, nonfiction, and poetry. Let's talk about the definition and an example of each one. +[70.51s -> 82.45s] Drama is a play for theater told by character dialogue or talking. Here's an example of a drama or play being performed in a theater. +[82.74s -> 92.88s] We can read drama and we can also watch it. Fiction is a story that did not actually happen in real life. +[93.62s -> 103.86s] An example of a very famous story that's fiction is Twilight. We know Twilight is fiction because it's about vampires, which aren't real. +[105.62s -> 120.43s] Nonfiction is writing that is real and factual or that actually happened. An example of nonfiction is any textbook you read in school, such as a science textbook or history textbook. +[120.85s -> 134.96s] This example is information that would be shown in a science textbook. Poetry is writing using language and sounds in special ways to express ideas. +[136.62s -> 149.07s] Here is a very simple and maybe even silly example of poetry. The rose is red, the violet's blue, sugar is sweet, and so are you. +[149.74s -> 163.15s] These words are told in a way that rhyme and have rhythm. We'll learn more about those two words later, but you can see when you hear these verses that poetry +[163.15s -> 174.86s] read differently than fiction, nonfiction, or drama. Now that we've learned what literary genres are, let's be more specific. +[175.70s -> 185.46s] These genres have subgenres. A subgenre is a smaller group or category. +[187.92s -> 197.04s] Literary genres and subgenres. Now we'll name subgenres of each of the four genres, along with examples. +[198.74s -> 206.58s] So, drama has two subgenres. One is comedy, and the other is tragedy. +[209.46s -> 223.66s] A comedy is a funny or humorous drama with a happy ending. One example of a very famous comedy is the comedy of errors by Shakespeare. Now, we are talking about comedy +[223.66s -> 237.65s] as a subgenre of drama, but we can also see comedies on television and in the movies. A tragedy is a sad drama with a sad ending. +[238.00s -> 244.62s] An example of a very famous tragedy is Romeo and Juliet by William Shakespeare. +[244.91s -> 258.48s] Like comedy, tragedy also began and still is performed as a drama or play. But also like comedy, we can now watch tragedies on television. +[258.48s -> 272.05s] and in the movies. Now let's talk about subgenres of fiction. The genre of fiction has several subgenres. Today we'll talk about eight of them. +[273.01s -> 285.97s] fantasy, folklore, historical fiction, mystery, realistic fiction, romance, science fiction, and thriller. +[288.50s -> 299.73s] Fantasy is a story in a fantasy world or a world that isn't real. An example of fantasy are the Harry Potter books. +[300.50s -> 307.12s] Harry Potter's world is full of magic and wizards. That's why it's fantasy. +[308.59s -> 322.48s] A second subgenre of fiction is folklore. Folklore is old cultural stories. These include fairy tales, fables, myths, legends, and tall tales. +[323.54s -> 336.05s] We'll discuss each type of folklore in a separate video. For now, just know that each of these is an example of types of folklore. Every country and culture has its own folklore. +[337.04s -> 346.29s] Here's an example of Russian folklore. This book is a collection of stories about the famous character, Baba Yagi. +[349.49s -> 358.10s] And here is an example of Mexican folklore. This is a story about La Llorona, or The Crying Woman. +[361.68s -> 365.55s] Another subgenre of fiction is historical fiction. +[366.03s -> 379.18s] This is a fiction story based on real history. One famous example of historical fiction is the novel Gone with the Wind by Margaret Mitchell. +[379.76s -> 393.30s] This story takes place during the Civil War in U.S. history. So the Civil War actually happened, but the characters in Gone with the Wind +[393.30s -> 400.21s] One of them is the famous character Scarlett O'Hara. The characters were not real. +[400.62s -> 409.26s] And what happened in the lives of the characters also was not real, although it was based on real history. +[411.79s -> 418.80s] Mystery is another subgenre of fiction. A mystery is a story about a crime. +[419.34s -> 427.79s] Here's an example. The novel And Then She Was Gone is a story about a girl who disappears. +[428.43s -> 437.90s] During this story, detectives and people living in the town she was in try to find where the girl is and what happened to her. +[439.89s -> 449.46s] The fifth subgenre of fiction we'll talk about today is realistic fiction. This is a story that seems real, but isn't real. +[450.03s -> 457.71s] Realistic fiction is set in modern times, and it's about characters who seem like real people. +[458.70s -> 472.43s] A well-known example of realistic fiction is the story Jane Eyre by Charlotte Bronte. The main character, Jane Eyre, has a difficult childhood as a young girl. +[472.85s -> 484.27s] She grows up to work in the home of a man named Mr. Rochester. The picture on this book cover shows this home. It looks real. +[484.75s -> 496.59s] And Jane Eyre seems like a real person. So does Mr. Rochester. But they're not real. That story is fiction. It's realistic fiction because it seems true. +[500.98s -> 511.95s] Another subgenre of fiction is romance, or a love story. The novel A Perfect Gentleman is an example of a romance. +[514.61s -> 519.28s] Science fiction is a story in the future with advanced technology. +[519.57s -> 532.80s] One well-known example of science fiction is The Hunger Games by Suzanne Collins. This story takes place about a hundred years into the future and involves a character named Katniss +[532.80s -> 545.46s] who's 16 years old. The government forces her and many other young people to battle each other in an event called the Hunger Games, which leaves only one survivor. +[546.90s -> 552.75s] Sometimes, science fiction can get confused with fantasy. +[553.14s -> 564.53s] The main difference between science fiction and fantasy is that science fiction is in a future world that has some similarities with our current world. +[564.88s -> 577.49s] It involves new inventions and technology, whereas fantasy happens in a world that is impossible, a world where, for example, animals talk. +[577.71s -> 580.66s] or other impossible things happen. +[582.99s -> 593.20s] And finally, a thriller or suspense is a story that makes readers nervous, excited, or even scared as they read. +[593.52s -> 606.77s] An example of a thriller is The Girl with No Past by Catherine Croft. In this story, readers learn secrets about a girl who appears in a town. +[607.22s -> 614.80s] The secrets they learn make readers feel nervous, excited, and sometimes scared as they read. +[615.34s -> 624.62s] Sometimes a thriller or suspense can be confused with a mystery, but actually mysteries are different from thrillers. +[624.91s -> 631.89s] The goal of a mystery is to solve a crime and figure out who did the crime. +[633.01s -> 645.87s] In a thriller, sometimes there was no crime, or readers already know at the beginning who did the crime. The goal of the thriller is to thrill the audience. +[645.87s -> 656.30s] by revealing secrets as the audience reads the book. Now we'll learn about subgenres of the genre nonfiction. +[657.01s -> 670.42s] Today we'll learn about five sub-genres of nonfiction, including biography, autobiography, narrative, periodicals, and reference materials. +[673.01s -> 678.45s] One subgenre of nonfiction is biography, or a story of a person's life. +[678.99s -> 692.98s] Here's an example of a well-known biography. This book is about the life of Albert Einstein, the famous scientist. It's written by the biographer or author Walter Isaacson. +[695.63s -> 704.59s] Another subgenre of nonfiction is autobiography, or a story the author writes about himself or herself. +[706.61s -> 717.90s] An example of a famous autobiography is The Autobiography of Benjamin Franklin. It's a book that Benjamin Franklin wrote about his own life. +[722.03s -> 731.79s] Another subgenre of nonfiction is narrative nonfiction, or a story or narrative that happened in real life. +[732.37s -> 746.24s] An example of narrative nonfiction is the book called Turn Right at Machu Picchu by Mark Adams. This book tells stories +[746.24s -> 751.76s] about explorers who rediscovered the place called Machu Picchu. +[752.66s -> 766.83s] The stories in this book are real. They actually happened. The characters are real, the places are real, and the events are real. That's what makes them narrative nonfiction instead of +[766.83s -> 767.73s] fiction. +[769.39s -> 782.78s] And finally, periodicals are magazines, newspapers, and journals that are written regularly. Regularly might mean once a week. It might mean once a month. +[782.78s -> 794.96s] or sometimes even just once a year. All of those things are called periodicals. The most common type of periodical we see is a daily newspaper. +[798.26s -> 803.92s] The last subgenre of nonfiction we'll discuss today is reference materials. +[804.18s -> 817.14s] These are books with facts in alphabetical order. Examples include a dictionary, thesaurus, and encyclopedia. Here's an example of a dictionary. +[817.58s -> 823.18s] Dictionaries list words in alphabetical order along with their meanings. +[826.86s -> 840.40s] And finally, the last subgenres we're going to discuss are subgenres of the genre poetry. Remember that poetry is writing using language and sounds and special ways to express ideas. +[840.66s -> 849.30s] The subgenres of poetry that we'll learn about today are lyric, narrative, and dramatic poetry. +[850.22s -> 861.07s] Now let's define the subgenres of poetry. The most popular and common subgenre of poetry is the lyric or a poem about the speaker's thoughts. +[862.19s -> 872.69s] Most poems you see and hear are lyrics. Examples of lyrics include elegy, ode, sonnet, and haiku. +[873.01s -> 882.13s] Today we won't talk specifically about elegy, ode, sonnet, and haiku, except to say each of them is a type of lyric. +[883.25s -> 897.84s] And here is an example of a lyric. This is a haiku written by a famous haiku writer. Fallen flower I see, returning to its branch. Ah, a butterfly. +[898.38s -> 904.43s] This lyric is a haiku written about the speaker's thoughts of a flower. +[905.07s -> 918.94s] Like all poetry, you see how the lyric uses syllables and sounds to express thoughts in a special way that's different from how fiction, nonfiction, +[918.94s -> 930.26s] and drama express thoughts. Another subgenre of poetry is narrative or a poem that tells a story. +[930.54s -> 938.42s] There are a few types of narratives, but one of them is an epic or a long poem about a hero. +[938.90s -> 953.04s] One famous example of an epic is Beowulf. Beowulf is an old poem that is about 3,000 lines long. That's a very long poem. It tells the story +[953.04s -> 963.54s] about a hero named Beowulf. Beowulf was a warrior who saves the king from a monster named Grendel. +[964.18s -> 972.66s] Usually epics include lots of battles and fights that the hero wins in the end. +[974.90s -> 988.82s] The last poetry subgenre we'll discuss today is dramatic poetry, or words spoken by a character. We see dramatic poetry in another genre. Can you guess which one? +[989.62s -> 1002.35s] We see dramatic poetry in the genre drama or plays. Three examples of dramatic poetry are soliloquy, dialogue, and monologue. +[1002.83s -> 1013.84s] We won't discuss the specifics and differences of soliloquy dialogue and monologue today, except to say that each of them is an example of dramatic poetry. +[1014.96s -> 1027.31s] Now, because William Shakespeare was a very famous drama writer, he's also responsible for many of the soliloquies, dialogues, and monologues we study today. +[1027.92s -> 1042.74s] Here's an example of a soliloquy by William Shakespeare that we see in the play Romeo and Juliet. In Act II, Scene II, Juliet says the following words to herself. +[1043.60s -> 1054.26s] Romeo is standing nearby, but she doesn't realize it. She says, "'Tis but thy name that is my enemy. What's in a name?' +[1054.54s -> 1066.93s] That which we call a rose by any other name would smell as sweet. In these words, Juliet is talking about Romeo, and what she's saying is, +[1067.25s -> 1075.82s] The name we call a person or an object doesn't matter. What matters is how we feel about that person or object. +[1078.16s -> 1091.86s] Because this quote is meaningful, it's a very famous soliloquy that we study when we study dramatic poetry. Now let's practice what we've learned. +[1092.27s -> 1105.04s] For each number, write the genre and subgenre described. Number 1. What is the genre and subgenre of a story about plants that come to life? +[1106.86s -> 1119.06s] Number two, a book about the life of a famous soccer star. Number three, an encyclopedia entry that describes vitamin E. +[1120.59s -> 1132.78s] 4. The humorous play, The Taming of the Shrew. 5. A long poem about a hero named Achilles. +[1133.94s -> 1145.65s] 6. A weekly newspaper called Main Street Times. 7. A sad play about the character, Oedipus Rex. +[1147.09s -> 1159.38s] 8. A poem about a girl's ideas about friendship. 9. A story about life in the year 3023. +[1160.18s -> 1170.42s] 10. A story about characters who lived during World War I. The characters are not real, but they seem real. +[1171.06s -> 1175.44s] Pause the video while you work and we'll check the answers in a moment. +[1186.29s -> 1190.10s] Are you ready to check the answers? Let's check +[1190.74s -> 1201.81s] Number one, the genre is fiction and the sub-genre is fantasy. We know it's fantasy because in the real world, plants can't come to life. +[1202.10s -> 1217.04s] So, the subgenre is fantasy, and we know that fantasy is not real or factual. It's fiction. Number two, the genre is nonfiction, and the subgenre is biography. +[1218.00s -> 1229.01s] We know this is a biography because it's the story of a person's life. And we know that biographies are real and factual. That makes them nonfiction. +[1229.87s -> 1236.94s] 3. The genre is nonfiction and the subgenre is reference material. +[1237.23s -> 1250.38s] We know that encyclopedias are a type of reference material, and we also know that reference material contains real and factual information. Therefore, the genre has to be nonfiction. +[1251.44s -> 1257.58s] 4. The genre is drama, and the subgenre is comedy. +[1257.97s -> 1266.90s] We know this is drama because it's a play. And we know that the subgenre is comedy because the play is humorous or funny. +[1268.43s -> 1282.74s] Number five. The genre is poetry, and the subgenre is epic. We know this is poetry because it's a poem. We know that it's an epic because epics are long poems about heroes. +[1283.92s -> 1296.53s] Number six. The genre is nonfiction, and the subgenre is periodical. We know this is a periodical because newspapers are a type of periodical. +[1296.98s -> 1305.55s] And we know that this is nonfiction because periodicals contain real and factual information. So the genre has to be nonfiction. +[1306.83s -> 1320.72s] Number seven. The genre is drama, and the subgenre is tragedy. We know this is drama because it's a play, and we know that the subgenre is tragedy because this play is sad. +[1322.32s -> 1335.22s] Number 8. The genre is poetry, and the subgenre is lyric. We know this is poetry because it's a poem. And we know it's lyric poetry because... +[1335.22s -> 1347.63s] It's about a person's ideas about a topic. That's what lyric poetry is. Number nine. The genre is fiction, and the subgenre is science fiction. +[1348.08s -> 1362.42s] We know this is science fiction because it's set far into the future, in the year 3023. We know it's fiction because it can't be real. It hasn't happened yet. So the genre has to be fiction. +[1362.99s -> 1370.38s] And number 10. The genre is fiction, and the subgenre is historical fiction. +[1370.99s -> 1378.61s] We know this is historical fiction because it took place in World War I, which was a real period in history. +[1378.99s -> 1389.17s] But the characters are not real even though they seem real. Because the characters aren't real, the story and the genre is fiction. +[1393.42s -> 1407.15s] Literary genres, the end. Our literary genre and subgenre practice for today is complete. I hope this video helped you understand what a literary genre and subgenre are and how to identify examples of each one. +[1407.15s -> 1408.78s] Thank you for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Literature_9.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Literature_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..45021583ee13101d4bc0438db5dc49174577e64c --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Literature_9.mp4.txt @@ -0,0 +1,55 @@ +[0.00s -> 12.27s] Hi everyone, my name is Mr Watson and in this video I'm going to be talking you through some of the most common poetic techniques to hopefully help you identify them in your analysis of poetry. +[14.42s -> 24.37s] So we start with alliteration Alliteration is a series of words in a sequence that contain the same consonant sound +[24.98s -> 38.58s] so an example would be Bob bit into the banana that he bought from Bumble there we have the repetition of the B sound and obviously B is a consonant sound and so +[38.58s -> 41.17s] that is why this is alliteration +[42.80s -> 55.98s] Next we have assonance. Now assonance is very similar to alliteration, except this time it uses the vowel sound. So it's a series of words in a sequence that contain the same vowel sound. +[57.78s -> 71.68s] an example would be the rain in Spain falls mainly on the plane the repetition of that a sound in rain, Spain, mainly and plane is a vowel sound and that is why +[71.68s -> 79.41s] It's assonance. Sibilance also fits in with the previous two techniques. +[81.07s -> 91.70s] so sibilance is a series of words in a sequence that contain the same soft consonant sounds sounds that often create something of a hissing sound +[93.55s -> 106.46s] We can clearly see this in the example. The slimy snake slithered through the sharp spiky grass. So if you were to read that out loud, you would hear a lot of ss sounds and th. +[106.46s -> 118.03s] sounds, okay? Quite aggressive hissing type sounds and that is what makes it sibilant. Moving on to imagery. +[119.12s -> 127.86s] Imagery is the use of descriptive language that appeals to the five senses, helping to create a vivid image in the reader's mind. +[129.23s -> 142.69s] So the example here is the bright glowing moon stood out against the deep black of the late night sky. So I've underlined the adjectives there that really help describe this scene and help +[142.69s -> 155.17s] create a very clear image in our minds. If there had been any adjectives describing the sounds that could be heard or the smells or the taste or anything like that +[155.17s -> 167.79s] that would also be imagery because it's helping us create that picture, create that image, that scene in our minds. Next we have metaphor. +[168.14s -> 173.94s] So a metaphor is when one object is described as being another unrelated object. +[174.32s -> 188.42s] So an example would be, life is a roller coaster. So life isn't literally a roller coaster, but what this metaphor does is it takes the qualities of the roller coaster and applies it to life. So... +[188.42s -> 201.74s] For example, a roller coaster can be exciting, thrilling, terrifying, nauseating. And all of these qualities are being applied to life in this example. +[203.41s -> 217.90s] A simile is a technique that is very similar to a metaphor. So a simile is when one object is compared to another unrelated object only this time using the word like or as. +[219.02s -> 233.22s] So a couple of examples here using both those terms, we've got she moved as quietly as a mouse, and we've also got she moved like a mouse. So just like with the metaphor, the second object, in this case it's the mouse and how they move, +[233.22s -> 242.30s] are having their qualities taken and applied to the first object which in this case is the she, the person, the character. So we have the mouse moving +[242.30s -> 254.96s] really really quietly and really kind of stealthily and those qualities are being taken and applied to the character and how she is moving in this moment it is important though to be aware +[254.96s -> 268.80s] when using similes and when looking for similes in other pieces of writing that just because the word like or the word as is used it doesn't always mean that it's a simile there has to be some form of comparison there +[268.80s -> 282.35s] for it to be a simile. So just bear that in mind. Okay next we have personification. Personification is when non-human objects or creatures are given human qualities. +[283.31s -> 292.70s] For example the camera watched over the street so the fact that the camera is being described as watching as an action their cameras +[292.70s -> 305.92s] I mean, yeah, you could say that that's kind of what they do. But in this sense, it's almost as if they're kind of keeping an eye on things. Yeah, surveilling it. And that is what makes it personification. And in the second example there, we've got each of the leaves were dancers. +[305.92s -> 318.03s] twirling without a care in the world so if we look at the leaves were dancers part you could say that that's a metaphor but it's the twirling without a care in the world section of +[318.03s -> 331.25s] that sentence that i would say is the personification because it is applying emotion to it leaves don't have emotions as far as we know so it's a real it's a human quality to have cares about the world +[331.25s -> 342.80s] because we have those emotions. In this case, the fact that the leaves are being described as not having a care in the world shows that they are capable of caring and therefore they're being personified. +[344.24s -> 351.95s] Okay, now we have rhyme. So rhyme is the repetition of syllables, typically at the end of a line. +[352.82s -> 366.82s] So there are three different kinds of rhyme that you can find in poetry. The first of all is probably the most common and the most recognisable, and that's the full rhyme. So, for example, cat and fat, bean and mean. +[366.82s -> 379.39s] kite and fight they are all full rhymes we also have something called a half rhyme which is a bit less obvious than a full rhyme so we see this with words like escaped and scooped +[379.39s -> 393.07s] So with those two words, we've got the pt bit at the end, which rhymes, which is a half rhyme. And we have milk and walk. So it's the k sound at the end, which makes it a half rhyme. +[393.30s -> 407.06s] There's also something called an internal rhyme and that's when the rhyme takes place within a single line Rather than starting on one and ending on another for example the stars never rise +[407.06s -> 416.11s] but I feel the bright eyes. So that is just one line of poetry and yet we have a rhyme within it with rise and eyes. +[416.11s -> 427.98s] internal rhyme is something that's very common in hip-hop and rap music because it creates a flow and it creates momentum which a lot of musical artists use in their work +[429.65s -> 438.13s] Next we have repetition. Repetition is fairly straightforward. It's when you use a word or phrase multiple times for emphasis. +[439.15s -> 452.69s] In this example, we must continue to fight the good fight. The word here that obviously the writer wants to emphasize is the word fight. Next we have rhythm. +[453.65s -> 460.14s] So rhythm is the pattern of sounds and syllables used to create a sense of flow and momentum. +[461.84s -> 474.93s] So there are different kinds of rhythms and I don't want to make this too complicated so what I'll do is I'll stick to a very popular common type of rhythm and that is called iambic pentameter. +[475.15s -> 488.50s] and what that means is it's basically a line of poetry that has 10 syllables which follows an unstressed stressed rhythm so what I've done there is I've colour coded this line +[488.50s -> 500.96s] with orange on the unstressed syllables and the blue on the stressed syllables so it would sound something like shall i compare thee to a summer's day +[500.96s -> 514.78s] so with that unstressed and stressed emphasis on those different words that creates a particular kind of rhythm something like a and that is a rhythm of iambic pentameter +[514.78s -> 528.88s] like i said there are many different kinds of rhythms with different numbers of syllables and different stress patterns and things like that so if you're interested by all means have a have a look online and do a bit of research into it but for now we'll just leave it with +[528.88s -> 533.52s] this one. Next we have couplets. +[534.19s -> 546.06s] So couplets are a pair of successive lines of verse, typically rhyming and of the same length. A good way to remember what a couplet is is to think of couple, meaning two. +[547.34s -> 561.26s] So an example would be I really wish the seagulls would just fly away and not ambush my garden every single day. So of course there we have two successive lines with away and day rhyming. +[562.74s -> 577.30s] Next we have enjambment or enjambment. I've heard it pronounced so many different ways but basically what this is is when one thought or idea in a line of poetry continues onto the next one without any punctuation. +[577.30s -> 586.86s] So this is often used to create flow and pace. For example, I'm feeling rather sleepy but I'm really not sure why. +[587.22s -> 599.28s] Okay, so there we have two lines, but if you notice after sleepy there is no punctuation And so the idea just carries on into the next line and that is enjambment or enjambment +[601.33s -> 606.16s] In contrast to Enjambment, or Enjambment, is Scizora. +[606.77s -> 620.75s] caesura is the use of punctuation in the middle of a line of poetry to create a deliberate pause so this is often used to slow down momentum to create more disjointed +[620.75s -> 634.06s] rhythms. So for example, to be or not to be. So that comma there in blue is there to break the line up, to slow it down. +[634.35s -> 636.94s] And that is Scizora. +[637.33s -> 651.92s] Okay, that's all for this video. I really hope you found it useful. If you did, please feel free to leave a like or leave a comment. If you have any questions, again, leave those in the comment section below and I will try and answer them as soon as I possibly can. If you're not subscribed, please feel free to... +[651.92s -> 661.97s] so you don't miss any future videos from me on this channel. Thank you very much for watching and I hope to see you next time. Bye for now! diff --git a/VideoMMMU_ASR_large/Humanities/new_Psychology_1.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Psychology_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..14e6508685822e45cf85869beefa559a0f46b53d --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Psychology_1.mp4.txt @@ -0,0 +1,61 @@ +[0.08s -> 11.84s] Right guys, welcome back to A-Level Psychology. The focus in this video is going to be social learning theory. This topic comes up in paper two as part of the approaches topic and it follows on directly from behaviorism. +[11.84s -> 23.70s] So if you haven't covered the behaviorism topic yet, or if you feel like you need a quick refresher, you can go ahead and click the link at the top of the screen now and remind yourself what that was all about. +[24.21s -> 34.93s] Over the next 15 minutes or so we're going to cover the basic assumptions and core elements of social learning theory. We're also going to look at a key study and then finish off with some evaluation points. +[34.93s -> 47.31s] If you want to see some exam questions or an example essay they're in a different video but you can access those either via the link on the screen now or at the end of the video which is where they're going to be linked again. +[47.92s -> 61.57s] Like behaviorism, social learning theory falls under the category of learning theories, and it was pioneered by Albert Bandura, who you can see on the screen now. Bandura agreed with the behaviorists that behavior is learned through experiences, +[61.57s -> 64.40s] and through operon and classical conditioning. +[64.53s -> 79.14s] However, the big difference with social learning theory is that the approach also says that people learn through the observation and imitation of role models, and that that happens via vicarious reinforcement. +[79.14s -> 92.37s] with the help of mediational processes. Now I'm well aware that I've just thrown a whole sentence of keywords at you but on the plus side that's just about all the keywords that you'll need for this lesson. +[92.37s -> 95.89s] And I'm going to go through each of them and break them down for you. +[96.72s -> 108.90s] So we'll start with vicarious reinforcement because it's kind of the big one for social learning theory. So if you remember from behaviorism, we talked about operant conditioning and we said that a behavior is learned if it's rewarded. +[108.90s -> 120.08s] Social learning theory takes that a step further and says that people learn behaviors by observing and imitating others. However, only if that behavior is seen to be rewarded. +[120.08s -> 133.22s] seeing somebody else receive a reward is known as vicarious reinforcement and it makes you want to carry out the same behavior because you anticipate a similar reward now all that is well and good +[133.22s -> 147.02s] But people don't just imitate anyone. Only certain people are worthy of imitation and those are people that we identify with. We have to consider them a role model in some form or another. +[147.02s -> 161.25s] They may have similar characteristics to us in terms of age, sex, gender, interests, personality. They may also enjoy a certain status. They may be attractive. They may be charismatic. +[161.25s -> 175.70s] for children you often find that they imitate their parents or their older siblings particularly if they're the same sex because very often they consider their parents to be role models but that tends to change as you get older because we tend to emancipate ourselves from our +[175.70s -> 189.97s] parents as we hit our teenage years, at which point we might consider a celebrity or a friend or somebody else in our life to be a role model. The social learning theorists call this identification. +[191.25s -> 204.29s] And the final element of social learning theory is the use of mediational processes. Now mediational processes are cognitive processes that are involved in the learning and the production of new behaviors. +[204.29s -> 218.51s] There are four mediational processes in total that are involved in the learning and the producing of new behaviors. So in order for a new behavior to be learned in the first place, it has to be seen and it has to be remembered. +[218.51s -> 233.41s] The processes that are at play here are called attention and retention. However, for a learned behavior to actually be produced and imitated, we need to be able to imitate it and we need to want to imitate it. +[233.41s -> 239.95s] So here the mediational processes are motor reproduction and motivation. +[239.95s -> 252.43s] Wanting to produce a behavior very often comes down to whether or not it's been witnessed being rewarded at some point or another. Okay, so this comes back to our vicarious reinforcement. +[252.78s -> 263.41s] If therefore all of these mediational processes are implemented, learning and imitation can take place, but they do all need to be implemented before that can happen. +[264.02s -> 278.61s] I have just made a video on an exam question for mediational processes as well. It's a six mark application question. So if you want to go and test yourself on your knowledge of the mediational processes, I will link the video up at the top of the screen. +[278.61s -> 293.52s] have a look at it. Now just consider the introduction of mediational processes marks a clear difference between behaviorism and social learning theory because behaviorism says that if a behavior is learned then it's going to be repeated. +[293.52s -> 296.82s] People have no choice. They will simply do it. +[296.82s -> 311.34s] Social learning theory on the other hand says that people do have a choice and that just because a behavior has been learned doesn't necessarily mean that it's going to be carried out. That will only happen if you're physically able to carry out the behavior and if you +[311.34s -> 324.29s] want to carry out the behavior because you believe that you'll get some kind of reward for doing so okay so social learning theory introduces this element of choice that didn't exist beforehand so +[324.29s -> 338.50s] to summarize and to come back to the sentence i said earlier social learning theory suggests that people learn through the observation and imitation of role models via vicarious reinforcement and with the help of mediational processes +[338.50s -> 350.03s] That would incidentally also make a nice little answer to a two-mark question, and it would also be a nice introduction to an essay if you were to ever write an essay on this topic. +[351.06s -> 361.04s] Now, I mentioned earlier that there is a key study that you need to know. It's called the Bobo Doll Study and it was conducted by Banjora et al. in 1961. +[361.36s -> 374.34s] As part of the Bobo doll study, children observed adults playing aggressively with a Bobo doll. And when these children were later observed playing with a variety of toys, including a Bobo doll, +[374.34s -> 387.41s] the researchers found that they behaved much more aggressively towards the doll and the other toys than those who'd observed a non-aggressive adult, which provides evidence for this idea of learning through observation and imitation. +[387.41s -> 401.42s] There's a picture of the original study. Across the top row you've got an adult being aggressive towards the Bobo doll and then in the two rows below you've got a boy and a girl imitating the behavior of the adult almost identically. +[401.42s -> 407.62s] Okay, so again, it just shows this idea of observation and imitation of a role model. +[407.62s -> 421.63s] Now the Bobadil study is quite nice because you can use it as an evaluation point if you want for social learning theory. You just have to be a little bit aware that you could also be asked to outline and evaluate a research study. +[421.63s -> 435.38s] into social learning theory at which point you would outline the Bobo doll study and you'd need different evaluation points. So I would still recommend that you get three or so evaluation points even though you have the Bobo doll study as well. +[435.70s -> 448.80s] So that brings us to the second part of the video and that is the evaluation section. I've got three evaluation points for you that should be plenty for any essay that you will be asked to write on this topic. +[448.80s -> 460.30s] So we'll start off with a strength, and that is that social learning theory acknowledges the importance of thinking before acting. Operant and classical conditioning do have their part to play in learning. +[460.30s -> 473.78s] but both of them are insufficient for explaining learning by themselves. Because if you think about it, learning would be inefficient and dangerous if we only relied on our own experiences. +[473.78s -> 480.69s] Just from an evolutionary point of view, we would only know if something was bad after it had done us harm. +[480.69s -> 489.36s] Whereas social learning theory allows us to watch somebody else make bad choices and then actively decide not to do the same. +[489.42s -> 502.64s] So this recognition of cognitive factors in learning means that social learning theory provides a much more comprehensive account of human learning and also a much more realistic account as well. However, +[502.64s -> 515.41s] A counterpoint to that is that social learning theory has been criticized for ignoring biological factors in learning. So Banjora himself maintains that learning itself is +[515.41s -> 525.26s] primarily determined by the environment. But there is recent research that suggests that observational learning could also be the result of mirror neurons. +[525.26s -> 539.57s] Now mirror neurons are specific nerve cells that allow us to empathize with others and imitate behaviors. So for example, if you see somebody laughing and you can't help but laugh as well, or if you see somebody crying, +[539.57s -> 544.66s] and you can't help but feel sad for that person, that is a mirror neuron. +[544.66s -> 556.27s] recent research suggests that it's not just about feeling the same as somebody else and empathizing with somebody else but also imitating behavior okay and this suggests that +[556.27s -> 569.42s] biological factors are hugely important, but also hugely under-emphasized in this theory. Okay, so you've got a nice little counterpoint there to your strengths. And then... +[569.42s -> 582.14s] A final limitation is that the evidence behind social learning theory comes from an experiment conducted on young children's behavior in a lab. +[582.14s -> 591.15s] The problem that we have here is that the Bobo doll study is massively artificial because that's not how aggression works in the real world. +[591.47s -> 605.63s] The fact that it was conducted in a lab with a Bobo doll also means that you could have had demand characteristics appear as part of this experiment, simply because the sole purpose of a Bobo doll is to hit it. +[605.63s -> 618.85s] Therefore, children may have simply been reacting to an item in a very natural way rather than imitating aggressive behavior, regardless of whether they saw somebody else act aggressively towards the doll or not. +[618.85s -> 631.66s] And that means that the research itself may tell us very little about how children learn in everyday life and it also tells us very little about how adults learn because adults weren't in the experiment. +[631.70s -> 638.61s] Okay, now this is a criticism of the Bobo doll study specifically however +[638.61s -> 649.60s] bear in mind the Bobo doll study underpins social learning theory and so technically it is also a limitation of social learning theory okay also remember please that +[649.60s -> 663.14s] In order to make this point effective, you have to link it to social learning theory and the Bobo doll study. You can't say that it's a lab study and therefore it's artificial and demand characteristics might have been a problem. +[663.14s -> 674.91s] If you do that, then you are simply providing a generic methodological limitation of lab studies, and it won't be creditworthy. You must tell us why... +[674.91s -> 679.73s] demand characteristics could have occurred in the Bobo doll study specifically. +[680.27s -> 690.90s] And that brings us to the end of the video. Now remember there are going to be some example exam questions linked on the screen now and so you can go and have a look at them if you want. +[690.90s -> 701.47s] The list of exam questions will get longer over time, so keep going back to see the new content. If you've got any questions, please pop them in the comment section below and I'll get back to you as soon as I can. +[701.47s -> 706.77s] I hope this has been helpful and I hope it's all made sense and thank you very much for listening. diff --git a/VideoMMMU_ASR_large/Humanities/new_Psychology_2.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Psychology_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b1fa5de6f5313deb7494663cce76bc327fd698bb --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Psychology_2.mp4.txt @@ -0,0 +1,30 @@ +[15.73s -> 26.08s] In the context of the operant conditioning theory, we use many everyday terminologies such as the words positive and negative. In everyday context, +[26.08s -> 38.77s] the word positive could be meaning something good and negative as something bad however in the context of the operant conditioning theory this is not what these words mean +[38.90s -> 51.82s] In the context of operant conditioning, the terminology positive stands for adding something and negative stands for removing something. Now keep this in mind. +[51.82s -> 58.38s] as it will help you understand the concepts of reinforcement and punishment even better. +[63.95s -> 75.25s] Now that we understand the concept of positive and negative in the context of operating conditioning, let's move on to understanding the concept of reinforcement or a reinforcer. +[75.98s -> 87.87s] A reinforcer can be defined as anything that increases the likelihood that a specific behavior will occur with greater intensity if the reinforcer is paired with that activity. +[87.87s -> 93.97s] A reinforcer can be a positive reinforcer or a negative reinforcer +[94.80s -> 107.98s] A positive reinforcer is a desirable stimulus which is added following an action with an intention to increase the said behaviour. Take for example, every time you finish your homework, +[107.98s -> 120.91s] your mother gives you your favourite treats or candies. In this scenario, the candies are the positive reinforcer that is likely to shape your behaviour to finish homework on time every day. +[120.91s -> 131.01s] Interestingly enough, it has been found that positive reinforcers or positive reinforcement can be used as a learning tool as it is extremely effective. +[131.01s -> 145.20s] For instance, it has been found that one of the most effective ways to increase achievement in school districts with below-average reading scores was to pay children to read wherein paying acted as a positive reinforcer. +[145.20s -> 149.41s] Freuer in 2010 found evidence for this. +[149.41s -> 163.70s] This study showed that when second grade students in Dallas were paid $2 each time they read a book and passed a short quiz about the book, the reading comprehension of these second graders increased significantly. +[166.51s -> 180.94s] The negative reinforcement or negative reinforcer, on the other hand, is the removal of an undesirable stimulus which is subtracted or removed following an action with the intention to increase the said behaviour. +[181.07s -> 195.01s] Let's take an example from everyday life. For instance, you dislike getting stuck in traffic on your way to work on a Monday morning. So to avoid the traffic, you wake up early and leave early. +[195.01s -> 199.31s] and thereby you avoid all of that Monday morning rush. +[201.23s -> 214.62s] Negative reinforcers work to shape and modify behaviors because aversive stimuli tend to involve some type of discomfort, either physical or psychological. Behaviors are negatively reinforced. +[214.62s -> 228.02s] when they allow you to escape from the aversive stimuli that are already present or allow you to completely avoid the aversive stimuli before they happen. Now there are two forms of reinforcers. +[228.02s -> 232.75s] we have primary reinforcers and secondary reinforcers. +[234.77s -> 247.90s] A primary reinforcer is any reinforcer that has some form of innate reinforcing quality. This means that the presence of the primary reinforcer by itself is enough +[247.90s -> 257.07s] for behaviour modification in the context of operant conditioning. Some common examples from everyday life of primary reinforcers include +[258.03s -> 269.36s] food that you enjoy, money or monetary reward of some form, material possessions that you value and some form of comfort such as sleeping or taking a nap. +[269.39s -> 279.18s] This is not an exhaustive list, but some of the most common types of primary reinforcers that we have around us in everyday life. +[279.98s -> 289.62s] Secondary reinforcers on the other hand has no inherent value and only has reinforcing qualities when linked with a primary reinforcer. +[289.62s -> 303.44s] For instance, when one gets a promotion in a job, that by in itself might not be reinforcing. But the fact that makes a job promotion more reinforcing is the salary hike. +[303.44s -> 311.92s] or the primary reinforcer of monetary gains that comes with it. This is therefore an example of a secondary reinforcer. +[312.72s -> 324.54s] Alright, that is the end of today's video. If you haven't already, subscribe to Braincyclopedia today, leave a like, share this video with someone you think will benefit from today's content. +[324.54s -> 332.93s] Comment below and leave your feedback or a future video request and press the bell icon to remain updated about new uploads. +[332.93s -> 345.33s] Follow us on all of our social media sites and join the family. The link of all of these sites are in the description box below. If you liked our content, please consider making a donation to our channel. +[345.33s -> 355.57s] on our buymecoffee.com page. The link of this will be pinned to the comment section as well as in the description box below. See you in our next video. diff --git a/VideoMMMU_ASR_large/Humanities/new_Psychology_3.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Psychology_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..75af3a2572b1df7f779a6a2aaa822bac23ce3bf3 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Psychology_3.mp4.txt @@ -0,0 +1,74 @@ +[3.28s -> 8.50s] Welcome to a video introduction to the major perspectives in psychology. +[12.11s -> 24.58s] The main objective is to differentiate between the seven perspectives in psychology. We will provide an overview of the seven perspectives and the biopsychosocial perspective. +[24.58s -> 34.26s] which is an integration of all seven perspectives. Then we will finish with a set of review questions to check for understanding. Here we go! +[37.87s -> 51.15s] The seven major perspectives in psychology are the psychodynamic, behavioral, humanistic, cognitive, biological, evolutionary, and sociocultural viewpoints. +[51.15s -> 55.15s] We will cover each in order, starting with the psychodynamic. +[59.41s -> 70.58s] The psychodynamic perspective is one of the earliest in psychology. In the early 1900s, Sigmund Freud, pictured at the left, is credited with founding the psychoanalytic viewpoint. +[70.58s -> 84.18s] which was the precursor to the modern psychodynamic approach. The main emphasis of the psychodynamic perspective is to uncover the unconscious dynamics, motives, and conflicts in the mind. +[84.18s -> 93.73s] The word unconscious refers to aspects of our mind that we're not aware of, and they're often rooted in our early childhood. +[93.73s -> 101.94s] Freud saw dream analysis as one way to uncover that latent or hidden meanings from the unconscious. +[102.06s -> 116.70s] When trying to differentiate the psychodynamic from the other perspectives look for key words like the unconscious or unresolved conflicts and focused on early or childhood experiences +[116.70s -> 123.38s] Other words like defense mechanisms and repression also reflect the psychodynamic view. +[124.69s -> 137.42s] One way to think about the psychodynamic perspective is through road rage. Have you ever felt intense road rage or witnessed someone else's and wondered what happened to them? +[137.42s -> 146.26s] maybe in their past, perhaps their childhood, to cause them so much anger and so much rage? That's a psychodynamic question. +[148.98s -> 162.10s] The behavioral perspective rejected studying the unobservable, unconscious mind of psychoanalytic theory. The behavioral perspective is strongly associated with learning. +[162.45s -> 175.52s] Early behavioral psychologists like John Watson and BF Skinner, both pictured at the top left, studied how the environment shapes our objective, observable behaviors. +[175.52s -> 190.38s] They thought to make psychology a true science, we should only study behavior that we can see and measure. They often used animals in their research, such as rats and the pigeon that's pictured at the bottom left. +[190.77s -> 205.42s] The crux of the behavioral perspective is how we learn. Key words to remember for the behavioral perspective are learning, conditioning, which is a fancy word for learning, reinforcement, and punishment. +[205.65s -> 212.72s] A simple example of the behavioral perspective shows how quickly we learn from experience. +[213.71s -> 227.89s] Why don't we touch a hot stove more than once? Because we learn from experience. In this gif, it seems like the cat has learned this lesson before the young boy and tries to protect him. +[227.89s -> 229.74s] from touching the hot oven. +[234.13s -> 245.82s] The humanistic perspective is sometimes called the third wave in psychology. It differed from the deterministic views of the psychodynamic and behavioral perspectives. +[245.82s -> 259.70s] Whereas psychoanalysts saw humans as controlled by unconscious early experience, and behaviorists saw humans as controlled by what they've learned from their experiences, humanists +[259.70s -> 273.49s] emphasized free will. In the 1960s people like Abraham Maslow and Carl Rogers, both pictured at the top right, saw human nature as positive and seeking growth. +[273.49s -> 279.66s] or to be the best version of ourselves, which Maslow termed self-actualization. +[279.66s -> 289.09s] You may be familiar with Maslow's hierarchy of needs and you've seen his pyramid before with self-actualization at the top and the lower needs below it. +[289.09s -> 295.06s] I found this fake version bottom right with Wi-Fi as the most basic human need. +[295.54s -> 309.78s] Key words to look for in the humanistic perspective are self-actualization, free will, choice, positive growth, and unconditional positive regard, which means showing warmth to others, +[309.78s -> 320.88s] without conditions. Humanistic psychologists want to encourage people to live their best lives which led to the foundation of positive psychology. +[320.98s -> 329.07s] In this gif, you can see Betty Boop dancing with her pals, clearly living their best lives. That's humanism. +[333.07s -> 343.63s] The cognitive perspective takes us back to the mind, but with a modern and experimental focus. It can be summarized in one word. Thinking. +[344.05s -> 358.53s] cognitive psychologists are interested in the mental processes used in thinking, knowing, remembering, and communicating. The big difference between the cognitive and the psychoanalytic view +[358.53s -> 362.77s] was that the cognitive view is focused on conscious thought. +[363.02s -> 375.41s] Whereas behaviorists focused on things you could see like observable behaviors, cognitive psychology refocuses on the covert or the mind and thinking. +[375.86s -> 388.40s] The cognitive perspective uses keywords with versions of the words like think, thoughts, memory, the mind, attention, and information processing. +[388.94s -> 397.04s] The cognitive perspective often wants to know how our thoughts affect how we interpret different situations. +[397.97s -> 405.71s] So in this gift prank, the floor of the elevator is a video screen, and the floor appears to drop while two men stand on it. +[406.22s -> 415.92s] Their interpretation of the falling floor causes them to jump back and grab the handrails. It's their thoughts that are driving their actions. +[419.09s -> 432.37s] The biological perspective in psychology is sometimes referred to as the medical model when talking about mental illness, or considered the neuroscience perspective because of a heavy emphasis on the brain. +[432.78s -> 441.87s] biological psychologists are interested in the genetics and physical body especially the brain just like this brain animation +[441.94s -> 455.22s] They study the brain's specialized cells or neurons and neurotransmitters. Other key terms for the biological perspective are genes, the nervous system, and hormones. +[455.66s -> 467.04s] One important question for biological psychologists, which we'll cover in the unit on health, is how does chronic stress impair our immune system? Have you ever noticed +[467.04s -> 474.83s] that you're the most likely to get sick right around midterms or finals week, that's a contribution of the biological perspective. +[478.19s -> 490.38s] In a similar vein to the biological perspective is the evolutionary view. Evolutionary psychology is grounded in Charles Darwin's theory of evolution and Darwin's pictured at the left. +[490.42s -> 502.86s] The evolutionary perspective often seeks to answer the why questions about human thinking and behavior. They rely on principles like natural selection and adaptation. +[502.86s -> 517.10s] the roles of survival and reproduction in favoring some ways of thinking and acting over others. The key words here are versions of the words adapt, survive, reproduce, +[517.10s -> 525.81s] natural selection. One applied why question is why do people get jealous? +[526.86s -> 539.23s] What's the purpose? An evolutionary psychologist would question how jealousy might have been adaptive or useful for our ancestors to help them survive and reproduce. +[539.23s -> 553.23s] Jealousy might function to secure access to a mate or to ward off rivals. Jealousy is an emotion common across cultures which suggests it might have an evolutionary basis. +[556.21s -> 567.74s] The last unique perspective is the sociocultural view. Influenced by sociology, the sociocultural perspective often takes a broader look at human behavior. +[567.74s -> 580.11s] They study how social interaction and culture influences behavior and mental processes. Key words to look for with the sociocultural perspective are society, +[580.11s -> 594.51s] culture, norms, social interaction, and social categories like gender, race, ethnicity, socioeconomic class or social class, and even religion or occupation. +[594.80s -> 603.57s] A sociocultural theorist would be interested in questions like, how does poverty affect both health and mental illness? +[603.95s -> 616.08s] In this GIF, you can see how the rates of poverty changed in the U.S. from 1998 through 2012. They increased dramatically throughout the South and parts of Appalachia. +[616.08s -> 622.51s] There is a relationship between these patterns of poverty and health and mental health outcomes. +[627.89s -> 635.15s] We've covered all the unique perspectives and understandably students often ask which one is right? +[635.41s -> 648.80s] Well, there's no right or best perspective. The modern view and the one that most psychologists adopt for studying the complexity of human thinking and behavior is the biopsychosocial model. +[648.80s -> 651.57s] which is also called an eclectic view. +[652.11s -> 664.66s] This model seeks to unify modern psychology by seeing all of the perspectives as interacting and interrelated. They see everything as connected. +[664.72s -> 672.30s] Now that we've covered all the individual perspectives and the biopsychosocial model, it's time to review +[675.73s -> 682.70s] Which psychological perspective focused on conscious thought? +[686.90s -> 692.27s] the cognitive perspective, emphasizing thinking and thought processes. +[694.90s -> 707.73s] Which psychological perspective was interested in how people can achieve their full potential by making positive choices? That's +[708.24s -> 713.87s] That's the humanistic perspective with a focus on positive growth and free will. +[717.62s -> 732.02s] Which psychological perspective focused on the role of adaptive behavior? That's Darwin and the evolutionary view. +[736.02s -> 743.44s] Which psychological perspective would study how genes influence criminal actions? +[746.83s -> 751.66s] That's the biological perspective with its focus on genetics. +[756.88s -> 763.34s] Which psychological perspective focused on the role of the environment shaping how we learn? +[768.69s -> 772.53s] That's the behavioral viewpoint, focusing on learning. +[776.40s -> 785.07s] Which psychological perspective seeks to integrate the approaches to better understand complex thoughts and behaviors? +[789.33s -> 793.84s] That's our integrated view of the biopsychosocial model. +[798.67s -> 812.50s] Which psychological perspective examines unconscious conflicts from early childhood? That's the psychodynamic view +[816.72s -> 825.23s] Which psychological perspective would investigate how social norms influence the amount of eye contact that we consider normal? +[830.38s -> 832.75s] That would be the socio-cultural view. +[835.54s -> 848.75s] And that concludes our review. I hope you found this helpful as a good way to review the seven major perspectives in psychology. The following are the image credits and then followed by some of the gift credits. Thank you. diff --git a/VideoMMMU_ASR_large/Humanities/new_Psychology_4.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Psychology_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..75af3a2572b1df7f779a6a2aaa822bac23ce3bf3 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Psychology_4.mp4.txt @@ -0,0 +1,74 @@ +[3.28s -> 8.50s] Welcome to a video introduction to the major perspectives in psychology. +[12.11s -> 24.58s] The main objective is to differentiate between the seven perspectives in psychology. We will provide an overview of the seven perspectives and the biopsychosocial perspective. +[24.58s -> 34.26s] which is an integration of all seven perspectives. Then we will finish with a set of review questions to check for understanding. Here we go! +[37.87s -> 51.15s] The seven major perspectives in psychology are the psychodynamic, behavioral, humanistic, cognitive, biological, evolutionary, and sociocultural viewpoints. +[51.15s -> 55.15s] We will cover each in order, starting with the psychodynamic. +[59.41s -> 70.58s] The psychodynamic perspective is one of the earliest in psychology. In the early 1900s, Sigmund Freud, pictured at the left, is credited with founding the psychoanalytic viewpoint. +[70.58s -> 84.18s] which was the precursor to the modern psychodynamic approach. The main emphasis of the psychodynamic perspective is to uncover the unconscious dynamics, motives, and conflicts in the mind. +[84.18s -> 93.73s] The word unconscious refers to aspects of our mind that we're not aware of, and they're often rooted in our early childhood. +[93.73s -> 101.94s] Freud saw dream analysis as one way to uncover that latent or hidden meanings from the unconscious. +[102.06s -> 116.70s] When trying to differentiate the psychodynamic from the other perspectives look for key words like the unconscious or unresolved conflicts and focused on early or childhood experiences +[116.70s -> 123.38s] Other words like defense mechanisms and repression also reflect the psychodynamic view. +[124.69s -> 137.42s] One way to think about the psychodynamic perspective is through road rage. Have you ever felt intense road rage or witnessed someone else's and wondered what happened to them? +[137.42s -> 146.26s] maybe in their past, perhaps their childhood, to cause them so much anger and so much rage? That's a psychodynamic question. +[148.98s -> 162.10s] The behavioral perspective rejected studying the unobservable, unconscious mind of psychoanalytic theory. The behavioral perspective is strongly associated with learning. +[162.45s -> 175.52s] Early behavioral psychologists like John Watson and BF Skinner, both pictured at the top left, studied how the environment shapes our objective, observable behaviors. +[175.52s -> 190.38s] They thought to make psychology a true science, we should only study behavior that we can see and measure. They often used animals in their research, such as rats and the pigeon that's pictured at the bottom left. +[190.77s -> 205.42s] The crux of the behavioral perspective is how we learn. Key words to remember for the behavioral perspective are learning, conditioning, which is a fancy word for learning, reinforcement, and punishment. +[205.65s -> 212.72s] A simple example of the behavioral perspective shows how quickly we learn from experience. +[213.71s -> 227.89s] Why don't we touch a hot stove more than once? Because we learn from experience. In this gif, it seems like the cat has learned this lesson before the young boy and tries to protect him. +[227.89s -> 229.74s] from touching the hot oven. +[234.13s -> 245.82s] The humanistic perspective is sometimes called the third wave in psychology. It differed from the deterministic views of the psychodynamic and behavioral perspectives. +[245.82s -> 259.70s] Whereas psychoanalysts saw humans as controlled by unconscious early experience, and behaviorists saw humans as controlled by what they've learned from their experiences, humanists +[259.70s -> 273.49s] emphasized free will. In the 1960s people like Abraham Maslow and Carl Rogers, both pictured at the top right, saw human nature as positive and seeking growth. +[273.49s -> 279.66s] or to be the best version of ourselves, which Maslow termed self-actualization. +[279.66s -> 289.09s] You may be familiar with Maslow's hierarchy of needs and you've seen his pyramid before with self-actualization at the top and the lower needs below it. +[289.09s -> 295.06s] I found this fake version bottom right with Wi-Fi as the most basic human need. +[295.54s -> 309.78s] Key words to look for in the humanistic perspective are self-actualization, free will, choice, positive growth, and unconditional positive regard, which means showing warmth to others, +[309.78s -> 320.88s] without conditions. Humanistic psychologists want to encourage people to live their best lives which led to the foundation of positive psychology. +[320.98s -> 329.07s] In this gif, you can see Betty Boop dancing with her pals, clearly living their best lives. That's humanism. +[333.07s -> 343.63s] The cognitive perspective takes us back to the mind, but with a modern and experimental focus. It can be summarized in one word. Thinking. +[344.05s -> 358.53s] cognitive psychologists are interested in the mental processes used in thinking, knowing, remembering, and communicating. The big difference between the cognitive and the psychoanalytic view +[358.53s -> 362.77s] was that the cognitive view is focused on conscious thought. +[363.02s -> 375.41s] Whereas behaviorists focused on things you could see like observable behaviors, cognitive psychology refocuses on the covert or the mind and thinking. +[375.86s -> 388.40s] The cognitive perspective uses keywords with versions of the words like think, thoughts, memory, the mind, attention, and information processing. +[388.94s -> 397.04s] The cognitive perspective often wants to know how our thoughts affect how we interpret different situations. +[397.97s -> 405.71s] So in this gift prank, the floor of the elevator is a video screen, and the floor appears to drop while two men stand on it. +[406.22s -> 415.92s] Their interpretation of the falling floor causes them to jump back and grab the handrails. It's their thoughts that are driving their actions. +[419.09s -> 432.37s] The biological perspective in psychology is sometimes referred to as the medical model when talking about mental illness, or considered the neuroscience perspective because of a heavy emphasis on the brain. +[432.78s -> 441.87s] biological psychologists are interested in the genetics and physical body especially the brain just like this brain animation +[441.94s -> 455.22s] They study the brain's specialized cells or neurons and neurotransmitters. Other key terms for the biological perspective are genes, the nervous system, and hormones. +[455.66s -> 467.04s] One important question for biological psychologists, which we'll cover in the unit on health, is how does chronic stress impair our immune system? Have you ever noticed +[467.04s -> 474.83s] that you're the most likely to get sick right around midterms or finals week, that's a contribution of the biological perspective. +[478.19s -> 490.38s] In a similar vein to the biological perspective is the evolutionary view. Evolutionary psychology is grounded in Charles Darwin's theory of evolution and Darwin's pictured at the left. +[490.42s -> 502.86s] The evolutionary perspective often seeks to answer the why questions about human thinking and behavior. They rely on principles like natural selection and adaptation. +[502.86s -> 517.10s] the roles of survival and reproduction in favoring some ways of thinking and acting over others. The key words here are versions of the words adapt, survive, reproduce, +[517.10s -> 525.81s] natural selection. One applied why question is why do people get jealous? +[526.86s -> 539.23s] What's the purpose? An evolutionary psychologist would question how jealousy might have been adaptive or useful for our ancestors to help them survive and reproduce. +[539.23s -> 553.23s] Jealousy might function to secure access to a mate or to ward off rivals. Jealousy is an emotion common across cultures which suggests it might have an evolutionary basis. +[556.21s -> 567.74s] The last unique perspective is the sociocultural view. Influenced by sociology, the sociocultural perspective often takes a broader look at human behavior. +[567.74s -> 580.11s] They study how social interaction and culture influences behavior and mental processes. Key words to look for with the sociocultural perspective are society, +[580.11s -> 594.51s] culture, norms, social interaction, and social categories like gender, race, ethnicity, socioeconomic class or social class, and even religion or occupation. +[594.80s -> 603.57s] A sociocultural theorist would be interested in questions like, how does poverty affect both health and mental illness? +[603.95s -> 616.08s] In this GIF, you can see how the rates of poverty changed in the U.S. from 1998 through 2012. They increased dramatically throughout the South and parts of Appalachia. +[616.08s -> 622.51s] There is a relationship between these patterns of poverty and health and mental health outcomes. +[627.89s -> 635.15s] We've covered all the unique perspectives and understandably students often ask which one is right? +[635.41s -> 648.80s] Well, there's no right or best perspective. The modern view and the one that most psychologists adopt for studying the complexity of human thinking and behavior is the biopsychosocial model. +[648.80s -> 651.57s] which is also called an eclectic view. +[652.11s -> 664.66s] This model seeks to unify modern psychology by seeing all of the perspectives as interacting and interrelated. They see everything as connected. +[664.72s -> 672.30s] Now that we've covered all the individual perspectives and the biopsychosocial model, it's time to review +[675.73s -> 682.70s] Which psychological perspective focused on conscious thought? +[686.90s -> 692.27s] the cognitive perspective, emphasizing thinking and thought processes. +[694.90s -> 707.73s] Which psychological perspective was interested in how people can achieve their full potential by making positive choices? That's +[708.24s -> 713.87s] That's the humanistic perspective with a focus on positive growth and free will. +[717.62s -> 732.02s] Which psychological perspective focused on the role of adaptive behavior? That's Darwin and the evolutionary view. +[736.02s -> 743.44s] Which psychological perspective would study how genes influence criminal actions? +[746.83s -> 751.66s] That's the biological perspective with its focus on genetics. +[756.88s -> 763.34s] Which psychological perspective focused on the role of the environment shaping how we learn? +[768.69s -> 772.53s] That's the behavioral viewpoint, focusing on learning. +[776.40s -> 785.07s] Which psychological perspective seeks to integrate the approaches to better understand complex thoughts and behaviors? +[789.33s -> 793.84s] That's our integrated view of the biopsychosocial model. +[798.67s -> 812.50s] Which psychological perspective examines unconscious conflicts from early childhood? That's the psychodynamic view +[816.72s -> 825.23s] Which psychological perspective would investigate how social norms influence the amount of eye contact that we consider normal? +[830.38s -> 832.75s] That would be the socio-cultural view. +[835.54s -> 848.75s] And that concludes our review. I hope you found this helpful as a good way to review the seven major perspectives in psychology. The following are the image credits and then followed by some of the gift credits. Thank you. diff --git a/VideoMMMU_ASR_large/Humanities/new_Psychology_5.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Psychology_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c1d2bc453f7323ca4686c258e36cd3be2c27e757 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Psychology_5.mp4.txt @@ -0,0 +1,77 @@ +[0.11s -> 7.63s] Hello students and welcome back to our next lesson in our AS Psychology course. Today we'll be looking at using different research methods. +[8.85s -> 20.85s] So conducting research. In the field of psychology there are lots and lots of different experiments going on all the time and we're going to have to be using different sorts of methods and techniques in order to get the +[20.85s -> 34.03s] results that we want from these different experiments. So there's going to be different ways to collect the data and each of these different sort of methods and techniques are called research methods and they're going to have their advantages and disadvantages. +[34.42s -> 48.53s] So first we'll start with a laboratory or a lab experiment. And this is an investigation in a controlled environment where there is a direct manipulation of the variables. So it's going to measure the dependent variable versus the independent variable. +[49.62s -> 62.80s] Its advantages are that you can easily control all the variables because you are in a controlled environment where only you manipulate everything going on. As a result, there's going to be sort of less errors and confounding variables which you can then control. +[63.28s -> 74.86s] The controlled conditions also make it more replicable and more valid, so you can conduct the experiment many times in order to try and get an average, and you should always get the same result because you are in a controlled environment. +[75.18s -> 87.82s] Also, it is much easier to decipher what the cause and the effect was because there are no other sort of extraneous or confounding variables that could mess with what the cause and effect really is. +[88.69s -> 103.18s] However, it does have its disadvantages. The first one being that it lacks ecological validity. And what this means is that ecological validity relates to really how like a real life situation it is. +[103.18s -> 116.54s] And because it isn't really a true reflection of what real life would be, we would call that it lacks mundane realism. And as a result, what we conduct in a lab may not really be the same. +[116.54s -> 131.38s] things that would happen in the real world. So as a result the sort of results that we get from that experiment may not be as valid as it would be if we were to conduct them in the real world where we do have a bunch of confounding variables that would impact the effect of whatever we're investigating. +[131.82s -> 140.42s] Another disadvantage is that if people are tested in a lab, they may be subject to things we call demand characteristics and evaluation apprehension. +[140.42s -> 151.06s] Now, what this means is that when people are being tested, they may behave differently or do things differently and not act the same because they know they are being tested. +[151.15s -> 161.65s] So as a result, because people aren't acting as their selves, this may not give a true indication of results to what really was going to be investigated and what the results should be. +[162.38s -> 174.61s] Next up we have a field experiment. This sort of contrasts from a lab experiment because instead of being in a controlled environment it is in a natural environment where an independent variable is manipulated to see its effect on the dependent variable. +[174.99s -> 189.76s] And of course we can pretty much take a look at the lab experiments advantages and disadvantages and contrast them. Its advantages are that it has higher ecological validity, less evaluation apprehension and demand characteristics. +[189.76s -> 201.97s] However, its disadvantages are that it is hard to control variables, people may not give informed consent, and it is harder to replicate. So, pretty much the opposite to what a lab experiment really is. +[203.44s -> 211.30s] Next up we have a natural quasi-experiment and this is the study of effects of a natural event where the independent variable is... +[211.30s -> 222.54s] sort of naturally manipulated. So an example of a natural quasi event may be the study of the impact on stress or anxiety of people following a volcanic eruption. +[222.90s -> 236.62s] So its main advantage is that it's going to have extremely high ecological validity because it is sort of natural observation in a natural event with naturally in sort of manipulated variables, so +[236.62s -> 243.95s] If you're going to take one word away from all this explanation, it is the word natural. It has very high ecological validity. +[244.75s -> 255.50s] Also, as the research has very little involvement, there are going to be much fewer demand characteristics and evaluation apprehension. So, it kind of seems... +[255.50s -> 264.66s] its advantages are exactly the same as a field study. So as a result, we can, you know, in our minds, using sort of what we've learned so far from the field experiment. +[264.66s -> 276.22s] Also decipher that the disadvantages are that it's hard to replicate and harder to control the variables and there may be very many confounding or extraneous variables which impact the sort of experiment. +[276.22s -> 285.46s] confounding variables and extraneous variables b variables which we have not accounted for in the first place and you can't really control so for example like the time of day +[285.58s -> 300.18s] Also, a disadvantage is that there are few opportunities to study these natural events. So we all know that a volcanic eruption doesn't come along all that often. So as a result, it's going to be hard to check or reconduct these experiments. +[300.18s -> 312.06s] experiments again and again. Another research method is correlational analysis, and this is a technique to see if a dependent variable and an independent variable are associated. +[312.06s -> 325.84s] And then it also measures the strength. So if you imagine a sort of scatter graph, that is what correlational analysis is really for. So drawing up the scatter graph is really correlational analysis. So the relationship can be casual. +[325.84s -> 339.90s] which means that there is a definite link between one variable and another. It can be left to chance, which means by some sort of lucky outcome there is an actual relationship when perhaps there may not have been. +[339.90s -> 350.86s] Or the relationship can be due to a confounding variable, which means that an anomalous or extraneous variable out there has made there be a correlation when really there shouldn't be in the first place. +[351.98s -> 356.98s] So it of course is going to have its advantages advantages the main advantage +[356.98s -> 371.25s] being that it allows to measure the strength of the correlation and trends can lead to research in a new sort of different project. So if we find out that there is a correlation between a number of ice cream sales and number of sort of. +[371.25s -> 384.74s] tuberculosis cases there may be a relationship between the two so there will be more research projects in order to try and see if sort of tuberculosis is linked towards the distribution of ice cream which you know sounds +[384.74s -> 391.28s] uh crazy which we will probably know but it's just an example okay next up we have its disadvantages +[391.28s -> 401.78s] And one of them is that it doesn't show the effect of confounding variables. So as a result, if there is a confounding variable, it's not going to show how the confounding variable actually affected the correlation. +[401.78s -> 414.22s] Similarly, we can't tell which variable will cause which, so whether it's the dependent variable which influenced the independent, or vice versa. And also, it doesn't state whether the relationship... +[414.38s -> 428.11s] whether the chance relationship that is is caused by the correlation whether it was just pot luck or whether you know the chance relationship may actually be casual but we actually you know haven't conducted enough research to find out if it actually is +[429.30s -> 439.89s] Next up we have naturalistic observation and what this is is that it's observing behaviour in a natural setting where the researcher does not influence the behaviour at all. +[440.11s -> 450.90s] So this can be a disclosed study of naturalistic observation, and this is where the researcher reveals himself or herself to the group, or an undisclosed +[450.90s -> 460.02s] sort of naturalistic observation where the researcher will remain hidden and observe everyone just from a remote area where they won't be able to tell that he or she is watching. +[460.94s -> 475.47s] The advantages are that it has high ecological validity because people will be in a natural setting. And also, if undisclosed, there will be no demand characteristics. So it pretty much reflects the real life situation and should give good results. +[475.47s -> 487.50s] However, the disadvantage is that if it is sort of disclosed there are definitely demand characteristics and evaluation apprehension So people will act differently and you won't get the results you wanted +[487.92s -> 499.78s] Also, it is hard to replicate because in a natural setting things are going to change every time you study it and Also, there is such thing called observer bias, which means the person that is observing +[499.78s -> 512.11s] may have sort of different subjective ideas of what the behavior is to another psychologist, for example. So as a result, that difference in views is called observer bias and their clash of +[512.11s -> 523.94s] observations may lead to invalid results if one of them is wrong and the other one is right. And finally, it is hard to control the variables because, of course, it is in a natural setting. +[523.94s -> 533.49s] So so far we've looked at quite a few of these cases already and you may have sort of observed that a lot of the disadvantages and advantages are very similar. +[533.49s -> 547.66s] Now, you can probably draw links between them. Those that are in a natural environment, in a natural setting, are going to have high ecological validity and are going to be hard to control the variables and hard to replicate, etc. So if you're ever stuck on the exam, just think. +[547.66s -> 562.26s] natural settings what can i gather from this and just right away you should be able to pick up the marks that you need to you know get full marks on that question next up we have controlled observation and this is basically observing behavior in a natural environment +[562.26s -> 572.14s] but the researcher can manipulate the effects of the situation. So it's kind of like the naturalistic observation, but the researcher then can change the sort of what's going on in the people's lives. +[572.14s -> 583.10s] So again, notice how it is a natural environment. So of course, we're going to know from our advantages and disadvantages, there's going to be high ecological validity and harder to control the variables. +[583.10s -> 591.63s] However, because it is a controlled observation, it's going to be a lot easier to replicate since the variables are going to be controlled yourself. +[591.95s -> 604.50s] And also because the setting is going to be controlled to a certain degree, it is easier for the researcher to focus on the behaviour because he's going to tell how they react to whatever aspects are being manipulated. +[605.01s -> 619.47s] Similarly, the disadvantage is are a lot similar to that of natural observation, and that is that there is going to be observed bias. And if undisclosed, there may be demand characteristics and evaluation apprehension. +[619.47s -> 631.98s] also okay so next up we have participant observation and what this is this is observing behavior from a natural setting where the researcher joins in the group for their everyday life +[631.98s -> 643.79s] So of course see how it says natural setting there is going to be high ecological validity, you know It's not gonna lack mundane realism and it's going to be easier to focus the behavior if the observer is in the group +[643.86s -> 655.52s] However, this is going to have a lot of disadvantages because there is no informed consent. It will be very hard to replicate. Since it is an observational method, there's going to be observer bias. +[655.52s -> 664.10s] and the presence of the researcher may influence the results because the researcher will in fact be +[664.10s -> 673.01s] Disclosed so he's going so he or she is going to show to the group that he's going to be there or she's going to be there And then as a result, they're going to act differently +[673.49s -> 680.66s] Okay, next up we have questionnaires, and this is a list of pre-written questions which a participant will answer. +[680.94s -> 690.90s] So you can probably think of these advantages and disadvantages yourself. It's fast, cheap, easy to replicate and the closed questions can be easily analysed and put into groups categorically. +[690.90s -> 705.41s] And disadvantages are that there's going to be a low response rate, close questions are going to give limited responses. There can be, you know, evaluation, apprehension and social desirability effects where people answer incorrectly just to make themselves look good. +[705.41s -> 716.72s] And also, if you do write a questionnaire with open questions, those are going to be hard to categorise and analyse. So a questionnaire is pretty straightforward, you can probably think of these yourself and just write away without even having to study it. +[717.20s -> 726.61s] Okay, the structured interview is a little more complicated. This is a conversation between the participant and the researcher where fixed questions are asked in a particular order face-to-face. +[726.61s -> 736.69s] so the advantages are that it will be fast cheap and easy to replicate just like a questionnaire and a researcher can easily focus on what he or she would like to see +[736.82s -> 749.60s] However, the disadvantages are that the closed questions will give limited responses, there can be social desirability effect, and evaluation apprehension. So, pretty much exactly the same as questionnaires, however... +[749.60s -> 757.68s] Because it is a structured interview, the researcher can focus on what he or she will want to pretty much take from the interview themselves. +[758.90s -> 768.96s] Okay, and finally we have unstructured interviews, and this is a conversation between the researcher and their participant with no fixed questions in no particular order. +[768.96s -> 777.89s] So, this will provide qualitative data, which is going to be in much more detail and easier to draw conclusions from, but it will be harder to categorise. +[777.89s -> 788.70s] And also it can develop into clearer answers with more profound meaning so the researcher can have a better idea of what the answers to the questions are really going to be, you know, meaning. +[788.70s -> 798.29s] However, the disadvantages are that there is going to be demand characteristics. It is going to be hard to compare and hard to replicate because there will be qualitative data. +[798.29s -> 809.86s] And also investigators may manipulate the answers if they are sort of asking the questions and writing down the answers. There may be some sort of... +[809.86s -> 817.42s] influential factor which causes the researcher or observer to then change what the answers really were. +[818.74s -> 832.27s] Okay, so here are some questions. What I'd like you to do is to pause the video and answer these. I would advise you to hide your notes so you can just do this from memory. And once you're ready, hit the play button and see how many of these questions you have gotten right. +[834.29s -> 841.89s] Okay, so here are the answers. If you did get all of them right, congratulations. I would advise you to move on to the next. +[841.89s -> 851.47s] video but if not I'd advise you to just go over your notes or rewind so that you can Check out what you have done wrong so you can get them right for your next test +[852.59s -> 857.66s] Okay, so this is the end of the lesson. Next lesson we will be looking at research design. +[857.66s -> 870.53s] If you are studying any other A-level subjects, I'd advise you to check out the channel and hopefully there you can find out the revision material you need in order to get your grades that you really want to get in them for the exams at the end of the year. +[870.53s -> 873.77s] So until then, thank you so much for watching and I'll see you next time. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_1.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ac1881608db4cb783197964bdee4aa407ceb9d21 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_1.mp4.txt @@ -0,0 +1,47 @@ +[1.36s -> 7.63s] Welcome to this Cheetah2U introduction to sociology topic video looking at social class. +[11.76s -> 22.64s] Sociologists often discuss the differences between social classes in the UK and how this shapes their experiences and life chances. But what is social class? +[23.15s -> 35.54s] Social class is a form of stratification of society. That is, a way of organising people based upon their social, cultural and economic characteristics to create a hierarchy within society. +[36.43s -> 51.41s] Traditionally, people were sorted into different social classes based upon their occupations and how skilled their work was perceived to be. But in more recent times, and with changes to the way we work, this is less useful in contemporary society. +[52.56s -> 61.74s] Many people choose to define their own social class and therefore class is seen as a subjective measurement of an individual's status in society. +[62.22s -> 74.46s] People are able to assign themselves to social class groups based upon the characteristics that they identify with the most. However, this also means that people can be categorized by others. +[74.46s -> 80.69s] as belonging to a particular social class and this can be a source of conflict and tension in society. +[86.77s -> 99.02s] The structure of the social class hierarchy has become more complex over the years, particularly with increased levels of education, de-skilling of workers and changes to sectors in which people are employed. +[99.86s -> 110.10s] On a very basic level, the traditional definitions of social class focus on three distinct groups. The upper class, the middle class and the working class. +[110.67s -> 119.79s] The upper class, often referred to as the elite, are those in society with the most power and resources often inherited from their families. +[120.30s -> 129.39s] The upper class also includes those who are titled, again often inherited titles such as hereditary peerages, lords and members of royalty. +[130.38s -> 142.64s] The middle class is traditionally defined as those in non-manual professions, particularly those in professional employment. Doctors, lawyers, accountants and even teachers are perceived to be from the middle classes. +[143.47s -> 155.95s] But as employment has changed and the UK economy has moved from being based on heavy industry to the service sector, this creates problems for our definition of middle class as non-manual labour. +[157.39s -> 163.82s] The working class are associated with manual occupations, construction, labouring and manufacturing. +[164.08s -> 177.17s] this definition is simplistic however as many in skilled trades such as plumbing electricians and construction will earn more than those in lower administrative positions such as clerical work and retail management +[177.20s -> 189.01s] yet will be perceived to be of a lower class. This demonstrates why occupation and income are insufficient to measure an individual social class in the 21st century. +[195.15s -> 202.99s] More recent measures of social class have attempted to examine the different tastes, attributes and likes of those in different social classes. +[204.14s -> 214.61s] French sociologist Pierre Bourdieu found that individuals of similar status tend to have similar tastes and attributes, what he called their habitus. +[215.09s -> 227.41s] This included both their occupation and their income, but also their levels of education and their social connections, and this interpretation is often used in more contemporary measures of social class. +[227.41s -> 241.07s] such as the Great British Class Survey in the early 21st century. More contemporary measures of class suggest there are up to seven distinct social groups based upon combinations of occupation, education and social connections. +[242.51s -> 253.34s] despite this greater prominence is given in society to individuals whose occupation is seen to be more valuable to society politicians business leaders doctors and lawyers +[253.34s -> 266.38s] are given higher status in society than nurses teachers factory workers and those working in public transport despite the importance of the latter roles to the functioning of the economy and the well-being of the nation +[266.38s -> 270.10s] as evidenced by the COVID-19 pandemic lockdowns. +[276.53s -> 287.18s] Sociologists that examine the relevance of social class suggest that individual social class influences their life chances, and this is explored throughout most sociology courses. +[288.02s -> 295.09s] Generally speaking, the lower an individual's social class, the more likely they are to suffer from a disadvantaged position. +[295.41s -> 303.57s] Those in working class areas will have a lower life expectancy than those in more affluent areas and also spend more of their life in poor health. +[304.02s -> 318.53s] for pupils from economically disadvantaged backgrounds they are less likely to achieve good educational outcomes than their peers whilst those in the lower social classes are often underrepresented in positions of power the media and in higher education +[318.53s -> 331.62s] particularly those universities with elite status. On an individual level, lower social classes are more likely to be disadvantaged in having access to adequate housing, have diets that are imbalanced, +[331.62s -> 345.42s] have limited access to a full range of healthcare provision, such as mental health services and preventative screening measures, attend schools with lower levels of achievement and funding, and face social exclusion in society. +[346.00s -> 356.37s] While some sociologists argue that class is no longer relevant, the scale of disadvantage for those in the lower social classes from birth to old age would suggest otherwise. +[360.27s -> 368.14s] Different sociological perspectives will take differing views of both the experiences of different social classes and the structure of the class system. +[369.04s -> 377.82s] Functionists argue that social class differences are inevitable in society, as society is meritocratic. People are rewarded based on their abilities. +[377.82s -> 384.88s] And this means that people who work hard and have the right attributes will be able to gain status and become socially mobile. +[385.65s -> 397.74s] They suggest that there is equality of opportunity in society and that everybody has the chance to succeed, and those that do are rewarded with higher status positions, what they call achieved status. +[398.93s -> 404.50s] Marxism, with its focus on class conflict, perhaps unsurprisingly would disagree. +[404.94s -> 415.82s] Traditional Marxists suggest that individuals are allocated to one of two social classes, the bourgeoisie and the proletariat, based upon their relationship to the means of production. +[416.30s -> 425.65s] If an individual owns capital, factories and resources, they are the bourgeoisie. If not, they are workers or the proletariat. +[426.13s -> 435.95s] This is quite a broad interpretation that concentrates most of society's power into the hands of very few individuals, something other sociologists have rejected. +[439.60s -> 453.74s] The New Right, like functionists, see society as meritocratic, but they also argue that there exists a further social class beneath the traditional working class, what they call the underclass. Those unable or unwilling to work. +[453.74s -> 456.24s] and are dependent upon state benefits. +[456.88s -> 471.28s] the new right argue that the underclass are inadequately socialized and the cause of many social problems in society something other sociological approaches criticize the new right for as being victim blaming and scapegoating +[472.66s -> 485.17s] Other approaches, such as postmodernists, reject the influence of individual social class, suggesting that society is too fragmented for individuals to conform to the norms and values of different social classes. +[485.20s -> 491.79s] stating that the greater individualism in society means that these collective norms and values no longer apply. +[492.98s -> 505.07s] Finally, social action theorists, such as Weber, have rejected Marx's idea of a simplified two-class system, instead suggesting that social class is multifaceted and diverse, +[505.07s -> 516.91s] taking into account an individual's economic situation their status in society and the power they have in their relationships with others arguing that social class is a subjective interpretation +[516.91s -> 525.68s] and as a result needs to be examined on an individual basis rather than attempting to categorise individuals into specific social classes. +[528.66s -> 535.54s] That concludes this tutor to you introduction to sociology topic video on social class. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_2.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ac1881608db4cb783197964bdee4aa407ceb9d21 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_2.mp4.txt @@ -0,0 +1,47 @@ +[1.36s -> 7.63s] Welcome to this Cheetah2U introduction to sociology topic video looking at social class. +[11.76s -> 22.64s] Sociologists often discuss the differences between social classes in the UK and how this shapes their experiences and life chances. But what is social class? +[23.15s -> 35.54s] Social class is a form of stratification of society. That is, a way of organising people based upon their social, cultural and economic characteristics to create a hierarchy within society. +[36.43s -> 51.41s] Traditionally, people were sorted into different social classes based upon their occupations and how skilled their work was perceived to be. But in more recent times, and with changes to the way we work, this is less useful in contemporary society. +[52.56s -> 61.74s] Many people choose to define their own social class and therefore class is seen as a subjective measurement of an individual's status in society. +[62.22s -> 74.46s] People are able to assign themselves to social class groups based upon the characteristics that they identify with the most. However, this also means that people can be categorized by others. +[74.46s -> 80.69s] as belonging to a particular social class and this can be a source of conflict and tension in society. +[86.77s -> 99.02s] The structure of the social class hierarchy has become more complex over the years, particularly with increased levels of education, de-skilling of workers and changes to sectors in which people are employed. +[99.86s -> 110.10s] On a very basic level, the traditional definitions of social class focus on three distinct groups. The upper class, the middle class and the working class. +[110.67s -> 119.79s] The upper class, often referred to as the elite, are those in society with the most power and resources often inherited from their families. +[120.30s -> 129.39s] The upper class also includes those who are titled, again often inherited titles such as hereditary peerages, lords and members of royalty. +[130.38s -> 142.64s] The middle class is traditionally defined as those in non-manual professions, particularly those in professional employment. Doctors, lawyers, accountants and even teachers are perceived to be from the middle classes. +[143.47s -> 155.95s] But as employment has changed and the UK economy has moved from being based on heavy industry to the service sector, this creates problems for our definition of middle class as non-manual labour. +[157.39s -> 163.82s] The working class are associated with manual occupations, construction, labouring and manufacturing. +[164.08s -> 177.17s] this definition is simplistic however as many in skilled trades such as plumbing electricians and construction will earn more than those in lower administrative positions such as clerical work and retail management +[177.20s -> 189.01s] yet will be perceived to be of a lower class. This demonstrates why occupation and income are insufficient to measure an individual social class in the 21st century. +[195.15s -> 202.99s] More recent measures of social class have attempted to examine the different tastes, attributes and likes of those in different social classes. +[204.14s -> 214.61s] French sociologist Pierre Bourdieu found that individuals of similar status tend to have similar tastes and attributes, what he called their habitus. +[215.09s -> 227.41s] This included both their occupation and their income, but also their levels of education and their social connections, and this interpretation is often used in more contemporary measures of social class. +[227.41s -> 241.07s] such as the Great British Class Survey in the early 21st century. More contemporary measures of class suggest there are up to seven distinct social groups based upon combinations of occupation, education and social connections. +[242.51s -> 253.34s] despite this greater prominence is given in society to individuals whose occupation is seen to be more valuable to society politicians business leaders doctors and lawyers +[253.34s -> 266.38s] are given higher status in society than nurses teachers factory workers and those working in public transport despite the importance of the latter roles to the functioning of the economy and the well-being of the nation +[266.38s -> 270.10s] as evidenced by the COVID-19 pandemic lockdowns. +[276.53s -> 287.18s] Sociologists that examine the relevance of social class suggest that individual social class influences their life chances, and this is explored throughout most sociology courses. +[288.02s -> 295.09s] Generally speaking, the lower an individual's social class, the more likely they are to suffer from a disadvantaged position. +[295.41s -> 303.57s] Those in working class areas will have a lower life expectancy than those in more affluent areas and also spend more of their life in poor health. +[304.02s -> 318.53s] for pupils from economically disadvantaged backgrounds they are less likely to achieve good educational outcomes than their peers whilst those in the lower social classes are often underrepresented in positions of power the media and in higher education +[318.53s -> 331.62s] particularly those universities with elite status. On an individual level, lower social classes are more likely to be disadvantaged in having access to adequate housing, have diets that are imbalanced, +[331.62s -> 345.42s] have limited access to a full range of healthcare provision, such as mental health services and preventative screening measures, attend schools with lower levels of achievement and funding, and face social exclusion in society. +[346.00s -> 356.37s] While some sociologists argue that class is no longer relevant, the scale of disadvantage for those in the lower social classes from birth to old age would suggest otherwise. +[360.27s -> 368.14s] Different sociological perspectives will take differing views of both the experiences of different social classes and the structure of the class system. +[369.04s -> 377.82s] Functionists argue that social class differences are inevitable in society, as society is meritocratic. People are rewarded based on their abilities. +[377.82s -> 384.88s] And this means that people who work hard and have the right attributes will be able to gain status and become socially mobile. +[385.65s -> 397.74s] They suggest that there is equality of opportunity in society and that everybody has the chance to succeed, and those that do are rewarded with higher status positions, what they call achieved status. +[398.93s -> 404.50s] Marxism, with its focus on class conflict, perhaps unsurprisingly would disagree. +[404.94s -> 415.82s] Traditional Marxists suggest that individuals are allocated to one of two social classes, the bourgeoisie and the proletariat, based upon their relationship to the means of production. +[416.30s -> 425.65s] If an individual owns capital, factories and resources, they are the bourgeoisie. If not, they are workers or the proletariat. +[426.13s -> 435.95s] This is quite a broad interpretation that concentrates most of society's power into the hands of very few individuals, something other sociologists have rejected. +[439.60s -> 453.74s] The New Right, like functionists, see society as meritocratic, but they also argue that there exists a further social class beneath the traditional working class, what they call the underclass. Those unable or unwilling to work. +[453.74s -> 456.24s] and are dependent upon state benefits. +[456.88s -> 471.28s] the new right argue that the underclass are inadequately socialized and the cause of many social problems in society something other sociological approaches criticize the new right for as being victim blaming and scapegoating +[472.66s -> 485.17s] Other approaches, such as postmodernists, reject the influence of individual social class, suggesting that society is too fragmented for individuals to conform to the norms and values of different social classes. +[485.20s -> 491.79s] stating that the greater individualism in society means that these collective norms and values no longer apply. +[492.98s -> 505.07s] Finally, social action theorists, such as Weber, have rejected Marx's idea of a simplified two-class system, instead suggesting that social class is multifaceted and diverse, +[505.07s -> 516.91s] taking into account an individual's economic situation their status in society and the power they have in their relationships with others arguing that social class is a subjective interpretation +[516.91s -> 525.68s] and as a result needs to be examined on an individual basis rather than attempting to categorise individuals into specific social classes. +[528.66s -> 535.54s] That concludes this tutor to you introduction to sociology topic video on social class. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_3.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..39acb3e9324c896e8dddad852ab0cf4506be5039 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_3.mp4.txt @@ -0,0 +1,53 @@ +[0.53s -> 5.65s] Welcome to this Tutor2U Introduction to Sociology video looking at Culture. +[8.30s -> 18.61s] Sociologists discuss culture in a variety of different contexts, so understanding how culture shapes human behaviour is important when studying sociology. But what is culture? +[19.12s -> 31.15s] The sociological definition of culture refers to the way of life of a particular group. Furthermore, it can be seen as being part of an individual's identity, who they are, how they act and how they think. +[31.89s -> 40.34s] Culture is what shapes the norms and values of social groups, and members of different social groups will often share similar cultural norms and values. +[40.46s -> 49.46s] These cultural norms and values can be shaped by many different social factors such as social class, geographical locality or belief in a common religion. +[50.26s -> 60.94s] Culture, quote simply put, is the way we live, and as a consequence everybody in society experiences culture, but often in different ways. +[65.71s -> 71.86s] When discussing culture, sociologists examine many different aspects of everyday life to try and understand it. +[72.34s -> 81.46s] One important aspect of culture is language, whether a common language such as English, Spanish, Arabic or Urdu, or regionalised dialects. +[82.03s -> 96.69s] This includes accents and idioms, forms of expression that are only understood by those in the know. It can also extend to signs and symbols, such as abbreviations, colloquialisms or slang, and even emojis and memes. +[97.49s -> 104.08s] A second aspect of culture is cuisine, and this may be more identifiable than other aspects of culture. +[104.43s -> 113.86s] Common foods and customs are often seen as being part of a culture, although in contemporary society many types of food that have been adopted is part of a global food culture. +[113.86s -> 124.69s] For example, Chinese food, Indian, Thai, Mexican and Arabic food is commonly eaten in the UK, despite traditional British food being seen as fish and chips or Sunday roast. +[125.81s -> 138.94s] clothing and forms of dress can be another identifier of culture as can the music and other forms of art that different cultures embrace different celebrations and rituals can also form part of an individual's culture +[138.94s -> 147.98s] And while the UK may be seen as a secular society , many different cultures will identify with a specific form of beliefs. +[148.75s -> 160.53s] Each of these factors represents the ways in which people live and how they behave in wider society, whether this is part of the mainstream culture of society or a reflection of a smaller group within it. +[163.54s -> 176.88s] There are many different types of culture that sociologists discuss. The most common form of culture is referred to when people discuss culture is mainstream or popular culture. This is the way of life of the majority of the population. +[176.88s -> 182.19s] and often when discussing society's norms and values, its mainstream culture they're referring to. +[182.70s -> 192.40s] It's often reflected in the fashions that people wear, the trends in film, food and music that are most popular, and the language spoken by the majority of the population. +[193.33s -> 202.42s] In contrast, folk culture is largely regionalised and reflects more traditional aspects of culture before people move to cities and towns. +[202.42s -> 210.48s] For example, Morris dancing, folk music, Irish dancing and the Highland Games are all aspects of different folk cultures across the UK and Ireland. +[211.12s -> 217.87s] This is more evident in music and the arts, but it can also extend to local holidays and celebrations. +[219.89s -> 234.70s] global culture refers to the influence of globalization on everyday life the increased diversity in society that has led to the development of a global culture one that has adopted aspects of cultures from around the world into a single global culture +[235.44s -> 242.96s] Examples of this can be seen in the foods that we eat, art, literature, film, and how these are becoming more similar across the world. +[243.34s -> 250.93s] Although some sociologists would suggest that this is a spread of Western culture rather than a true melting pot of cultures. +[252.46s -> 265.50s] Other types of culture that are often discussed on sociology courses are high and low culture. High culture often reflects the tastes and attitudes of those in the highest status positions in society, the middle and upper classes. +[265.50s -> 274.74s] and is assumed to be more sophisticated and complex and therefore has higher value. For example, theatre, opera, ballet and classical music. +[275.63s -> 285.97s] In contrast, low culture is seen as being the culture of the working classes, and has a lower value in the eyes of many commentators. +[286.45s -> 292.91s] Soap operas, sports and electronic gaming are seen as simplified and not adding intellectual value. +[293.71s -> 307.25s] Some sociologists would suggest that this is a form of cultural elitism, looking down upon the tastes and attitudes of the working class. And this highlights one of the problems sociologists have when identifying and defining different cultures. +[308.59s -> 322.29s] Finally, while the majority of society adopt mainstream or global cultures, there are groups within society that reject or replace the cultural norms and values of society with alternative ones. These groups or subcultures +[322.29s -> 335.25s] adopt their own norms and values and this is often seen through music fashion film and literature for example musical subcultures such as goths punks ravers mobs and rockers +[335.25s -> 349.84s] All of these groups have adopted their own norms and values independent from mainstream society. So how do different sociological perspectives view culture? +[350.10s -> 365.01s] Functionalism, being a consensus theory, argues that society's culture is a reflection of the norms and values of those within it. They suggest that the majority of society agree with the norms and values that society holds, what they call a value consensus. +[365.33s -> 369.78s] This means that the majority accept and conform to a similar way of living. +[370.06s -> 383.60s] Those that don't accept the value consensus will either reject or replace these social norms and values and this leads to the formation of subcultures. These groups within society that have their own norms and values that are independent +[383.60s -> 385.52s] from mainstream culture. +[389.42s -> 403.79s] Conflict theories reject the idea that society's culture is a reflection of the norms and values of the majority and instead suggest that social institutions, controlled by the most powerful groups in society, impose cultural norms and values upon people. +[404.21s -> 411.70s] Marxists suggest that society's culture is a reflection of the norms and values of the elite, what they call hegemonic norms and values. +[412.21s -> 419.70s] These norms and values are those of the capitalist classes, making people consume goods which increases the wealth of the bourgeoisie. +[420.53s -> 432.27s] Feminists, on the other hand, suggest that society's culture is male-dominated or patriarchal and that society's culture largely reflects the interests of men over those of women. +[435.82s -> 448.85s] Social action theories such as interactionism take a differing viewpoint on culture. They argue that culture is a social construction, that it is made by people and therefore is based upon how people interpret the different signs, symbols, +[448.85s -> 451.89s] language and behaviors that exist in society. +[452.78s -> 466.30s] Other sociologists, such as postmodernists, suggest there is no longer a dominant culture in society, that the increased diversity and globalisation of society have meant that individuals all have their own understanding of culture. +[466.30s -> 474.70s] and that this is a personal reflection of who they are and their identity rather than being representative of everybody in society. +[475.25s -> 488.98s] They believe that there is not one culture, but rather that society's culture has become fragmented or broken up, and individuals choose their own norms and values based upon their life experiences. +[492.40s -> 503.57s] Defining culture can be problematic for sociologists because individuals will place different values on aspects of culture and will each have their own interpretation of what parts of culture are valuable. +[504.05s -> 518.14s] This makes it difficult to have an agreement on social norms and values, the value consensus, and as a result culture means different things to different people. For example, whilst one group may value the teachings of a religion, +[518.14s -> 519.76s] Others may not. +[521.26s -> 533.49s] Another issue with defining culture is that social norms and values change rapidly, and this leads to culture developing at a pace that leaves people often confused. This is particularly true of youth cultures. +[533.49s -> 544.56s] that become part of the mainstream culture. As these norms and values change rapidly there can be resistance to these from the dominant groups in society. +[546.19s -> 552.98s] Finally, definitions of culture can vary across different social groups, between nations and over time. +[553.42s -> 568.02s] For example, alcohol consumption may be seen as part of the cultural norm in the UK, but in other cultures this may be prohibited. Likewise, attitudes to child rearing, education and family life all differ from one culture to the next. +[568.02s -> 582.77s] making it difficult to define cultural norms on a universal scale. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_4.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..39acb3e9324c896e8dddad852ab0cf4506be5039 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_4.mp4.txt @@ -0,0 +1,53 @@ +[0.53s -> 5.65s] Welcome to this Tutor2U Introduction to Sociology video looking at Culture. +[8.30s -> 18.61s] Sociologists discuss culture in a variety of different contexts, so understanding how culture shapes human behaviour is important when studying sociology. But what is culture? +[19.12s -> 31.15s] The sociological definition of culture refers to the way of life of a particular group. Furthermore, it can be seen as being part of an individual's identity, who they are, how they act and how they think. +[31.89s -> 40.34s] Culture is what shapes the norms and values of social groups, and members of different social groups will often share similar cultural norms and values. +[40.46s -> 49.46s] These cultural norms and values can be shaped by many different social factors such as social class, geographical locality or belief in a common religion. +[50.26s -> 60.94s] Culture, quote simply put, is the way we live, and as a consequence everybody in society experiences culture, but often in different ways. +[65.71s -> 71.86s] When discussing culture, sociologists examine many different aspects of everyday life to try and understand it. +[72.34s -> 81.46s] One important aspect of culture is language, whether a common language such as English, Spanish, Arabic or Urdu, or regionalised dialects. +[82.03s -> 96.69s] This includes accents and idioms, forms of expression that are only understood by those in the know. It can also extend to signs and symbols, such as abbreviations, colloquialisms or slang, and even emojis and memes. +[97.49s -> 104.08s] A second aspect of culture is cuisine, and this may be more identifiable than other aspects of culture. +[104.43s -> 113.86s] Common foods and customs are often seen as being part of a culture, although in contemporary society many types of food that have been adopted is part of a global food culture. +[113.86s -> 124.69s] For example, Chinese food, Indian, Thai, Mexican and Arabic food is commonly eaten in the UK, despite traditional British food being seen as fish and chips or Sunday roast. +[125.81s -> 138.94s] clothing and forms of dress can be another identifier of culture as can the music and other forms of art that different cultures embrace different celebrations and rituals can also form part of an individual's culture +[138.94s -> 147.98s] And while the UK may be seen as a secular society , many different cultures will identify with a specific form of beliefs. +[148.75s -> 160.53s] Each of these factors represents the ways in which people live and how they behave in wider society, whether this is part of the mainstream culture of society or a reflection of a smaller group within it. +[163.54s -> 176.88s] There are many different types of culture that sociologists discuss. The most common form of culture is referred to when people discuss culture is mainstream or popular culture. This is the way of life of the majority of the population. +[176.88s -> 182.19s] and often when discussing society's norms and values, its mainstream culture they're referring to. +[182.70s -> 192.40s] It's often reflected in the fashions that people wear, the trends in film, food and music that are most popular, and the language spoken by the majority of the population. +[193.33s -> 202.42s] In contrast, folk culture is largely regionalised and reflects more traditional aspects of culture before people move to cities and towns. +[202.42s -> 210.48s] For example, Morris dancing, folk music, Irish dancing and the Highland Games are all aspects of different folk cultures across the UK and Ireland. +[211.12s -> 217.87s] This is more evident in music and the arts, but it can also extend to local holidays and celebrations. +[219.89s -> 234.70s] global culture refers to the influence of globalization on everyday life the increased diversity in society that has led to the development of a global culture one that has adopted aspects of cultures from around the world into a single global culture +[235.44s -> 242.96s] Examples of this can be seen in the foods that we eat, art, literature, film, and how these are becoming more similar across the world. +[243.34s -> 250.93s] Although some sociologists would suggest that this is a spread of Western culture rather than a true melting pot of cultures. +[252.46s -> 265.50s] Other types of culture that are often discussed on sociology courses are high and low culture. High culture often reflects the tastes and attitudes of those in the highest status positions in society, the middle and upper classes. +[265.50s -> 274.74s] and is assumed to be more sophisticated and complex and therefore has higher value. For example, theatre, opera, ballet and classical music. +[275.63s -> 285.97s] In contrast, low culture is seen as being the culture of the working classes, and has a lower value in the eyes of many commentators. +[286.45s -> 292.91s] Soap operas, sports and electronic gaming are seen as simplified and not adding intellectual value. +[293.71s -> 307.25s] Some sociologists would suggest that this is a form of cultural elitism, looking down upon the tastes and attitudes of the working class. And this highlights one of the problems sociologists have when identifying and defining different cultures. +[308.59s -> 322.29s] Finally, while the majority of society adopt mainstream or global cultures, there are groups within society that reject or replace the cultural norms and values of society with alternative ones. These groups or subcultures +[322.29s -> 335.25s] adopt their own norms and values and this is often seen through music fashion film and literature for example musical subcultures such as goths punks ravers mobs and rockers +[335.25s -> 349.84s] All of these groups have adopted their own norms and values independent from mainstream society. So how do different sociological perspectives view culture? +[350.10s -> 365.01s] Functionalism, being a consensus theory, argues that society's culture is a reflection of the norms and values of those within it. They suggest that the majority of society agree with the norms and values that society holds, what they call a value consensus. +[365.33s -> 369.78s] This means that the majority accept and conform to a similar way of living. +[370.06s -> 383.60s] Those that don't accept the value consensus will either reject or replace these social norms and values and this leads to the formation of subcultures. These groups within society that have their own norms and values that are independent +[383.60s -> 385.52s] from mainstream culture. +[389.42s -> 403.79s] Conflict theories reject the idea that society's culture is a reflection of the norms and values of the majority and instead suggest that social institutions, controlled by the most powerful groups in society, impose cultural norms and values upon people. +[404.21s -> 411.70s] Marxists suggest that society's culture is a reflection of the norms and values of the elite, what they call hegemonic norms and values. +[412.21s -> 419.70s] These norms and values are those of the capitalist classes, making people consume goods which increases the wealth of the bourgeoisie. +[420.53s -> 432.27s] Feminists, on the other hand, suggest that society's culture is male-dominated or patriarchal and that society's culture largely reflects the interests of men over those of women. +[435.82s -> 448.85s] Social action theories such as interactionism take a differing viewpoint on culture. They argue that culture is a social construction, that it is made by people and therefore is based upon how people interpret the different signs, symbols, +[448.85s -> 451.89s] language and behaviors that exist in society. +[452.78s -> 466.30s] Other sociologists, such as postmodernists, suggest there is no longer a dominant culture in society, that the increased diversity and globalisation of society have meant that individuals all have their own understanding of culture. +[466.30s -> 474.70s] and that this is a personal reflection of who they are and their identity rather than being representative of everybody in society. +[475.25s -> 488.98s] They believe that there is not one culture, but rather that society's culture has become fragmented or broken up, and individuals choose their own norms and values based upon their life experiences. +[492.40s -> 503.57s] Defining culture can be problematic for sociologists because individuals will place different values on aspects of culture and will each have their own interpretation of what parts of culture are valuable. +[504.05s -> 518.14s] This makes it difficult to have an agreement on social norms and values, the value consensus, and as a result culture means different things to different people. For example, whilst one group may value the teachings of a religion, +[518.14s -> 519.76s] Others may not. +[521.26s -> 533.49s] Another issue with defining culture is that social norms and values change rapidly, and this leads to culture developing at a pace that leaves people often confused. This is particularly true of youth cultures. +[533.49s -> 544.56s] that become part of the mainstream culture. As these norms and values change rapidly there can be resistance to these from the dominant groups in society. +[546.19s -> 552.98s] Finally, definitions of culture can vary across different social groups, between nations and over time. +[553.42s -> 568.02s] For example, alcohol consumption may be seen as part of the cultural norm in the UK, but in other cultures this may be prohibited. Likewise, attitudes to child rearing, education and family life all differ from one culture to the next. +[568.02s -> 582.77s] making it difficult to define cultural norms on a universal scale. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_5.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..903c2b958e9f8e1a8df2025521ad81eebf82bf22 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_5.mp4.txt @@ -0,0 +1,41 @@ +[0.00s -> 8.02s] Welcome to this Tutor2U sociology topic video on global development, looking at theoretical approaches to trade. +[10.22s -> 21.84s] In previous videos we've looked at trade and in this video we're going to focus on how the different theoretical approaches to development view the value of trade as a means to enable development. +[22.64s -> 34.22s] The three main approaches differ in their approaches to trade. Modernisation theories see trade as essential in moving through Rostow's stages of development and becoming a self-sufficient and modern nation. +[34.32s -> 38.86s] in a similar vein to the development of Western nations through the Industrial Revolution. +[39.82s -> 51.76s] neoliberals too see trade as beneficial as it enables developing nations to establish principles of entrepreneurship individualism and innovation and become less reliant upon the west for aid +[52.75s -> 66.27s] dependency theorists however focus on the inequalities in trade relationships between the west and developing nations instead they see trade relationships as an evolution of colonialism neo-colonialism +[66.27s -> 76.69s] enabling them to obtain cheap resources and labour and maintain control over the developing world. And in this video, we're going to examine these approaches in more detail. +[79.95s -> 94.80s] Firstly, modernisation theory. Drawing upon his experience working for the US State Department, Rostow's model of modernisation suggested that nations needed to adopt many of the principles that saw Western nations, particularly the UK, +[94.80s -> 99.63s] developing to industrial economies in the 1800s and early 1900s. +[100.40s -> 110.26s] Rostow argued that the prime driver of change from agricultural society to an era of mass consumption was a nation's ability to trade effectively. +[111.09s -> 124.18s] At each stage, generating a surplus of products and selling those for a profit allows developing nations to reinvest the profit back into the economic infrastructure and move forwards. +[124.66s -> 135.70s] from selling primary goods such as cash crops in the agricultural stage, investing those profits into light manufacturing such as textiles, and diversifying their output as they take off. +[136.43s -> 146.58s] once this basic infrastructure is developed further profits are invested into heavier manufacturing and better transport infrastructures as a nation drives to maturity +[146.86s -> 158.93s] Eventually, their economy would be based around service sector work and consumption, and their agricultural past would be left behind as a truly developed modern nation emerges. +[159.38s -> 164.46s] However, in practice there are many barriers to this process. +[166.16s -> 174.70s] Neoliberals also favour trade, particularly as an alternative to aid, although this does not exclude them from using aid as a means to an end. +[175.34s -> 188.50s] Neoliberals argue that Western nations established their position of dominance through the development of trade, and, like modernization theorists, cite Western European nations as an example for developing nations to aspire to. +[189.36s -> 200.40s] However, rather than developing from within, neoliberals argue that developing nations should look to Western expertise to help them develop their economic infrastructure. +[200.53s -> 209.49s] Again, critics would argue this is a form of ethnocentrism, assuming that models that worked in the West can easily be applied to different cultures. +[210.61s -> 217.71s] For Reed Henry, the process of development is a convenient tool in order to facilitate increased trade liberalisation. +[219.38s -> 234.06s] They argue that there is a need to use Western expertise. This is encouraged through developing free trade policies and structural adjustment policies that are attached to aid donations helps them to achieve this. +[234.90s -> 244.30s] these policies advocate that in order to develop nations should remove obstacles to western investment such as trade tariffs +[245.52s -> 259.66s] developing nations should also privatize their public services usually used in western companies and that they should encourage the growth of individualism and innovation part of which includes moving to formal employment +[259.66s -> 262.96s] Once again, usually for Western TNCs. +[264.08s -> 276.24s] However, implementation of these ideas, according to neoliberals, will lead to trade developing as TNTs are able to purchase resources found in the developing world, for example minerals and precious metals. +[276.88s -> 284.59s] Further indigenous workers will then be employed by these TNCs and gain stable employment and this contributes to gross national income. +[285.33s -> 297.23s] this will then contribute to other sectors as workers are able to purchase goods and services with the investment of tncs being seen to produce what is called an economic multiplier effect +[297.23s -> 312.08s] having greater impacts across the economy so that more money comes out than investment is put in perhaps unsurprisingly critics of these ideas come from marxists or dependency theorists +[313.10s -> 325.65s] Dependency theorists argue that trade is a form of neo-colonialism, replacing the old colonial masters from which developing nations have gained their independence, and replacing them with transnational corporations. +[325.97s -> 337.84s] They focus on the exploitative relationships between TNCs and their workers, with low pay in comparison to their Western counterparts and poor working conditions, often unsafe and long hours. +[338.96s -> 351.89s] dependency theorists also suggest that tnts are able to exploit cheap land and natural resources often circumventing environmental regulations and causing damage through air and water pollution +[353.39s -> 362.13s] Elwood argues that the arrival of TNCs into the developing world leads to a race to the bottom in terms of prices for primary goods. +[362.32s -> 373.71s] This then has the effect of leading to desertification as local producers attempt to produce more goods to maintain their income, which leaves land infertile and unusable. +[374.26s -> 384.30s] This has been called the social violence of the market by Greenfield. Local producers will struggle to keep afloat, having to produce more to receive less. +[384.72s -> 398.77s] While this occurs, transnational corporations are able to use their political power gained from courting elected officials to circumvent labour and environmental legislations designed to protect those that are being exploited. +[399.28s -> 408.40s] This is often achieved through the development of export processing zones, where low pay, long hours and union intimidation is commonplace. +[410.38s -> 419.89s] Now trade has impacts on other areas of development too. AIDs are often dependent upon the opening up of free trade markets and in doing so the involvement of +[419.89s -> 431.09s] international governmental organisations must be called into question, with organisations such as the IMF and the World Trade Organisation pressurising nations to remove barriers to overseas investment. +[431.66s -> 443.12s] Furthermore, there are changes to employment practices as trade develops. More people are required in formal employment, and this has the potential to move people into cities and create social mobility. +[445.68s -> 459.89s] Finally, trade also links into health and education, with Western providers competing for a share of lucrative privatised health and education markets, as well as the need for a more skilled and educated workforce. +[459.89s -> 473.55s] than would be present in subsistence farming. That concludes this Tutor2U sociology topic video on global development, focusing on theoretical views of trade. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_6.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..903c2b958e9f8e1a8df2025521ad81eebf82bf22 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_6.mp4.txt @@ -0,0 +1,41 @@ +[0.00s -> 8.02s] Welcome to this Tutor2U sociology topic video on global development, looking at theoretical approaches to trade. +[10.22s -> 21.84s] In previous videos we've looked at trade and in this video we're going to focus on how the different theoretical approaches to development view the value of trade as a means to enable development. +[22.64s -> 34.22s] The three main approaches differ in their approaches to trade. Modernisation theories see trade as essential in moving through Rostow's stages of development and becoming a self-sufficient and modern nation. +[34.32s -> 38.86s] in a similar vein to the development of Western nations through the Industrial Revolution. +[39.82s -> 51.76s] neoliberals too see trade as beneficial as it enables developing nations to establish principles of entrepreneurship individualism and innovation and become less reliant upon the west for aid +[52.75s -> 66.27s] dependency theorists however focus on the inequalities in trade relationships between the west and developing nations instead they see trade relationships as an evolution of colonialism neo-colonialism +[66.27s -> 76.69s] enabling them to obtain cheap resources and labour and maintain control over the developing world. And in this video, we're going to examine these approaches in more detail. +[79.95s -> 94.80s] Firstly, modernisation theory. Drawing upon his experience working for the US State Department, Rostow's model of modernisation suggested that nations needed to adopt many of the principles that saw Western nations, particularly the UK, +[94.80s -> 99.63s] developing to industrial economies in the 1800s and early 1900s. +[100.40s -> 110.26s] Rostow argued that the prime driver of change from agricultural society to an era of mass consumption was a nation's ability to trade effectively. +[111.09s -> 124.18s] At each stage, generating a surplus of products and selling those for a profit allows developing nations to reinvest the profit back into the economic infrastructure and move forwards. +[124.66s -> 135.70s] from selling primary goods such as cash crops in the agricultural stage, investing those profits into light manufacturing such as textiles, and diversifying their output as they take off. +[136.43s -> 146.58s] once this basic infrastructure is developed further profits are invested into heavier manufacturing and better transport infrastructures as a nation drives to maturity +[146.86s -> 158.93s] Eventually, their economy would be based around service sector work and consumption, and their agricultural past would be left behind as a truly developed modern nation emerges. +[159.38s -> 164.46s] However, in practice there are many barriers to this process. +[166.16s -> 174.70s] Neoliberals also favour trade, particularly as an alternative to aid, although this does not exclude them from using aid as a means to an end. +[175.34s -> 188.50s] Neoliberals argue that Western nations established their position of dominance through the development of trade, and, like modernization theorists, cite Western European nations as an example for developing nations to aspire to. +[189.36s -> 200.40s] However, rather than developing from within, neoliberals argue that developing nations should look to Western expertise to help them develop their economic infrastructure. +[200.53s -> 209.49s] Again, critics would argue this is a form of ethnocentrism, assuming that models that worked in the West can easily be applied to different cultures. +[210.61s -> 217.71s] For Reed Henry, the process of development is a convenient tool in order to facilitate increased trade liberalisation. +[219.38s -> 234.06s] They argue that there is a need to use Western expertise. This is encouraged through developing free trade policies and structural adjustment policies that are attached to aid donations helps them to achieve this. +[234.90s -> 244.30s] these policies advocate that in order to develop nations should remove obstacles to western investment such as trade tariffs +[245.52s -> 259.66s] developing nations should also privatize their public services usually used in western companies and that they should encourage the growth of individualism and innovation part of which includes moving to formal employment +[259.66s -> 262.96s] Once again, usually for Western TNCs. +[264.08s -> 276.24s] However, implementation of these ideas, according to neoliberals, will lead to trade developing as TNTs are able to purchase resources found in the developing world, for example minerals and precious metals. +[276.88s -> 284.59s] Further indigenous workers will then be employed by these TNCs and gain stable employment and this contributes to gross national income. +[285.33s -> 297.23s] this will then contribute to other sectors as workers are able to purchase goods and services with the investment of tncs being seen to produce what is called an economic multiplier effect +[297.23s -> 312.08s] having greater impacts across the economy so that more money comes out than investment is put in perhaps unsurprisingly critics of these ideas come from marxists or dependency theorists +[313.10s -> 325.65s] Dependency theorists argue that trade is a form of neo-colonialism, replacing the old colonial masters from which developing nations have gained their independence, and replacing them with transnational corporations. +[325.97s -> 337.84s] They focus on the exploitative relationships between TNCs and their workers, with low pay in comparison to their Western counterparts and poor working conditions, often unsafe and long hours. +[338.96s -> 351.89s] dependency theorists also suggest that tnts are able to exploit cheap land and natural resources often circumventing environmental regulations and causing damage through air and water pollution +[353.39s -> 362.13s] Elwood argues that the arrival of TNCs into the developing world leads to a race to the bottom in terms of prices for primary goods. +[362.32s -> 373.71s] This then has the effect of leading to desertification as local producers attempt to produce more goods to maintain their income, which leaves land infertile and unusable. +[374.26s -> 384.30s] This has been called the social violence of the market by Greenfield. Local producers will struggle to keep afloat, having to produce more to receive less. +[384.72s -> 398.77s] While this occurs, transnational corporations are able to use their political power gained from courting elected officials to circumvent labour and environmental legislations designed to protect those that are being exploited. +[399.28s -> 408.40s] This is often achieved through the development of export processing zones, where low pay, long hours and union intimidation is commonplace. +[410.38s -> 419.89s] Now trade has impacts on other areas of development too. AIDs are often dependent upon the opening up of free trade markets and in doing so the involvement of +[419.89s -> 431.09s] international governmental organisations must be called into question, with organisations such as the IMF and the World Trade Organisation pressurising nations to remove barriers to overseas investment. +[431.66s -> 443.12s] Furthermore, there are changes to employment practices as trade develops. More people are required in formal employment, and this has the potential to move people into cities and create social mobility. +[445.68s -> 459.89s] Finally, trade also links into health and education, with Western providers competing for a share of lucrative privatised health and education markets, as well as the need for a more skilled and educated workforce. +[459.89s -> 473.55s] than would be present in subsistence farming. That concludes this Tutor2U sociology topic video on global development, focusing on theoretical views of trade. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_7.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..47056ead31ecdb821174f214913117988c651124 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_7.mp4.txt @@ -0,0 +1,48 @@ +[0.85s -> 8.53s] Welcome to this Tutor2U topic video on global development, looking at theoretical approaches to globalization. +[11.54s -> 23.47s] While sociologists are in general agreement that society has undergone a process of globalization over the last 30 years, not all sociologists agree that this is necessarily beneficial to society. +[24.30s -> 33.17s] As with many social changes in society, there are perspectives that welcome the change, whilst others are critical of the impacts of a change such as globalisation. +[33.58s -> 46.70s] there are different approaches to globalization often linked into other theories of development and how the social and economic changes that have accompanied globalization impact on society and the process of development +[47.38s -> 62.35s] those favoring a more global society are neoliberal views often referred to as hyperglobalist perspectives who view globalization positively in part due to the breakdown of trade barriers and increased global consumption patterns +[62.93s -> 75.12s] other theorists are more critical such as pessimistic globalism that sees globalization not as a merging of cultures but rather the imposition of western culture on other societies +[75.12s -> 89.84s] a process referred to as cultural imperialism. Marxist theories also take a critical view of globalisation, particularly that of Wallerstein's world systems theory, which we've examined earlier in this series when looking at theories of development. +[90.45s -> 101.68s] finally a middle ground in the debate over whether globalization is positive or negative is put forward by transformationalists those adopting the postmodern view of society +[101.68s -> 116.02s] and how many people choose aspects of globalization with which to identify. In this video, we're going to look at each of these perspectives in turn. Firstly, hyperglobalism. +[116.27s -> 125.30s] hyperglobalists have an optimistic view of the process of globalization seen as having many benefits for society and in particular development +[125.68s -> 138.08s] Sen argues that the greater international cooperation between technology and scientific communities gives us greater access to advancements in these areas and helps us to solve global issues. +[138.08s -> 145.33s] For example, international cooperation in the manufacture of COVID vaccines and the growth of communications networks such as the Internet. +[146.48s -> 158.16s] Hyperglobalists suggest that this has been enabled by the adoption of neoliberal economic policy, particularly free trade, as it removes economic barriers and lessens state ownership. +[158.16s -> 163.98s] enabling TNCs to work across borders and promote innovative solutions to global issues. +[164.75s -> 174.96s] This helps provide the developing world with opportunities for social and economic growth, as TNCs are able to use these advancements in tackling problems in different nations. +[175.92s -> 184.69s] Finally, hyperglobalists see the adoption of free trade as a way in which nations can develop and prosper economically. +[185.65s -> 197.62s] global culture has created global demand for goods and services and this provides developing nations with opportunities to produce these goods and export them to the consumer markets particularly in the west +[198.03s -> 211.18s] however critics of this approach suggest that this leads to exploitation with many developing nations being seen as low-wage economies and thus ripe for tncs to exploit cheap labor and increase their profit margins +[211.57s -> 217.71s] Another globalist approach doesn't see globalization as having brought the benefits that hyperglobalists suggest. +[218.16s -> 231.12s] Instead, pessimistic globalists take a critical view of the process of globalization, arguing that rather than the emergence of a truly global culture, instead there is a bit of form of cultural imperialism. +[231.12s -> 245.94s] that enforces western values onto nations in the developing world and this can be seen through approaches such as modernization theory and how social engineering is used to promote ideas of meritocracy entrepreneurialism and individualism into the developing world +[246.83s -> 258.58s] pessimistic globalists see this mass global culture of consumerism and adopting a homogeneous approach to society as being responsible for the end of indigenous folk cultures +[258.58s -> 264.02s] as mass marketing and western consumer goods become desirable in parts of the developing world. +[265.01s -> 274.66s] this is reinforced through the adoption of neoliberal economic policies that allow tncs to trade in nations to expand the markets available for their products +[274.66s -> 281.04s] and pessimistic globalists argue that developing nations are unable to reject free market policies. +[281.52s -> 292.74s] this is because international governmental organizations stipulate that if developing nations want aid they must adhere to strict conditions what are called structural adjustment policies +[292.74s -> 303.50s] and these stipulate free trade and privatisation of industries. This has led to the world becoming more similar, or to put it another way, more Western. +[304.27s -> 314.96s] ritzer argues that society has undergone a process of mcdonaldization whereby goods and services can be produced in a standardized and de skilled way anywhere in the world +[314.96s -> 327.57s] which has created employment opportunities in the developing world in low paid low skilled jobs individuals will follow a specific template of how to produce goods that is the same in multiple global locations +[328.21s -> 339.98s] furthermore barber and schultz argue that there has been a disneyfication of society transforming society into a safe and commercial enterprise for individuals to consume without risk +[343.89s -> 357.71s] Wohl's system theory also views globalization with suspicion. Wallerstein's theory identifies an economic motive for change behind the process for globalization, one which separates nations into three distinct tiers of the modern world system. +[358.22s -> 367.79s] This is organized into a basic hierarchy, with core nations at the top able to exploit the cheap labor and resources of the periphery and semi-peripheral nations. +[368.21s -> 382.45s] while simultaneously they benefit from sales of high-value consumer goods to these markets similarly the semi-peripheral nations newly industrialized nations can exploit the peripheral nations in the same way +[382.99s -> 395.28s] Unlike traditional Marxist theories, Wallerstein's world system theory examines how nations might move from the periphery to the semi-periphery, or alternatively fall from being a core nation to semi-peripheral. +[396.08s -> 407.86s] globalization has allowed this hierarchy to exist with a race to the bottom a desire to find even cheaper labor and resources motivating nations to exploit one another +[408.53s -> 418.13s] This has been facilitated by the process of globalization, whereby TNCs are able to exploit nations in the periphery who are desperate for overseas investment. +[418.96s -> 430.19s] however it is rare that this investment produces an increase in economic output for the nations with the majority of profits returning to the tncs rather than nation states +[430.64s -> 442.06s] this in a true marxist sense leads to alienation and exploitation of those in peripheral nations a result of the opening of markets fueled by globalization +[445.39s -> 452.59s] Finally, transformationalists. Their view is a middle ground between the more critical and optimistic views already presented. +[452.91s -> 464.21s] as a postmodern approach they see that the process of globalization has led to people and nations having the ability to pick and choose elements of western culture to adopt +[464.82s -> 474.42s] by no means has globalization gone unchallenged in society with the rise of nationalism and religious fundamentalism being a result of increased globalization in society +[474.77s -> 483.92s] But instead of blindly accepting or rejecting a global culture, individuals adopt elements of global culture and develop hybrid identities. +[484.56s -> 496.82s] for example in the united arab emirates which despite adopting western consumerism and leisure patterns maintained strict adherence to islamic law and arabic culture +[497.14s -> 511.18s] this glocalization adopting global elements to local cultures can be seen in other parts of the world too even in the west with a rise in nationalist agendas in politics yet maintaining global trade patterns +[511.70s -> 523.41s] this can also be seen through the spread of democratic ideas in parts of the world with authoritarian rule in the spring of two thousand eleven there were many popular uprisings against authoritarian rule +[523.41s -> 533.84s] whilst current protests for improvement of women's rights in Iran can be linked to a greater desire for democratic rule in the region, whilst not wanting to conform to Western ideas. +[534.13s -> 548.78s] this demonstrates the pick-and-mix nature of globalization something postmodernists highlight that concludes this tutor to you sociology topic video on global development looking at theories of globalization +[549.17s -> 550.85s] Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_8.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..47056ead31ecdb821174f214913117988c651124 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_8.mp4.txt @@ -0,0 +1,48 @@ +[0.85s -> 8.53s] Welcome to this Tutor2U topic video on global development, looking at theoretical approaches to globalization. +[11.54s -> 23.47s] While sociologists are in general agreement that society has undergone a process of globalization over the last 30 years, not all sociologists agree that this is necessarily beneficial to society. +[24.30s -> 33.17s] As with many social changes in society, there are perspectives that welcome the change, whilst others are critical of the impacts of a change such as globalisation. +[33.58s -> 46.70s] there are different approaches to globalization often linked into other theories of development and how the social and economic changes that have accompanied globalization impact on society and the process of development +[47.38s -> 62.35s] those favoring a more global society are neoliberal views often referred to as hyperglobalist perspectives who view globalization positively in part due to the breakdown of trade barriers and increased global consumption patterns +[62.93s -> 75.12s] other theorists are more critical such as pessimistic globalism that sees globalization not as a merging of cultures but rather the imposition of western culture on other societies +[75.12s -> 89.84s] a process referred to as cultural imperialism. Marxist theories also take a critical view of globalisation, particularly that of Wallerstein's world systems theory, which we've examined earlier in this series when looking at theories of development. +[90.45s -> 101.68s] finally a middle ground in the debate over whether globalization is positive or negative is put forward by transformationalists those adopting the postmodern view of society +[101.68s -> 116.02s] and how many people choose aspects of globalization with which to identify. In this video, we're going to look at each of these perspectives in turn. Firstly, hyperglobalism. +[116.27s -> 125.30s] hyperglobalists have an optimistic view of the process of globalization seen as having many benefits for society and in particular development +[125.68s -> 138.08s] Sen argues that the greater international cooperation between technology and scientific communities gives us greater access to advancements in these areas and helps us to solve global issues. +[138.08s -> 145.33s] For example, international cooperation in the manufacture of COVID vaccines and the growth of communications networks such as the Internet. +[146.48s -> 158.16s] Hyperglobalists suggest that this has been enabled by the adoption of neoliberal economic policy, particularly free trade, as it removes economic barriers and lessens state ownership. +[158.16s -> 163.98s] enabling TNCs to work across borders and promote innovative solutions to global issues. +[164.75s -> 174.96s] This helps provide the developing world with opportunities for social and economic growth, as TNCs are able to use these advancements in tackling problems in different nations. +[175.92s -> 184.69s] Finally, hyperglobalists see the adoption of free trade as a way in which nations can develop and prosper economically. +[185.65s -> 197.62s] global culture has created global demand for goods and services and this provides developing nations with opportunities to produce these goods and export them to the consumer markets particularly in the west +[198.03s -> 211.18s] however critics of this approach suggest that this leads to exploitation with many developing nations being seen as low-wage economies and thus ripe for tncs to exploit cheap labor and increase their profit margins +[211.57s -> 217.71s] Another globalist approach doesn't see globalization as having brought the benefits that hyperglobalists suggest. +[218.16s -> 231.12s] Instead, pessimistic globalists take a critical view of the process of globalization, arguing that rather than the emergence of a truly global culture, instead there is a bit of form of cultural imperialism. +[231.12s -> 245.94s] that enforces western values onto nations in the developing world and this can be seen through approaches such as modernization theory and how social engineering is used to promote ideas of meritocracy entrepreneurialism and individualism into the developing world +[246.83s -> 258.58s] pessimistic globalists see this mass global culture of consumerism and adopting a homogeneous approach to society as being responsible for the end of indigenous folk cultures +[258.58s -> 264.02s] as mass marketing and western consumer goods become desirable in parts of the developing world. +[265.01s -> 274.66s] this is reinforced through the adoption of neoliberal economic policies that allow tncs to trade in nations to expand the markets available for their products +[274.66s -> 281.04s] and pessimistic globalists argue that developing nations are unable to reject free market policies. +[281.52s -> 292.74s] this is because international governmental organizations stipulate that if developing nations want aid they must adhere to strict conditions what are called structural adjustment policies +[292.74s -> 303.50s] and these stipulate free trade and privatisation of industries. This has led to the world becoming more similar, or to put it another way, more Western. +[304.27s -> 314.96s] ritzer argues that society has undergone a process of mcdonaldization whereby goods and services can be produced in a standardized and de skilled way anywhere in the world +[314.96s -> 327.57s] which has created employment opportunities in the developing world in low paid low skilled jobs individuals will follow a specific template of how to produce goods that is the same in multiple global locations +[328.21s -> 339.98s] furthermore barber and schultz argue that there has been a disneyfication of society transforming society into a safe and commercial enterprise for individuals to consume without risk +[343.89s -> 357.71s] Wohl's system theory also views globalization with suspicion. Wallerstein's theory identifies an economic motive for change behind the process for globalization, one which separates nations into three distinct tiers of the modern world system. +[358.22s -> 367.79s] This is organized into a basic hierarchy, with core nations at the top able to exploit the cheap labor and resources of the periphery and semi-peripheral nations. +[368.21s -> 382.45s] while simultaneously they benefit from sales of high-value consumer goods to these markets similarly the semi-peripheral nations newly industrialized nations can exploit the peripheral nations in the same way +[382.99s -> 395.28s] Unlike traditional Marxist theories, Wallerstein's world system theory examines how nations might move from the periphery to the semi-periphery, or alternatively fall from being a core nation to semi-peripheral. +[396.08s -> 407.86s] globalization has allowed this hierarchy to exist with a race to the bottom a desire to find even cheaper labor and resources motivating nations to exploit one another +[408.53s -> 418.13s] This has been facilitated by the process of globalization, whereby TNCs are able to exploit nations in the periphery who are desperate for overseas investment. +[418.96s -> 430.19s] however it is rare that this investment produces an increase in economic output for the nations with the majority of profits returning to the tncs rather than nation states +[430.64s -> 442.06s] this in a true marxist sense leads to alienation and exploitation of those in peripheral nations a result of the opening of markets fueled by globalization +[445.39s -> 452.59s] Finally, transformationalists. Their view is a middle ground between the more critical and optimistic views already presented. +[452.91s -> 464.21s] as a postmodern approach they see that the process of globalization has led to people and nations having the ability to pick and choose elements of western culture to adopt +[464.82s -> 474.42s] by no means has globalization gone unchallenged in society with the rise of nationalism and religious fundamentalism being a result of increased globalization in society +[474.77s -> 483.92s] But instead of blindly accepting or rejecting a global culture, individuals adopt elements of global culture and develop hybrid identities. +[484.56s -> 496.82s] for example in the united arab emirates which despite adopting western consumerism and leisure patterns maintained strict adherence to islamic law and arabic culture +[497.14s -> 511.18s] this glocalization adopting global elements to local cultures can be seen in other parts of the world too even in the west with a rise in nationalist agendas in politics yet maintaining global trade patterns +[511.70s -> 523.41s] this can also be seen through the spread of democratic ideas in parts of the world with authoritarian rule in the spring of two thousand eleven there were many popular uprisings against authoritarian rule +[523.41s -> 533.84s] whilst current protests for improvement of women's rights in Iran can be linked to a greater desire for democratic rule in the region, whilst not wanting to conform to Western ideas. +[534.13s -> 548.78s] this demonstrates the pick-and-mix nature of globalization something postmodernists highlight that concludes this tutor to you sociology topic video on global development looking at theories of globalization +[549.17s -> 550.85s] Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/new_Sociology_9.mp4.txt b/VideoMMMU_ASR_large/Humanities/new_Sociology_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d2b268eddd644acc9e53189b7fd05d724fb121cc --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/new_Sociology_9.mp4.txt @@ -0,0 +1,39 @@ +[0.00s -> 6.99s] Welcome to this tutor2u sociology topic video on global development looking at urbanization and development. +[7.41s -> 18.06s] Urbanisation is the process of large sections of the population moving from rural areas to towns and cities and this was a key factor in the success of the Industrial Revolution in the UK. +[18.42s -> 27.73s] In the developing world we normally associate nations as having large rural populations and traditionally this has been the case. However in recent years +[27.73s -> 35.02s] as industrialisation generates employment in towns and cities, there has been a growth in the urban populations of developing nations. +[35.34s -> 48.05s] This can be seen by the growth of megacities in the developing world, large cities with populations in the millions, and these megacities are increasingly being seen as staging posts for trade in the developing world. +[50.77s -> 59.50s] Now, urbanisation is seen by many sociologists as being a desirable aspect of development, as it has many benefits, some of which are listed below. +[59.86s -> 71.18s] Urban populations allow people to have greater access to formal employment, healthcare and education, particularly as developing nations increasingly operate westernised models of healthcare. +[72.14s -> 85.17s] a further benefit of industrialization is the changing norms and values that come with urban living this is particularly useful for the passing on of western ideologies such as consumerism which will benefit trade +[85.17s -> 92.34s] challenging patriarchal views of women in employment. Of course, critics see this as a form of Western imperialism. +[93.23s -> 106.16s] further changes such as movements towards democracy occur with greater urban populations the ability of people to organize and protest in urban areas means that there is a greater need for government by consent +[106.67s -> 119.54s] Finally, urban spaces mean increased technology and communication between individuals and this enables greater innovation, something less likely to occur in isolated rural areas. +[120.14s -> 126.90s] However, urbanisation also comes with great challenges, particularly rapid urbanisation. +[127.31s -> 142.29s] much as in western europe during the mass urbanization that accompanied the industrial revolution urbanization in the developing world has seen the growth of diseases of modernity poor mental health substance abuse violence and crime +[142.90s -> 156.37s] Urban areas are also centres of exploitation with large populations requiring work and this enables TNCs to offer significantly lower wages to those in the developing world than they do to Western workers. +[156.82s -> 166.16s] They are also able to enforce long hours and poor working conditions as there is a large reserve army of labour in urban areas, thus leading to exploitation. +[166.83s -> 179.47s] This is most evident in export processing zones, where local employment legislation can be avoided and these are utilised by many TNCs for assembling products at a cheaper rate than in the West. +[180.53s -> 194.29s] Urban areas are also responsible for the increased transmission of disease, something sadly evidenced throughout the COVID-19 pandemic. With many people living in close proximity, transmission of disease is rapid. +[194.86s -> 207.92s] Furthermore, poor housing and sanitation in rapidly expanding cities can lead to outbreaks of communicable diseases such as typhoid and diphtheria, which spread rapidly through overcrowded areas of cities. +[208.62s -> 213.86s] Another limitation of urbanisation is that the signs of inequality are more obvious. +[213.86s -> 224.50s] with TNCs setting up corporate headquarters and executives living in luxury skyscrapers, while workers are often left in temporary or poor accommodation on the outskirts of city areas. +[224.50s -> 229.39s] The favelas in Rio and Sao Paulo are evidently wealthy and the workers in Brazil. +[230.19s -> 242.83s] Rapid urbanisation also causes environmental pressure points. Overpopulation and the lack of adequate sanitation leads to pollution, while land surrounding the city is subject to desertification and deforestation. +[242.83s -> 256.18s] as urban areas rapidly expand outwards. Modernization theorists see the benefits of urbanization in the process of development, in part because it brings many positives to the process of development. +[257.14s -> 270.61s] Changing attitudes in cities towards consumerism and employment aid the process of development, while urban populations provide the workers for industrialisation to expand and function adequately. +[271.95s -> 279.41s] Urbanisation also led to the city becoming a staging post for trade and a development of the conditions for take-off. +[279.86s -> 288.59s] Cross argues that changes in attitude lead to individuals developing the entrepreneurial and innovative skills required for nations to thrive. +[289.55s -> 302.78s] furthermore modernization theorists argue that without urbanization the industrial revolution in the west would never have occurred and as such see the process as highly desirable however in western europe +[302.78s -> 311.73s] urbanization was less rapid than is expected in the developing world and many of the issues faced by developing nations still occurred +[312.11s -> 326.08s] Dependency theorists have a more negative view of urbanization. While it's still desirable, they argue that the city leads to greater exploitation of workers. They highlight the growing inequalities between workers and those that employ them, +[326.08s -> 329.58s] and argue that cities are rife with the exploitation of workers. +[332.34s -> 343.41s] In modern society, unemployment in cities has increased as Western companies use increasingly mechanised production processes, yet have a large reserve army of labour to choose from. +[343.82s -> 355.86s] This generates competition between workers and fear of challenging exploitation as they can easily be replaced. Furthermore, while modernisation theorists celebrate the transmission of Western values +[355.86s -> 366.54s] Dependency theorists see this as a form of cultural imperialism, transforming people's collectivism and desire to help their fellow man into individualism and self-interest. +[367.18s -> 379.81s] and finally dependency theorists argue that cities use up surplus capital that could be used in the process of development by spending on vanity projects such as museums art galleries and theatres +[379.81s -> 384.82s] that only the wealthy will be able to visit or to attract foreign visitors. +[385.68s -> 395.28s] There are many links between urbanisation and other aspects of development. Urban areas can influence the type of healthcare, education and employment that is offered in the developing world. +[395.44s -> 403.66s] Furthermore, the rapid growth of urban areas leads to increased environmental pressures, not just on developing nations, but on a global scale. +[404.27s -> 418.16s] finally urbanization enables the norms and values of western capitalism to be transmitted to the population faster than if there was a large rural population and this impacts on gender equality attitudes to employment +[418.16s -> 429.62s] potentially conflict. That concludes this tutor to you sociology topic video on global development focusing on urbanization and development. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Humanities/validation_Psychology_22.mp4.txt b/VideoMMMU_ASR_large/Humanities/validation_Psychology_22.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..314f69542f59c204782c0cd1ac71a5587cbc17fb --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/validation_Psychology_22.mp4.txt @@ -0,0 +1,69 @@ +[11.50s -> 17.78s] In this lecture we're going to continue our discussion of stress with a focus on coping strategies. +[18.64s -> 29.36s] When we talk about coping with stress, we can categorize approaches to coping in at least four broad categories. The first we can call emotion-focused coping. +[29.36s -> 41.46s] Emotion-focused coping is the type of coping that focuses on the emotional and physiological effect of stress. The goal with emotion-focused coping is to feel better in the midst of stress. +[41.74s -> 50.32s] We might also look at problem-focused coping. Problem-focused coping focuses more on altering the causes or the source of stress. +[50.32s -> 64.19s] The goal is to alter or remove the stressor itself to reduce the stress being caused. We can also think about prevention as a way of approaching stress by altering the physical environment or building resistance. +[64.19s -> 73.65s] And lastly, we can think about countering the stress response, what we sometimes call stress management. This will actually be addressed in the subsequent lecture. +[75.98s -> 88.38s] So emotion-focused coping is defined as cognitive or behavioral responses to emotions that result from stress. Again, the goal is to try to feel better in the midst of stress. +[88.38s -> 100.77s] Emotion-focused coping by itself is rarely ideal when it is used exclusively. Now, it can be used perhaps in combination with more problem-solving or problem-focused approaches. +[100.77s -> 105.54s] In some situations, emotion focused coping is the only option. +[105.54s -> 117.89s] for example, inescapable or traumatic stress. Imagine people who are prisoners of war or perhaps people who are kidnapped or in situations like that where the stress is +[117.89s -> 129.62s] Really, there's very little can be done to alter the stress. In those situations, the only thing that can be done and must be done is emotion-focused coping strategies, and those, of course, can be very helpful. +[130.29s -> 144.26s] Avoidance is a common emotion-focused coping strategy that is particularly problematic. Avoidance is what people do when they're in situations that they just don't like, they don't feel good about, they cause a lot of stress, and they try to avoid them. +[144.26s -> 158.34s] Well, this becomes problematic, especially if it prevents effective behavioral responses. A good example of this that may relate to students in this class, exams are typically sources of stress for students. +[158.34s -> 172.66s] Well, one way of coping with that stress is to avoid, to try to forget that there's an exam upcoming or to not crack the books or do any kind of studying. Obviously, that's going to be a problem because that actually makes the stressor. +[172.66s -> 177.54s] or worse and the stressor of the exam is probably coming whether you like it or not. +[177.54s -> 189.33s] It's more appropriate in those situations to do more problem-focused coping, perhaps combined with some emotion-focused coping. But emotion-focused coping, like avoidance itself, is only going to make things worse. +[191.76s -> 197.34s] When people use effective emotion-focused coping, there are a number of strategies that can be very helpful. +[197.34s -> 209.14s] One is to engage positive emotions. People who do this tend to be folks who are more optimistic. They find the positive in the midst of negative or difficult situations. +[209.14s -> 222.35s] Finding a sense of gratitude or counting one's blessings, even in the midst of stress or even trauma, is another good example of looking for some positive emotion, even in the midst of some difficulty. +[222.86s -> 228.29s] Another type of effective emotion-focused coping is finding benefits or meaning. +[228.29s -> 242.58s] In our common language, we talk about looking for the silver linings. Every cloud has a silver lining is a popular saying. Sometimes we look for ways that this particular stressor might be helping us learn a lesson or helping us to grow. +[242.58s -> 256.78s] or mature. Sometimes people will lean on a spiritual tradition, for example Christianity, to look for things like, you know, why is God putting this in my path? Or trying to understand how one... +[256.78s -> 266.05s] might be growing in their sense of God or closeness with God in the midst of a stress or a difficult situation, as another example. +[266.05s -> 276.88s] One thing we see in the scientific literature is a concept called post-traumatic growth. You're probably familiar with something called post-traumatic stress syndrome or PTSD. +[276.88s -> 287.78s] quite widely known about today. But we also know there's a phenomenon that many people experience called post-traumatic growth, where people often, after a difficult stressor, +[287.78s -> 298.02s] will look back on that and realize that they have learned or grown in an important way and they actually see some positive in that experience. +[298.02s -> 304.59s] In my own family's experience, we had a very difficult situation years ago where my oldest daughter was diagnosed with cancer. +[304.59s -> 314.21s] led to a very difficult couple of years of watching her go through some very difficult medical procedures. Of course +[314.21s -> 323.18s] Her very survival was at times in question, a very stressful trying time for everyone in my family and certainly myself. +[323.18s -> 335.47s] I recall, however, about a year after that experience at a lunch, actually, with one of our pastors. And she asked us the question if things were starting to get back to normal. +[335.47s -> 342.59s] And my response to her that kind of surprised even me was I said to her, I kind of hope things don't go back to normal. +[342.59s -> 356.72s] Because one of the things that I think my wife and I both grew out of that experience is a sense of gratitude and appreciation for everyday things, for not taking things for granted. +[356.72s -> 369.10s] And we saw that as something that was a benefit we derived from that situation that we didn't want to lose, in quotes, go back to normal. So that might be an example of a kind of post-traumatic growth. +[369.55s -> 383.98s] Another thing people may do is engage in what we call emotional approach. Instead of avoiding the emotions or trying to suppress emotions, actually taking the time to express those emotions, perhaps to process through some thinking or some worry. +[383.98s -> 397.46s] Have you ever had the situation where you feel like you just need a good cry? Anybody experience that? That's an example of emotional approach. Instead of trying to suppress the need to cry or express some emotions, +[397.46s -> 407.20s] go ahead and take some time to express it. Sometimes that's a very positive way of coping. Lastly, accommodating the stressor is another option. +[407.20s -> 420.56s] Some of you may be familiar with what's called the Serenity Prayer that comes out of Alcoholics Anonymous and similar communities. They have a prayer that goes, God grant me. +[420.56s -> 432.43s] the courage to change the things I can, the wisdom, or excuse me, the patience to accept the things I cannot, and the wisdom to know the difference. +[432.43s -> 446.58s] That's an example of trying to capture this strategy of accommodating stressors. Sometimes the best thing we can do is accept the reality of a situation and incorporate it into one's new lifestyle, perhaps one's new identity. +[446.58s -> 460.83s] Another example of this that we'll touch on later in the course is sometimes people have to come to terms with a new diagnosis of a chronic illness. And that chronic illness may involve some loss to identity or lifestyle. +[460.83s -> 474.74s] But people who adjust the best and cope the best have a sense of accepting that new reality, incorporating it, embracing it, and moving on with life as best they can within the possible new limitations. +[477.97s -> 486.67s] We then can also look at problem-focused coping. Problem-focused coping is coping that seeks to really tackle the stressor head-on. +[486.67s -> 498.90s] Examples for this are a number of different things, including asking for assistance or help, asking for expert help, perhaps learning something new to tackle a different problem is an example. +[498.90s -> 510.16s] seeking out information or education so for example if you are starting a new business and the finances are overwhelming +[510.16s -> 520.14s] you because maybe you're just not, you don't have the experience or the knowledge to know how to manage that part of the business. A good problem-solving, problem-focused strategy. +[520.14s -> 529.87s] To cope with that stressor is to go learn more about the finances of the business. Try to educate yourself to be able to tackle that part a little more effectively. +[529.87s -> 539.07s] Using logic or reason to avoid over-exaggerating a stressor. How many of you have ever made a mountain out of a molehill? You're familiar with that phrase. +[539.07s -> 547.22s] Well, sometimes we need to step back, get some perspective, and really think through this dresser and think if perhaps we are making a mountain out of that molehill. +[547.57s -> 556.35s] Of course, another strategy is to engage in problem solving and make a plan of action. The figure on this slide illustrates one potential process of a problem solving. +[556.35s -> 567.42s] process, and you can see how if one follows a process like this, it's going to be really taking that source of stress or that problem head on. And lastly, of course, acting on any steps that can be taken. +[567.42s -> 577.02s] You may have had the experience yourself or known someone who was in a stressful situation, perhaps knew what could and should be done. +[577.02s -> 588.72s] but just didn't take those steps and that perhaps made the stressor worse or at least did not make it any better. Acting on steps that can be taken is of course the opposite of avoidance as we discussed earlier. +[588.72s -> 596.56s] Avoidance is problematic. If there are things that can be done, it's probably best to just take those on and move in that direction. +[598.77s -> 608.94s] Another thing that we can think of is perhaps preventing stress. Anything that we could do to remove future stressors is another way of coping with stress. +[609.14s -> 621.10s] Stress is one of those things where sometimes it's easier to prevent than deal with once it's manifest. So there's a number of things we can do to think about preventing stress. One is to build social support networks. +[621.10s -> 631.57s] Build relationships and close relationships. Connect with individuals. Join groups. Because when those stressors come along, those are an important buffer in helping to cope with that stress. +[632.11s -> 646.29s] Exercise and develop a healthy active lifestyle that includes a healthy diet. Those sorts of things also could sort of reinforce the body to endure the physiological effects of a stress response. +[646.77s -> 658.22s] Utilizing effective time and financial management are good things. It's always better to try to avoid having more tasks than there is time, so effective time management. +[658.22s -> 667.12s] or perhaps to find oneself in a real financial predicament, it's much easier to prevent those than to cope with them once they manifest. +[667.31s -> 679.82s] Sometimes people need to find different environments. Perhaps the situation with your housing, your neighborhood, the city in which you live needs to be changed in order to deal with stress. +[679.82s -> 690.54s] I lived for five years in Seattle, Washington, which was a beautiful, awesome city. But my gosh, the traffic was terrible. And I could tell that it was wearing on me, even though I was much younger then. +[690.54s -> 700.14s] just watching my life waste away in the brake lights ahead of me was very stressful for me, especially having grown up in a more rural community where +[700.14s -> 711.89s] You didn't waste any time stuck in traffic. I found that very stressful and decided really at that time that that wasn't the kind of community that I wanted to live for my life. It didn't feel healthy to me. +[712.30s -> 720.69s] And lastly, preparing for anticipated stressors. Sometimes there's stressors that are out there that we know are coming and we can take steps to prepare. +[720.94s -> 732.82s] A good example of this is starting school. You know, as August starts to come around and summer is winding down, you're probably prepared that school, you're aware that school is coming and it's wise to start preparing. +[732.82s -> 742.48s] you go and buy school supplies, you pick up your textbooks, you get everything lined out so that when that day school starts, you've got pretty much everything else taken care of. +[742.48s -> 753.31s] If you've ever had that experience where the first day of classes arrive and you're still trying to figure out where you're going to live and buy your textbooks and all this business, that's incredibly more stressful. +[753.31s -> 763.63s] then kind of taking care of business in advance so that when the stressor begins, you're able to have less on your plate and deal more directly with that stressor alone. +[764.91s -> 775.50s] So that gives us some overview of some of the various ways for coping. In our next lecture, we'll talk about a variety of other strategies that we call broadly stress management techniques. diff --git a/VideoMMMU_ASR_large/Humanities/validation_Psychology_6.mp4.txt b/VideoMMMU_ASR_large/Humanities/validation_Psychology_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..44c931d672911e095949705f7783481032525780 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/validation_Psychology_6.mp4.txt @@ -0,0 +1,11 @@ +[0.00s -> 4.78s] Bypass Publishing presents Difficult Topics Explained. +[5.07s -> 15.42s] Schedules of Reinforcement Applications. This segment is to simply give you some examples of the different schedules of reinforcement. We'll start with Fixed Interval. +[15.42s -> 28.98s] Fixed interval requires that you wait a specified period of time after completing the correct response before you'll be reinforced. An example of fixed interval is used by someone who gets paid every two weeks at their job. +[28.98s -> 39.30s] They have to show up to work and do all their assigned tasks, but no matter how fast they work or how many tasks they complete, they don't get paid until after the two weeks have transpired. +[39.30s -> 53.12s] Fixed interval schedules tend to produce overall response rates that are low and that increase as the time for reinforcement gets closer. This is called a scalloped response pattern. Now an example of variable interval. +[53.12s -> 66.34s] Variable interval would be, say, when someone waits for an elevator. Anytime they have to wait an unpredictable amount of time, they are on a variable interval schedule. People press the elevator button over and over again when they're in a hurry. +[66.34s -> 79.58s] but they only need to press the button once. It doesn't matter how many times you press it again, you just have to wait for it to arrive. Variable interval schedules produce steady rates of responding. Now for fixed ratio. +[79.58s -> 92.56s] Imagine you had a summer job where you stuffed envelopes and got paid for every 100 envelopes you stuffed. When you get paid for a set number of items you complete or sell, that's an example of a fixed ratio schedule. +[92.56s -> 102.96s] Fixed ratio schedules produce high rates of responding that decline immediately after the reinforcer is received. This is called a post-reinforcement pause. +[102.96s -> 116.08s] A classic example of a variable ratio schedule is known as the one-armed bandit, which is a slot machine. You must pull the arm an unspecified number of times before you are reinforced with a jackpot. +[116.08s -> 129.55s] Sometimes you can just put in a few quarters, pull the arm once, and win a big jackpot. Other times you pull and pull, but still never win. Variable ratio schedules produce high and steady rates of responding. diff --git a/VideoMMMU_ASR_large/Humanities/validation_Psychology_7.mp4.txt b/VideoMMMU_ASR_large/Humanities/validation_Psychology_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fdfc73d7cab940266665dd2f69fe576561d2690e --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/validation_Psychology_7.mp4.txt @@ -0,0 +1,10 @@ +[0.00s -> 8.34s] Welcome to Two Minute Neuroscience, where I simplistically explain neuroscience topics in two minutes or less. In this installment, I will discuss the neuron. +[9.62s -> 23.17s] This is a brain. Estimates vary, but right now the best guess seems to be that our brains contain around 85 billion neurons. The neuron is a nerve cell, and it's the primary functional unit of the nervous system. This is a generic image of a neuron. +[23.17s -> 28.94s] Neurons actually come in all shapes and sizes, but this is the prototypical version of a neuron that you'll often see in a textbook. +[29.58s -> 38.21s] The structures extending from the left side of the neuron that look a little bit like tree branches are called dendrites. Dendrites are the area where neurons receive most of their information. +[38.21s -> 52.30s] There are receptors on dendrites that are designed to pick up signals from other neurons that come in the form of chemicals called neurotransmitters. Those signals picked up by dendrites cause electrical changes in a neuron that are interpreted in an area called the soma, or the cell body. +[52.82s -> 63.54s] The soma contains the nucleus, which contains the DNA, or genetic material, of the cell. The soma takes all the information from the dendrites and puts it together in an area called the axon hillock. +[63.95s -> 74.16s] If the signal coming from the dendrites is strong enough, then a signal is sent to the next part of the neuron which is called the axon. At this point, the signal is called an action potential. +[74.80s -> 82.35s] The action potential travels down the axon, which is covered with myelin, an insulatory material that helps prevent the signal from degrading. +[83.06s -> 96.48s] The last step for the action potential is the axon terminals, also known as synaptic buttons. When the signal reaches the axon terminals, it can cause the release of neurotransmitter. These purple structures represent the dendrites of another neuron. +[96.48s -> 104.34s] When a neurotransmitter is released from axon terminals, it interacts with receptors on the dendrites of the next neuron, and then the process repeats with the next neuron. diff --git a/VideoMMMU_ASR_large/Humanities/validation_Sociology_22.mp4.txt b/VideoMMMU_ASR_large/Humanities/validation_Sociology_22.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..bf9d3d805adde0a355cf7f34af656256ecf5b6c3 --- /dev/null +++ b/VideoMMMU_ASR_large/Humanities/validation_Sociology_22.mp4.txt @@ -0,0 +1,28 @@ +[0.18s -> 9.46s] Hi, this is Pat Johnson, your sociology instructor. In this mini lecture, we're going to talk about the concept of cultural universals. +[11.44s -> 22.90s] So what's a cultural universal? Well, let's go back a little bit to our last discussion about culture shock and what culture is. +[22.99s -> 27.79s] If you remember, I started the discussion on culture shock. +[27.79s -> 39.41s] by explaining a situation I experienced that was extremely disturbing to me because I was in a culture very different from what I was used to. +[40.24s -> 54.66s] well culture shock begs the question of are there any cultural universals what's a cultural universal our author tells us that a cultural universal +[54.66s -> 65.57s] is a value or behavior that is shared by all human cultures. So these are things that don't change from culture to culture. +[65.57s -> 75.95s] or at least in their general form don't change your author lists a few different cultural universals let's take a look at them +[77.87s -> 86.06s] Communication is a cultural universal. All cultures have a grammatically complex language. +[86.67s -> 96.38s] if you're like me and you've ever tried to learn another language or two you may realize how different languages can be +[96.38s -> 109.10s] But all cultures do have language. They have a form of communication that has a grammar that is a way for people to convey meaning to each other. +[110.77s -> 115.94s] Another cultural universal is dependence on material objects. +[115.94s -> 127.25s] Now the clipart that I used for this cultural universal might look a little bit more cluttered than what your value system is. +[127.28s -> 140.45s] Some of you may be minimalists or at least trying to downsize the amount of stuff that you have. Still though, we all have stuff and +[140.45s -> 151.63s] we depend on that as humans so all cultures have dependence on material objects some just to a greater extent than others +[153.17s -> 162.38s] another cultural universal is marriage all cultures have some type of marriage as a means to care for children +[162.38s -> 175.70s] as we go through this course we'll see that marriage can take many forms some marriages involve more than two people some involve as in our country only two people +[175.82s -> 180.69s] But we'll see that all cultures have some form of marriage. +[182.51s -> 192.99s] Another cultural universal that our author lists is religious beliefs. All cultures have religious beliefs, some type of spiritual values. +[192.99s -> 204.40s] Again, these can differ greatly from culture to culture. Different cultures can also depend on religion or have more +[204.98s -> 212.66s] religious beliefs in other cultures, but all cultures have some type of religious belief within the population. +[214.38s -> 227.47s] Our author also lists property rights as a cultural universal. So we'll see when we look at different political systems that they can vary +[227.47s -> 238.03s] greatly as far as who owns the means of production in a society, but all societies, all cultures have some type of property rights. +[239.63s -> 254.21s] another cultural universal is something called the incest taboo the incest taboo is basically who you can or cannot have sex with sexual intercourse with in a culture +[254.21s -> 262.30s] What's interesting about the incest taboo is that in just about all cultures +[262.30s -> 275.38s] it is considered taboo in other words extremely prohibited to have sex with your immediate family your parents your siblings or your children +[275.41s -> 288.50s] Beyond that, when we get to first cousins or second cousins, that does vary from culture to culture. But within that small immediate group, there is a cultural universal. +[288.50s -> 297.15s] called the incest taboo so again in this module in this chapter we're going to look at how +[297.15s -> 305.30s] cultures differ from each other, but I want you to remember that there are some cultural universals that all cultures share. diff --git a/VideoMMMU_ASR_large/Medicine/dev_Clinical_Medicine_4.mp4.txt b/VideoMMMU_ASR_large/Medicine/dev_Clinical_Medicine_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f598f8196fd651fbea25f5646a7ee8609f97e3d2 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/dev_Clinical_Medicine_4.mp4.txt @@ -0,0 +1,9 @@ +[0.75s -> 15.09s] Hi everyone, this is Dr. Manu Krishnan K. Welcome to another session on Let's Hack an X-ray. And today we will be discussing about the Smith's fracture. In the previous session, we have seen how the Collis fracture happens and we have seen the X-ray. +[15.31s -> 29.62s] Similarly, we will discuss what is Smith's fracture today. So what is Smith's fracture? The fracture of distal end of radius with the ventral or volat displacement of the fragment is termed as the Smith's fracture. +[29.62s -> 41.09s] Here we have an X-ray which shows a Smith's fracture. And here you can see this is the lower end of radius. You can clearly see the clean margins without any discontinuity here. +[41.09s -> 54.46s] While on the other side where there is a smith's fracture, you can see the axis. Here the lower end of the radius has been broken and it is displaced forwards or ventrally towards the palmar side. +[54.46s -> 68.88s] And that's why that is called as a Smith's fracture. So let's compare it with that of the Collis fracture. Here we have both hand in hand where you can see the Smith's fracture where the displaced fracture fragment is. +[68.88s -> 82.61s] displays forwards and while in case of the college fracture it is displaced backwards so that is a major difference between the smith's fracture and college fracture so let's see the causes of smith's fracture +[82.61s -> 96.40s] a fall onto the flexed wrist here you can see the diagram which represents the flexed wrist and if you fall on that flexed wrist the chances of the lower end of radius to get fractured and the fragment to get +[96.40s -> 109.79s] displaced forwards is more and that's why this particular fracture happens or it can also be caused by a direct blow to the back of the wrist so here we have a clear representation you can see the lower end +[109.79s -> 123.93s] and the displaced fragment is moved forwards and that is smith's fracture so if you have any further queries regarding the radiological anatomy do post them as the comments below thank you diff --git a/VideoMMMU_ASR_large/Medicine/test_Basic_Medical_Science_219.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Basic_Medical_Science_219.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..9f884e66c20fcd4b7a019735a2df71787a060a9c --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Basic_Medical_Science_219.mp4.txt @@ -0,0 +1,67 @@ +[0.50s -> 14.59s] In this lesson we're going to take a look at another example of how neurons, when they're arranged in certain ways, can do some useful computations. In this case we'll look at how brains can determine the location of a sound in space. +[14.59s -> 18.26s] To begin, consider this person here just looking forward. +[18.26s -> 32.40s] And of course, we have two ears, a left ear and a right ear. And if the sound happens to be directly in front of us, the sound waves, those vibrations in air, will be detected by both ears simultaneously. +[32.40s -> 46.53s] Now notice if the sound is at an angle from our direction, the head position here, the sound is off to the left here a little bit, the sound waves are going to strike the left ear before they strike the right ear. +[46.53s -> 59.42s] And so when researchers thought about how brains might compute the location of sound in space, they thought this might be one possible mechanism. Perhaps the brain is measuring or detecting the delay. +[59.42s -> 65.15s] inactivity of the two auditory receptors in the ears here and that delay +[65.15s -> 78.82s] would then be correlated to the position of the sound in space. So imagine the sound source goes all the way over here 90 degrees from the direction of gaze of the person. In this case, the sound will hit the left ear first. +[78.82s -> 92.67s] and the right ear second, but the delay will be maximum when the sound is over here. There'll be a little less delay when it's here, there'll be zero delay when the sound is directly in front of the person. So the magnitude of the delay +[92.67s -> 102.82s] in the activation of the auditory pathways for the left and the right the magnitude of that delay, how big is that delay, is correlated to the position of the sound in space. +[102.82s -> 109.26s] So, in principle, then it was possible that maybe what brains are doing is somehow detecting the delay. +[109.84s -> 122.35s] Well, how would that happen? So to begin the investigation, then you want to find places in the brain where the right ear information and left ear information are converging. If you're going to detect a delay in activity. +[122.35s -> 134.45s] you'll need to be comparing the activation in both those ears. So they wanted to find a place in the auditory pathway where left and right ear information was converging in some place in the brain. +[137.04s -> 143.12s] And here we see a diagram of precisely where that location is. +[143.12s -> 157.65s] So here we have the right ear over here. Now inside the inner ear are hair cells. And these are the sensory cells that convert vibrations into electrical signals. The eighth nerve would be the auditory nerve. And so action potentials will raise. +[157.65s -> 166.26s] down here into the cochlear nucleus and then these cochlear nuclear cells are going to send axons down here to this structure called the superior olivary nucleus. +[166.26s -> 180.69s] Now, interestingly, this is the first place then where information from both ears converges, because here's the hair cells in the inner ear of the left ear, and they're going to respond to vibrations, and they'll send action potentials, and they will converge. +[180.69s -> 187.97s] in this olivary nucleus. So researchers were interested in determining how the +[187.97s -> 202.26s] the neurons in the superior olivary nucleus were arranged. Perhaps they're arranged in a way that can detect a delay in the activity between the right ear and the left ear. You'll recall if the sound is directly in front of the person, the two hair cells here left +[202.26s -> 204.91s] and right will be activated simultaneously. +[204.91s -> 217.52s] If the sound is off to the left here, the left ear will be activated, then the right ear, and that will be a maximum delay when the sound is on either side, 90 degrees from the person's line of sight. +[217.52s -> 226.00s] So let's take a look at how the neurons were arranged in the superior olivary nucleus. And this research was, a lot of it was done on birds, birds of prey who... +[226.00s -> 238.30s] It's obviously useful to be able to localize sound in space because their food would make sound, and then they can find their food. So this is what they found in the superior olivary nucleus. They found a pattern. +[238.30s -> 249.26s] of wiring that look like this here's the right cochlear nerve so that's this one coming in here here's the left cochlear nerve that's this one coming in here +[249.26s -> 260.88s] And the green cells would be the superior olivary nucleus cells. A nucleus is just a cluster of neurons. So the superior olivary nuclear cells are the green ones here. One, two, three, four, five. +[261.10s -> 271.97s] Now notice each neuron or each axon that comes in to the system is branching, right? So if action potentials are going to come down this axon action potentials will split +[271.97s -> 282.11s] action potentials will go down here and the same frequency of action potentials will go down here and again split and so action potentials are going to arrive at each of these terminals +[282.11s -> 296.43s] But, of course, in the left nerve, action potentials will arrive at cell 1 first, and it will take some time to get to cell 2, take a little more time to get to cell 3, take a little more time to get to cell 4, and finally to cell 5. The same principle applies... +[296.43s -> 310.64s] for the right nerve. Now, we'll make an assumption in the system that action potentials travel at the same speed. And again, we're going to make the assumption that the target cells here, 1, 2, 3, 4, 5, only respond when both of their inputs are simultaneously +[310.64s -> 312.98s] active so again spatial summation +[313.55s -> 327.09s] Now with those two assumptions then, it became clear how this system can actually compute the delay of activation between the two auditory nerves. +[328.50s -> 341.31s] So to see how this works, let's take the case of the sound coming from directly in front of the person. You'll recall in our other diagram here when the sound is in front, both ears are activated. +[341.31s -> 355.39s] simultaneously, so there will be zero delay. So under conditions of zero delay, let's see which of these neurons will be activated. Well, if the sound comes from the front, both the left and the right will be activated simultaneously. +[355.39s -> 366.59s] action potentials will begin at the same time. Let's take the left first. So for the left side here, the action potentials will reach cell number one. +[366.59s -> 380.94s] But by the time they reach cell number one, the action potentials over here have not even begun to get close to cell number one. They're only at the beginning stage of the process here, right? So in the time it takes action potentials from the left nerve to get to cell number one, +[380.94s -> 394.90s] number one, the action potentials in the right nerve have only reached cell number five. And so the idea is that because only one of the inputs for cell number one was activated, cell number one will not respond. +[394.90s -> 404.58s] because it doesn't have the second input. It hasn't had time. The action potentials didn't have time enough to get all the way down here in the right nerve. +[404.58s -> 418.96s] So because the action potentials only activate one of the inputs and not both, this cell does not fire. Neither does cell number five respond because it's only receiving input from the right cochlear nerve. +[418.96s -> 433.17s] action potentials. The action potentials in the left cochlear nerve haven't had time to get all the way down to cell 5. Well, if we just wait a little bit longer, the action potentials in the left will reach cell 2. The action potentials in the right will reach cell 4. If we wait a little long, +[433.17s -> 440.43s] the action potentials and the left will resell three at the same time the action potentials in the right reach cell three +[440.43s -> 454.70s] It's cell 3, then, that will get simultaneous activity in both of its inputs, sufficient to drive the target cell. So enough sodium gets into the cell, and that cell will generate its own action potential. And the idea is, then, the output of... +[454.70s -> 468.91s] of this system would go to, say, some motor neurons that would orient your head in the direction where the sound is coming from. So in this case, this motor, let's call this a motor neuron, would keep you facing forward. +[468.91s -> 470.86s] where the sound came from. +[471.22s -> 485.81s] Now, when both arrive at cell 3 at the same time, that's not the end of the process. Remember, the action potentials keep on going down to cell 2 for the right pathway, and for the left pathway, keep on going down to cell 4 and then cell 5. But remember, none of those cells will fire. +[485.81s -> 500.02s] either, because only one input is active, and you need both for the target cell to fire. So when the sound is directly in front, cell number three will get coincident activity, will get simultaneous activity in the inputs. +[500.02s -> 514.69s] And if that cell's output is hooked up to the motor system, it will direct your head, right, your direction of gaze and your head towards the sound, which would be directly in front. +[514.69s -> 528.98s] Now let's take a look at the other interesting example. Let's say the sound comes from 90 degrees from the right. And that would be a case of maximum delay. So the sound's going to strike the right ear. Action potentials will get a head start in the right nerve. +[528.98s -> 538.18s] there will be some time delay, then the sound reaches the left ear and the action potentials here are delayed a little bit. +[538.18s -> 551.41s] And so the idea is this being the maximum delay, then the right ear action potentials will have the maximum head start. And they will get all the way down to cell one by the time. +[551.41s -> 555.92s] the left ear's delayed action potentials get to cell one. +[556.27s -> 567.44s] So cell number one will get simultaneous activity in the two pathways, in the two inputs, when the sound is 90 degrees to the right. +[567.44s -> 575.76s] And the idea then is cell number one would activate a motor neuron that would turn your head 90 degrees to the right to localize the sound. +[576.24s -> 587.09s] Or to respond to the sound that the system has already localized here. Likewise, if the sound came from the left, the left ear gets the head start. +[587.09s -> 593.62s] Those action potentials can go all the way down here by the time the right ear action potentials reach cell 5. +[593.62s -> 606.24s] Now again, right, so in that situation, cell 5 is going to represent that the sound is way over here to the left, 90 degrees to the left, and the motor neuron will make your head turn to the left to see it. But that doesn't... +[606.24s -> 620.13s] and the action potentials, right, just because that cell fires. They keep on going down here, but none of these cells will get simultaneous activity in both of their inputs, so they will not fire. Only cell 5 in that case. So, in summary, when the... +[620.13s -> 634.94s] When the sound is directly in front, cell number three will get simultaneous activity only. So in a sense, the activity here in the system represents that the position of the sound is directly in front. +[634.94s -> 647.06s] If the sound were 90 degrees to the right, cell number 1 would get simultaneous activity. So activity in this cell represents the location of sound 90 degrees to the right. +[647.06s -> 661.42s] If the sound came from the directly 90 degrees to the left, cell number 5 gets simultaneous activity. So activity in cell number 5 represents the location of sound is 90 degrees to the left. So in this way, sometimes these are called delay lines. +[661.42s -> 674.16s] lines or coincidence detectors. These delay lines, again, the way the neurons are arranged, can do some useful computing. What the system is doing is measuring, in a sense, the delay. +[674.16s -> 688.59s] that occurs when a sound is at a certain location in space. So our auditory pathway is arranged in such a way that certain places in the auditory pathway get information from both ears and in particular the superior olivary +[688.59s -> 702.80s] nucleus, and that system is wired up in such a way that these cells can, in a sense, represent the delay of activity of the two auditory pathways. And that delay is correlated to the location of this. +[702.80s -> 704.24s] in space. +[707.06s -> 721.65s] Here we see a nice summary diagram of this when the sound from the purple speaker right directly in front It's going to be the purple cell that will be Activated right so sound will hit the two ears simultaneously and so only the middle +[721.65s -> 730.67s] cell will be the one that gets simultaneous activity from both inputs. If the sound comes from the red one here, you're going to get maximum delay. +[730.67s -> 737.17s] And the right ear will respond first, then the left. And so the right ear ones have... +[737.17s -> 751.57s] head start right and the left ear ones will be delayed and consequently it'll be this red cell here that will be active when the cell comes from the right and on the other hand if it came from the blue speaker here maximum delay on the other side +[751.57s -> 762.80s] The left ear gets the head start, so those action potentials will race all the way down here and get to the blue cell at the same time as the action potentials from the right ear get there as well. diff --git a/VideoMMMU_ASR_large/Medicine/test_Clinical_Medicine_173.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Clinical_Medicine_173.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..942e4a29e4eaa71048c3cf19e933ba424bcc0433 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Clinical_Medicine_173.mp4.txt @@ -0,0 +1,108 @@ +[0.00s -> 8.06s] Hello and welcome back to another anatomy tutorial. Today we're going to be looking at the anatomy of the pelvis by looking specifically at a pelvic radiograph. +[8.06s -> 20.37s] Now when we look at the pelvis itself, we can see that we have a right and a left pelvic bone fusing centrally at the pubic symphysis and separated posteriorly by our sacrum. +[20.37s -> 33.81s] Now these pelvic bones actually develop in three different segments. If we have a look at this x-ray, we can see the three separate segments developing, which will eventually fuse to form one pelvic bone. +[34.00s -> 44.77s] We've got our ilium here making up our iliac crest at the top of the pelvis here. Posteriorly, we've got our ischium and anteriorly, we've got our pubis. +[44.77s -> 52.93s] These three bones also fuse to form our acetabulum which is where our femur will articulate creating our hip joint. +[52.93s -> 60.26s] Now as always when we're looking at a radiograph it's good to have a conceptual or at least a 3D understanding of the anatomy. +[60.26s -> 74.42s] So if we have a look at this 3D rendered CT of the pelvis, we can see those pelvic bones here articulating with our femur, creating our hip joint and our sacrum separating those pelvic bones posteriorly. +[74.42s -> 88.08s] We have our fourth and our fifth lumbar vertebra here with the transverse processes, our intervertebral disc. And the L5 vertebra, the fifth lumbar vertebra, articulates with our sacrum here. We can see our sacrum has a... +[88.08s -> 101.90s] broad base superiorly heading down towards the sacral apex inferiorly at the apex of the sacrum we have these small bones here known as the coccyx or coccygeal bones and our sacrum has these +[101.90s -> 106.77s] holes or foramina anteriorly which are anterior sacral foramina +[107.15s -> 117.26s] The sacrum curves, it's a concave shape like that, and superiorly on the sacrum we have this bony outcropping known as the sacral promontory. +[117.26s -> 122.19s] And that makes this distance here, the AP distance, quite narrow within the polis. +[122.19s -> 132.50s] Our sacroalar then spread out laterally towards our SI joint, our sacroiliac joints, both right and left sacroiliac joints. +[132.50s -> 146.86s] we can see our iliac wings fanning out laterally here with our iliac crest and we can see this bony outcropping here which is known as the anterior superior iliac spine and below that is our anterior inferior iliacs +[146.86s -> 157.01s] spine. We can see that the iliac wings are also concave like that and our iliacus muscle lies in the belly of this concavity here. +[157.01s -> 171.50s] So our iliac wings now head anteriorly towards the pubis. So our pubis comes anteriorly towards the pubic symphysis and we have a superior pubic ramus and an inferior pubic ramus which heads out more. +[171.50s -> 184.56s] posteriorly and inferiorly. That inferior pubic ramus heads towards the ischium and our sitting bones here or the part where the bone would touch our seat as we sit is known as the ischial tuberosity. +[184.56s -> 197.68s] Our ischium then heads up towards our ilium posteriorly, making up our ischial bone. Posteriorly here, you can see our ischial spine also extending towards our sacrum on that side. +[197.90s -> 210.75s] Our acetabulum is the hollowed out portion created by all three parts of the pelvis and that creates the socket for our ball and socket joint of the hip. Now our acetabula actually face slightly +[210.75s -> 224.24s] anteriorly allowing our femur to come anterior allowing our legs to come out anterior to us and prevents those legs going back too far we can't sit with our legs crossed behind us or at least i can't +[224.24s -> 238.38s] Then we have our femoral head, which articulates with that acetabulum, our femoral neck heading towards our proximal femur, as well as our greater and lesser trochanters, which are important attachment sites for various muscles. +[239.15s -> 251.44s] If we were to rotate this pelvis round, we can look at an angle posteriorly. We can see the iliac wing here and iliac crest. Here we have the attachment site for our gluteus muscles. +[251.44s -> 260.91s] and you can see anteriorly we have our anterior superior iliac spine and our anterior inferior iliac spine here posteriorly they're often forgotten about +[260.91s -> 271.10s] posterior superior iliac spine and posterior inferior iliac spine right at that SI joint as the iliac crest comes towards our sacrum here. +[271.10s -> 277.26s] Here we can see our posterior sacral foramina allowing for those nerve roots to exit the sacrum. +[278.10s -> 288.03s] We can see our ischium or ischial bone much more clearly here posteriorly and see how it makes up that posterior wall of our acetabulum. +[288.03s -> 302.19s] Here is our ischial spine that we saw earlier pointing towards our sacrum and our ischial tuberosity here. On the right-hand side of the patient, you can see the superior pubic ramus and the inferior pubic ramus of our pubic bone. +[302.42s -> 317.01s] When we think about the acetabulum itself, we can talk about this rim here being the posterior acetabular rim. And anteriorly, we have our anterior acetabular rim. And then that thin bone heading out towards our ischium here. This is our +[317.01s -> 331.62s] posterior wall of the acetabulum we also have an anterior wall of the acetabulum so now that we've got a better 3d understanding of the pelvis let's have a look at our frontal radiograph and start by naming some of the bony landmarks +[331.62s -> 343.87s] We can start in the proximal femur here. We can see our lesser trochanter and our greater trochanter of the femur. And the line between these two is our intertrochanteric line. +[343.87s -> 352.98s] Then our femoral neck heading up to the head of the femur, which is sitting within this acetabulum. This is our hip joint here. +[353.49s -> 368.08s] the posterior rim of our acetabulum you can see here and it's a bit more difficult but you can see our anterior rim of the acetabulum here we know that those acetabular sockets lie facing slightly anterior that's why our anterior rim +[368.08s -> 377.38s] is a bit more medial here. Often that anterior rim goes in line with the superior pubic ramus so that's another way to find that anterior rim. +[377.38s -> 389.07s] And often the morphology between people is quite different. So we can see the relationship between the posterior and anterior rims might change as the anterior version of that acetabulum changes. +[389.62s -> 404.24s] We can then see our superior pubic ramus and our inferior pubic ramus with our pubic symphysis here. And this line is known as our pectineal line across that superior border of our superior pubic ramus. +[404.24s -> 410.83s] You can see our ischial tuberosity here and our ischium heading off posteriorly behind that acetabular joint. +[410.96s -> 424.29s] Here is our anterior superior iliac spine and our anterior inferior iliac spine of the iliac wing and iliac crest going across the top. There's our posterior superior iliac spine. +[424.29s -> 429.39s] Maybe this is quite difficult to see is our posterior inferior iliac spine. +[430.06s -> 445.04s] We can see our lumbar vertebra here. We can see our L5 lumbar vertebra with its transverse processes here. Our intervertebral disc space. We can also see the vertebral spines heading out posteriorly there. +[445.94s -> 459.14s] It's quite difficult because of all the gas within the bowel here to see the sacrum well, but we can see our SI joint here, our sacroiliac joint with our sacral alar here. And further down, we can see our coccyx bones coming down here. +[459.14s -> 473.62s] and then lastly we're looking at the sacrum here we know that our ischial spines point backwards towards our sacrum and actually if i head back to this image here we can see that this ischial spine is pointing towards our sacrum and there's actually a ligament that comes here +[473.62s -> 483.12s] we will look at later between our ischial spine and the sacrum as well as our ischial tuberosity in the sacrum which makes two separate foramina posteriorly here +[484.08s -> 498.67s] So we've had a look at our bony landmarks. Let's have a look at some pelvic lines. Now the pelvis itself creates a ring of bone. And when we fracture that ring, often as any ring created in the body, one fracture in the ring often leads to another fracture. +[498.67s -> 505.98s] the ring and with pelvic radiographs often fractures are quite difficult to see or are occult we can't see them at all +[505.98s -> 517.78s] And we can draw a couple of lines within the pelvis. And if there's disruption of those lines, we should really suspect a pelvic fracture. And if we identify one pelvic fracture, we should then go looking for a second pelvic fracture. +[517.87s -> 526.96s] So the first line is this main pelvic ring that I've shown you before. And the first half of that main pelvic ring is known as our iliopectineal line. +[526.96s -> 540.03s] I told you here is our pectineal line, so we go from the ileum to our pectineal line is our iliopectineal line. It must be nice and smooth there. We can then draw a line inferiorly called our ilio-ischial line. +[540.03s -> 554.38s] And this line up here must be nice and smooth as well, our ilio-ischial line. That ilio-ischial line comes on the medial surface of the ischium here and then heads up to the superior surface of that inferior pubic ramus. +[554.86s -> 568.32s] We can also draw a line known as Shenton's line where we follow the medial border of this proximal femur, ignore this lesser trochanter, we follow that up towards the neck of the femur, curve medially and that should +[568.32s -> 573.71s] go nice and smoothly with the inferior border of that superior pubic ramus there. +[574.45s -> 586.22s] Other lines we can look at are these arcuate lines of the sacrum. You see these lines heading out posteriorly here, which helps us to identify any sacral fractures, those arcuate lines coming across like that. +[586.42s -> 597.20s] We can then think of the pelvis as also having an anterior and a posterior column, and it's a strong column of bone that we can draw all the way from the ilium down into. +[597.20s -> 609.81s] Firstly, our anterior column, which is our superior pubic ramus up into the island. That's known as our anterior column of the pelvis. We also have a posterior column from our ischium. +[609.81s -> 623.86s] all the way up into our ileum that's our posterior column of the pelvis and again when going through a pelvic x-ray it's important to look at these lines and any disruption of those lines increases our index of suspicion for a fracture +[624.46s -> 631.54s] Now let's go about the difficult task of naming the various muscles that attach to these bony features that we've labeled +[631.54s -> 646.13s] Now it's gonna feel like a very long list of muscles that I'm going through and the reason I'm going through This is one to gain an appreciation for the relationship between the muscles and the bones of the pelvis But two and it's a fact that we can't get away from is that in exams often, you know +[646.13s -> 660.34s] asked to name the bony feature but asked to name a muscle or a ligament that attaches to that feature so I'm going to go through the major ones here there are smaller muscles and ligaments that I'm not going to mention but by far and away these are the ones that you really do need to know +[660.34s -> 664.56s] looking at a pelvic x-ray especially when you're in an anatomy exam +[664.62s -> 676.94s] So let's start by having a look at our psoas muscle that comes from the lower lumbar vertebra, as well as our iliacus muscle that sits in that concavity of the wing of the ilium here. +[677.07s -> 691.66s] Those two then come down and join together to form our iliopsoas muscle that heads towards our lesser trochanter of the femur here. And you can actually see that little fat line of where that iliopsoas muscle comes down and joins to that lesser trochanter. +[691.66s -> 705.02s] cancer we can then look at our anterior superior iliac spine which has our sartorius muscle that heads all the way down to the tibia it actually bypasses the femur heads from the pelvis all the way down to the tibia +[705.02s -> 712.46s] Our rectus femoris then attaches to this anterior inferior iliac spine heading down towards the femur there. +[712.85s -> 723.20s] We can look at our greater trochanter. Now our greater trochanter has a lot of muscles coming posteriorly and attaching to that greater trochanter or just below the greater trochanter. +[723.20s -> 735.12s] And the way I go about learning these muscle attachments is by starting at the superior border of our pelvis and heading our way down and thinking of the various muscles that head down posteriorly. +[735.12s -> 747.89s] So let's start at the top here. We have our gluteus minimus and gluteus medius muscles that head from that posterior surface of these iliac wings and head down towards the greater trochanter itself. +[748.05s -> 758.96s] Inferior to that we get our piriformis muscle which heads from this lateral border of our sacrum, posteriorly round towards our greater trochanter. +[759.12s -> 769.39s] Below the piriformis muscle, we have our superior and inferior glamella muscles that head out and attach just below the attachment of that piriformis muscle. +[769.97s -> 784.56s] Then we can think about this obturator foramen that's created by the superior pubic ramus and inferior pubic ramus. And on the internal surface of that obturator foramen, we have what's known as our obturator internus. It's coming from the +[784.56s -> 795.12s] inside of the pelvis, heading posteriorly behind the neck of the femur here, behind the ischium here and heading towards our greater trochanter there. +[795.66s -> 806.58s] We then have a muscle called the quadratus femoris that comes from the lateral border here of the ischium and also heads out just below the greater trochanter inserting on that side. +[806.74s -> 818.51s] And lastly we can think of the muscle on the external surface of this obturator foramen known as our obturator externus which attaches just below the greater trochanter in the trochanteric notch. +[818.51s -> 832.94s] So all of those muscles are heading from the pelvis to the posterior aspect of this greater trochanter. And there are many muscles that attach to the anterior aspect of the greater trochanter, which are more involved with the femur itself, involved in extension. +[832.94s -> 838.77s] the knee and we're going to talk more about those muscles when we look specifically at the hip and the femur itself +[839.09s -> 848.96s] We can then look at muscles of abduction that cause the lower limb to abduct and we can think about those in a superficial and a deep layer. +[848.96s -> 859.97s] In our superficial layer, we have our pectineus. Easy to remember, comes from the pectineal line heading towards the femur. And just medial to the pectineus, we have our adductor longus. +[859.97s -> 867.76s] deep to the adductor longus we have our adductor brevis as well as our gracilis muscle it's those four muscles that are part of our adductor +[867.76s -> 882.03s] complex so those are the major pelvic muscles that i want to cover here we're not going into the internal pelvic muscles we'll look more closely at that when we look at an mri of the pelvis and we're looking at the relationship of those muscles with the rectum and other organs +[882.03s -> 894.14s] within the pelvis itself. So we've named them major muscles, and the muscles of the pelvis are largely involved in movement, movement of the hip joint, as well as actually extending across that knee joint for some of those muscles. +[894.14s -> 899.58s] But a major function of the pelvis is not only movement, but it's also weight bearing or stability. +[899.58s -> 913.90s] and the way this pelvis is designed is to allow us to take central weight over our spine here and distribute it evenly to our legs and we need some way to distribute the weight being put through the sacrum here into now +[913.90s -> 927.70s] our lower limbs and the way we do that is with some clever geometry and let me just get my pen out here and we can draw some of that so we can see that our weight is coming here through the spine and +[927.70s -> 941.36s] wedging onto our sacrum here we can see our sacrum is taking most of the weight here now when we draw an arch we can get a shape like this if you think of an arch being built by five bricks here in this image +[941.36s -> 948.35s] we have the top of our arch which is known as a keystone it allows for weight to then be distributed +[948.35s -> 962.64s] evenly on either side of the arch and that's exactly what the sacrum does it prevents our spine from falling through this way and distributes that weight out through the pelvis and into our lower limbs now in order for this distribution to happen without the +[962.64s -> 974.91s] bones falling away from one another we need quite strong ligaments to hold all of this in place so let's finish off by having a look at some of the major pelvic ligaments that provide stability within the pelvis +[974.91s -> 988.72s] The first ligament that we can look at is our iliolumbar ligaments that connect our ilium to our lower lumbar vertebra. That allows for some stability of those iliac wings to not be pushed away from our sacrum like that. +[989.01s -> 1002.67s] We then have sacroiliac ligaments, both anterior and posterior sacroiliac ligaments that provide stability across these SI joints. Those ligaments run from a medial to lateral trajectory. +[1002.80s -> 1014.45s] We then have ligaments that stabilize the hip joint itself. We've got three major ligaments heading from the pelvis to the femur surrounding the neck of this femur. +[1014.64s -> 1029.06s] Those ligaments are the iliofemoral ligament, our pubofemoral ligament, and our ischiofemoral ligament. And the way those ligaments wrap around the neck of the femur there, they go around it in a spiral pattern. +[1029.06s -> 1043.44s] what that spiral does it allows us to flex our hip allows our leg to come out anteriorly and as our hip flexes that spiral loosens it unwinds allowing for more movement of that femur anteriorly +[1043.44s -> 1054.08s] but as we head our femur posteriorly extend our hip the spiral tightens and prevents anterior dislocation of that femoral head from our acetabulum +[1054.08s -> 1068.45s] Now, as we mentioned, those acetabuli lie facing forward, so we don't want that hip to pop out anteriorly. And it's those spiral ligaments, the iliofemoral, pubofemoral, and ischiofemoral ligaments that prevent that hip from popping out. +[1068.45s -> 1070.62s] anteriorly from that acetabulum. +[1070.62s -> 1085.10s] we then have a ligament that heads from our anterior superior iliac spine to our pubic bone here and this is what's known as our inguinal ligament our inguinal ligament heading across here and as you may recall our inguinal ligament makes up the floor +[1085.10s -> 1097.23s] of our inguinal canal and then lastly we mentioned a ligament heading from our sacrum towards our ischium that creates two foramina posteriorly within the pelvis itself +[1097.23s -> 1111.54s] that's what's known as our sacrospinous ligament coming from the sacrum to our ischial spine here as well as our sacral tuberous ligament from our sacrum to our ischial tuberosity there posteriorly it goes behind this +[1111.54s -> 1116.00s] superior pubic ramus. This creates a foramen here. +[1116.00s -> 1130.58s] This is our greater sciatic foramen and our lesser sciatic foramen. So posteriorly, we've got our greater sciatic foramen as well as our lesser sciatic foramen. Anteriorly, we have these obturator foramina here. +[1130.58s -> 1144.24s] Now actually not much passes through these obturator foramina. There's actually an osseous membrane or ligamentous membrane in between our superior and inferior pubic rami. And we have that obturator externus and obturator internus muscle. +[1144.24s -> 1146.99s] Overlying that obturator for Raymond. +[1148.30s -> 1162.90s] So we've covered a lot the pelvis at first glance looks quite simple But there's so many bony features and muscles interlocking between one another and ligaments heading in all different directions And the best way to learn this is to start by labeling the bony features +[1162.90s -> 1174.42s] Become confident in identifying the various different bony features and then think about muscle movement and where the muscles need to attach in order to create the movement that that muscle functions to do. +[1174.42s -> 1185.28s] but knowing where these muscles attach can be really important and the most common example of this before we end off is our iliopsoas muscle that attaches to this lesser trochanter here +[1185.28s -> 1194.16s] often this trochanter can be avulsed off of the bone here when tension has been put through our iliopsoas muscle and causes a break of this +[1194.16s -> 1206.19s] bony prominence here and that can happen on our anterior superior iliac spine our greater trochanter a whole bunch of areas and knowing these attachments helps you to identify where those different fractures can occur +[1206.19s -> 1220.62s] so it's been a lot go through the lecture multiple times if you need to become more and more familiar with the anatomy this is going to need to be second nature before we then head into a pelvic or hip mri and try and identify even smaller more detailed anatomy +[1220.62s -> 1234.83s] And if you like this way of learning by looking at a radiograph and then layering on the various different pieces of anatomy, cementing the anatomy in your mind, consider subscribing to this channel, liking the video, letting me know that you like it and speaking to me in the comments. +[1234.83s -> 1237.11s] Until next time, I'll see you all. Goodbye. diff --git a/VideoMMMU_ASR_large/Medicine/test_Clinical_Medicine_312.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Clinical_Medicine_312.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5830fbbc16cb1756723558c47722e6f296d13c68 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Clinical_Medicine_312.mp4.txt @@ -0,0 +1,58 @@ +[5.68s -> 18.16s] Hello, in this video, we're going to talk about oncogenetics, the mechanism of cancer from a gene point of view. In order to understand this, we have to learn again about the cell cycle. +[18.51s -> 29.49s] So a normal cell can just be at rest. This is at a quiescent phase, the G0 phase. The cell can then enter the cell cycle. +[31.28s -> 43.89s] The first phase of the cell cycle is known as the G1 phase, the growth phase. This is where the cell's organelle duplicates. So here you can see the mitochondria of the cell is duplicated. +[44.08s -> 51.92s] After the growth I phase is the S phase, also known as the synthesis phase. This is when the DNA duplicates. +[52.59s -> 64.34s] After the S phase, there is a G2 phase, where the cell essentially grows again, the growth phase, and prepares itself for the M phase. +[64.40s -> 75.31s] The M phase is also known as mitosis, where a cell, which is now already essentially, divides into two identical daughter cells. +[75.38s -> 81.36s] These new cells can then re-enter the cell cycle or go back to the G0 phase. +[82.96s -> 96.85s] Now, the cell cycle is, as it looks, a continuous cycle. However, things can go wrong throughout the cell cycle. And so it's important to have checkpoints to make sure that there are no problems along the way. +[96.88s -> 107.60s] The first checkpoint is actually at the end of the G1 phase, called the G1 checkpoint. This is to make sure that there's no problems in the DNA and in the cell itself. +[108.53s -> 119.28s] The second checkpoint is at the G2 checkpoint. This is to make sure that the cell has no problems before it enters mitosis. And then there's another checkpoint at the M phase as well. +[119.41s -> 124.16s] The cell cycle is a continuous progression from G1, S, G2, and M. +[124.16s -> 136.56s] but what actually drives the cell through the cell cycle well when a cell enters the cell cycle it will start making proteins allowing it to go and progress through the cell cycle +[136.56s -> 148.96s] these proteins are your cyclins and your cdks which are the drivers of the cell cycle so for example a cell wants to enter the cell cycle the cell will start producing +[148.96s -> 161.52s] proteins the cdk and cyclins in the early g1 phase cdk 4 and 6 are produced and when cyclin d binds onto this it will cause a reaction to occur +[161.52s -> 173.39s] inside that cell it will cause e2f to detach from the retinoblastoma protein when e2f is released it acts like a transcription factor allowing that particular cell +[173.39s -> 185.04s] to progress through to the s phase however at the end of the g1 phase before the s phase there's also another cdk in cycling cdk2 and cyclin e +[185.04s -> 192.02s] Once at the S phase, the cell will produce another CDK and cyclin, CDK1 and 2, and even cyclin A. +[192.27s -> 206.69s] And then the G2 phase, again, CDK1 and cyclin B. And these CDK and cyclins, again, will allow the cell to progress through the cell cycle. So CDK and cyclins are the drivers of the cell cycle. If you have +[206.69s -> 215.98s] to low amounts of CDK and cyclin, the cell doesn't really progress through the cell cycle. But if you have too much cyclin and CDK, +[215.98s -> 228.14s] then you get these cells that continuously enter the cell cycle and thus you get this uncontrolled growth of cells and this is one of the mechanisms of cancer so what can potentially cause +[228.14s -> 238.58s] an increase in CDK and cyclins within the cell. So this is where genetic mutations come in. So the mechanism of cancer, genetic mutations. +[239.22s -> 252.66s] So let's just look at this normal cell and pull out its genetic material, which is DNA. DNA is a double-stranded helix made up of four types of nucleotides. Now, mutations can occur +[252.66s -> 256.50s] within the DNA which will cause changes to that cell. +[256.85s -> 270.45s] Some types of mutations include point mutations, a single change in a nucleotide. Another is what's called DNA amplification. When a certain gene gets amplified so many times, it could be a bad gene, for example. +[270.45s -> 279.30s] Then there's another one called chromosomal rearrangement where the chromosome basically attach to one another where it shouldn't. +[279.30s -> 292.74s] And another one is called epigenetic modifications, such as methylation and acetylation above genes. And this can essentially silence certain genes and even cause genes to become more... +[292.74s -> 304.02s] more active and so you can imagine with these mutations a normal cell can become a cancerous cell and so when the cell enters the cell cycle you get an un +[304.02s -> 317.49s] controlled cell growth, it bypasses all the checkpoints, you get uncontrolled cell growth. And these uncontrolled cell growth is essentially caused by two main changes that occurs in cancer cell. +[317.49s -> 325.71s] These are 1. Activation of oncogenes such as the RAS gene and your MYC gene. +[326.03s -> 337.71s] The other change is the inactivation of tumor suppressor genes, such as inactivation of p53, APC, and BRCA1 and 2. +[338.96s -> 352.58s] So the mechanism of uncontrolled cell growth as we discussed the point mutations, the gene amplification, the chromosomal rearrangements, the epigenetic modifications, these mechanisms of uncontrolled cell growth +[352.58s -> 365.49s] essentially causes two main things in the cancer cell. These are activation of oncogenes and inactivation of tumor suppressor genes. So now let's look at +[365.49s -> 378.74s] each of these in a bit more detail, beginning by looking at oncogenes first. So let's begin by looking at oncogene activation, looking at the Ras and MYC gene as an example. +[379.25s -> 393.95s] So let's look at this cell here that's about to enter the cell cycle at the G1 phase. Now normally, normally our cell contains DNA and normally our cells contain a gene called the Ras gene. +[393.95s -> 406.21s] Now, the Ras gene makes the Ras protein, which basically is an intracellular protein that sits below the plasma membrane. Next to it is a receptor, the growth factor receptor. +[406.21s -> 418.62s] Now obviously normally when a cell enters the cell cycle there needs there is a growth factor which stimulates the growth factor receptor when the growth factor is stimulated it will actually +[418.62s -> 433.01s] activate the Ras protein. Once the Ras protein is activated, it will cause a cascade of intracellular phosphorylation of other proteins, which will essentially at the end activate a transcription factor. +[433.04s -> 447.47s] Once this transcription factor is activated, it will essentially go to the DNA and read the genes to make proteins, to make proteins for cell growth, particularly to make proteins +[447.47s -> 460.94s] to allow this cell to go from the G1 phase to the S phase. And these proteins are the CDK and cyclins we talked about. So you can imagine what would happen if you have a mutation in the Ras gene. +[461.01s -> 467.84s] When you have a mutation in the RAS gene, you are making actually RAS proteins which are already activated. And so you get... +[467.84s -> 482.19s] always this cascade of phosphorylation events and you always get the activation of these transcription factors and so you are over producing at the end these proteins for cell growth such as the cyclins and CDKs. +[483.22s -> 496.43s] Now the MYC gene is another one. The MYC gene normally makes proteins in our body. These proteins are important for cell growth, cell survival, and also cell activity. +[496.69s -> 510.78s] And so when you have a mutation of the MYC gene, the cell becomes more cancerous. You get more cell growth, more cell activity, and more cell survival. And so activation of these oncogenes, activation of the RAS gene, +[510.78s -> 522.86s] and the MYCG, for example, will allow a cell to bypass the checkpoints of the cell cycle and will allow the cell to have an uncontrolled cell growth. +[524.75s -> 538.19s] Now normally the cell has a mechanism to stop any abnormal cells from progressing to the cell cycle. This is where tumor suppressor genes come in. So for example, let's just say the cell gets held up at the G2 phase. +[538.29s -> 542.77s] because it has an abnormal DNA. It has a damaged DNA. +[543.12s -> 556.45s] This cell that was stopped with the damaged DNA will not progress through the cell cycle because it is abnormal. It has a damaged DNA. So now let's talk about how this happened. Let's talk about tumor suppressor genes normally. +[556.45s -> 570.32s] focusing on p53 so let's zoom into this cell the cell contains damaged dna when there's damaged dna the cell produces p53 proteins which can act like a transcription factor +[572.53s -> 579.73s] It will read the DNA and will actually make proteins. It will make proteins for cell arrest, such as p21. +[582.80s -> 596.51s] what does p21 do well p21 is a protein that causes cell arrest it actually inhibits the cdk and cyclins and thus it inhibits the drivers of the cell cycle +[596.51s -> 598.96s] so the cell cycle will not progress. +[599.54s -> 611.63s] p53 will also make proteins important for cell repair and so hopefully when the cell is arrested the cell can repair itself it can repair the DNA +[612.72s -> 622.51s] The p53 protein will also make proteins important for apoptosis. If the cell cannot repair itself, it has to die, because we don't want any abnormal cells. +[623.76s -> 630.83s] So you can imagine now if you have inactivation of tumor suppressor genes, such as inactivation of p53. +[633.81s -> 641.09s] When you have inactivation of p53, you are not making proteins for cell arrest. You're not making proteins for +[641.09s -> 654.75s] cell repair you're not making proteins for apoptosis and so you have this cell that enters the cell cycle and can bypass the checkpoints and continuously grow and proliferate and so in summary the genetic changes that occur +[654.75s -> 663.44s] in cancer are the inactivation of the tumor suppressor genes and the activation of the oncogenes. +[663.47s -> 673.52s] And so you have this cell that enters the cell cycle and can bypass the checkpoints and continuously grow and proliferate. I hope this video was helpful. Thank you for watching. diff --git a/VideoMMMU_ASR_large/Medicine/test_Diagnostics_and_Laboratory_Medicine_154.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Diagnostics_and_Laboratory_Medicine_154.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..37187ef3e10e036bf84ef26288fe78f3efe71d47 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Diagnostics_and_Laboratory_Medicine_154.mp4.txt @@ -0,0 +1,50 @@ +[0.00s -> 12.88s] Welcome back to this short tutorial from Pathology Made Simple at ilovepathology.com This is in continuation with the Neoplasia topic series for undergraduate medical students +[12.88s -> 21.55s] This is the part 11 of Neoplasia series and in this part I will be discussing about the grading and staging of cancer. +[21.55s -> 31.28s] 10 to 15 minutes we will see what grading and staging means. We will look into various types of grading and we will understand this by some examples. +[31.28s -> 38.83s] What are these grading and staging? Grading and staging are basically the methods or parameters which are used to +[38.83s -> 53.10s] quantify the probable clinical aggressiveness of a given neoplasm which means to say that whether the given neoplasm behaves aggressively or not that is what we will understand by knowing the grading and staging of cancers. +[53.10s -> 66.16s] So basically they are used to evaluate the level of severity of cancer. Grading is based on the degree of differentiation of the tumor cells. Differentiation basically means how close the tumor cells +[66.16s -> 68.24s] resembles to that of a normal tissue. +[68.24s -> 82.58s] Grade is actually a measure of how abnormal the cancer cells look under the microscope. In contrast staging is based on the size of the primary lesion and its spread so it is a measure of how +[82.58s -> 86.24s] large the tumor is and how far this tumor has spread. +[86.24s -> 100.06s] okay so now you have understood the basic difference between grade and stage rate so grade is basically how abnormal the cancer cell look under the microscope whereas stage is basically how large the tumor is and how far this has spread +[100.06s -> 111.79s] There are different categories of grades and stage. Grading is basically indicated by the letter G which is followed by a number or quantified as either low grade or high grade. If it is followed by a number it is +[111.79s -> 122.02s] G1 to G4 whereas the most common staging system uses TNM system which we will be discussing in great detail. +[122.02s -> 126.88s] This is way back in 1920, this article from Broders. +[126.88s -> 141.30s] devised a method to grade squamous cell carcinomas into four different grades. Most of the tumors are categorized into these grades grade 1, grade 2, grade 3 and grade 4. +[141.30s -> 147.62s] Grade 1 means they are well differentiated tumours which means the tumour cells look like normal +[147.62s -> 158.61s] tissue cells that is why they are low grade tumours. The grade 3 are poorly differentiated tumours where most of the cells look abnormal and they are of high grade tumours. +[158.61s -> 172.88s] Those tumors in between these two grades are called as moderately differentiated tumor. The tumor cells somewhat look abnormal and they are intermediate grade categories. Whereas grade 4 is called undifferentiated. +[172.88s -> 181.26s] tumour and almost all the cells are abnormal they are highly anaplastic cells and this is the highest grade. +[181.26s -> 195.60s] right so grade 1 grade 2 grade 3 grade 4 grade 1 is lower grade and grade 4 is the highest grade of tumor this is an example of squamous cell carcinoma this is a well differentiated squamous cell carcinoma you can make out that +[195.60s -> 197.49s] it resembles +[197.49s -> 211.82s] To that of a normal squamous cells in that it is showing these evidence of keratinization. These are squamous pulse. This is what you see in well differentiated squamous cell carcinoma. Only few of these squamous pulse are +[211.82s -> 224.96s] seen in moderately differentiated carcinoma. In poorly differentiated carcinoma, we do not see any of those, whereas in undifferentiated carcinoma, it is actually difficult to make out that this has a squamous cell origin, right? These are undifferentiated. +[224.96s -> 239.25s] What we need to understand is that grading can be different for different carcinomas. What I have explained you is for the squamous cell carcinomas. Grading can also be three tied we talked about G1 to G4 they are four tied. +[239.25s -> 252.83s] it can be three tired or two tired three tired means you know it is just well differentiated moderately differentiated and poorly differentiated whereas two tired means you know it's very simple low grade and high grade tumors okay but what +[252.83s -> 263.50s] is important is as the grade increases the tumor tends to grow and spread faster but the grading can be subjective. +[263.50s -> 277.84s] not only that it can vary in different areas of the same tumor so that is the reason why staging is of greater value than grading in predicting the course of tumors okay now let's see what staging is we know that stage +[277.84s -> 292.05s] is based on the size of the primary lesion and its spread right it is basically a measure of how large the tumor is and how far it has spread see most of the solid tumors they are staged into five broad categories which includes stage +[292.05s -> 306.26s] 0 stage 1 stage 2 stage 3 and stage 4 stage 0 they are not invasive cancers they are carcinoma in situ whereas stage 1 are the ones which are early stage we are very small and localized cancers stage +[306.26s -> 320.46s] 2 is slightly larger and extended to the nearby places. Stage 3 is much larger than the stage 2 and extended to nearby places and to lymph nodes as well whereas stage 4 is the advanced stage in which the tumour has spread into other parts +[320.46s -> 321.78s] to the body. +[321.78s -> 336.14s] What helps in staging, how do we actually stage, how do clinicians stage these neoplasms based on various parameters like based on the physical examination findings, based on the laboratory investigations, could be routine or blood investigations or serum investigations. +[336.14s -> 349.14s] Based on the radiological examinations could be as simple as X-rays or ultrasound examinations or it can be CT scan or even PET scan or finally it +[349.14s -> 360.86s] These biopsies can also help in staging of tumours. The biopsies can be incisional biopsy or the whole tumour can be excised when it is called excision biopsies. +[360.86s -> 375.25s] Now what do we mean by TNM classification? This is a classification which was developed by American Joint Committee on Cancer. It is also known as AJCC staging system which helps in describing the cancer in +[375.25s -> 389.46s] great detail TNM, T stands for describes the original or primary tumor T for tumor it describes the size and extent of the tumor whereas N stands for nodes it describes the spread of cancer. +[389.46s -> 399.39s] to nearby nodes. M stands for metastasis. It describes metastasis are spread into distant organs or distant sites. +[399.39s -> 406.70s] There are different categories of staging. I will explain you only two such categories one is clinical staging +[406.70s -> 421.09s] Another is pathological staging. Whatever I have told you till now is clinical staging where we take the help of physical examination, laboratory investigations, radiological examinations and incisional biopsy. Whereas pathological staging includes all these +[421.09s -> 435.41s] as well as the complete pathological findings of the excised tumor. Once the tumor is excised completely the pathologist will study the entire tumor in great detail and that is also included +[435.41s -> 441.33s] and this gives more precise information than the clinical staging. +[441.33s -> 455.70s] right so this is this this is a basic difference between clinical and pathological stage let us understand staging of cervical cancer so this is stage one where the cancer is confined just to the cervix and stage two you know this disease +[455.70s -> 469.58s] is involved in the cervix as well as it is extended beyond the cervix but it is not to the lower third of vagina. It is not extended too much beyond the upper two thirds of the vagina nor it is extended into the +[469.58s -> 483.86s] pelvic wall. This is stage 2. Whereas stage 3 is the disease is extended into the pelvis as well as into the lower third of vagina. Whereas stage 4 as I told you it has invaded into the distant organs. +[483.86s -> 498.06s] invaded the rectum, the bladder and even the intestines. Even it can include distant metastasis to abdominal organs like liver and spleen. So that is stage 4. Now why do we need to +[498.06s -> 501.41s] know these stages. What staging conveys +[501.41s -> 515.70s] to the clinicians so basically we should know that as the stage increases the five year survival rate drastically decreases look at this stage one cancers the five year survival rate is around 86 percent whereas stage four +[515.70s -> 529.90s] cancers the five year survival is seven percent so that is the importance of staging of cancers now we understood the concept of grading and staging right so grading means how abnormal the cells look under the +[529.90s -> 542.62s] Microscope G1, G2, G3, G4 well differentiated, moderately, poorly and undifferentiated or it can be as simple as low grade and high grade. Staging basically is TNM staging. +[542.62s -> 557.07s] That completes this topic. If you have liked this video hit the like button, do comment, do not forget to subscribe, do share if you find this video helpful and keep waiting for the next tutorial where will be discussing about the various aspects of lab diet. +[557.07s -> 558.87s] of cancer thank you diff --git a/VideoMMMU_ASR_large/Medicine/test_Diagnostics_and_Laboratory_Medicine_72.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Diagnostics_and_Laboratory_Medicine_72.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7e2635b7abc7afd050ec52d87ef55aadc7d1848e --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Diagnostics_and_Laboratory_Medicine_72.mp4.txt @@ -0,0 +1,72 @@ +[4.91s -> 12.08s] Hello everyone, so today I am going to teach you about oligodendroglioma brain tumor, which is one of the common glioma brain tumor. +[12.62s -> 25.42s] It's a diffuse, infiltrating, slow-growing brain tumor. Right? Alright. Now, as per the World Health Organization 2016 definition, a case is +[25.68s -> 37.81s] defined as an oligodendroglioma adult type only if there is a presence of mutation of IDH1 and 2 along with 1p and 19q co-delation. +[37.81s -> 43.65s] That is short arm of chromosome number 1 and long arm of chromosome number 19. So that is the definition. +[43.65s -> 56.21s] now epidemiology or geographical burden of the oligodendrogramma so it constitute three percent of all primary central nervous system malignancy right three percent and it is +[56.21s -> 64.46s] it constitute five percent of the all glial neoplasm right so it is one of the glial brain tumor +[65.62s -> 78.05s] And it is commonly seen in the male male predominance is seen and fourth and fifth decade is involved commonly means 40 to 50 year of age group and 50 to 60 year of age group involved commonly. +[78.05s -> 81.39s] Now the site of these oligodendroglioma. +[82.99s -> 93.30s] So the most common site of this brain tumor is a frontal lobe. This red colored is a frontal lobe, right? So it commonly involves frontal lobe. +[93.94s -> 98.48s] That is a common site of involvement of oligogendroglioma. +[99.47s -> 111.22s] however remember that rarely cerebellum brain stem spinal cord you know temporal lobe and parietal lobe as well can be involved rarely it can be involved right +[111.98s -> 116.66s] And see the tumour involved white and grey matter both. +[118.54s -> 133.52s] All right. Now let's see the etiology of this oligodendro glioma. Why it occurs. So you will surprise that there is a no known risk factor. It's a sporadic tumor without any significant risk factor. +[135.25s -> 146.98s] all right now clinical feature how the patient will present so the oligodendroglioma patient mainly be present with central nervous system manifestation because it is a brain tumor +[146.98s -> 155.09s] So the common presentation is seizure, patient having convulsions. Then patient can also complain of constant headache, severe headache. +[156.82s -> 171.41s] the another clinical presentation could be cognitive impairment like impairment in the speech impairment in walking right focal neurological deficit also can be observed so all this presentation is according to the area of brain involvement right according to +[171.41s -> 185.30s] site all right now diagnosis how will you diagnose the case of oligotendro glioma so friends for the diagnosis first of all MRI is needed MRI will locate the brain tumor +[185.30s -> 194.83s] right then you have to typify the brain tumor for that surgical or stereotactic brain biopsy needs to be done and that is sent for histopathological examination +[194.83s -> 208.98s] There are certain methods available to detect the IDH gene mutation as well. Because you know as per the WHO IDH gene mutation is needed for the diagnosis. Then methods also available to detect the 1p and 19q co-deletion. +[209.17s -> 217.98s] so all the we will see each method over one by one right so first of all we will see the methods to detect the idh +[217.98s -> 231.18s] gene mutation which is required for the diagnosis so for that mutation detection first of all commonly you can do immunohistochemistry second you can do next generation sequencing +[232.27s -> 233.52s] Right? +[234.10s -> 248.88s] The third method to detect the IDH gene mutation is a droplet digital polymerase chain reaction, which is also known by the name DDPCR. It can be done. DDPCR, right? Sanger, you know, Sanger sequencing also can be done. +[249.14s -> 263.39s] So, all these are methods to detect the IDH gene mutation. Then, second, you need to detect the 1p and 19q co-delation as well. So, there are methods available for that also. The commonly used method is fluorescent in-situ hybridization. +[263.39s -> 269.04s] You know it will detect the short arm of chromosome number 1 and long arm of chromosome number 19 co-dilation. +[269.46s -> 281.62s] all right polymerase chain reaction obviously uh can be done if this is not available then eric comparative you know genomic hybridization also can be done +[283.02s -> 289.01s] Alright, now what will be the gross appearance of this oligodendroglioma? +[289.46s -> 303.63s] so grossly first of all it involves the frontal lobe right and as you can see in this diagram the mass is circumscribed you know it's a circumscribed why circumscribed mass and it is of gray to pink color +[303.63s -> 317.39s] you can see that it's a pink color mass and areas of cystic degeneration hemorrhage and necrosis and calcification can be seen usually hemorrhage and calcification is observed all right +[317.84s -> 332.43s] now microscopic appearance of this oligodendroglioma if you do the if you do the biopsy then what is the histopathological appearance now we will see the main histopathological microscopic appearance of oligodendroglioma which is our main focus +[332.43s -> 345.39s] for this today's lecture so first of all in the microscopy you know the cells are very closely back the cells are very closely back +[345.65s -> 354.16s] The cells is having the small round monotonous nucleus. Nucleus is very small round and monotonous. You know they look similar. +[354.19s -> 367.98s] The nucleus is only slightly larger than the normal oligodendrocyte. Otherwise, it looks like a normal oligodendrocyte. The nuclear chromatin is salt and pepper variety. Like that of small cell malignancy, right? +[369.01s -> 383.28s] You know, one of the interesting fact is that the cell membrane is very distinct. You will observe a very beautiful distinct cell membrane. And sometimes small nuclei can be observed in the oligogendroglioma. +[384.27s -> 397.42s] Alright. The main characteristic finding of the oligodendroglioma is that there is a presence of perinuclear clearing which is known by the name perinuclear halo. And perinuclear halo +[397.42s -> 402.94s] known by the name fried egg appearance because it looked like an fried egg +[402.94s -> 416.72s] right perinuclear clearing is seen white colored clearing is seen and it's a formalin fixation artifact so you will not observe it in frozen section intraoperative smear or cross preparation right all right +[417.20s -> 427.92s] now usually the tumor is very well differentiated but sometime anaplastic feature can be seen like that of necrosis mitosis and microvascular proliferation otherwise +[427.92s -> 438.98s] it's a very well differentiated tumor with a fibrillary astrocyte morphology as well can be seen right it's a commonly well differentiated tumor but sometimes anaplastic features can be seen +[438.98s -> 453.65s] you know network of thin wall branching blood vessels is also seen which is known by the name chicken wire appearance which I will show you in the diagram the microcalcification seen in this disease is known by the name calcospherides +[454.19s -> 467.23s] so friends this is the histopathological appearance of oligodendroglioma suppose if you do the biopsy of oligodendroglioma and examine it microscopically then it looks like in this image +[467.23s -> 481.47s] you can clearly see that the cells are very small monotonous right and the nucleus is very you know round small and very monotonous they are not highly pleomorphic so this is the image of oligodendroglioma +[481.47s -> 494.13s] right see this is the 10x view of oligotendro glioma you can clearly see that it's a separated by this thin blood vessel all these are thin blood vessels right they are separating the cell nest +[494.13s -> 504.72s] so this thin network of this thin you know blood vessel thin wall blood vessel is known by the name chicken wire appearance and if we observe this cell +[505.14s -> 516.96s] in the 40x view suppose if we examine this particular cell morphology in the higher magnification then you can clearly see that you know the cell nucleus is very small +[516.96s -> 527.94s] monotonous and the round and the nuclear cell membrane is you know very distinct very distinct cell membrane and the chromatin is you know salt paper type in few area +[527.94s -> 542.48s] and sometimes a small nuclei can be observed in the nucleus and you can clearly see that there is a presence of perinuclear halo right surrounding the nucleus there is a +[542.48s -> 554.48s] clearing which is known by the name perinuclear halo which is a formalin fixation artifact and which is a known by the name fried egg appearance which is a hallmark of the diagnosis of oligodendroglioma +[555.47s -> 568.94s] See, this is the diagram from the, you know, Rosai Ackerman book. And in this particular diagram, you can clearly see that very prominent perinuclear halo is seen in the all oligodendro slide. +[569.84s -> 581.60s] and if you observe carefully then this nucleus is not much much pleomorphic they are only slightly larger than normal oligodendrocyte so it looks like a normal oligodendrocyte +[581.60s -> 594.02s] and perinuclear clearing is seen in the all the oligotendrocyte you can clearly see a perinuclear halo clearing which is known by the name fried egg appearance and this is the small +[594.02s -> 607.28s] blood vessel thin network of small blood vessel which give the appearance like that of chicken wire appearance and you know sometime the oligodendrocyte in the cytoplasm contain the fibrillar hyaline material +[607.47s -> 618.30s] and you know this particular oligodendrocyte known by the name minichemistrocyte minichemistrocyte so this is the minichemistrocyte variant of oligodendroglioma +[618.30s -> 630.46s] so this was about the light microscopic appearance of oligodendroglioma is very it's very easy to diagnose histopathologically now which are the positive stains +[630.46s -> 633.42s] for diagnosis of oligotendrochromia. +[633.74s -> 647.01s] So the positive IHC stains include first of all IDH1 mutation, right? IDH1 is positive, particularly R132H that is positive in greater than 90% cases. Second one is Olig1 and Olig2. +[647.01s -> 660.46s] can be seen can be positive right see these are the ihc markers you know now the diagnosis is shifted to the ihc diagnosis based on morphology only oligodendro glioma is not diagnosed +[660.46s -> 672.14s] you know gfap also is positive atrx and sox10 marker is also positive and the fifth marker that is positive is p53 +[673.42s -> 684.11s] right all right ki67 also positive in less than five percent of the cells so these are the ihc stains which will put positive in the oligotendroclima +[685.87s -> 696.26s] Now, oligodendroglioma often contain GFAP-positive minigamistrocyte. You know, minigamistrocyte contain, you know, it harbor... +[696.26s -> 708.43s] inclusions in the cytoplasm like rolled you know rolled intracytoplasmic bodies particularly of filamentous substance right so that is many chemistry site +[709.14s -> 721.58s] now triad positivity for the idh1 mutation then atrx and p53 if all these three are positive then it is a case of oligodendroplioma it is useful to distinguish it +[721.58s -> 735.06s] from idh mutant variety of astrocytoma so that are useful marker for the diagnosis this triad all right now grading so usually oligodendro glioma is of who grade +[735.06s -> 746.22s] tumor right it's a WHO grade 2 tumor but if anaplastic features are present then it's a grade 3 variety +[750.77s -> 762.45s] All right, now prognosis of oligodendroglioma. You might have question, if I have oligodendroglioma brain tumor, then will I survive? So yes, it's a very slow growing tumor. +[762.45s -> 773.23s] the patient is usually having very long survival the patient survive for 11 to 15 year and you know favorable prognostic features are if the patient is young age +[774.06s -> 785.46s] you know if the patient is having the tumor in the frontal lobe you know if if patient present mainly with the seizures convulsions +[788.05s -> 802.38s] and you know if great you know if a greater extension extent of the surgical resection then also it's a favorable criteria so all these are favorable features the patients survive longer if these features are present now treatment +[802.51s -> 804.02s] Obviously, +[806.51s -> 818.74s] As it's a brain tumor, total resection should be done. If possible, total resection of the tumor should be done. Radiotherapy can be given in the oligodendroglioma, right, to treat it. +[818.74s -> 823.82s] if surgical resection not possible then radiotherapy can be given chemotherapy also can be tried +[824.72s -> 838.54s] particularly with the drug you know uh temozolomide it can be given sometimes chemotherapy also can be given thanks for watching and friends see you soon with the next video till then take care and bye-bye thank you diff --git a/VideoMMMU_ASR_large/Medicine/test_Pharmacy_141.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Pharmacy_141.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..aec925f40316ef1131f2d6208e7938e2179f2b97 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Pharmacy_141.mp4.txt @@ -0,0 +1,19 @@ +[0.43s -> 11.58s] hello everyone welcome to my channel simple bio lectures today we are going to discuss about the classification of organisms by based on the their carbon and energy source +[11.58s -> 21.49s] So as we all know that all organisms require energy for their survival and growth. Now this energy might be coming from either a chemical source or a light source. +[21.49s -> 32.11s] If the energy is coming from a chemical source then the organisms are known as chemotrophs and if the energy is coming from a light source then the organisms are known as phototrophs. +[32.11s -> 45.86s] Now, this chemotrophs and phototrophs can be further divided into two subtypes based on the carbon source. If the carbon source is CO2, then they are known as chemoautotrophs. If the carbon source is organic compounds, then they are known as chemo heterotrophs. +[45.86s -> 59.26s] Similarly for photo troughs if the carbon source is CO2 then they are known as photo auto troughs and if the carbon source is organic compounds they are known as photo hetero troughs. Now the difference between this auto troughs. +[59.26s -> 67.90s] okay both the autotrophs and both the heterotrophs is that the autotrophs use raw materials like co2 and chemical or co2 and light +[67.90s -> 81.49s] to produce organic compounds and these organic compounds which are produced by this both this autotrophs are used by the heterotrophs both chemo heterotrophs and photo heterotrophs so autotrophs okay +[81.49s -> 92.14s] are producers in the environment and heterotrophs are consumers which are dependent on the autotrophs for their carbon source. +[92.14s -> 104.77s] now this chemo auto troughs include examples like hydrogen sulfur iron nitrogen and carbon monoxide oxidizing bacteria okay now let's move on to chemo hetero troughs now in chemo hetero troughs +[104.77s -> 112.83s] The final electron acceptor can either be O2 or it cannot be O2. So based on that it is classified further. +[112.83s -> 127.12s] If it is O2 in electron transport chain which occurs in the membrane of the mitochondria, if the final electron acceptor is O2 then all the which includes all the animals, fungus, protist, bacteria and also humans. +[127.12s -> 136.29s] And therefore we require O2. And if it is not O2 then it can be either organic compound. So in the case of fermentation. +[136.29s -> 147.65s] now fermentation like alcohol preparation or this curd preparation it occurs in the absence of O2 and in that the electron acceptor are organic compounds +[147.65s -> 160.58s] now other than organic compounds the electron acceptor can also be inorganic compounds like nitrates sulfates etc and the examples is pseudomonas nitrificans okay so now let's move on to the phototrophs +[160.58s -> 167.97s] and photo autotrophs so photo autotrophs can either emit oxygen or they don't emit oxygen +[167.97s -> 177.31s] so if they emit oxygen they are known as oxy oxygenic and if they don't release oxygen in the environment they are known as an oxygenic okay so if they use +[177.31s -> 190.93s] H2O to reduce CO2 and emit oxygen then they are known as oxygenic and if instead of H2O they use some other compounds like H2S or only H2 then they don't release oxygen and then they are known as anoxygenic. +[190.93s -> 201.12s] so oxygenic photosynthesis occurs as we all know that in plants okay algae and cyanobacteria and an oxygenic photosynthetic occurs in green and purple bacteria +[201.12s -> 212.59s] Now this examples of this photo hetero troughs include green non sulfur bacteria and purple nulls and for bacteria So that's it for today guys. Thank you for watching this video. Bye. Bye diff --git a/VideoMMMU_ASR_large/Medicine/test_Pharmacy_231.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Pharmacy_231.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a81d49270bf1283eb9ccf2bfed228b30130f3548 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Pharmacy_231.mp4.txt @@ -0,0 +1,65 @@ +[0.00s -> 6.19s] Let's talk about these five major types of chemical reactions. We'll look at examples of each. +[6.19s -> 18.72s] and learn how to tell them apart so that you can look at a chemical reaction and classify it figure out what type it is the first reaction we're going to talk about is the synthesis reaction these are sometimes called combination reactions +[18.72s -> 31.17s] Now, synthesis is just a fancy word that means making, and that's exactly what happens in a synthesis reaction. A compound is made from simpler materials. Here's an example. +[31.17s -> 45.78s] comes together with oxygen gas to make carbon dioxide, CO2. What we make in this reaction is more complex than the two simple things that we start with. Here's another example. We take sodium +[45.78s -> 55.97s] and chlorine gas, Cl2, and that makes sodium chloride NaCl. What we end up with is more complex than the simple things we started with. +[55.97s -> 66.02s] Now a quick word about the equations that I'm using in this lesson. Some of these equations I'm going to be talking about, like this one right here, are unbalanced. +[66.02s -> 80.34s] So there might not be exactly the same number of atoms on both sides of the equation. Now normally, it's really important to balance equations. But when we're going to be learning about the different types of reactions, the balancing numbers can be a little bit distracting. +[80.34s -> 93.98s] I just want you to focus on the elements and how they're rearranging or combining with each other in different ways. That being said, a synthesis reaction is one where we start with simple materials and put them together. +[93.98s -> 107.66s] to make something more complex. If we want to represent a synthesis reaction more generally or more generically, we could say that it looks kind of like this. We have A and B combining to make AB. +[107.66s -> 120.22s] here a and b are different elements or they're different compounds coming together to make something more complex so that's a synthesis reaction let's move on a decomposition reaction is kind of the opposite of a synthesis reaction +[120.22s -> 134.48s] In a synthesis reaction, we put things together. In a decomposition reaction, a compound is broken down into simpler compounds or all the way down to the elements that make it up. So in this example here, we have water. +[134.48s -> 141.87s] H2O and it's breaking down into hydrogen and oxygen gas. These are the elements that make it up +[141.87s -> 154.85s] Now in a decomposition reaction, you don't have to break things down all the way down to their basic elements. You can also break them down just into simpler compounds. For example, here we have CaCO3. +[154.85s -> 161.38s] calcium carbonate and that gets broken down to two simpler compounds CAO +[161.38s -> 174.64s] CO2 it's not like we're taking this and breaking it down into just calcium and just carbon and just oxygen but still because these are simpler compounds it is also a decomposition reaction +[174.64s -> 184.61s] So if we wanted to come up with sort of a generalized way to write a decomposition reaction, we could write it like this. AB breaking apart into A plus B. +[184.61s -> 198.21s] where a b is some kind of compound and a and b are simpler compounds or elements okay combustion reactions combustion is basically a fancy word for burning and when something burns +[198.21s -> 211.23s] what happens is that a compound containing carbon and hydrogen and sometimes oxygen combines with oxygen gas to produce carbon dioxide and water here in my example ch4 +[211.23s -> 221.22s] which is the chemical formula for methane, that's a type of natural gas, combines with oxygen and it forms carbon dioxide and water, H2O. +[221.22s -> 235.17s] Now, we can start with different things in a combustion reaction. And as it says here, the compound usually contains carbon and hydrogen. So here is another example of a combustion reaction. This one starts with C3. +[235.17s -> 247.94s] h8 which is the chemical formula for propane another type of natural gas and just like with this reaction we combine c3h8 with o2 and this gives us carbon dioxide +[247.94s -> 262.00s] and water so these two reactions are essentially identical except for the number of carbons and hydrogens in the compound that we start with it turns out that a lot of things that we burn like natural gas +[262.00s -> 273.94s] diesel, gasoline are really, really similar and they only really differ in the number of carbons and hydrogens that are in the molecules that make them up. +[273.94s -> 279.62s] So, combustion reactions for a wide variety of compounds look pretty similar. +[279.62s -> 289.81s] Now, as this definition says, sometimes we have oxygen in the compound that we're burning. Here is one example of a combustion reaction that has oxygen in it. +[289.81s -> 299.87s] This is the chemical formula for ethanol or ethyl alcohol and you can see that just like these it has lots of carbons and hydrogens except it also has oxygen as well. +[299.87s -> 311.20s] But that's no big deal because it combusts just like the other two by combining with oxygen and making CO2 and H2O. So if we wanted to come up with a general way. +[311.20s -> 323.95s] to write the formula for a combustion reaction it might look a little bit like this we start out with something that has carbon and hydrogen in it and we can have different numbers of carbons and hydrogen so that's why i put this x +[323.95s -> 337.50s] and why here because the number of carbons and hydrogens varies and it doesn't really matter either. Sometimes the compound has oxygen in it which is why I put the oxygen here in parentheses. We take this compound, it combines with oxygen, +[337.50s -> 350.86s] and it produces carbon dioxide and water so this here is the generic general equation for a combustion reaction single replacement reactions break my heart and in a minute you'll see why +[350.86s -> 363.25s] So in a single replacement reaction, what happens is that one element that starts out by itself replaces another element in a compound, kicking it out. And here's an example to show you what I mean. +[363.25s -> 374.10s] We start out with iron, Fe, which is this element that's by itself. And iron combines with CuCl2, which is copper chloride. +[374.10s -> 387.15s] Okay, so copper and chloride are paired up here. But what happens is iron kicks out the copper, the Cu. So the Cu ends up by itself, and the Fe, the iron, +[387.15s -> 400.48s] takes the place of that copper so now the iron and the cl they are now paired up now i like to use a dance analogy to explain this and it reminds me of something that happened all the time in high school +[400.48s -> 412.19s] Here's what's going on. We have a dancing couple, the purple and the green, and they're so happy dancing together, or at least the purple guy is pretty happy dancing. And then red comes along. +[412.19s -> 423.81s] And red is like, hey purple, I'm so much cooler, get out of the way, I want to dance with green. And so poor purple gets booted out and red ends up dancing with green. +[423.81s -> 435.78s] Purple ends up all by himself, standing up against the wall, pretending to text, pretending to play a game on his cell phone. But, you know, he's really actually sad because he's just been booted from this dancing couple. +[435.78s -> 447.71s] So you'll see that this is exactly what's going on in the single replacement reaction, right? Fe, iron, is like red here, coming up to a dancing couple of Cu and Cl. It boots out Cu. +[447.71s -> 461.97s] cu ends up by itself and then red iron takes the place that cu had and iron ends up paired with cl here's one more example of a single replacement reaction you can see how this works +[461.97s -> 475.84s] Cu in this case is the red character and Cu goes to a dancing couple of Ag silver and nitrate AgNO3 Cu boots out Ag +[475.84s -> 483.18s] so ag ends up by itself and cu takes ag's place by pairing up with no3 +[483.57s -> 496.62s] So that is how a single replacement reaction happens. And a generalized reaction for that would look like A, which is the element that starts out by itself, plus BC, that's the dancing couple. +[496.62s -> 509.10s] and then that gives us b by itself which is this element that got booted out and then a and c ending up paired together so that's a single replacement reaction so finally +[509.10s -> 521.78s] here's the double replacement reaction now i should mention that single and double replacement reactions are sometimes also called single displacement and double displacement just in case your teacher textbook uses a different term for them +[521.78s -> 536.05s] Okay, so double replacement reactions are not nearly as heartbreaking as single replacement reactions. Here's why. Because in a double replacement reaction, what happens is the positive and negative ions in two compounds just switch places. +[536.05s -> 550.26s] Nobody gets kicked out in a double replacement reaction. In a double replacement reaction, it's just like you have two different pairs of dancing couples. And the red, which used to be with the gray, ends up with the green. +[550.26s -> 559.71s] And the purple, which used to be with the green, ends up with the gray. Nobody gets kicked out. Nobody sat up against the wall with their cell phones. We're just switching. +[559.71s -> 568.22s] dancing partners. So here is a chemical equation that shows a double replacement reaction. We start out with Ba and Cl together. +[568.22s -> 582.38s] and then Na and SO4 together and they just switch places. So Ba ends up with SO4. There it is. And Na ends up with Cl. There it is right there. All of these compounds are ionic. +[582.38s -> 595.89s] which means that we can break them down into the positive and negative ions that they're made up of. So here the positive ions are in purple and the negative ions are in green. +[595.89s -> 610.16s] as you can see the positive and the negative just switch places so ba two plus and cl minus were initially paired up but then ba goes and it gets switched it finds a new dance +[610.16s -> 624.14s] partner it has to find the other negative ion right so the other negative ion here is so42 minus so ba2 plus and so42 minus end up together making ba so4 and then sodium +[624.14s -> 636.10s] Na1 plus has to find the other negative ion, which here is Cl minus, and they end up paired up over here. Na1 plus and Cl1 minus making NaCl. +[636.10s -> 648.90s] Here's another example of a double replacement reaction, okay? I'll break this down into its ions right away, and we get this. We start with K plus and Br minus paired together. +[648.90s -> 660.46s] and Ag1 plus and NO3 1 minus pair together, and then they just switch the positive and negative. So K plus goes and finds the other negative ion. +[660.53s -> 668.50s] Which here is no three one minus K plus and no three one minus end up together in AG one plus silver +[668.50s -> 677.65s] looks for the other negative ion, which is Br1-, and Ag1+, and Br1- end up paired up together, making AgBr. +[677.65s -> 690.29s] So, that is a double replacement reaction, and if we wanted to come up with a general or generic way to explain it, we could use this reaction here, where we have AB, where A and B are paired up, +[690.29s -> 704.29s] plus CD, where C and D are paired up. And then they switch partners to give us AD and BC. So that is a double replacement reaction. So these are our five major types of chemical reactions. +[704.29s -> 717.65s] In synthesis, simple things combine together to make something more complex. In decomposition, something complex breaks apart into simpler pieces. In combustion +[717.65s -> 727.95s] A compound that contains carbon, hydrogen and sometimes oxygen comes together with oxygen gas to make carbon dioxide and water. +[727.95s -> 739.81s] Single replacement and double replacement are our two dance floor reactions. In single replacement an element that's by itself combines with two elements that are paired up. +[739.81s -> 753.49s] It kicks one of those elements out so that element ends up on its own and then that element takes its place. In double replacement, it's like two dancing couples where the partners just trade places. +[753.49s -> 759.49s] a and b and c and d start out paired together and then a and d end up together +[759.49s -> 773.17s] and b and c end up together so those are the major types of chemical reactions in the next video we'll do some practice problems so you can look at a bunch of different reactions and figure out what type they are diff --git a/VideoMMMU_ASR_large/Medicine/test_Pharmacy_96.mp4.txt b/VideoMMMU_ASR_large/Medicine/test_Pharmacy_96.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5116290c51814eb1a98eddcbe001ee01c520e2d8 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/test_Pharmacy_96.mp4.txt @@ -0,0 +1,53 @@ +[2.19s -> 4.56s] Alright, so halo carbons +[4.88s -> 18.85s] Hologens are in group 17. Any organic compound that contains a halogen substituent is a halocarbon. More specifically, if a halogen replaces a hydrogen when attached to carbon, +[18.85s -> 29.30s] that is called an alkyl halide. So we'll use both these terms when we're talking about halogens on organic molecules. This is an example. +[29.55s -> 43.47s] of an alkyl halide. The difference between alkyl and areal halides are we have group 17 halogen elements bonded to a benzene ring. That makes it an areal. +[43.47s -> 50.90s] halide so here's the diagram over here for an aerial halide fluorine onto a benzene ring +[51.82s -> 65.98s] What we want to do is we want to talk about naming halocarbons. We talked a little bit about this yesterday, and you know a little bit about this already, so that's good. For alkyl halides, okay, so not attached to benzene rings. +[65.98s -> 78.18s] The big thing is the prefix indicates which halogen is present. So if we have fluoro or chloro or bromo or iodo. +[78.18s -> 92.14s] we replace the "-ene", so chlorine would be chloro, okay? So you change the ending of the halogen name from "-ene", to "-o", so it would be like... +[92.69s -> 101.68s] chloro would be the first part of a of a compound with chlorine on it +[102.45s -> 116.27s] If more than one kind of halogen is present in the same molecule, the atoms are listed alphabetically. So if you have chlorine and fluorine attached to the same carbon chain, then you would name +[116.27s -> 119.06s] Chlorine first because it comes alphabetically first. +[119.54s -> 132.37s] The chain also must be numbered in a way that gives the lowest position number to the substituent that comes first in the alphabet. So let's say we're talking about a carbon chain. It has to be numbered. +[132.37s -> 138.54s] with the lowest number for the first element that is +[140.21s -> 153.14s] If you have, let's say you have three carbons here, and I've got fluorine on the first carbon. What this point right here is saying is that... +[153.14s -> 166.05s] You can't say that this is three chloro. You can't say three, but you have to say one. Okay? And if there is something like this, okay? +[166.05s -> 179.54s] there's a chlorine here and a fluorine on this one, then you would have to say the chlorine is written first, so this would have to be carbon number one. So it would be one chloro, two fluoro. +[179.89s -> 192.90s] But we'll get into naming. I'll show you some examples here in a second. Let's talk about the benzene ring here finally. Similarly, the benzene ring in an aerial halide. +[192.90s -> 200.85s] is numbered to give each substituent that is each each one of the halogens the lowest number possible +[201.49s -> 214.35s] So a benzene ring is numbered to give each substituent the lowest possible number. That's a bit of a redundant phrase I see right there, the lowest possible number possible. Awesome. +[220.27s -> 225.39s] So if we move to the next page, we have some examples that I want to walk through with you. +[226.38s -> 240.88s] So, A, right here, this is a benzene ring, right? And this is a chlorine that's attached to one of the carbons on the benzene ring. And so this would be chlor, that's for the chlorine. +[241.07s -> 255.47s] remember chloro not chlorine and then benzene we just say chlorobenzene there's no numbers because there's only one chlorine and it's just attached to one of the carbons so it doesn't matter we don't have to number the carbons there's just one +[255.47s -> 260.05s] substitute there okay if we look over to +[260.75s -> 274.18s] B okay there's actually two here so I'm going to just draw a line right there there's actually two compounds there so in the first one we have a carbon chain +[274.18s -> 288.34s] One, two, right? Methane, ethane. So this is ethane, single bond ethane. And we have a halogen attached to one of the carbons. The name for this is fluoroethane. +[288.88s -> 294.00s] So again, the pieces are floor for fluorine. +[294.29s -> 307.70s] We always have a little O in there because that's the common, you know, that's how you name these halogen compounds. And then F right here is the one, two carbons. Ane is this single bond. +[308.21s -> 311.60s] Right? So that's the pieces there. +[313.39s -> 327.60s] Now, we have no numbers here for this one either. We don't need numbers. Why? Because if the fluorine was attached to this carbon, it still would be the same molecule. It would just be flipped around, right? So it's not actually a different isomer. +[328.50s -> 330.06s] Questions on that one? +[333.78s -> 347.68s] all right so if we go to move to this one now this one has a chain of three carbons in a row so that's where the probe comes from all single bonds so that's where the ain +[347.68s -> 355.09s] comes from and we see that we have a fluorine here and a fluorine here +[355.73s -> 364.11s] So we would have to describe this molecule, and we would have to say which carbons the fluorines are on. +[364.50s -> 376.66s] And obviously, you know, we count 1, 2. We wouldn't say 2, 3 because we want to keep the numbers as low as possible. So there's 1. +[377.30s -> 389.04s] And there's 2 for the fluorines. So this is why you say 1,2-difluoro... +[392.37s -> 404.53s] So it starts getting a little complicated. You have to name the carbons that the fluorines are attached to. If there's two of the same, it's got to be di. If there's three of the same, it'll be tri, and so on. +[405.20s -> 419.54s] Fluoro, make sure you do that because that's their fluorines. And then the carbon chain is three long, so it's prop, all single bonds, propane. So just take a moment to stare at that. +[430.32s -> 437.30s] In example C here, you see we have a bromine, we have a fluorine, we have a chlorine. +[439.31s -> 450.98s] And so you have to name them in alphabetical order, right? So which one comes first? The bromine has to come first. So in the notes, this one right here. +[450.98s -> 462.13s] The chain must be numbered so that the lowest position number is given to the first one that comes alphabetically. Right? So that's what they mean here. This has to be carbon 1. +[462.61s -> 470.83s] because the bromine is on it. So it's one bromo. Remember it's the O there, so you attach the O there, one bromo. +[471.38s -> 482.35s] Then which one do you name next? Well, you've got to name the chlorine next because remember it's alphabetical. And that would be on carbon 3 then. So 1-bromo-3-chloro. +[484.62s -> 495.76s] Then you have to name the other one. So 2-fluoro. There are four carbons in total. Only single bonds. Butane. +[500.24s -> 509.65s] So once again, we have 1-bromo-3-chloro-2-fluoro-butane. +[515.57s -> 526.38s] Okay, a couple more examples here. A couple more examples in D here. So D... +[528.08s -> 535.09s] This is a benzene ring. So remember, it's just attached at one spot, so it's fluorobenzene. That's pretty easy. +[536.98s -> 551.60s] When we have more than one halogen attached, now we have to start to number them, right? So we know that there are six carbons in a benzene ring. The bromine gets listed first because it's alphabetical. It comes first. +[551.63s -> 557.65s] So this is going to be the one carbon. So you say one dash bromo. +[558.19s -> 572.91s] And after you name the number of the carbon, you put a dash, and then what's there. So one bromo, and then it doesn't matter which way you count, if you go up or you go down, two, three. +[573.49s -> 582.16s] Okay? And if you do that way, you've got to go four, five, six. See that? So we have iodines. +[583.15s -> 595.31s] on number three and number five. So three comma five, because they're the same. Di, because there's two of the same. Iodo, and of course it's benzene. +[595.89s -> 603.41s] So the naming, there's a lot of pieces to the naming here, okay? And it'll take some practice. +[604.88s -> 617.62s] and I'll give you some practice on this, questions from the notebook and stuff like that, but you need to study these rules, and that's the rules for the halocarbons and the aerial halides. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_1.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a4c07697d63f6586ca9deee854b5a3aef731a3bf --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_1.mp4.txt @@ -0,0 +1,12 @@ +[0.08s -> 4.69s] In today's video, I'm going to talk about copper and Malaysian. +[5.42s -> 16.24s] So a follower of mine sent me this microscopic image of a semen sample of a 44 year old male. +[16.72s -> 27.44s] So copper amylase are amyloid bodies that are commonly found within the lumen of cellular acne adjacent to damaged prostate epithelium. +[27.76s -> 40.91s] They are said to be reservoirs of acute inflammatory proteins that indicate past exposure to infections that may also contribute to physical trauma and inflammation to the surrounding prostate tissue. +[41.62s -> 54.48s] Corporate amylase can be located in the prostate gland where it indicates inflammation or benign prostate cancer. It can also be found in the nervous system, specifically the brain. +[54.48s -> 68.43s] where mostly it's because of old age or in some cases neurodegenerative diseases. You can also find it in the lung where it is indicative of non-neoplastic lung diseases. +[68.43s -> 75.28s] Sometimes, copper amylase can also be found in other organs, for example, the uterus. +[78.38s -> 92.37s] Copper and Malaysia can be found in semen in that prostate cancers develop from the gland cells in the prostate. So gland cells make prostate fluid or the mucofluid. +[92.37s -> 106.40s] that is added to semen. So, if you have copper and Malaysia present in the prostate gland, it is possible that they can be stripped together with the semen which is being ejaculated from the penis through +[106.40s -> 119.47s] urethra, therefore making it possible that it can also be found in urine because urine and semen share the urethra as the exterior site. To my fellow scientists, +[119.47s -> 133.66s] if copper emulation is found either in semen or urine you might advise your patient to also go for prostate cancer screening don't forget to follow like and share this video +[133.66s -> 134.80s] Thank you. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_10.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f64469384feb2288816afb02da6dc99a50bf7005 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_10.mp4.txt @@ -0,0 +1,36 @@ +[0.00s -> 2.77s] Let's talk about hydrogen bonds. +[2.77s -> 17.04s] Depicted here, I have three different types of molecules. On the left, I have ammonia. Each ammonia molecule has one nitrogen bonded to three hydrogens. In the middle, I have something you're probably very familiar with. In fact, you're made up of. +[17.04s -> 28.35s] of it, which is water. Each oxygen is bonded to two hydrogens. And then here on the right I have hydrogen fluoride. Each fluorine is bonded to one hydrogen. +[28.35s -> 36.94s] Now, why are these types of molecules interesting and what does that have to do with hydrogen bonds? And the simple answer is, +[36.94s -> 46.26s] In each of these cases, you have hydrogen bonded to a much more electronegative atom. Even though these are covalent bonds, they're going to be +[46.26s -> 56.72s] polar covalent bonds, you are going to have a bond dipole moment that goes from the hydrogen to the more electronegative atom. From the hydrogen. +[56.72s -> 69.12s] to the more electronegative atom, from the hydrogen to the more electronegative atom. The more electronegative atom is going to hog the electrons. The electrons are gonna spend more time around that. So that end of the molecule +[69.12s -> 76.61s] is going to have a partial negative charge, and then the ends with the hydrogen, those are gonna have partial positive charges. +[76.61s -> 86.62s] Another way to think about it is if you added these dipole moments, you would have a net dipole for the entire molecule that would look something. +[86.62s -> 99.86s] that would look something like that. So we are dealing with polar molecules and the polarity comes from both the asymmetry and you have a very electronegative atom bonded to hydrogen. +[99.86s -> 113.41s] Oxygen, very electronegative atom bonded to hydrogen. So this end of the molecule is partially negative. This end of the molecule or these ends of the molecule are partially positive. For hydrogen fluoride, this end is partially positive. +[113.41s -> 126.77s] This end is partially negative. And so what do you think could happen when these molecules interact with each other? The nitrogen end right over here of this ammonia could be attracted to one of these hydrogens that has a partially positive charge right over there. +[126.77s -> 135.76s] Or this hydrogen, the partial positive charge, might be attracted to that nitrogen that has a partial negative charge. +[135.76s -> 148.88s] And this attraction between the partial positive hydrogen end and the partially negative end of another molecule, those are hydrogen bonds. And they are an intermolecular force that will +[148.88s -> 163.25s] be additive to the total intermolecular force from say things like London dispersion forces, which makes you have a higher boiling point than you would have if you just thought about London dispersion forces. And to make that clear, you can look at this. +[163.25s -> 173.95s] You can see all of these molecules are formed between period two elements and hydrogen. In fact, all of these molecules have similar +[173.95s -> 188.24s] molar masses, methane, ammonia, hydrogen fluoride, and water. If we were just thinking about London dispersion forces, London dispersion forces are proportional to the polarizability of a molecule, which is proportional. +[188.24s -> 202.45s] to the electron cloud size, which is proportional to the molar mass. And generally speaking, as you go from molecules formed with period two elements to period three elements to period four elements to period five elements, you do see that as the +[202.45s -> 212.69s] the molar mass of those molecules increase, there is that general upward trend of the boiling point, and that's due to the London dispersion forces. +[212.69s -> 226.99s] But for any given period, you do see the separation. In particular, you see a lot of separation for the molecules formed with oxygen, fluorine, and nitrogen. These molecules, despite having similar molar masses, have very different boiling. +[226.99s -> 236.38s] So there must be some other type of intermolecular forces at play above and beyond London dispersion forces. And the simple +[236.38s -> 250.70s] The answer is yes. What you have at play are the hydrogen bonds. Now some of you might be wondering, well look at these molecules formed with period three elements and hydrogen or period four elements and hydrogen. They also don't have the +[250.70s -> 264.91s] the same boiling point, even though you would expect similar London dispersion forces because they have similar molar masses. And the separation that you see here in boiling points, this too would be due to other things other than London dispersion forces. +[264.91s -> 277.63s] In particular, dipole forces would be at play. But what you can see is the spread is much higher for these molecules formed with nitrogen and hydrogen, fluorine and hydrogen, and oxygen and hydrogen. +[277.63s -> 286.16s] And that's because hydrogen bonds can be viewed as the strongest form of dipole-dipole forces. +[286.16s -> 297.97s] Hydrogen bonds are a special case of dipole-dipole forces. When we're talking about hydrogen bonds, we're usually talking about a specific bond dipole. +[297.97s -> 304.24s] the bond between hydrogen and a more electronegative atom like nitrogen, oxygen, and fluorine. +[304.24s -> 318.54s] And so we're specifically talking about that part of the molecule, that hydrogen part that has a partially positive charge being attracted to the partially negative end of another molecule. So it's really about a bond dipole with hydrogen bonds versus +[318.54s -> 325.04s] a total molecular dipole when we talk about dipole-dipole interactions in general. And so you could imagine +[325.04s -> 336.13s] It doesn't even just have to be hydrogen bonds between a like molecule. You could have hydrogen bonds between an ammonia molecule and a water molecule, or between a water molecule and a hydrogen fluoride molecule. +[336.13s -> 343.79s] And I mentioned that these are really important in biology. This right over here is a closeup of DNA. +[343.79s -> 358.06s] you can see that the base pairs in DNA, you can imagine the rungs of the ladder, those are formed by hydrogen bonds between base pairs. So those hydrogen bonds are strong enough to keep that double helix together, but then they're not so. +[358.06s -> 367.63s] so strong that they can't be pulled apart when it's time to replicate or transcribe the DNA. Hydrogen bonds are also a big deal in proteins. +[367.63s -> 381.90s] You learn in biology class that proteins are made up of chains of amino acids, and the function is heavily influenced by the shape of that protein, and that shape is influenced by hydrogen bonds that might form between the amino acids. +[381.90s -> 393.90s] that make up the protein. So hydrogen bonds are everywhere. There are many hydrogen bonds in your body right now, mainly not just because of the DNA, mainly because you're mostly water. +[393.90s -> 398.52s] Life as we know it would not exist without hydrogen bonds. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_11.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5c4167f1f10dd9c4777deabd03ce3b590205816d --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_11.mp4.txt @@ -0,0 +1,17 @@ +[0.00s -> 14.29s] When trying to differentiate muscle types, first you should ask yourself is it striated? Striations are just these light and dark stripes that you see very clearly in the skeletal muscle. +[15.25s -> 22.99s] As soon as it is striated, you know it must either be skeletal or cardiac. +[23.28s -> 35.57s] Cardiac distriations are less obvious. If you look closely enough, you can see some light and dark bands, but you can always see +[35.92s -> 41.62s] intercalated discs in cardiac muscle. So those are those darker +[41.74s -> 52.02s] lines that are going in the same direction as the other striations. If you see those you automatically know that it's cardiac muscle. +[53.33s -> 64.66s] The smooth muscle does not have any striations at all. It doesn't have intercalated discs. And that's what is going to help you identify as smooth. +[65.07s -> 74.96s] So now let's try the practice questions and if you're getting them wrong and you don't know why, just leave me a comment and I'll try to point you in the right direction. +[86.22s -> 96.62s] So when you look at this, you see striations, but you don't see intercalated discs, which is how you know it is skeletal muscle. +[109.42s -> 118.38s] So when you look at this, because you don't see striations and there's definitely not any intercalated discs, you know that it is smooth muscle. +[129.58s -> 135.15s] Because this is striated and no intercalated discs, it is skeletal. +[148.43s -> 156.46s] It is very hard to see any striations in this picture, however, you do see intercalated discs. +[158.06s -> 169.20s] Here's one. There's one. There's one. They're all over the place. So once you see those, you know it is cardiac. And also I'll point out that +[169.20s -> 181.17s] cardiac muscle does branch so it's not just a straight line so it also tends to look less organized and less like neat even rows than the other two +[193.36s -> 198.86s] So there are clearly no striations, no intercalated discs, so it's smooth. +[210.48s -> 218.54s] And once again, you can obviously see intercalated discs and it does have that very branched appearance. +[218.99s -> 232.37s] All right, so those are all the examples I have for you. If you're having trouble differentiating any of them, I suggest you try to get a bunch of examples of each type and put them side by side. +[237.62s -> 244.48s] So that's all my advice for you today. Hope that was helpful. Have a great day and have fun learning. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_13.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f93673596c23be145e84830f875f7cc7ff165baf --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_13.mp4.txt @@ -0,0 +1,30 @@ +[0.00s -> 9.55s] We're now going to talk about cranial nerves 3, 4, and 6. I put these together because cranial nerves 3, 4, and 6 all innervate the extraocular muscles. +[9.55s -> 22.54s] And so we'll do these together and then we'll cover cranial nerve 5 that seems to be skipped. So cranial nerve 3 is the oculomotor nerve. Cranial nerve 4 is trochlear nerve. Cranial nerve 6 is abducens nerve. These three cranial nerves innervate our... +[22.54s -> 30.86s] extraocular muscles or the muscles around the eye that move it. We're going to focus on the extraocular motor nerve. +[30.86s -> 45.07s] first. It's orientation. Here we have a lateral view of the skull and it's a lateral view of the orbit on the left side. So if we then take that region and then blow it up, that's the illustration or the illustrative view of what we're looking at. +[45.07s -> 58.77s] Okay, so lateral view of the orbit on the left side. The oculomotor nerve's origin and course. It arises from the midbrain as well as cranial nerve 4. It then courses to this opening in the skull that's known as the superior +[58.77s -> 69.47s] Orbital fissure, SOF is just its abbreviation. So here we have a view of the skull and we zoom in. The superior orbital fissure is this opening there. +[69.47s -> 82.94s] of the upper part of the orbit and it's a fissure which means it's a big opening, not just a hole, a big opening because a lot of cranial nerves are going to course through that superior orbital fissure. All right, so now the +[82.94s -> 92.88s] Cranial nerve 3 then courses from the supraorbital fissure into the orbit and it innervates muscles, extraocular muscles of the eye. But it also goes to the pupil. +[92.88s -> 104.29s] and the lens and works on that from an autonomic parasympathetic level. So let's talk first about the somatic motor to the extraocular muscles. All right, so +[104.29s -> 117.23s] and then we'll talk about the visceral motor to the pupillary constrictor and ciliary muscles. All right, to begin, oculomotor nerve provides somatic or somatic motor innervation to the inferior oblique muscle. +[117.23s -> 131.60s] It also gives somatic innervation to our inferior rectus muscle and to the medial rectus muscle and to the superior rectus muscle and to the levator labi superiors. +[134.42s -> 140.35s] and to the levator palpebrae superioris, that muscle that elevates the eyelid. +[140.35s -> 154.67s] the somatic motor to all these extraocular muscles of the eye that move the eye around. Well, to show that, so there's our cell body. It's in the midbrain. It's a motor neuron. So it arises from a homologous structure of the ventral horn gray matter. We call it the +[154.67s -> 160.45s] oculomotor nucleus and it sends off all these motor neurons that innervate these muscles. +[160.45s -> 170.22s] However, there's also visceral motor to two different muscles, the pupillary constrictor and the ciliary muscles. And so there is another one that arises from +[170.22s -> 184.45s] a homologue to the lateral horn gray matter that's called the accessory oculomotor nucleus, and it sends information to then a peripheral ganglion called the ciliary ganglion, which then sends information to the front of the eye. +[184.45s -> 194.46s] So one of those muscles that cranial nerve 3 innervates is called the pupillary constrictor muscle because when you shine a light in the eye, shing, it's going to constrict and get really small. +[194.46s -> 205.65s] It also is going to then innervate the ciliary muscles that when they contract change the shape of the lens which allows you to focus your lens +[205.65s -> 209.58s] for visual information right in front of you or far away. +[211.12s -> 225.42s] So here's the course and function of the oculomotor nerve from a different view. There is our midbrain and cranial nerve number three coursing through the cavernous sinus. +[225.42s -> 235.76s] to the supraorbital fissure and then to extraocular muscles, EO, as well as to the pupillary constrictor and the ciliary muscles. +[236.40s -> 246.99s] So let's now talk about the trochlear nerve, shall we? Cranial nerve number four, its origin and course. It also rises from that midbrain and courses to that superior orbital fissure. +[246.99s -> 259.25s] and then it's going to course through that superior orbital fissure and then to a muscle that's known as our superior oblique. It gets the name superior oblique because it courses up +[259.25s -> 263.94s] wraps around this thing called a trochlea, which is a pulley, and then... +[263.94s -> 274.62s] there's the trochlea, which is where the nerve name comes from, trochlear nerve, and then courses at an oblique angle over on top of the eye, hence the name superior for above oblique from an angle. +[274.62s -> 288.90s] So let's do this trochlear nerve again. There's our midbrain. It arises from actually the back of the midbrain and then courses up to the cavernous sinus to the superior and traverses the supraorbital fissure and then innervates one muscle. +[288.90s -> 302.91s] the superior oblique. Now let's talk about the occipital ribosomal nerve. The occipital ribosomal nerve has the following origin and course. It arrives from the pons, courses to our superior orbital fissure, and oh, there's the superior orbital fissure again. +[302.91s -> 313.66s] And it's going to innervate the lateral rectus. So let's draw on. It looks sloppy. I recognize that lateral rectus. And if we cut, that's how it gets that reflected view. +[313.66s -> 321.42s] of that lateral rectus and it's going to innervate just one muscle. That's it. So here we've got the pons that +[321.42s -> 330.58s] abducens nerve coursing to the cavernous sinus to the superior orbital fissure and then to that lateral rectus muscle. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_15.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3f81c22867c6e25dbf9a3f4f98a68782b7b13bb8 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_15.mp4.txt @@ -0,0 +1,21 @@ +[22.13s -> 33.33s] Hello to you all. Now today we're going to look at one of the largest structures in the brain, one that takes up a large percentage of the volume of the cerebral. This is the corona radiata, an internal capsule. +[33.68s -> 44.98s] Now you'll instantly see that I've referred to the two elements as a single structure. This is because the internal capsule is, in effect, a continuation of the corona radiata, a topic we shall return to a little later on. +[46.06s -> 53.81s] So, what is this structure and what is its function? Well, we'll start by looking at the coronal section of the brain. +[54.42s -> 62.00s] From this section you can hopefully see the difference between the grey matter and the white matter . +[62.29s -> 75.12s] In the very centre of the brain lies the thalamus, a collection of sensory and motor nuclei. Either side of the thalamus there is a region of white matter. This is the internal capsule, running between the thalamus and the lentiform nucleus. +[75.63s -> 84.66s] If you follow this structure upwards, you'll see that it radiates out to all parts of the cortex, looking a bit like a crown. The corona radiata. +[86.26s -> 100.06s] The coronoradiator and internal capsule are both made up of afferent and efferent projection fibres that carry information to and from the cerebral cortex. And while it looks like it's just a mass of random fibres, it is actually highly organised. +[100.06s -> 105.14s] with very specific tracks projected to or from selective cortical regions. +[106.70s -> 118.00s] Efferent fibres are mostly concerned with motor function, either directly as axons of upper motor neurons or indirectly via projections to the striatum of the basal nuclei. +[119.73s -> 131.63s] Motor neurons in the cortical spinal, cortical bulba, and cortical nuclear pathways project from the motor regions of the cortex, passing between the thalamus and the lentiform nucleus, and on to the cruciabula. +[134.64s -> 145.90s] Afferent fibres mostly rise from the thalamus. Sensory fibres from the anterolateral tract and dorsal columns project to the ventropostolateral nucleus of the thalamus, or VPL. +[146.70s -> 159.60s] The thalamus also receives motor inputs from the basal nuclei and the cerebellum by the ventrolateral nucleus, or VL, while visual and auditory fibers project to the genicular nuclei, part of the metathalamus. +[160.66s -> 166.51s] Now there are other videos that explain these tracks, so if you want to know more about them, then please watch them as well. +[168.69s -> 178.26s] The thalamus is a major processing centre buried in the middle of the brain and fibres from this structure project to all parts of the cerebral cortex via the thalamic radiations. +[178.74s -> 187.86s] These fibres form much of the afferent component of the corona radiata and internal capsule. This can be seen most clearly if we look at a horizontal section through the brain. +[188.37s -> 202.29s] If we look at this image, you can hopefully see that the internal capsule is bent in the middle to form two limbs, the anterior and posterior limbs. The bend in the middle is known as the genu, or knee. +[202.83s -> 214.96s] Fibres passing through the anterior limb project to the frontal lobe while those passing through the posterior limb project principally to the occipital lobe although also to the temporal and parietal lobes. +[216.34s -> 227.22s] Fibres projecting vertically pass to the somatosensory cortex as third-order sensory neurons and to the supplementary or premotor cortices as part of the motor control systems. +[228.14s -> 233.23s] Projections from the geniculate nuclei form the optic and auditory radiations. +[234.29s -> 245.68s] So hopefully you can see that. While the white matter in the cerumen looks like a jumbo of fibres, in fact it's highly organised. Many fibres of the corona radiata and turtle capsule are actually one and the same. +[245.87s -> 250.80s] And these two structures are really just a continuation of each other. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_2.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0632d4857530aa126fc3d8b7b21954e1245ddf0b --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_2.mp4.txt @@ -0,0 +1,41 @@ +[3.92s -> 6.69s] Muscles. They're quite magnificent. +[6.69s -> 20.98s] The muscular system consists of muscles, and often when we think of muscles, we think about certain ones that you can identify right under the skin, like biceps or triceps. But muscles are so much more than that. This video is not going to focus on the name. +[20.98s -> 28.83s] of all kinds of different muscles, but more about muscle tissue and how muscle contraction works—the actin-myosin cycling. +[28.83s -> 41.26s] First, let's talk about muscle tissue. Muscle tissue is made up of muscle fibers. These fibers are the muscle cells, and they have structure that aids in their function. There are three types of muscle tissue we'll discuss. +[41.26s -> 49.79s] Cardiac muscle tissue. Like its name suggests, it's in the heart. The muscle fibers are branched, striated, or striped. Each fiber has a nucleus. +[49.79s -> 64.11s] At the ends of the fibers, you'll find something called intercalated disc. These are really important because they're involved in helping the cardiac muscle tissue contract in an organized, wave-like pattern. This muscle tissue control is involuntary. That is, you +[64.11s -> 74.34s] You do not consciously control it. Smooth muscle tissue. It's smooth, really just meaning here it doesn't have striations or stripes. Each fiber has one nucleus. +[74.34s -> 88.58s] And each fiber is spindle-shaped, meaning they are wide in the middle and then taper off at both ends. You'll find them in the digestive system, in arteries and veins, in the bladder, in the eyes, changing the iris size. They're also involuntary. +[88.58s -> 102.90s] Skeletal muscle tissue. This is the one you think about with biceps or triceps because skeletal muscle is what attaches to bone or skin and is involved with voluntary control, meaning you can consciously control it. You can choose to pick up that +[102.90s -> 115.54s] biology textbook, if you could zoom in to see these skeletal muscle fibers are striped or striated. The fibers are long cylinders that are multinucleated. Fancy term for multiple nuclei. +[115.54s -> 129.81s] All muscle tissue have some characteristics to mention. It can stretch or extend, extensibility. It can retract back to its starting length, elasticity. Muscle tissue also has excitability. That means these cells have the ability to be stimulated. +[129.81s -> 139.86s] In the case of muscle tissue, their membranes can have electrical changes and send action potentials. Muscle tissue also has the ability to contract, or contractility. +[139.86s -> 153.86s] There are some differences in how the contraction happens in the three tissue types. For the rest of this video, we're really going to focus on that last tissue mentioned, skeletal muscle. Let's look a little bit about how they're named, how they're arranged, and how they contract. +[153.86s -> 162.99s] Many skeletal muscles are named by their location or their shape. Many have Latin or Greek root words in them, so checking out a root word definition list can be really helpful. +[162.99s -> 176.32s] For example, rectus femoris, it's a muscle on the thigh, or rectus abdominis, that's a muscle on the abdomen. The Greek letter delta looks like a triangle, which is a fitting name for deltoids, a triangular shaped muscle. +[176.32s -> 190.64s] There are some beautiful diagrams of skeletal muscles where you can explore the many muscle names and locations. As we mentioned, many skeletal muscles can pull on bones. The part that attaches to the bone that will be moved is called the insertion, and the part that attaches to a +[190.64s -> 205.62s] fixed part of the bone is called the origin. There could be several muscles involved in a single action. The main muscle doing the work, the prime mover, is called the agonist, whereas antagonists are muscles that do the opposite action, which is helpful for keeping position. +[205.62s -> 219.70s] If we zoom into some skeletal muscle at the cellular level, how does it do what it does? How does it contract? This is probably the most exciting part of the video. Okay, so imagine you have some skeletal muscle like the biceps muscle. +[219.70s -> 226.59s] That muscle is made up of many muscle fibers, which remember, are muscle cells. By the way, some of these cells are big. +[226.59s -> 240.88s] Of course, generally cells are microscopic, but these muscle cells can have lengths up to 30 centimeters long. Anyway, inside a muscle fiber are multiple myofibrils, which are long cylinders. Each myofibril has sections that repeat, called +[240.88s -> 253.33s] And it's the arrangement of these sarcomeres that contribute to the skeletal muscle's striated look. There's a lot to a sarcomere, and that's where we're going to focus. So the sarcomere has a protein known as actin. +[253.33s -> 266.29s] Actin makes up what is known as thin filaments. The sarcomere also has a protein called myosin. Myosin makes up thick filaments. To try to remember which one is which, I try to remember that the word thin is almost in the word actin. +[266.29s -> 280.62s] Minus the H though, but close enough to help me remember. Anyways, both of these are essential in causing muscle contraction. Enter the sliding filament model of muscle contraction. Now, as we often tell you, we're going to do a simplified version. When you're ready for more to explore, check out our video. +[280.62s -> 293.55s] description. Okay, so we have actin, thin filaments. We have myosin, thick filaments. We have these Z lines here where a sarcomere ends, and these Z lines are where the thin filaments attach. +[293.55s -> 304.77s] The thick filaments are held by accessory proteins in this area called the M line. The big, super important concept here is this. The sarcomere must shorten for muscles to contract. +[304.77s -> 313.90s] The thick and thin filaments themselves do not shorten. So the way that is going to happen is that we're going to slide past each other. And they do. +[313.90s -> 325.79s] When the sarcomere contracts, the thin filaments will be pulled by the thick filaments towards the center. There is overlap of the thin and thick filaments. Z lines will be moved closer together. +[325.79s -> 340.21s] How are they doing that? So let's zoom into this here. Showing a thin filament on top, that's actin. Thick filament on bottom, that's myosin. Myosin has structures here called myosin heads. Hundreds of them, actually, but we're just going to focus on one. +[340.21s -> 352.27s] And here we show the myosin head is bound to ATP. It hydrolyzes the ATP , which are both still bound to the myosin head. +[352.27s -> 366.54s] The myosin head can now bind to the actin. We call this a cross bridge. The myosin head performs a power stroke, which will also involve the release of ATP and the phosphate. Power stroke meaning the thin filament slides towards that sarcomere. +[366.54s -> 373.73s] center. A new ATP molecule binds the myosin head, and that is what lets the myosin head detach. +[373.73s -> 385.78s] Without ATP, the myosin head would not detach. This is actually the reason for rigor mortis, how muscles can be rigid after an organism dies, is the organism is no longer producing ATP. +[385.78s -> 389.36s] ATP is needed for the myosin to separate from the actin. +[389.36s -> 401.26s] So, during muscle contraction, you can imagine all these hundreds of cross bridges forming and breaking and power strokes happening in each sarcomere throughout the time of a muscle contraction. +[401.26s -> 414.18s] It's popular in bio to compare the myosin heads to tiny little oars of a boat, and because there would be some attached at any given time during a contraction, it prevents the actin from slipping back to its original position. +[414.18s -> 427.07s] But there's more. A muscle isn't always contracting. There is regulation in that it's not just cycle after cycle. A lot of this regulation involves the ability of the myosin heads to bind to the actin in the first place. +[427.07s -> 437.97s] The actin has something called tropomyosin on it. It's a regulatory protein, and it blocks the myosin binding sites on the actin. We're drawing it like a ribbon here, blocking sites. +[437.97s -> 452.30s] Another thing called troponin, or really a troponin complex, is a set of more regulatory proteins. Together, these regulatory proteins block those myosin binding sites. And if the myosin doesn't bind the actin, the muscle can't contract because that's +[452.30s -> 462.83s] thin filament isn't going to be sliding. But when a neuron stimulates a muscle, it can trigger a release of calcium, and those little calcium ions bind to the troponin. +[462.83s -> 471.26s] The troponin has a conformational change and this lets the tropomyosin move off the myosin binding sites. Now the myosin heads can bind. +[471.26s -> 484.24s] pretty fascinating way to regulate. Next time you pick up that biology textbook, you might want to pause to reflect on the amazing events occurring in your skeletal muscles. Well, that's it for the Amoeba Sisters, and we remind you to stay curious. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_3.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a57147e44365ae022c495dcf98c593dfdc3f6c58 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_3.mp4.txt @@ -0,0 +1,35 @@ +[8.53s -> 18.61s] Cells are the smallest living units of an organism. All cells have three things in common, no matter what type of cell they are. +[18.96s -> 32.91s] All cells have a cell membrane, which separates the inside of the cell from its environment, cytoplasm, which is a jelly-like fluid, and DNA, which is the cell's genetic material. +[34.86s -> 48.05s] There are two broad categories of cells. The first category is eukaryotic cells. They have organelles, which include the nucleus and other special parts. +[48.82s -> 55.47s] Eukaryotic cells are more advanced complex cells such as those found in plants and animals. +[57.01s -> 69.79s] The second category is prokaryotic cells. They don't have a nucleus or membrane-enclosed organelles. They do have genetic material, but it's not contained within a nucleus. +[69.79s -> 76.82s] Prokaryotic cells are always one-celled or unicellular organisms, such as bacteria. +[79.98s -> 91.98s] So what are organelles? Organelle means little organ. Organelles are the specialized parts of a cell that have unique jobs to perform. +[92.56s -> 102.67s] Let's start with the nucleus, the control center of the cell. The nucleus contains DNA, or genetic material. +[102.99s -> 114.29s] DNA dictates what the cell is going to do and how it's going to do it. Chromatin is the tangled, spread-out form of DNA found inside the nuclear membrane. +[116.08s -> 130.26s] When a cell is ready to divide, DNA condenses into structures known as chromosomes. The nucleus also contains a nucleolus +[130.67s -> 144.02s] which is a structure where ribosomes are made. After ribosomes leave the nucleus, they will have the important job of synthesizing or making proteins. +[147.50s -> 161.71s] Outside the nucleus, the ribosomes and the rest of the organelles float around in cytoplasm, which is the jelly-like substance. Ribosomes may wander freely within the cytoplasm. +[162.03s -> 174.42s] or attach to the endoplasmic reticulum, sometimes abbreviated as ER. There are two types of ER. Rough ER has ribosomes attached to it. +[174.42s -> 178.38s] And smooth ER doesn't have ribosomes attached to it. +[179.76s -> 189.90s] The endoplasmic reticulum is a membrane-enclosed passageway for transporting materials such as the proteins synthesized by ribosomes. +[191.98s -> 205.46s] Proteins and other materials emerge from the endoplasmic reticulum in small vesicles, where the Golgi apparatus, sometimes called the Golgi body, receives them. +[206.61s -> 213.36s] As proteins move through the Golgi body, they're customized into forms that the cell can use. +[215.57s -> 227.44s] The Golgi body does this by folding the proteins into usable shapes or adding other materials onto them such as lipids or carbohydrates. +[230.10s -> 239.44s] Vacuoles are sack-like structures that store different materials. Here, in this plant cell, the central vacuole stores water. +[242.83s -> 254.58s] Going back to the animal cell, you will see an organelle called a lysosome. Lysosomes are the garbage collectors that take in damaged or worn out cell parts. +[254.77s -> 266.90s] They are filled with enzymes that break down this cellular debris. The mitochondrion is an organelle that is the powerhouse for both animal and plant cells. +[268.02s -> 278.22s] During a process called cellular respiration, the mitochondria make ATP molecules that provide the energy for all of the cell's activities. +[279.73s -> 291.38s] Cells that need more energy have more mitochondria. Meanwhile, the cell maintains its shape through a cytoskeleton. +[291.89s -> 302.90s] The cytoskeleton includes the thread-like microfilaments, which are made of protein, and microtubules, which are thin, hollow tubes. +[305.04s -> 319.63s] Some organisms such as plants that are photoautotrophic, meaning they capture sunlight for energy, have cells with an organelle called a chloroplast. +[319.89s -> 328.18s] The chloroplast is where photosynthesis happens. It's green because it has a green pigment called chlorophyll. +[330.51s -> 342.13s] Plant cells also have a cell wall outside of their cell membranes that shape, support, and protect the plant cell. Animal cells never have a cell wall. +[343.50s -> 347.95s] There are many other unique structures that only some cells have. +[348.40s -> 361.55s] Here are just a few. In humans, for example, the respiratory tract is lined with cells that have cilia. These are microscopic hair-like projections that can move in waves. +[361.68s -> 367.98s] This feature helps trap inhaled particles in the air and expels them when you cough. +[371.79s -> 384.08s] Another unique feature in some cells is flagella. Some bacteria have flagella. A flagellum is like a little tail that can help a cell move or propel itself. +[384.34s -> 389.58s] The only human cell that has a flagellum is a sperm cell. +[391.22s -> 400.82s] In summary, remember eukaryotic cells are plant and animal cells with a nucleus and membrane-enclosed organelles. +[402.35s -> 414.99s] while prokaryotic cells are unicellular organisms without these things. All cells have a cell membrane, cytoplasm, and genetic material. +[416.53s -> 423.50s] And even though only plant cells have chloroplasts, both plant and animal cells have mitochondria. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_4.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..76019c09f71da30c4b3434e27e948c3215904148 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_4.mp4.txt @@ -0,0 +1,45 @@ +[4.18s -> 18.77s] This is lesson seven and this is going to be a relatively short video because most of what I want you to learn this week you're going to be reading about and you're going to be able to to pick it up from the book and also from any videos that you +[18.77s -> 32.98s] I might have for you but we're carrying on with central vestibular dysfunction and we're moving on into some more of the somatosensory things that you're going to see beyond the the visual vestibular portion so again we're looking +[32.98s -> 47.18s] at selecting appropriate assessments and interventions for these people. And I know we haven't really talked yet about interventions and that's somewhat purposeful because I think the bulk of what we need to look at is how do we assess these folks. +[47.18s -> 61.39s] Once we can figure that out, the interventions are going to follow fairly easily, fairly readily. We're going to know what to do. As you'll recall, there are these central connections that we have in our vestibular system. +[61.39s -> 75.60s] particular, some of the ones that we're going to be concerned about today are the vestibulospinal and vestibulocolic reflex and some of the things that we're going to be seeing, especially when the cerebellum is impaired. So how do we take a look at cerebellum? +[75.60s -> 89.81s] signs you might have learned how to do a cerebellar screening previously but there's some good directions in chapter 8 and you can also take a look at the videos provided for you by the textbook +[89.81s -> 102.74s] cerebellar screening but finger to nose test is of course where you have the person touching their nose with their finger and seeing if they can target their nose eyes open eyes closed +[102.74s -> 117.23s] And then finger, nose, finger to my finger. That's the finger to point to point test. And then heel to shin. And I'm not going to be able to demonstrate that in the video because I can't get. +[117.23s -> 131.44s] my legs up to where you can see them on the screen but that is where you're going to take the heel of one foot and drag it down the shin of the opposite leg and if you see dysmetria or tremors in the lower extremities with that then +[131.44s -> 145.65s] that would be impaired. And then diatocokinesia or dysdiatocokinesia, those rapidly alternating movements. Can they do those and keep those in sync? And then you're also going to do arms extended, eyes closed to see if there is a drift or +[145.65s -> 159.86s] So if those cerebellar signs show up, then you know that there's something going on in the cerebellum that is impacting the person's balance system as well. So what are some of the things that can happen? +[159.86s -> 171.66s] that can cause a central dysfunction. Concussion, dizziness is a frequent symptom of concussion and both the vestibuloocular reflex and the balance are impacted as a result. +[171.66s -> 180.45s] 96% of people diagnosed with concussion have a vestibular component to their injury and yet it's so ignored in practice. +[180.45s -> 194.77s] We as therapists need to be more proactive in helping people who have concussions in managing the vestibular component of their dysfunction. And it's also been proven in the literature that vestibular rehabilitation improves symptoms. +[194.77s -> 208.98s] after a concussion so after the period of rest that a person has after a concussion we need to beginning immediately or very soon after that and outcomes are going to be higher for people to progress and recover from their +[208.98s -> 223.57s] vestibular component if we target the individual specific deficits. So if we're looking at a student's ability to look at the board in the classroom or an athlete's ability to do the specific moves that they need to do for their sport. +[224.85s -> 226.96s] now stroke +[226.96s -> 241.26s] can be an older person, but it doesn't always have to be. In fact, the typical person that has a cerebellar stroke is a 50-year-old male. And they're going to have some different symptoms like we talked about before. They might have moderate nausea, but severe. +[241.26s -> 244.43s] imbalance. They're going to have those three D's. +[244.43s -> 258.74s] quite likely. They might have some other neurological symptoms, and they're going to be very slow to compensate. These are those people with that constant hum of vertigo, I call it. It's constantly there, never gets a whole lot better, but it can get worse. +[258.74s -> 263.12s] with with you know greater amounts of movement +[263.95s -> 278.54s] We've talked about vestibular migraines in the past too, but here are a few statistics or criteria for you as to how a physician would diagnose vestibular migraines. So if you notice these things, this would be a reason to... +[278.54s -> 285.60s] refer them to a physician who specializes in migraines, going through the person's referring physician in order to do that. +[285.60s -> 297.09s] So a person would have at least five episodes with vestibular symptoms of moderate or severe intensity lasting five minutes to 72 hours. +[297.09s -> 306.38s] So they would have to have episodes of vertiginous symptoms. They would also have to have a current or previous history of migraine. +[306.38s -> 318.29s] And migraine features during at least 50% of the episodes. So they might have a unilateral headache, which did you know that that's a hallmark of a migraine is that they're very hemi. +[318.29s -> 332.59s] They're oriented toward one side of the brain. Photophobia or phonophobia, so they're light and sound sensitive. And they might have that visual aura that people get before migraines, the floaters, the flashers, the curtain of light. +[332.59s -> 343.66s] that people describe. And also another criteria is that it's not better accounted for by another vestibular or ICD diagnosis. +[343.66s -> 357.94s] Another central condition that can cause vertigo is going to be a seizure disorder. People who have severe migraine disorders will often have seizures, and vestibular provocation can bring about seizures. +[357.94s -> 372.14s] to be very aware of as you're working with these clients. Can we change seizures in rehab? No. Can we help people manage their symptoms, manage the kind of the fallout that they have with their vestibular symptoms? +[372.14s -> 380.08s] Yes. So what are some of the other central diagnoses that might cause vestibular problems? +[380.08s -> 394.35s] Parkinson's disease, multiple sclerosis, cerebellar dysfunction of any kind or any other disease or disorder that impacts the vestibular cerebellar or cerebral pathways. I one time had the misfortune of having a client who +[394.35s -> 404.43s] had not been diagnosed with Parkinson's disease, and she came to me, and I'm like, man, that doesn't look right. That looks like a gait that is... +[404.43s -> 418.77s] You know, it's a central gate. And, of course, I'm not a physical therapist, but I've seen enough people walk that I know, you know, a dysfunctional and central-looking gate when I see it. So I referred her back to her physician, and she did indeed. +[418.77s -> 429.97s] She'd have Parkinson's disease, got placed on the Parkinson's medication, and fortunately, at least for during that time period, all her symptoms went away, so that was very helpful. +[429.97s -> 441.25s] A reminder here that sometimes what you're seeing is not central. It could be cardiac. It could be psychogenic. +[441.25s -> 452.00s] People who describe what sometimes sound like central dysfunction can be having psychogenic or other non-vestibular causes of vertigo. +[452.00s -> 466.29s] So what is our intervention for central vertigo? Just in general, we want to, first of all, get a diagnosis. We want to find out exactly what's going on with this person. I also once had a client who had a pituitary tumor, and he knew he had... +[466.29s -> 480.50s] a tumor but his symptoms kept progressing and progressing and I finally sent him back to his physician and they did another MRI and indeed his tumor had grown and unfortunately for him it was a very poor outcome for him. +[480.50s -> 484.26s] and so we stopped therapy at that time. +[484.26s -> 498.74s] People tend to be slow to compensate with a central vestibular issue, so they're going to respond best if we're more gentle with them. So gentle habituation, putting them through some gentle motions that they can. +[498.74s -> 505.78s] habituate to using that brain plasticity to accommodate to that motion. +[505.78s -> 520.21s] also dealing with their motion sensitivity, and also lots of compensatory strategies, wearing the sunglasses, dimming the lights, learning how to move and how to arrange their environment in a way that... +[520.21s -> 534.42s] their sensitivity is most helpful in the literature it is shown that people demonstrate improved balance after vestibular rehab but the vertiginous symptoms can continue especially +[534.42s -> 541.36s] in the case of vestibular migraine. Thank you very much and we'll see you in the next episode. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_5.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..82a78d314b71602e88acfcadb424f40c7b843288 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_5.mp4.txt @@ -0,0 +1,53 @@ +[0.00s -> 14.29s] Hey guys, it's Medicosus Perfectionellus where medicine makes perfect sense. We continue our physiology playlist. In previous videos, we have talked about sympathetic nervous system and parasympathetic nervous system. Today, we'll compare between the cholinergic and the adrenergic. +[14.29s -> 17.50s] fibers with that said now let's get started +[17.50s -> 30.77s] Let me just tell you that I have a playlist on this channel called Comparisons, where we compare between gout versus pseudogout, aspergillus fumigatus versus aspergillus flavus, iron deficiency anemia versus anemia of chronic disease. +[30.77s -> 34.96s] cartaginous syndrome versus situs and versus totalis +[34.96s -> 49.26s] and yes cholinergic versus adrenergic all right let's get into it so here is your spinal cord segment you draw a line in the sand anything behind sensory anything in front is motor with few exceptions as you know all of the autonomic fibers are motor +[49.26s -> 55.60s] they are never sensory and that's why they start here lateral horn cell in front of the line because they are motor +[55.60s -> 69.90s] after they leave the lateral horn cell they go into the ventral root or ventral ramus and then they become spinal nerve and since we are talking autonomic nervous system we will relay in a ganglion so we have preganglionic fiber and postganglion +[69.90s -> 79.86s] fibers. The preganglionic is usually B-type, which means it's thin and myelinated. It appears white. But C is unmyelinated. It appears gray. +[79.86s -> 85.65s] These preganglionic fibers secrete acetylcholine. That's why we call them cholinergic fibers. +[85.65s -> 99.92s] However, the postganglionic, it depends. If you're parasympathetic, you'll secrete acylcholine and we will call you cholinergic. But if you're sympathetic, you'll secrete norepinephrine most of the time and we will call you adrenergic because norepinephrine is the same as... +[99.92s -> 111.06s] nor adrenaline sympathetic or adrenergic basically you're running from a tiger you're running from your life fight flight fright parasympathetic on the other hand is rest digest +[111.06s -> 123.90s] read eat and take a dump and while reading you got emotional and you started crying yes lacrimal gland is parasympathetic it's the sphenopalatine ganglion it's your facial nerve +[123.90s -> 138.34s] And facial nerve has some autonomic fibers. So here is your sympathetic nervous system thoracolumbar. Here is your parasympathetic nervous system craniosacral. And we have talked about this before. Any preganglionic fiber is... +[138.34s -> 153.04s] cholinergic translation it secretes acetylcholine however post ganglionic fibers it depends if i am sympathetic i'll secrete norepinephrine most of the time but if i am parasympathetic i'll secrete what acetylcholine all the time +[153.04s -> 167.41s] don't forget that sympathetic is catabolic while parasympathetic is anabolic which makes perfect sense in sympathetic you're running from a tiger you gotta be catabolic because you need to break down carbohydrate into glucose burn the glucose in glycolysis to +[167.41s -> 179.54s] get you some energy so that you can run on the other hand parasympathetic you're sitting on a toilet and eating a sandwich eating a sandwich let's build up energy let's store some energy for a rainy day so you'll convert +[179.54s -> 187.50s] glucose into glycogen, for instance. Here is your sympathetic response, fight and flight, as discussed in the past videos. +[187.50s -> 200.13s] the antecedent ones in this playlist called physiology here is your parasympathetic response rest digest eat read and take a dump all of this was dissected in detail in the preceding videos +[200.13s -> 213.41s] now the big picture types of fibers you have central fibers before the ganglia and peripheral fibers after the ganglia okay all of these central fibers are cholinergic they secrete acetylcholine all of them whether you're targeting a skeletal muscle +[213.41s -> 227.70s] or you're targeting your ganglion and please do not forget that your adrenal medulla is a modified ganglion so all of these will secrete acylcholine therefore they are cholinergic fibers whether they are parasympathetic sympathetic or just +[227.70s -> 238.29s] for skeletal muscle, and this is motor, not autonomic. Post-ganglionic, we disagree. If I'm parasympathetic, I'll security acetylcholine, hashtag cholinergic. +[238.29s -> 252.56s] But if I am sympathetic, I'll secrete noradrenaline. Hashtag adrenergic. With the exception of sympathetic to sweat glands, these fibers secrete acetylcholine. Hashtag cholinergic. So you have central fibers and peripheral fibers. Central fibers, some of them are somatic. This is N. +[252.56s -> 260.91s] sub M, M for muscle. Some of them are preganglionic autonomic. The receptor is N sub N, N for neuron, because a ganglion is a neuron. So. +[260.91s -> 270.70s] Peripheral fibers, we gotta be careful. If you are parasympathetic, you'll secrete acetylcholine and you're cholinergic. But if you are sympathetic, you'll secrete noradrenaline. Hashtag adrenergic. +[270.70s -> 285.25s] cholinergic fibers adrenergic fibers cholinergic could be nicotinic receptor or musconic receptor even the nicotinic is divided into n sub n and n sub m you find n sub m on skeletal muscles n sub n on ganglia and on your adrenal medulla +[285.25s -> 297.52s] adrenergic fibers for the sympathetic system receptors are either alpha or beta not only this every one is also 2 alpha 1 or alpha 2 beta 1 or beta 2 shamefully there is also beta 3 for lipolysis +[297.52s -> 306.82s] How many types of cholinergic receptors do you know? I know two types. Each has got two sites. I know nicotinic and muscarinic. Oh, all of these are cholinergic. +[306.82s -> 316.98s] And each one is subdivided into two subtypes. So nicotinic, we have the neuromuscular junction, N sub M, and the postganglionic cell bodies, N sub N. This is your ganglia. +[316.98s -> 328.62s] Muscular neck, on the other hand, you have organs supplied by the parasympathetic, all of them are muscular neck, and only two organs supplied by the sympathetic, sweat glands, and in some textbooks, the blood vessels of skeletal muscles. +[328.62s -> 342.67s] Okay, medicosis, I have a question now. Sympathetic almost always secreted norepinephrine. Why did the sympathetic change its mind and secreted acetylcholine when it was contacting a sweat gland? Let me tell you. Acylcholine is parasympathetic, right? +[342.67s -> 355.90s] Right. Parasympathetic is secreto motor, right? Right. Secreto. Yeah. Acetylcholine is the hero of secretions. If you want to secrete anything, acetylcholine is the best. Oh, I get it. +[355.90s -> 363.57s] Now here is your cholinergic fiber and here is your adrenergic fiber. Cholinergic fiber. I'm cholinergic. What do you mean? I secrete acetylcholine. +[363.57s -> 371.38s] Perfect. Where did you get this acetylcholine from? From acetyl CoA and choline. No kidding. What's the enzyme? Choline. +[371.38s -> 385.68s] acetyltransferase love it acetylcholine gets stored in vesicles these are clear vesicles and then you have an action potential coming in opening voltage-gated calcium channel calcium ions rushing in rupturing the vessel +[385.68s -> 397.10s] by exocytosis and then acetylcholine is out. Acetylcholine has three options. I can act on N sub N receptors if this is a ganglion or an adrenal medulla. +[397.10s -> 410.62s] I can act on N sub M receptor if this is a neuromuscular junction or a motor end plate on a skeletal muscle. Or I can act on muscarinic receptor if this is a smooth muscle or a cardiac muscle. +[410.62s -> 414.83s] Okay, Asshole Colleen, you have performed your job properly. Now let's remove you. +[414.83s -> 429.58s] Oh, why would you like to remove me? Because if we leave you alone, you will lead to dumbbells, diarrhea, urination, meiosis, bronchospasm, bradycardia, emesis, lacrimation, sweating, salivation. This could be fatal. This is like organophosphate poisoning. Let's get rid of you. +[429.58s -> 444.06s] Now comes the choline esterase enzyme or the acetylcholine esterase enzyme. Let's degrade this acetylcholine. Let's break it down into choline and acetate. The choline will be recycled and let's make new acetylcholine and so on and so forth. +[444.06s -> 458.35s] Adrenergic fibers, on the other hand, they secrete noradrenaline or norepinephrine. How do you make norepinephrine? Here's the song. Phenylalanine, tyrosine, dopedupamine, norepinephrine, and stop. But if this is an adrenal medulla, phenylalanine... +[458.35s -> 463.81s] Epirucine, dopedupamine, norepinephrine, epinephrine. Why? +[463.81s -> 478.32s] Because the adrenal medulla has PNMT enzyme, phenylethanolamine, and methyltransferase enzyme, the adrenal medulla is capable of converting your norepinephrine into the more potent epinephrine. However, the adrenergic nerve endings do not have +[478.32s -> 484.82s] this PNMT enzyme therefore they cannot make adrenaline they can only make noradrenaline +[484.82s -> 495.58s] Okay, now I have norepinephrine in my vesicles. Calcium comes in through an action potential, ruptures the vesicle by exocytosis. Norepinephrine is out. Norepinephrine has two choices. It can act on alpha receptors. +[495.58s -> 508.80s] or beta receptors for two different functions okay i have performed my job properly let's remove me okay we will remove you the most common mechanism is active reuptake into the nerve terminus +[508.80s -> 517.98s] There is another mechanism we can destroy you and break you down by malenzyme inside the synaptic terminus or by COMT enzyme. +[517.98s -> 532.27s] which is catecholamine, because this is a catecholamine, O, which means zero, we will put the methyl group in a bad position, in a zero position, converting this valuable norepinephrine into pieces of trash. That's why it's called zero methyltransferase. +[532.27s -> 544.64s] Next, some of this norepinephrine will stay in your blood, making you alert so that you can be careful and pay attention while running from a tiger. However, in your blood there is no such thing as acetylcholine. +[544.64s -> 555.68s] It got broken down by the pseudocolinous trace. Some quick notes. The MAO enzyme can regulate presynaptic level in the mobile pool, but it cannot regulate the ones stored in the vesicle. +[555.68s -> 567.87s] You can take it to the next level and learn about centrally acting cholinergic antagonists, peripherally acting cholinergic antagonists, nicotinic agonists, nicotinic antagonists, muscarinic agonists, muscarinic antagonists. +[567.87s -> 577.63s] Alpha agonists, alpha blockers, beta agonists, beta blockers. In my autonomic pharmacology course, go to medicosisperfectionalist.com and download it today. It's on sale. +[577.63s -> 585.66s] And here is today's question. Which of the following is true about norepinephrine? Let me know the answer in the comment section. You'll find the answer in the next video. +[585.66s -> 599.56s] thank you for watching please subscribe hit the bell and click on the join button you can support me here or here go to my website to download my pharmacology courses as always be safe stay happy and study hard this is medicosis perfect snails where medicine makes perfect sense diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_6.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..bce59d533d4fbee62cb3911cfd7ae8957c8c55ca --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_6.mp4.txt @@ -0,0 +1,89 @@ +[11.76s -> 22.38s] This is the second video in this short series on obstructive lung disease, and today I'll be discussing the pathogenesis and pathophysiology of asthma and COPD. +[23.47s -> 34.99s] The primary learning objectives are first to be able to describe the immune system's role in the pathogenesis of asthma and COPD, including a comparison of the mechanisms of inflammation in each. +[35.06s -> 42.86s] And second, to be able to describe the pathophysiology of COPD, including the mechanisms of hypercapnia and hypoxemia. +[43.89s -> 57.97s] I'll start with the immune system's role in the pathogenesis of the two main types of obstructive lung disease, which will lead into the more macroscopic physiologic derangements, which will ultimately help us to understand the symptoms of each. +[58.70s -> 69.89s] Two quick disclaimers with the first part of this video. First, I appreciate that many viewers may know relatively little about the inner workings of the immune system. And second, +[69.89s -> 81.10s] the immunology of obstructive lung disease is extremely complex. As a quick demonstration of the latter issue, if you do a quick google image search for pathogenesis of asthma, +[81.10s -> 94.45s] You'll find hundreds of diagrams outlining the relationship between different cell types like B cells and T cells, with arrows pointing all kinds of different directions, and various chemical mediators called interleukins, +[94.45s -> 107.17s] liberally sprinkled throughout. And the most frustrating aspect of these diagrams aren't their complexity, but rather their variety. No two examples seem to be showing the exact same process. +[107.17s -> 118.74s] Some highlight the role of mast cells and IgE antibodies, while some others highlight the role of the balance between two types of T cells called T helper 1 and T helper 2. +[118.90s -> 130.27s] And each provides a set of the important chemical mediators, yet each list is different. So why is this? Why can't these diagrams all agree with one another? Well, here's the short answer. +[130.27s -> 137.81s] The complete process is just too complex to show in one diagram, and science's understanding of it continues to change. +[139.18s -> 153.70s] What I'll present here regarding the immune system's role in asthma and CUPD will be the extremely simplified version which focuses only on those aspects which are the most critical to the process and which we are most certain reflects reality. +[153.70s -> 160.37s] In other words, this will not be the complete story, but it will be enough of the story for the routine clinical care of patients. +[161.90s -> 174.99s] With classical asthma, known more formally as allergic asthma or extrinsic asthma, the initial immunological trigger for the development of symptoms is exposure to an inhaled allergen, +[174.99s -> 187.63s] for example pollen grains. When the allergen reaches the epithelium of the trachea or bronchi, it might be cleared from the body by mucociliary transport, avoiding an immunologic response completely, +[187.73s -> 195.98s] or it could be taken up by a cell type called dendritic cells which exist throughout the body including the airway epithelium. +[196.34s -> 208.56s] Dendritic cells, which contain numerous sheet-like extensions of the cell membrane, act as so-called antigen presenting cells. This means that they take up an antigen like an allergen, process it, +[208.56s -> 221.84s] and then present it to T lymphocytes. Depending upon the circumstance, this could activate a cell type called CD4 T helper type 1 or CD4 T helper type 2. +[222.16s -> 233.84s] Relative overexpression of type 2 instead of type 1, which is due to a combination of genetic and environmental factors, is a major aspect of allergic asthma. +[234.32s -> 249.04s] Once the dendritic cell has presented the processed allergen to T helper II cells, there are two key consequences. One response is release of a chemical mediator called interleukin-5, usually abbreviated IL-5. +[249.04s -> 257.30s] This increases activity from eosinophils, which then are responsible for release of pro-inflammatory cytokines and leukotrienes. +[257.65s -> 269.78s] The second consequence of T helper II cells is stimulation of a type of B lymphocyte called plasma cells, which is mediated by IL-4, IL-5, and IL-13. +[269.90s -> 283.54s] These plasma cells then release an antibody type called IgE, which then binds to mast cells, causing release of preformed granules containing histamine, leukotrienes, and a compound similar to leukotrienes, +[283.54s -> 286.13s] called prostaglandin D2. +[286.74s -> 299.10s] So, in summary, exposure to an environmental allergen leads to sequential activation of T helper cells, eosinophils, plasma cells, and mast cells with the end result being release of +[299.10s -> 309.46s] proallergic and proinflammatory compounds, histamine, leukotrienes, cytokines, and prostaglandin D2. So then what? +[309.78s -> 319.06s] The immediate acute response to these chemical mediators is a combination of bronchospasm, bronchial wall edema, and increased mucus secretion. +[319.57s -> 332.48s] Chronically, over weeks to years, chronic exposure to the triggering allergens will eventually lead to bronchial hyper-responsiveness, chronic bronchial wall inflammation, and airway smooth muscle hypertrophy +[332.48s -> 337.84s] which could lead to some degree of error obstruction even in between exacerbations. +[338.67s -> 349.97s] What I've listed here as the acute and chronic response should not be confused with the so-called early and late phases of the allergic reaction, both of which would be considered part of an acute response. +[351.12s -> 361.28s] Irrespective of whether it's the acute or chronic response, the primary physiologic consequence is airway obstruction, which then leads to increased mechanical work of breathing, and if severe, +[361.28s -> 367.66s] will lead to hypoventilation and eventually to hyperinflation and life-threatening gas exchange abnormalities. +[368.88s -> 382.99s] There is a slight age dependence to the pathogenesis of asthma. Patients who initially present as children tend to show more allergic type hypersensitivity to typical antigens. As mentioned earlier, this is known as extrinsic asthma +[382.99s -> 385.26s] and is the process I just reviewed. +[385.84s -> 399.02s] In contrast, a minority of patients with asthma initially present as adults. They tend to show more non-allergic type sensitivity to irritant inhalational exposures such as cigarette smoke and air pollution. +[399.06s -> 405.78s] This illness may seem to be initially triggered by acute pneumonia, and it's known as intrinsic asthma. +[408.21s -> 417.74s] Moving on to COPD, the immunological pathogenesis appears to not be as complex as with asthma, but the pathophysiology is quite involved. +[418.19s -> 431.66s] First, the overwhelming majority of COPD is caused by cigarette smoke. Inhaled smoke activates alveolar macrophages with release of IL-8. IL-8 can stimulate CD8 T cells +[431.66s -> 444.30s] to release TNF-alpha among many other chemokines. IL-8 can also locally attract neutrophils, which release proteases, which are enzymes that digest other proteins. +[445.81s -> 451.76s] Next, let me show you the numerous downstream effects that the smoking-induced chronic inflammation has in the lungs. +[452.37s -> 465.55s] First, there is proliferation of a cell type called fibroblasts in the walls of the small airways. These are the cells which are responsible for creating the extracellular matrix and the structural protein collagen. +[465.58s -> 475.44s] When these are produced in excess, it leads to airway fibrosis and scarring. As mentioned, there is increased expression of proteases which destroy the lung parenchyma. +[476.02s -> 488.72s] There is airway mucous cell metaplasia in which mucous glands develop in places where they are not previously present and mucous cell hyperplasia in which previously present mucous glands increase in size. +[488.82s -> 501.74s] These both result in a combination of increased mucus production and mucus viscosity. Defective immune response to infection leads to pathological bacterial colonization of the airways. +[502.00s -> 511.44s] And if present, chronic hypoxemia leads to pulmonary vasoconstriction and vascular remodeling, which results in pulmonary hypertension. +[512.72s -> 525.10s] So finally, what are the end results of these distinct pathological processes? In other words, what are the consequences that we're going to actually see at the bedside or which a patient might actually complain of? +[526.19s -> 539.98s] Airway fibrosis, destruction of lung parenchyma, and increased airway mucus collectively lead to airway obstruction, hyperinflation, hypercapnia which is an elevated carbon dioxide level on the blood, +[540.02s -> 545.97s] hypoxemia, which is a decreased oxygen level, and ultimately chronic dyspnea. +[546.86s -> 561.33s] The increased mucus also leads to a predisposition to develop mucus plugs, which as the term implies occurs when the glob of mucus is so large and thick that it blocks a large airway and the patient has difficulty clearing it with coughing. +[561.46s -> 575.63s] Mucus plugs can be life-threatening when they occur in a patient with severe pre-existing pulmonary disease. The increased mucus and bacterial colonization leads to a chronic cough and the patients are also predisposed to pneumonia. +[576.46s -> 590.59s] Finally, pulmonary hypertension will lead to signs and symptoms of right heart failure, a condition occasionally known as core pulmonale. These signs and symptoms may include lower extremity swelling, ascites, elevated jugular venous pressure, +[590.59s -> 599.79s] and when particularly severe, liver dysfunction. Collectively, these consequences comprise the primary features of COPD. +[603.18s -> 612.56s] It's important to note here that there are some patients who develop COPD who do not smoke, in whom the pattern of pathophysiology may be slightly different. +[612.88s -> 618.35s] For example, patients with a genetic disease alpha-1 antitrypsin deficiency. +[618.77s -> 631.20s] Alpha-1 antitrypsin is an inhibitor of the proteases released by neutrophils, particularly one called neutrophil elastase. When the patient has a deficiency of this inhibition as a consequence of a defective gene, +[631.20s -> 640.83s] the result may be destruction of lung parenchyma as the predominant or even sole pathologic change in the lungs. Depending upon the specific genotype a patient has, +[640.83s -> 649.20s] The subsequent emphysematous changes in the lungs may occur spontaneously in young adulthood, or may only occur if the patient begins smoking. +[650.13s -> 663.02s] There are still yet other patients who develop COPD despite no smoking history and no problems with the alpha-1 antitrypsin gene. The pathogenesis of the disease in these individuals is not as well understood. +[665.01s -> 676.11s] Occasionally, clinicians and some textbooks may refer to a dichotomy of COPD manifestations in which patients are said to be either a quote blue bloater or a quote pink puffer. +[676.18s -> 690.77s] Historically, blue bloaters were those patients with predominantly chronic bronchitis, in whom the primary pathology was airway inflammation, which resulted in moderate to severe hypoxemia from hypoventilation, which would then lead to right sided heart failure. +[690.86s -> 702.22s] They were blue because of cyanosis from the hypoxemia and bloated from the volume overload from the heart failure. This was a clinical diagnosis made upon examination of the patient. +[703.34s -> 717.63s] The pink puffers were those with predominantly emphysema. Their hypoxemia tends to be more mild, yet their work of breathing subjectively appears greater than in the blue bloater. These patients may suffer from COPD-related weight loss, +[717.63s -> 723.22s] which is referred to as pulmonary cachexia, the exact mechanism of which remains elusive. +[723.54s -> 733.01s] Unlike blue bloaters, diagnosis of a pink puffer requires something more than the exam. It requires radiographic or even pathologic evidence of emphysema. +[734.38s -> 748.69s] Although these two categories are still discussed in medical school lectures and in board review books, they are not clinically useful, since the vast majority of patients fall somewhere in the spectrum in between and have features of both extremes. +[751.12s -> 761.65s] When listing the primary features of COPD a few minutes ago, I mentioned hypercapnia and hypoxemia. I'm going to spend a minute a piece reviewing the mechanism of each in more detail. +[762.16s -> 776.40s] So first, hypercapnia. Hypercapnia is partly the consequence of airway inflammation, which leads to increased airway mucus and bronchial wall thickening. It is also partly the consequence of the destruction of lung parenchyma, +[776.40s -> 782.90s] which leads to decreased outward airway traction. Together those three factors result in airway obstruction. +[783.31s -> 797.54s] Obstructed airways lead to air trapping, whereby not all of the air inhaled can be exhaled, which will result in hyperinflation. Hyperinflation has two consequences. One is the development of positive end-expiratory pressure +[797.54s -> 810.13s] and the other is flattening of the diaphragm. These lead to decreased tidal volume, abbreviated V sub T, which leads to a decrease in alveolar ventilation, abbreviated V dot sub A. +[810.16s -> 820.05s] Also contributing to the decreased alveolar ventilation is the decreased effective surface area of the alveolar capillary membrane caused by the parenchymal destruction. +[820.75s -> 834.50s] From the alveolar ventilation equation, we know that the partial pressure of CO2 in the arteries is inversely proportional to alveolar ventilation. In other words, the less alveolar gas is exchanged with the outside environment per unit time, +[834.50s -> 846.10s] the higher the arterial partial pressure of CO2 will be. Although initially high CO2 levels felt by the central respiratory centers in the brain stem trigger an increase in ventilation, +[846.10s -> 860.69s] If this cannot be accomplished due to the aforementioned physical limitations, eventually the brain becomes less sensitive to changes in arterial CO2. This helps to sustain the hypercapnia in chronically hypoventilating patients. +[862.13s -> 871.25s] Now what about the hypoxemia? Of the four main mechanisms of hypoxemia in the human body, COPD commonly triggers three of them. +[871.66s -> 886.32s] First, from the alveolar gas equation, we know that high PaCO2 from hypoventilation will necessarily lead to decreased alveolar oxygen levels, which will necessarily lead to decreased arterial oxygen levels. +[886.99s -> 900.08s] Next, in normal healthy lungs, as a general rule, the best ventilated parts also tend to get the most blood flow, a balance called ventilation-perfusion matching, often abbreviated VQ matching. +[900.21s -> 904.21s] The matching is not perfect, but still reasonably good. +[904.53s -> 916.30s] However, in COPD the combination of hypoventilation which is not uniformly distributed across all lung segments combined with parenchymal destruction which is also not uniformly distributed +[916.40s -> 926.99s] ventilation and perfusion becomes mismatched thus some pulmonary blood flow gets wasted so to speak by travelling to parts of the lung where gas exchange is occurring less effectively +[928.37s -> 940.77s] The final mechanism is related to the previous one in that it's caused by the decreased surface area of the alveolar capillary membrane, resulting in impairment of oxygen diffusion. For those interested, +[940.77s -> 953.94s] Rate of diffusion is defined by Fick's law, where rate of gas diffusion is directly proportional to the surface area of the diffusing membrane. If one-third of the lung volume has been replaced with giant bullae from parenchymal destruction, +[953.94s -> 961.33s] the effective surface area available for diffusion will have become significantly decreased, thus contributing to hypoxemia. +[962.10s -> 974.58s] For completeness' sake, the fourth mechanism of hypoxemia, which COPD does not directly involve, is right-to-left shunting of blood, for example in congenital heart disease or in a pulmonary AVM. +[976.72s -> 981.81s] I'll end with a chart that compares the inflammation seen in asthma with that seen in COPD. +[982.10s -> 995.92s] In asthma, the primary cell types involved in generating and sustaining the inflammation are CD4 T cells, specifically type II helper T cells, eosinophils, plasma cells, and mast cells. +[996.88s -> 1009.71s] In COPD, the inflammation predominantly involves macrophages, neutrophils, and CD8 T cells. The key chemical mediators in asthma are IL-4, IL-5, and IL-13. +[1009.71s -> 1024.66s] while in COPD they are IL-8 and TNF-alpha. And finally, the predominant site of inflammation in asthma is the proximal airways, and in COPD it's the distal airways and long parenchyma. +[1027.60s -> 1039.54s] That concludes this video on the pathogenesis and pathophysiology of asthma and COPD. The next video in this series will discuss the diagnosis and management of stable disease. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_9.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..89f09cdf3ec12ff5d6504b64bd7e9865fe307de7 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Basic_Medical_Science_9.mp4.txt @@ -0,0 +1,66 @@ +[10.42s -> 20.91s] This is a neuron which has four main parts. The dendrites receive information. The cell body processes and integrates that information. +[20.91s -> 31.57s] The axon carries the information along long distances from one part of the neuron to another, and the axon terminal transmits the information to the next cell in the chain. +[32.02s -> 42.45s] A bundle of axons traveling together is called a nerve. Nerves can be very long as they often need to transmit information over long distances. +[43.60s -> 58.16s] As we just saw, the dendrites are the part of the neuron that receives incoming signals. Based on the strength of this incoming stimulation, the neuron must decide whether to pass that signal along or not. +[58.22s -> 71.82s] If the stimulation is strong enough, the signal is transmitted along the entire length of the axon in a phenomenon called an action potential. When this happens, we say the neuron fires. +[73.84s -> 87.42s] Transmission of a neuronal signal is entirely dependent on the movement of ions or charged particles. Various ions including sodium, potassium, and chloride +[87.42s -> 100.85s] are unequally distributed between the inside and the outside of the cell. The presence and movement of these ions is not only important when a neuron fires but also at rest. +[100.91s -> 107.28s] To start, let's think about the positively charged sodium and potassium ions. +[109.26s -> 123.82s] When a neuron is not sending a signal, it is considered to be at rest. In a typical neuron in its resting state, the concentration of sodium ions is higher outside the cell than inside. +[124.02s -> 132.56s] The relative concentration of potassium ions is the opposite, with more ions inside the cell than outside. +[132.72s -> 140.75s] This ionic separation occurs right at the cell membrane and creates a chemical gradient across the membrane. +[143.12s -> 151.98s] Because ions are charged particles we also need to consider their charge when thinking about their distribution across the membrane. +[152.69s -> 159.92s] At rest, there are more positively charged ions outside the cell relative to the inside. +[160.37s -> 171.34s] This creates a difference in charge across the membrane which is called an electrical gradient. Together with the chemical gradient we already mentioned, +[171.34s -> 184.42s] We refer to this ionic imbalance as the electrochemical gradient. The difference in total charge inside and outside of the cell is called the membrane potential. At rest +[184.42s -> 198.30s] When no signals are being transmitted, a neuronal membrane has a resting potential of approximately minus 70 millivolts. This means that the inside of the cell is approximately 70 millivolts +[198.30s -> 208.82s] less positive than the outside. Both the chemical and electrical gradients we just discussed contribute to establishing this potential. +[208.85s -> 223.82s] While the inside of the cell has a net negative charge and the outside of the cell has a net positive charge, the charges line up at the membrane and the bulk solution on either side is actually electrically neutral. +[224.56s -> 238.86s] The resting membrane potential is the point where the cell has achieved electrochemical equilibrium. This means that the concentration gradient and the electrogradient for each ion is equal and opposite. +[239.98s -> 254.26s] Ions cannot simply move across the membrane at will. Instead, they need a protein embedded in the membrane to facilitate their movement. Most ions cross the membrane through a structure called an ion channel. +[254.38s -> 259.86s] Ions move through channels by passive diffusion along their concentration gradient. +[261.62s -> 275.52s] Some ion channels are always open, but many require a signal to tell them to open or close. For example, voltage-gated channels only open when the membrane potential reaches a certain value. +[275.52s -> 283.68s] On the other hand, ligand-gated ion channels are triggered to open when they are bound by a specific molecule. +[283.68s -> 292.14s] Mechanically gated ion channels open in response to physical forces such as changes in length or changes in pressure. +[292.82s -> 302.64s] Most ion channels are selectively permeable, meaning that they only allow one or a small subset of ions to pass through. +[302.99s -> 316.51s] Voltage-gated ion channels, for example, typically only allow a single ion to cross the membrane when they open. This means that we need separate channels for each ion, i.e. +[316.51s -> 321.78s] voltage-gated sodium channels as well as voltage-gated potassium channels. +[323.95s -> 334.99s] As ions move through a channel and cross from one side of the cell membrane to the other, they cause the membrane potential of the cell to move away from its resting potential. +[335.18s -> 348.70s] If the resulting change in membrane potential is small, we call this a graded potential. Graded potentials can vary in size, can be either positive or negative. Our transient +[348.70s -> 353.71s] and typically do not result from the opening of voltage-gated ion channels. +[354.03s -> 367.60s] When ion channels open and a graded potential occurs, the neuron moves quickly to reset its membrane potential to resting values. This is accomplished primarily by the use of the sodium potassium pump. +[367.60s -> 379.46s] which uses the energy generated by ATP hydrolysis to actively transport ions across the membrane against their concentration gradient. In other words, +[379.46s -> 391.09s] Sodium is transported to the outside of the cell where its concentration is higher, and potassium is transported back into the cell where its concentration is higher. +[391.09s -> 400.53s] One cycle of this pump transports three sodium ions outside the cell and brings two potassium ions inside the cell. +[400.85s -> 411.46s] This unbalanced charge transfer contributes to the separation of charge across the membrane and also to the ionic concentrations we see at rest. +[411.46s -> 423.02s] thus restoring the chemical and electrical gradients to their resting levels. Maintaining these ionic balance in neurons is so important that this process can account for 20 +[423.02s -> 437.74s] to 40% of the brain's total energy use. Only when the resting membrane potential and ion distributions are maintained at precise levels will the neuron be poised and ready to fire an action potential. +[441.10s -> 454.48s] When the outside stimulation is large enough to bring the membrane potential in the neuron body up from minus 70 millivolts to the threshold voltage of minus 55 millivolts or higher, +[454.48s -> 460.72s] This triggers an action potential at the axon hillock, which then travels down the axon. +[462.54s -> 473.58s] Voltage-gated sodium channels have three states, open, closed, and inactivated. At rest, the sodium channel is closed. +[474.19s -> 485.90s] Once the cell membrane reaches the threshold voltage, the channel changes to an open position and sodium rushes into the cell because of the electrochemical gradient. +[486.13s -> 499.82s] As positive sodium ions enter the cell, the membrane potential becomes less negative and more positive as it approaches 0 millivolts. This is called depolarization. +[500.02s -> 513.34s] Eventually the voltage gradient goes to zero and beyond zero up to a positive 30 millivolts. This is called an overshoot. As the membrane potential becomes positive +[513.34s -> 524.14s] the sodium channel inactivation gate shuts, making the channel inactivated. This stops the flow of sodium ions into the cell. +[525.62s -> 534.29s] The change in membrane potential also opens the voltage gated potassium channels, though they open and close more slowly. +[536.24s -> 550.10s] Because of the potassium electrochemical gradient, potassium ions flow out of the cell, making it less positive and eventually negative. This process is called repolarization. +[552.75s -> 564.24s] Because the potassium channels are a little slow to close, for a brief period the membrane potential is hyperpolarized. It's more negative than the resting potential. +[564.94s -> 569.42s] During hyperpolarization, the potassium channels close. +[569.74s -> 581.17s] Throughout all this, the sodium potassium pump is still working. The pump restores the chemical gradients by putting the sodium and potassium back in place. +[581.36s -> 596.02s] and the pump re-establishes the potential gradient by moving more sodium ions out than potassium ions in. This returns the membrane potential back to its resting potential. +[596.59s -> 603.79s] During repolarization, the inactivated sodium channels won't respond to any stimulus at all. +[604.21s -> 616.72s] During this time, the neuron is in its absolute refractory period, the period of time when a nerve cannot fire another action potential, no matter how strongly it's stimulated. +[617.52s -> 629.68s] The absolute refractory period prevents action potentials from happening again too quickly and prevents the action potential from traveling backwards along the axon. +[630.42s -> 642.61s] During hyperpolarization, the sodium channels are closed and the inactivation gate opens. There is no change in sodium flow, but now they could be opened again. +[642.77s -> 656.70s] This is called the relative refractory period, because while the sodium channels could open, it would take a larger than usual stimulus to reach threshold, because the cell is hyperpolarized +[656.70s -> 659.57s] due to the potassium still leaving the cell. +[660.50s -> 674.06s] The amplitude of the action potential for a particular neuron, that is, the maximum voltage in one neuron during an action potential, never changes. An action potential doesn't get +[674.06s -> 680.53s] bigger with a bigger stimulus, it's all or nothing. It either happens or it doesn't happen. +[681.33s -> 694.51s] What can change is the frequency of the action potential. A neuron might fire many more times per second in response to, say, an intense pain and less frequently +[694.51s -> 697.07s] in response to a gentle breeze. +[700.72s -> 713.52s] Some axons transmit action potentials faster than others. One variable that increases conduction velocity is the presence of myelin sheets around axons. +[713.78s -> 728.22s] myelin speeds up transmission through a process called saltatory conduction, in which the action potential signal appears to jump along the part of the axon covered by the sheath. In the peripheral nervous system, +[728.22s -> 737.97s] The sheaths are formed from glial cells known as Schwann cells. There are small gaps between Schwann cells called the nodes of Ranbir. +[738.48s -> 751.54s] The action potential appears to jump from node to node, speeding the transmission. In the central nervous system, the sheaths are made by cells known as oligodendrocytes. +[751.89s -> 761.90s] To review, with no stimulus, the membrane is at its resting potential. A small stimulus causes a graded potential. +[762.80s -> 769.46s] and a stimulus above the threshold creates an action potential and the neuron fires. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_1.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..832689ed2826438f3fccdde4901345615c372d2b --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_1.mp4.txt @@ -0,0 +1,59 @@ +[0.00s -> 9.10s] It's the last video in hematology at least for now because I still have bonus videos and let's talk about coagulation disorders later. +[9.10s -> 16.30s] Next Saturday, by the way, we're going to start a new series, which is about fluids and electrolytes, acid-base disturbance. +[16.30s -> 30.62s] So today let's talk about ESR, a garbage test. Just get your blood in a test tube and wait for like an hour. The red blood cells are gonna sediment. You get your ruler that you used to use in fifth grade and measure this distance and boom. +[30.62s -> 42.94s] Boom, you have your ESR. Useless. Words of wisdom. ESR is one of the most worthless tests there is, and yet one of the most commonly ordered. And it means absolutely nothing. +[42.94s -> 49.20s] i love it is this how we're gonna start a video about esr yes indeed because it's garbage mostly +[62.29s -> 74.29s] As you know, your blood is made of plasma and cells. Cells mostly are red blood cells. We're talking millions. That's why the normal hematocrit is 45%. Let's talk about plasma. +[74.29s -> 88.32s] 55 of blood water and proteins mostly water by the way how much water five percent of your total body weight so if you're an average adult male and your weight is 60 kilograms +[88.32s -> 102.48s] times five percent equals three liters of plasma 55 45 cells about two liters that's why your normal blood volume is about five liters on average +[102.48s -> 105.89s] water has electrolytes and proteins are albumin +[105.89s -> 120.21s] globulin albumin small but numerous and it's responsible for the oncotic pressure because in osmosis we care about the number of particles not the mass or the size we care about numbers albumin is most numerous +[120.21s -> 134.66s] It exerts the most osmosis. Globulin is large but less numerous. And we have types of globulin. We have alpha globulin, beta globulin, gamma globulin, which are your immunoglobulins. And the beta globulins are your clotting factors. +[134.66s -> 146.38s] what happens when you leave blood in this tube it sediments it's called gravity okay this is the oxygenated blood because we get it from the vein and this tube is called wisterdern tube +[146.51s -> 158.26s] And we add an anticoagulant because what's the use? And when you leave it, it's gonna do it like this. 55% of plasma on the top. It's light. It's watery. +[158.26s -> 169.62s] then the red blood cells are going to sediment they are heavy increased density so they are in the bottom between the plasma and red blood cell is the buffy coat layer very very very thin +[169.62s -> 184.19s] and contains white blood cells and platelets. Your red blood cells are in millions. These are thousands. They are teeny, teeny, tiny if compared to the red blood cells. Look at this wonderful definition. Erythrocyte sedimentation rate, the rate at which erythrocytes sediment. Genius. +[184.19s -> 197.33s] as you know in physics any rate is change in something over change in time the denominator has to be time so we know velocity change in distance over change in time esr change in distance over change in time +[197.33s -> 208.93s] reported in millimeters per hour so leave this test tube for one hour and let's say that your normal esr was 15 millimeters per hour +[208.93s -> 223.17s] which means after one hour we measured this distance or length and it was 15 millimeters today it's performed via automated analyzer do you think like the pathologist has time to measure this distance with his like ruler no +[223.17s -> 237.15s] he's in his ferrari the lab technician is doing all the work as time passes sedimentation increases but esr stays the same because it's a rate you idiot so +[237.15s -> 251.92s] here is at zero time 15 minutes it's gonna be like this 30 minutes it's gonna be like this one hour it's gonna be like this esr stays the same yes indeed you wanna prove okay let's let's measure this so let's say that this distance is 10 millimeters +[251.92s -> 256.14s] and in half an hour which equals +[256.78s -> 270.10s] 20 over 1 which equals 20 so the esr is 20 millimeters per hour after one hour this distance was 20 over one hour so the normal esr is 20. +[270.10s -> 278.24s] millimeters per hour see it's the same sedimentation increases but ESR stays the same it's a rate +[278.24s -> 290.24s] And here's a quick joke for you. What do they call a test tube that has finished its higher education? Answer, a graduated cylinder. Ha ha ha. +[290.24s -> 303.84s] Steps of sedimentation. First, rollo formation. Red blood cells are stacked on top of each other. Then settling, then packing to the bottom of the test tube. It's like the average American adult. First, they lift together. +[303.84s -> 317.90s] Then they settle down and marry. Then after they become empty nesters, they pack their stuff and move to a smaller house called downsizing. What are the normal ESR values if you are a man under 50 years old? +[317.90s -> 331.66s] the normal is 15 or less if you're a woman less than 50 years old it's 20 or less men more than 50 it's 20 or less so the esr increases as you get older generally speaking +[331.66s -> 342.21s] Women over 50, 30 or less. Factors affecting sedimentation. We have pro-sedimentation factors that are increasing the sedimentation and increasing the ESR. +[342.21s -> 354.51s] or anti-sedimentation factors decreasing sedimentation and decreasing esr the pro factors are fibrinogen and immunoglobulins basically basically they are plasma proteins +[354.51s -> 368.58s] Anything that increases rollo formation, which was the first stage in sedimentation, will raise the ESR. Anti-sedimentation factors, such as negative charges on top or on the surface of red blood cells. +[368.58s -> 380.32s] As you know, opposites attract, similars repel. Physics, baby. So when the red blood cells repel each other, it takes longer for them to sediment to the bottom of the test tube. +[380.32s -> 394.13s] your professor might have told you about the negative charges as an anti-sedimentation factor but why do we have negative charges on the surface of red blood cell because the red blood cell is a cell and it has a cell membrane a cell membrane is a lipid bilayer +[394.13s -> 404.14s] which is made of phospholipid and cholesterol. The phospholipid is phosphate and lipid. The phosphate are like this. They have negative charges. +[404.14s -> 418.00s] Also, the main source of negative charges are the carbohydrates or the glycocalyx of the cell membrane on top of the membrane. That's why the red blood cell membrane is negatively charged. So, as Rho low formation occurs, +[418.00s -> 429.07s] occurs weight or density increases so sedimentation is faster which raises the ASR let's talk about IgM which is the biggest immunoglobulin +[429.07s -> 443.34s] It's big and it can overcome the negative charge on the surface of the red blood cell. So red blood cells are going to sediment faster, leading to increased erythrocyte sedimentation rate. So in cases of cold agglutinin disease, which I've talked about in a previous video, +[443.34s -> 455.49s] we had IgM in cold weather, your IgM gets active. Cold agglutinants, red blood cells stick together, clogging vessels. If it happens in your nose and fingertips, you get Raynaud's phenomenon. +[455.49s -> 466.86s] This is tissue ischemia. What's the treatment? Warm the patient. When you warm the patient, IgM is not active. Two red blood cells are not going to stick together. You're not getting Raynaud's phenomenon. Wonderful. +[466.86s -> 477.79s] So what are the conditions that increase the ESR and what are the conditions that decrease the ESR? Increase ESR, you have inflammation, infection, why? Increase fibrinogen and IgG. +[477.79s -> 491.70s] Same reason. So inflammation includes lupus, rheumatoid arthritis infection includes something like TB. How about anemia? Yes, because anemia you have less red blood cells, so you have less negative charges. +[491.70s -> 504.62s] On the surface of the red blood cells, you will have less repulsion force. How about macrocytosis? The cells are larger. They're going to hug themselves faster. +[504.62s -> 515.90s] and they're gonna settle sooner, increasing the ASR. How about multiple myeloma? Yes, because multiple myeloma, you have increased ROLO formation because of the para-protein IgG. +[515.90s -> 530.10s] Waldenstrom macroglobulinemia because it has the largest immunoglobulin, IgM, that can overcome the negative charges. Pregnancy, why? Because pregnant women have dilutional anemia. Same thing, you have relatively less negative charges. +[530.10s -> 544.08s] so you have less repulsion forces these red blood cells are gonna sediment sooner how about conditions that decrease the esr hyperviscosity syndrome especially if the hyperviscosity is caused by increased number of red blood cells +[544.08s -> 553.42s] more red blood cells more negative charges more repulsion force which lead to them settle slowly +[553.42s -> 560.40s] Polycythemia, same reason. You have lots of red blood cells, lots of negative chores. Sickle cells. Sickle cells cannot form Rolo. +[560.40s -> 571.26s] microcytosis they are small it takes a lot of time for them to get close to each other and hug each other and settle spherocytosis again less rollo formation +[571.26s -> 583.87s] so i've spent the entire video trashing the esr as a useless test but there is one instance where esr is very important it's gonna save the patient's vision or eyesight it's gonna save your day it's gonna save you a lawsuit +[583.87s -> 596.88s] and it's gonna save you legal fees so this is called giant salad rice typically an old old lady comes in complaining of problems with her jaw okay it's very stiff it hurts like mad +[596.88s -> 610.59s] and it's very tender over her temporal area, like temporal bone, when you hear these symptoms, quickly order an ESR. If ESR comes back normal, you have ruled out giant cell arthritis. Why? +[610.59s -> 623.86s] increased sensitivity of the test it can rules out which means increased negative predictive value when the test is negative which means that patient strongly does not have the disease +[623.86s -> 637.87s] If ESR is very high in case of giant cell arthritis, just with suspicion, go ahead and give steroids fast, fast to save the patient's vision. Okay, in sickle cell disease, if the patient is asymptomatic, +[637.87s -> 651.81s] ESR is low. Why? There is no ROLO formation. But in painful crises, you have inflammation, so you have lots of fibrinogenon IgG. ESR is going to be high. In sickle cell trait, however, this is a good question. +[651.81s -> 662.43s] There are no sickle cells. Those ESR should be normal. Most of the time. ESR and CRP love each other, both elevated in cases of inflammation. +[662.43s -> 676.53s] is our starts to rise 24 to 48 hours after the onset inflammation wait okay good things happen to those who wait is our elevation is one of the minor criteria for diagnosis of rheumatic fever called the jones criteria +[676.53s -> 687.78s] so in this video we have talked about physics physiology pathology hematology immunology clinical medicine epidemiology jack of all trades is a master of none medicosis has proven this to be wrong +[687.78s -> 701.04s] Jack of all trades is a master of some. Maybe Metacosis is the exception. Question of the day. Why is Isar normally higher in females? If you understand this video and can answer this question correctly, then I've done my job properly. +[701.04s -> 715.12s] If you can't answer this question, there is no hope for me or for you. Don't forget to subscribe. You can get all of my notes that I'm drawing in these videos on Patreon. Go to patreon.com forward slash metacosis. You can view, download, and print. Enjoy my videos. +[715.12s -> 721.33s] Thank you so much. Until next time, be safe, stay happy, and study hard. We're done with hematology. Yay! diff --git a/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_11.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..254c96d520638b27f346bfdb4681ad14a5161e34 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_11.mp4.txt @@ -0,0 +1,9 @@ +[0.00s -> 13.66s] The tongue is an important organ in the mouth, as it provides many important functions for your body. The tongue is comprised of skeletal muscle covered by a mucous membrane that helps to keep the tongue moist. The tongue has a root, a tip, +[13.66s -> 27.94s] and a central body to its structure. The upper surface of the tongue is covered by small rough elevations called papillae. There are four types of papillae, fungiform, circumvallate, foliate, and filiform. +[27.94s -> 41.63s] Fungiform papillae are mushroom-shaped bumps that are found near the tip and sides of the tongue. Each of these contains only a few taste buds. Circumvalate papillae are large and dome-shaped, and they are the least-numbered papillae +[41.63s -> 54.64s] usually between 10 and 12 on a tongue, and together they form a v-shape. Each of these is housed by a deep narrow depression and they contain thousands of taste buds. Foliate papillae have a leaf-like shape +[54.64s -> 68.58s] and are found on the sides of the tongue toward the root of the tongue. They house about a hundred or so taste buds. Filiform papillae are short and spiked and they are scattered among the fungiform papillae. These papillae do not house taste buds +[68.58s -> 82.59s] as they help us detect food texture. Taste buds are located in the walls and grooves of papillae and most adults have between 2,000 and 4,000 buds in total. Taste buds consist mainly of a taste pore, sensory cells, +[82.59s -> 95.04s] taste hairs, and nerve fibers. On the bottom or under surface of the tongue is the lingual frenulum, which helps anchor the tongue to the floor of the mouth. The tongue has many important functions in the body. +[95.04s -> 108.18s] such as crushing food against the roof of the mouth and softening and manipulating food prior to swallowing. The tongue allows us to sense the taste of food and the texture of food. Our ability to move the tongue helps with speech. +[108.18s -> 118.29s] And it also plays an important role in physical intimacy. And that be the structure and the functions of the tongue. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_25.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_25.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..be549fd67590277b32d64ef49feee81aa164889e --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_25.mp4.txt @@ -0,0 +1,55 @@ +[3.50s -> 15.41s] Hello, in this video we're going to talk about thyroid nodules. A thyroid nodule is technically a goiter, which means an enlarged thyroid gland. A thyroid nodule can be defined as a nodule goiter. +[15.41s -> 24.75s] Thyroid nodule is usually identified by the patient on routine examination or incidentally on imaging such as a CT neck or CT chest. +[24.75s -> 37.57s] When someone notices a lump on their neck or thyroid, I guess one of the most concerning things is could this be cancer? Majority of thyroid nodules are benign. Thyroid cancer make up about 5% of the cases. +[37.57s -> 52.53s] And there are factors that increases the suspicion of cancer, such as if the thyroid nodule is in children, young adults, a person with a history of radiation to the neck or head, and also someone who has a family history of thyroid cancer. +[54.19s -> 68.05s] A thyroid nodule is actually very common. 50% of the population have it, but only 10% can actually be felt. Like all thyroid diseases, it is more common in women, and the incidence increases with age. +[68.27s -> 82.61s] Majority of thyroid nodules as we discussed are benign, 95% of cases. Some common examples of benign thyroid nodules are thyroid adenoma, which can be a basic benign follicular adenoma. +[82.61s -> 95.87s] the most common cause of a solitary thyroid nodule. Of course, this adenoma can undergo mutation in its thyroid stimulating hormone receptor, and can progress to become a toxic adenoma, which is also benign. +[95.87s -> 107.25s] A toxic adenoma is where the adenoma becomes hyperfunctioning and produces a lot of T3 and T4 irrespective of thyroid stimulating hormone. +[108.18s -> 117.87s] Another cause of a thyroid nodule is toxic multinodular goiter. As the name suggests, toxic, here again the thyroid nodules have autonomous +[117.87s -> 125.14s] production of T3 and T4. It's producing a lot of T3 and T4 irrespective of thyroid stimulating hormone. +[125.58s -> 138.54s] A thyroid cyst is another cause of thyroid nodule, and essentially is a fluid sac. Another cause of thyroid nodule is Hashimoto's thyroiditis, which is an autoimmune disease characterized by antibodies against +[138.54s -> 148.66s] thyroid peroxidase and the thyroid gland, resulting in thyroid damage. This inflammation and damage to the thyroid causes the nodules to form. +[149.36s -> 160.02s] 5% of thyroid nodules are cancerous and there are many types of thyroid cancer, which we will not talk about, but the most common thyroid cancer is papillary thyroid cancer. +[160.56s -> 173.26s] There are features of the thyroid nodule which may sway one to think that it is cancerous and this includes being a non-functional thyroid nodule, meaning the thyroid nodule doesn't produce any thyroid hormones. +[173.71s -> 183.86s] Another feature of the thyroid nodule can be that if it's an irregularly shaped thyroid nodule, this also may suggest cancer. +[184.08s -> 197.52s] There are a number of investigations that can be ordered for people with thyroid nodules. These include thyroid stimulating hormone levels in the blood, thyroid ultrasound, a radionucleotide scan, also known as a thyroid scan or +[197.52s -> 210.38s] thyroid scintigraphy, there's so many names for it, a blood test looking at free T3 and T4, and for a definitive diagnosis, a fine needle aspiration of the thyroid nodule with an ultrasound. +[210.42s -> 223.60s] Because thyroid nodules are so common, not everyone gets a fine needle aspiration, and there are only specific indications for it. In the next part of this video, we will follow an approach to someone +[223.60s -> 230.10s] who presents with a thorough nodule. This approach can also be used with someone who has a diffuse goiter as well. +[230.61s -> 243.01s] So we begin with the identification of the thyroid nodule through history and of course examination. Looking at the brain, the hypothalamus produces thyrotropin-releasing hormone, TRH. +[243.01s -> 255.79s] which targets the anterior pituitary gland to release thyroid stimulating hormone, TSH. This thyroid stimulating hormone will then of course target the thyroid gland to produce T3 and T4. +[256.37s -> 268.50s] The first thing to order with anyone with a thyroid nodule or a thyroid pathology is thyroid stimulating hormone levels and a plus minus ultrasound of the thyroid gland. +[269.81s -> 276.75s] If the thyroid stimulating hormone level is high or normal, an ultrasound should be ordered. +[277.20s -> 289.38s] High thyroid stimulating hormones should raise suspicion of hypothyroidism. The ultrasound helps assess the anatomy of the thyroid gland and the nodule and its adjacent structures. +[289.38s -> 302.58s] It provides more anatomical detail than the thyroid nucleotide scan. The thyroid ultrasound can help identify any suspicious features of cancer. Suspicious ultrasound findings include +[302.58s -> 310.51s] a nodule greater than one centimeter solid and hypoechoic a nodule that is large or rapidly growing +[310.99s -> 320.53s] a nodule with microcalcification, a nodule with central vascularity, a nodule that is taller than it is wider. +[320.91s -> 335.38s] After the ultrasound is done, the next question to ask is, does this thyroid nodule meet the criteria for a fine needle aspiration? The criteria for a fine needle aspiration includes those suspicious findings we just talked about on ultrasound. +[335.38s -> 341.90s] So if yes, there is suspicious findings on ultrasound, then a fine needle aspiration should be performed. +[342.45s -> 355.60s] If there is no suspicious findings and the thyroid nodule does not meet the fine needle aspiration criteria, then we just monitor the nodule and may repeat a thyroid ultrasound in a few months time. +[357.33s -> 371.34s] Focusing now on fine needle aspiration, it is essentially where you use a needle and aspirate the content of the thyroid nodule with the help of the ultrasound. The aspiration is sent to the laboratory for cytology +[371.34s -> 381.74s] to see the cells in more detail. The fine needle aspiration results are then classified into what's called the Bethesda classes of which there are six. +[384.30s -> 394.90s] Class 1 is a non-diagnostic result, which means that probably insufficient samples were taken. In this scenario, it is advised to repeat the fine needle aspiration. +[395.25s -> 407.54s] Class II is benign adenoma. Class III is atypia of undetermined significance or follicular of undetermined significance. In this scenario, it is important to monitor the nodule. +[407.92s -> 419.98s] For classes 4, 5, and 6 which are follicular neoplasia, suspicious for malignancy, and malignancy, a thyroidectomy is advised. +[419.98s -> 428.37s] A thyroidectomy can be partial or complete which basically means removal of part or all of the thyroid gland. +[429.71s -> 441.97s] Now to recap, we came down the pathway where there was initially normal or high TSH levels. Important that people with high +[441.97s -> 452.14s] TSH, high thyroid stimulating hormones, these guys should also be screened for causes of hypothyroidism such as Hashimoto's disease if indicated. +[453.17s -> 467.70s] Now let us follow the algorithm when there is low TSH. Low TSH, which is low thyroid stimulating hormone levels, should ring alarm bells for hyperthyroidism. Because remember, +[467.70s -> 479.07s] high T3 and high T4 will have a negative feedback to reduce TSH release. When someone has low TSH, the next investigation should be a thyroid scintigraphy. +[479.07s -> 489.49s] A thyroid scintigraphy is also known again as a thyroid radionucleotide scan and also known as a thyroid scan. Iodine is an important component of thyroid hormones. +[489.49s -> 502.19s] A thyroid scintigraphy is where a chemical tagged molecule such as iodine is given. Iodine is taken up by the thyroid gland normally. If the thyroid nodule does not take up any iodine, it is non-functional. +[502.19s -> 515.12s] and means it does not synthesize or produce any thyroid hormones. The other side is an autonomous nodule where the nodule is taking up iodine to produce thyroid hormones. When a nodule +[515.12s -> 527.26s] has uptake of iodine on the thyroid scan. It is called a hot nodule and it is rarely cancerous. A cold non-functioning nodule on the other hand raises suspicion of +[527.26s -> 533.58s] thyroid cancer and should have an ultrasound with consideration of a final aspiration for a definitive diagnosis. +[535.25s -> 547.02s] A hot autonomous nodule can either be taking up way too much iodine than the rest of the thyroid gland, or it is taking up iodine at the same concentration or level as the rest of the thyroid gland. +[547.18s -> 552.37s] To be exactly sure, it is advised that free T3 and T4 be measured. +[552.94s -> 562.77s] A normal T3 and T4 with low TSH is a clinical diagnosis of subclinical hyperthyroidism. +[563.06s -> 572.50s] subclinical hyperthyroidism will require monitoring because subclinical hyperthyroidism can evolve and become hyperthyroidism. +[573.10s -> 585.42s] A high T3 and T4 with low TSH means hyperthyroidism. The nodule is responsible for producing excess T3 and T4. +[585.94s -> 594.42s] And because this is a nodule, and it's taking up a lot of iodine on the scan, it is likely to be a toxic adenoma. +[598.80s -> 609.33s] Toxic adenoma is either managed by surgery, a thyroidectomy, or by radioactive iodine. In this treatment, radioactive iodine is given +[609.33s -> 622.86s] which will be mostly taken up by the hyperactive autonomous nodule. The radioactive iodine will break down, emitting radioactive waves, destroying the tissue. +[622.86s -> 627.54s] thus hopefully shrinking the thyroid nodule or making it less functional. +[628.34s -> 638.83s] So we just looked at an approach to a thyroid nodule, and this same approach can be used for someone with a diffuse goiter. I hope this video was helpful. Thank you for watching. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_3.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..512c26fe258955d53f22536c9689ff65e1c8b504 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Clinical_Medicine_3.mp4.txt @@ -0,0 +1,95 @@ +[12.18s -> 25.74s] Hello everyone. I'll be talking to you today about abdominal x-rays or abdominal radiographs, if you prefer. Here's a general outline of what I'll be covering. I'll start with their indications, followed by typical views. +[25.74s -> 38.54s] Then I'll discuss normal anatomy as seen on x-ray. And I'll end by reviewing 15 to 20 common abnormalities which any clinician should feel comfortable identifying. +[39.02s -> 50.13s] I will not be discussing the general physics principles of radiographs as they're covered in my first video on my chest x-ray series. A link to that is in this video's description. +[50.64s -> 63.31s] As a lead-in to the indications, I'll first point out that chest films get a 10 episode series on strong medicine, while abdominal films only get this one video. The reason for that... +[63.31s -> 74.75s] abdominal films have a much more limited role in 21st century medicine. Some people joke that in the era of easy-to-obtain abdominal CT and point-of-care ultrasound, +[74.75s -> 86.03s] There's almost no reason to even order an abdominal film anymore. But while they are much less common than they were a generation ago, they still have some role today. +[86.54s -> 99.98s] First, they are useful for the emergent evaluation of bowel gas, as in suspected small bowel obstruction, or for the emergent evaluation of pneumoperitoneum, that is, air inside the peritoneal cavity. +[99.98s -> 105.74s] usually from a bowel perforation if CT is not immediately available. +[106.29s -> 120.72s] Abdominal x-rays are useful in the assessment of radio-opaque foreign bodies, that is, the ingestion or insertion of objects. They are also helpful with the assessment of the positioning of lines and tubes and other medical devices. +[121.36s -> 134.00s] There are a few other uncommon indications, but these are the main ones. Some internists and internal medicine residents will use them to assess stool burden in patients with severe constipation, but... +[134.00s -> 144.78s] I'm not personally convinced that that's an appropriate use of the test. When considering the relative value of ordering an abdominal x-ray, you should keep in mind that the radiation it delivers +[144.78s -> 159.50s] is at least 10 times that received during a PA chest x-ray. So it's not negligible for younger patients, though it's still far less than the amount of radiation delivered during a CT scan of the abdomen and pelvis. +[160.98s -> 175.18s] Now let's talk views. There are three main ones. The first is by far the most common, the supine AP view. AP meaning that the x-ray beam travels from the anterior side of the patient to the posterior side. +[175.28s -> 187.98s] This view is useful for identifying most pathology, that is in situations where abdominal x-rays are useful at all. The term supine AP view is often used interchangeably with the acronym KUB. +[187.98s -> 198.46s] which stands for kidneys, ureters, and bladder. I've heard some radiologists object to using these terms as true synonyms, but to a non-radiologist this difference is semantics. +[198.46s -> 208.30s] provided that an accurate indication for the test is placed in the x-ray order, that way the radiology technologist can shoot the proper film regardless of what you call it. +[208.66s -> 223.20s] Another view is the upright abdominal view. What's shown here is technically an upright PA view, in which the x-ray beam travels from the posterior to the anterior of the patient, though this view can also be taken with the patient facing forward. +[223.20s -> 235.06s] in which case it could technically be referred to as an upright AP view. But unlike with chest films, in which there is a significant difference between the AP and PA views, there is not with upright abdominal films. +[235.06s -> 242.22s] This view is best specifically for identifying small bowel obstructions, which is really its only major indication. +[243.12s -> 256.86s] And then there is the upright chest view, which as shown is also a PA view. You might wonder why a chest view is included in a discussion of abdominal radiography. It's because an upright chest is the best view for identifying +[256.86s -> 268.66s] pneumoperitoneum, often referred to as free air under the diaphragm. This just shows up better on the upright chest film because of a better view of the diaphragms as compared to an upright abdominal film. +[268.78s -> 277.68s] A chest film will also help to assess for intrathoracic conditions, which could lead to preferred pain to the abdomen, such as a lower lobe pneumonia. +[278.22s -> 288.50s] For patients who are unable to stand, a left lateral decubitus film in which a patient is lying down on their left side is the preferred view to identify pneumoperitoneum. +[289.68s -> 303.58s] You will rarely hear someone mention an abdominal x-ray series or the so-called abdominal three-view or abdominal three-way. This is a largely obsolete series consisting of the three views we just focused on. +[303.58s -> 317.10s] the supine abdominal view, an upright abdominal view, and a PA chest view. Alternatively, for patients who cannot stand, the upright abdominal and PA chest are replaced with a left lateral decubitus film +[317.10s -> 330.67s] plus or minus an AP chest view. It's honestly been years since I've had a patient receive this specific collection of films, as there are few indications in which all these views would be indicated in the same patient. +[330.67s -> 340.21s] and CT and point-of-care ultrasound are now used in such situations. Next we'll talk about normal anatomy on an abdominal film. +[340.69s -> 355.18s] To understand normal anatomy, you need to keep in mind that one of the major limitations of x-rays is that they don't distinguish between structures of similar densities, and there are only five basic densities seen. Black means gas. +[355.18s -> 367.34s] dark gray is fat, light gray is soft tissue or fluid, white is bone and other calcifications, and intense white is metal. So an organ like the kidney or spleen +[367.34s -> 380.70s] which is soft tissue surrounded by soft tissue and fat can be difficult to discern and more generally abdominal films are very poor for identifying pathology of all solid organs including the kidneys spleen +[380.70s -> 395.31s] liver, pancreas and reproductive organs. Abdominal films are best for looking at bowel gas patterns, which is where most people start their interpretation, excluding a very brief assessment of technical quality and confirmation of the view. +[395.79s -> 407.82s] Differentiating small and large bowel is not always possible, but there are a few clues one can use. First, the small bowel tends to be centrally located, while the large bowel is on the periphery. +[408.50s -> 422.93s] The small bowel's mucosal folds, known as valvulae connoventes, or Kirkring folds, are relatively thin and span the width of the bowel, while the mucosal folds in the large bowel are called haustra, which are relatively thick +[422.93s -> 434.99s] and usually do not span the width of the bowel. The upper limit of normal for the diameter of small bowel is 3 cm, for the large bowel it's 6 cm for most of the colon, but 9 cm for the cecum. +[434.99s -> 444.27s] Some references also list 9 centimeters as the upper limit for the sigmoid colon as well. Overall, this is known as the 3-6-9 rule. +[444.53s -> 456.69s] This film is not a normal abdominal film, but rather shows toxic megacolon in a 10-year-old with inflammatory bowel disease, but it is a particularly good example of the central versus peripheral bowel distribution. +[458.35s -> 472.06s] One of the most challenging things about the interpretation of abdominal films is that the range of normal is subjectively much wider than it is for chest films. And therefore it takes viewing many more abdominal films than chest films +[472.06s -> 475.86s] They feel comfortable in distinguishing normal from abnormal. +[476.30s -> 488.82s] Next, let's look at the normal anatomy of solid organs on abdominal x-ray. As mentioned earlier, the solid organs are all poorly visible on plain radiographs. In this case, we can identify the location of the liver. +[489.33s -> 497.33s] The kidneys are a little more subtle, but a normal spleen and pancreas will not typically be visible on plain films. +[498.22s -> 510.19s] Then there are musculoskeletal structures. Obviously, these include the ribs. This is the lowest one, the posterior twelfth rib, the vertebrae, the sacrum, +[510.67s -> 522.29s] The ilium, the largest of the three pelvic bones. There is not a distinguishable demarcation between the ilium and the pubis and ischium in adults, as the three pelvic bones normally become fused. +[522.48s -> 534.93s] Abdominal films will usually catch the head of the femur as it articulates with the acetabulum. And finally, there is a triangular shaped shadow on either side of the vertebral column, which is caused by the psoas muscle. +[535.86s -> 546.99s] And in extreme brief, since upright chest films are occasionally ordered for the evaluation of abdominal symptoms and intra-abdominal pathology, we of course have the heart and great vessels in the middle. +[546.99s -> 557.10s] with the right and left lung and the respective hemidiaphragms on either side. There is a link to a complete discussion of chest x-ray anatomy in the video description. +[558.19s -> 572.08s] For the remainder of the video, I'll run through some common abnormalities identifiable on x-ray. Here is probably the most classic abdominal x-ray finding, at least in adults. If not apparent from the supine film, the upright film may give it away. +[572.18s -> 586.30s] This is a mechanical small bowel obstruction, or SBO, caused by a physical anatomic obstruction to the movement of intraluminal contents forward through the bowel. The most common etiology in adults is something called adhesions. +[586.30s -> 591.98s] which in short are bands of scar tissue usually caused by prior abdominal surgeries. +[592.50s -> 601.33s] The main feature of an SBO on X-ray is multiple centrally located dilated loops of bowel with multiple air fluid levels on the upright view. +[601.74s -> 611.76s] Although not directly related to the diagnosis, these films also show nice examples of valvulae conventes, the small bowel mucosal folds which span the entire width of the bowel. +[612.53s -> 625.31s] This other upright film may not be as immediately obvious an example of an SBO, but it is a good example of something called the String of Pearls sign, in which a chain of small air bubbles are caught between mucosal folds +[625.31s -> 637.74s] within an otherwise fluid-filled bowel loop. Each one looks round instead of having miniature versions of classic air-fluid levels due to the effect of water's surface tension at that smaller scale. +[638.67s -> 651.63s] Here's a supine film in a patient with something called an ileus, which in common usage is used synonymously with adynamic ileus, in which there is an absence of normal peristalsis, leading to bowel distension. +[651.76s -> 665.78s] Distinguishing an ileus from a mechanical SBO on plain films can be difficult, if not impossible. Often the clinical context may be necessary to distinguish them in that a mechanical SBO is usually the reason a patient presents to the hospital. +[665.78s -> 672.08s] Whereas for an ileus, that's usually something that develops after the patient has already been admitted for something else. +[673.23s -> 687.10s] Here's another classic x-ray diagnosis. This is a sigmoid volvulus. This is when the sigmoid colon, normally located in the lower left quadrant, rotates around itself, choking off its blood supply like kinking a garden hose. +[687.10s -> 700.69s] It is an imminently life-threatening diagnosis requiring emergent endoscopic or surgical management, with the endoscopic option only appropriate for patients presenting before the development of peritonitis or perforation. +[701.17s -> 713.49s] Radiographic findings include a massively dilated colon. Halstra within the affected segment are usually absent. And this bowel gas pattern is sometimes referred to as the coffee bean sign. +[715.34s -> 727.23s] Volvulus can also involve the cecum, which is normally located in the right lower quadrant. Cecal volvulus also results in a massively dilated colon, but haustra are usually present as indicated. +[727.23s -> 740.91s] and there is a lack of colon seen in the right lower quadrant. And now showing the two forms side by side for comparison, because they do look a little similar. Sigmoid volvulus is the more common form. +[742.70s -> 755.70s] Here is another classic and much more benign finding. This is a patient with constipation. We see soft tissue-like capacities with internal mottled air within the large bowel. That is all feces. +[756.91s -> 770.06s] Here's a finding called thumb printing, in which thumb-shaped indentations in the bowel wall are caused by edema of haustra related to infection and or inflammation. Regarding its potential etiologies, +[770.06s -> 780.94s] It is most classically associated with inflammatory bowel disease, but can also be seen in infectious colitis such as C. diff, diverticulitis, and ischemic colitis. +[781.87s -> 794.96s] I'm going to move from abnormalities of intraluminal gas to those of extraluminal gas. And there are two main ones to worry about. The first is best seen on an upright chest film, which we already discussed a little earlier. +[794.96s -> 808.83s] specifically we can see free air collecting immediately under the diaphragm, indicating the presence of pneumoperitoneum. The list of potential etiologies of pneumoperitoneum is very long, but the main considerations include peptic ulcer disease, +[808.83s -> 821.18s] bowel ischemia from any cause appendicitis colitis perforation of a diverticulum in the setting of diverticulitis penetrating abdominal wall trauma such as a stab or gunshot wound +[821.18s -> 834.18s] the ingestion of a foreign body resulting in bowel perforation, and as a complication from endoscopy. Last, pneumoperitoneum can be observed after either laparoscopic or open abdominal surgery. +[834.18s -> 844.21s] In this circumstance, air usually remains visible for 2-3 days on average, with almost all post-surgical patients having resolution of the air within 7 days. +[844.69s -> 857.55s] As mentioned, while discussing the x-ray views, in patients unable to stand upright, pneumoperitoneum can be evaluated with a left lateral decubitus film, where the gas will collect between the intra-abdominal contents and the abdominal wall. +[858.70s -> 871.89s] The other significant extra-luminal gas abnormality is more subtle. It's called pneumatosis intestinalis and is air within the bowel wall itself. It can affect either the large or small bowel. +[872.05s -> 885.33s] There are many etiologies, which include intestinal ischemia and infarction, peptic ulcer disease, inflammatory bowel disease, C. diff colitis, it's been observed to occur in asthma and COPD, +[885.46s -> 895.54s] any form of a significant immunocompromise, including steroid use, chemotherapy, and AIDS, mechanical ventilation, and, once again, as a complication from endoscopy. +[896.98s -> 909.63s] The next major category of abnormalities is calcifications, the first of which is nephrolithiasis, more commonly known as kidney stones. The majority of kidney stones contain calcium, and so are radio opaque on x-ray. +[909.63s -> 918.45s] They can be present in the renal pelvis, ureter, bladder, or urethra. Here's an example of one probably in the proximal ureter. +[918.96s -> 927.70s] And here's an example of what's called a staghorn calculus, which is a very large stone that occupies some or all of the renal pelvis. +[929.23s -> 934.93s] Gallstones are another finding sometimes seen on x-ray, although only a minority are visible. +[935.25s -> 944.40s] Gallstones can be present in the gallbladder as they are here, as well as the cystic duct, common bile duct, or they can be visible as they pass through the bowel. +[945.71s -> 959.33s] And here is an example of pancreatic calcifications. This finding, particularly when diffuse, as in this image, is most classically associated with chronic pancreatitis, such as that caused by chronic heavy alcohol use. +[959.33s -> 973.87s] But focal and or smaller calcifications can also be seen in cystic fibrosis, in pancreatic cancer, and even rarely as a finding only related to advanced age, in which case they are referred to as senile calcifications. +[974.96s -> 984.27s] The final category of abnormalities are foreign bodies. Here's an example of a hip prosthesis, likely in an older patient who had severe osteoarthritis. +[985.49s -> 992.02s] You can see a variety of hardware related to spinal surgery. This is a fusion within the lumbar spine. +[993.01s -> 1004.85s] This finding is a little more subtle at first glance because it's lined up in front of the vertebral column, but that fine, net-like structure is an endovascular repair of an aortic aneurysm. +[1006.22s -> 1020.46s] This elongated foreign body might be puzzling until you realize that it's within the ureter. This is a ureteral stent, also called a double J or JJ stent. It's coiled at both ends to prevent migration with the upper coil within the renal pelvis. +[1020.46s -> 1022.42s] and the lower coil within the bladder. +[1023.73s -> 1036.66s] This next one is actually a pelvic x-ray rather than an abdominal x-ray, but both can show this, an intrauterine device or IUD, which is inserted into the uterus as a means of contraception. +[1036.66s -> 1045.36s] This here is the correct location in which it is oriented as an upright T, in the midline, and just inferior to the pelvic rim. +[1045.90s -> 1055.47s] While IUDs can be malpositioned within the uterus, which can be seen on x-ray, they can also perforate the uterus and migrate to various places within the abdomen and pelvis. +[1057.36s -> 1067.63s] And finally, we have pathologic foreign bodies. Pathologic foreign bodies can get into the abdomen and pelvis either by ingestion, rectal insertion, +[1067.89s -> 1079.86s] from penetrating abdominal trauma, or from something being accidentally left behind during a surgery, such as surgical sponges, shown here, which should be made to be radiopaque for this exact reason. +[1081.30s -> 1093.30s] One of the most common and important foreign bodies to see on x-ray is the small, uniform, flat circular opacity, which only looks like an ellipse here because it's usually seen from an angle. +[1093.81s -> 1108.02s] While many of these are coins, which are generally benign and will usually pass through the bowels and be expelled with feces without difficulty, some are actually buttoned batteries, which can cause internal chemical burns, leading to perforation +[1108.02s -> 1119.60s] peritonitis and death. It's been estimated that about half of deaths from button battery ingestion occur due to someone misidentifying the battery on x-ray as a coin. +[1119.92s -> 1132.27s] In addition to button batteries generally being smaller than coins, they will also usually have a double ring visible. But the absence of such a visible ring does not rule out the possibility of it being a battery. +[1132.37s -> 1138.54s] Films of any flat, circular ingested items should be carefully reviewed with a radiologist. +[1140.24s -> 1153.17s] That concludes this introduction and overview of abdominal x-rays. If you found it helpful, please remember to like and share it, and consider checking out Strong Medicine's accompanying video series on an approach to chest x-rays. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_1.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d6af1def101f6a07de2719e1568848073c3e4a90 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_1.mp4.txt @@ -0,0 +1,100 @@ +[4.50s -> 16.50s] Good morning. I'm Diego Nunez from Mass General Brigham in Boston, and on behalf of the International Outreach Committee of the American Reagan Race Society, +[16.50s -> 28.24s] I would like to welcome you to this year's global exchange session, featuring collaboration with the Spanish Society of Medical Radiology, SARAM. +[28.24s -> 37.33s] It is my distinct pleasure to introduce you to our moderator, Carlos Torres, who is professor of radiology at... +[37.33s -> 50.54s] University of Ottawa, and they have put together really an interesting program where there will be three speakers representing the American Rank and Race Society and three speakers from CERAM. +[50.54s -> 60.08s] Without further ado, they have this great topic on current imaging of brain tumors from child to adult. Carlos, take it away. +[62.13s -> 76.56s] Thank you very much, Diego, for that kind introduction. So let's get the session started. I would like to introduce our first speaker, Dr. Raymond Huang, who is a neuroradiologist. He's an associate professor. +[76.56s -> 90.93s] at Harvard Medical School, and he works at Brigham and Women's Hospital. And he's going to talk on imaging diagnosis of CNS tumors in the context of the new 2021 WHO classification. Welcome, Raymond. +[93.84s -> 103.89s] Thank you. Good morning, everyone. And I would like to say thank the organizer for inviting me to give this session. And it's great to be in person to give the talk. +[104.37s -> 118.67s] So these are my disclosure, none are relevant to this talk. So today I would like to discuss some of the imaging science and the use of advanced imaging technology to help us diagnose CNS tumors. +[118.67s -> 127.02s] focusing on some of the new changes to the WHO criteria and also go over some of the pitfalls and challenges. +[127.41s -> 137.68s] So I want to start with a case. This is a 58-year-old lady who came to us with a very vague symptom, vertical, very common. +[137.68s -> 148.96s] get MRI, and in this case we see a non-enhancing small lesion in the corpus callosum. And the diagnosis then, we don't know what this is, probably not related to the symptom, but this is... +[148.96s -> 160.94s] Probably some kind of, it could be, you know, tumor, glioma, or demyelinating. It's very nonspecific, just like many things. But it does cross corpus callosum, and this is an older patient. So recommendation was follow-up in three months to see how he behaved. +[160.94s -> 171.94s] without any invasive procedure now. In three months, the lesion looked about the same size, or appearance and no enhancement, so identical picture nearly. +[171.94s -> 183.60s] Okay, so the recommendation then, you know, similar or cannot exclude glioma that can grow slower, probably a low-grade glioma since it hasn't changed, or, you know, some kind of demyelinating process that, you know, hasn't changed. +[183.60s -> 189.26s] So, recommendation then was maybe we need a longer term follow-up, one year, so that sounds reasonable. +[190.19s -> 203.87s] So this is at six months before patient, you know, as you get to the scheduled imaging, present with symptom. So now we are looking at a multi-focal. +[203.87s -> 217.20s] necrotic-appearing enhancing mass crossing corpus callosum. So this is what we typically are used to, the classic appearance of glioblastoma. So my question to the audience, just for thought now, +[217.20s -> 229.36s] what would you do differently at the early initial presentation or at the three-month time point? And whatever we do, would that make a difference to patients' outcome? +[230.51s -> 241.17s] Another case similar, we have a also older patient, non-enhancing tumor, had a biopsy showing astral cytoma grade 2. +[241.17s -> 252.54s] Grateful for the patient, you know, I mean, that is not glioblastoma, even though this is a primary, likely primary brain tumor at this age. But a month later, a patient developed an enhancing nodule. +[252.54s -> 266.46s] and that was resected and turned out also to be glioblastoma. So with these two cases, I want to go over some of the evolution of the +[266.46s -> 274.58s] over the past few decades. And starting with 2007, and believe it or not, some of the 2007 concepts are still +[274.58s -> 285.06s] we see those in the new radiology textbooks. So I want to make sure that we see how these have been evolved to the new criteria. In WHL 2007 +[285.06s -> 296.16s] It was primarily a histological diagnosis for diffuse gliomas for adults. And starting from grade two to grade four with increasing +[296.16s -> 309.02s] aggressiveness with histological features of increasingly, you know, with necrosis, proliferation of vessels. And on imaging, we correlate the lower grade tumors tend to be non-enhancing, no necrosis. +[309.02s -> 320.61s] On the events imaging, it doesn't have elevated blood volume or high, it doesn't have any low diffusivity or hyperseriality. And on spectroscopy, tend to be low choline. +[320.61s -> 333.02s] relative to NAA, and whereas the high grade tumor are the opposite, we see more necrosis, more nodular enhancement, and with this imaging, advanced imaging feature pointing to higher grade tumors. +[333.02s -> 346.78s] So that has been the framework for a long time. And come in 2016, there has been introduction of the use of molecular markers to divide these tumors. +[346.78s -> 357.44s] And the reason for that is these molecular-based division is a lot more accurate in reflecting patients' prognosis. So for example, +[357.44s -> 370.98s] an IDH mutant glioblastoma, they do a lot better than the IDH wild type glioblastoma. And therefore IDH has been the key molecular marker for the diagnosis of brain tumor. +[370.98s -> 384.70s] And, well, but despite that, you know, our framework for imaging diagnosis, this is histological diagnosis plus a few markers, IDH and this one, 1p19q correlation. +[384.70s -> 395.89s] allow us to divide oligodendroglioma versus the astrocytoma IDH mutant. And it removes some of the ambiguity for +[395.89s -> 409.42s] In the past, we called some of these mixed tumors by histology. Now we are able to divide them by molecular status. So this is an early framework to integrate molecular status to histological diagnosis. +[409.42s -> 422.64s] And in 2021, last year, there are a few more changes which are quite striking. One is that the glioblastoma has been removed from the... +[422.64s -> 430.59s] IDH mutant type tumors, which means we cannot really call secondary glioblastoma anymore. +[430.59s -> 438.77s] That's one major change. So that will really make a distinct population for these younger patients. +[438.77s -> 453.12s] tumors that are coming from younger patients versus the older patients who are getting these much more aggressive IDH wild-type tumors. Not only that, a new addition is that there are a few molecular markers that can +[453.12s -> 458.99s] be used to diagnose glioblastoma, and that is independent of histological grading. +[458.99s -> 473.14s] So even if patient doesn't have any necrosis or microvascular proliferation, which was required to diagnose glioplastoma, that right now with the molecular mutation with these... +[473.14s -> 486.50s] mutations, you can diagnose glioblastoma. And that can cause a lot of problems for radiologists for now. Like, why do we see a non-enhancing tumor? +[486.50s -> 499.76s] It can be a glioblastoma, but we cannot be confident in calling that at that stage. And that is exactly the reason we are seeing these tumors that are diagnosed as glioblastoma. +[499.76s -> 512.88s] early on when we do these biopsies now. But for management, it's actually a lot better for patients to know that this is going to be a bad tumor. It's going to turn into something necrotic and rapidly growing very fast. +[512.88s -> 522.45s] So, you know, you have to be more aggressive in treating these tumors. And also, get these patients to proper treatment, but also in clinical trial. +[522.45s -> 532.50s] selection to make sure that we don't treat, you know, getting patient to be enrolled in low-grade tumor trials because they're going to be behaved like glioblastoma. +[532.98s -> 545.76s] And some of the new advanced imaging technology allows us to be a little bit better than what we can see morphologically. So the IDH1-2 mutation +[545.76s -> 558.70s] I just want to give a very quick review in the Krebs cycle of the cell metabolism. The IDH wild-type proteins that catalyze +[558.70s -> 572.24s] the conversion of isocitrate to alpha-gyloglutarate. And in the mutant version of that, it shuts down this conversion in an exchange. +[572.24s -> 583.81s] they overexpress 2-hydroxyglutarate or 2-HG. And this compound can be detected by MR spectroscopy. And it's with this... +[583.81s -> 597.58s] The method is basically changing the TE to 97 in the 3T machine, and you can see this 2.25 parts per million peak distinctly. It's very small. +[597.58s -> 610.96s] but using quantitative measurements, we can isolate this peak quite nicely. Just to give you an example again, this is a 64 similar non-enhancing tumor presenting with vague symptom. +[610.96s -> 621.18s] And, of course, this can be either low or high grade. We can tell IDH or not. It's sort of infiltrated, appearing pretty typical for glioma. But with spectroscopy, +[621.18s -> 632.85s] the lesion showed a small 2-HT peak, so it turned out to be a grade 2 esocytoma. +[633.49s -> 647.36s] We've been asked why it doesn't matter since the patient is going to get surgery anyway going to get the IDH diagnosis by molecular methods why do we bother to know ahead of time well it turns out +[647.36s -> 660.80s] The non-enzyme tumors, if it's of an IDH variant, if you can resect the entire tumor, patients do have a lot better prognosis. Whereas the IDH wild type, it's not clear, meaning it doesn't... +[660.80s -> 674.93s] probably doesn't matter what you do. The tumor probably already spread far beyond what we can see. And so that is ongoing work to improve the spectroscopy and see how we can help. +[674.93s -> 689.07s] clinically. In the next few minutes, I'm going to show some of the specific imaging signs that allow us to diagnose some of these tumors, especially the oligodendroglyoma. +[689.07s -> 698.29s] If we see a cortical lesion that's expansile and has some calcification, it has very specific +[699.12s -> 713.68s] very high specificity for oligodendroglioma. Unfortunately, it's not very sensitive. Only about half the patient or fewer will have these imaging signs. +[713.68s -> 727.86s] and they tend to be more commonly in the frontal lobe and they can show some elevated blood volume and the edema tend to be mild in the lower grade stage. Occasionally they can hemorrhage. So let's look at this case. +[727.86s -> 739.57s] a 42-year-old male with a cortical lesion in the hand area of the precentral gyrus. It's mildly expensile, non-enhancing. +[739.57s -> 752.56s] And you can see on the susceptibility imaging a bit of a dark signal. So that turned out to be calcification, and we can be very confident, even though surgeons were probably not happy to be touching this area. +[752.56s -> 761.07s] causing major deficit in the left hand, that we know that this is not going to be a glioblastoma. This is going to be a +[761.07s -> 775.17s] a nice-behaving and a life expectancy for this likely is going to be over 10 years. In contrast to this case, there's this very heterogeneous, very large, a lot of edema. +[775.17s -> 788.02s] So an older patient can easily be a high-grade glioblastoma. But on the CT you can see coarse calcifications. +[788.21s -> 794.56s] Sorry, this is a grade three oligodendrochleoma with +[794.56s -> 804.85s] with component that's already been transformed but still kept the calcification that tells us that it used to be probably a nice behaving grade two tumor and it has time to evolve to this large. +[805.94s -> 819.90s] Another imaging sign I want to point out, I think some of you may know and heard of it, but this is an important sign that has been reported during the last two, three years and validated in large datasets. +[819.90s -> 830.61s] It's called a T2 mismatch sign. And this is a very specific sign, nearly 100%, for this particular genotype, an IDH mutant tumor. +[830.61s -> 844.37s] It's a non-code-deleted tumor, meaning it's an astrocytoma. And the sign basically says, if you have a mass that is well-circumscribed on the T2-weighted images. +[844.37s -> 856.58s] on the flare image, the central part of that becomes dark with a very bright rim. Again, you know, no edema, no enhancement, it's a very nice well-circumscribed mass. With this sign, +[856.58s -> 870.42s] then 99% over, you're going to be right that this is this particular genotype. Unfortunately, again, just like similar to the calcification sign on the other goals, it's only about half, 50% sensitivity. +[870.42s -> 877.36s] So if you see it, it's great. It helps you diagnose it with high confidence. But if you don't see it, it doesn't mean that it's not this type of tumor. +[878.64s -> 893.30s] This is just one example of that, you know, non-enhancing tumor, bright on the T2, dark on the flare with a bright rim. This is consistent with the astrocytoma, non-decolated tumor. +[894.38s -> 906.40s] this is a more challenging case now not only again young patient but not only one lesion but three lesions get in the brain it was came to us as a route +[906.40s -> 917.60s] demyelinating disease in young patients, multiple Y matter lesions. It does involve the cortex and the Y matter. It does have some trace of +[917.60s -> 931.20s] T2 mismatch sign, meaning it's bright on T2, some dark component, but it doesn't really fit perfectly, meaning the T2 is not homogeneously bright on T2, there's some dark areas. +[931.20s -> 944.66s] to try to figure out what this could be with the spectroscopy. And it shows a very distinct 2HG peak. So this is consistent with an IDH mutant tumor. +[944.66s -> 958.18s] The diagnosis, it turned out to be grade 3 astrocytoma. Not only this one, they also resected this guy and the third tumor. And all of them have the same histology and molecular status. +[958.18s -> 972.98s] So, as you can see, some of these tumor can start with these nice signs and evolve and start looking different, but if you look carefully, you can actually see trace of those signs and if you put other data together, you can actually make. +[972.98s -> 987.10s] quite confident diagnosis, this is not the emanating disease. In the last few minutes, I want to, what we spend most of our time focusing on the adult type diffuse glioma. +[987.10s -> 994.45s] And Dr. Ho is going to go through the pediatric tumors. But I want to point out the WHO2. +[995.02s -> 1007.70s] have these Pediatric type tumors as more likely defined as separate category because they have very different behavior clinically from the +[1007.70s -> 1020.78s] the other type of diffuse gliomas, and they tend to be occurring in young kids. But I want to point out one case here. This is an older gentleman who presented to us with a hemorrhagic mass, as you can see. +[1020.78s -> 1032.72s] on the SWI image, there are dark areas. It's enhancing. It's primarily intraventricular with some edema, right? So looking at this, well, in hemorrhage mass in adult. +[1032.72s -> 1045.28s] probably a high-grade glioma, metastasis. You can probably entertain vascular lesions like cavernoma, except that there's no T1 shortening. +[1045.28s -> 1056.21s] This turned out to be one of these pediatric type diffuse low-grade glioma of the MAPK pathway, which has... +[1056.21s -> 1068.05s] the BRAF and FGFR. And these tumors tend to be hemorrhagic. I want to show this case just because it becomes much more complex now with molecularly defined status. +[1068.05s -> 1075.10s] And these pediatric-type tumors do occur in adults, like in this case, in a 60-year-old man. +[1075.10s -> 1086.99s] Of course, these are rare, but we're going to see more of these tumor dots going to be behaving very differently from glioblastoma or medicine, other high-grade tumors in adults. +[1086.99s -> 1100.94s] Lastly, I want to close with this case. This is a 25-year-old male who came to a neurosurgical clinic. This is a pre-op imaging showing a well-circumscribed temporal parietal mass. +[1100.94s -> 1114.82s] And it's very young, so we're expecting some probably likely low grades given that it's a very well-circumscribed young patient. The DWI is very high, the ADC is sort of intermediate to low, but it's not like acute infarct low. +[1114.82s -> 1127.42s] A patient presented with just one-time seizure, otherwise healthy and non-enhancing. So at the time, we're thinking, well, this could be a glioma, but it doesn't. +[1127.42s -> 1138.45s] follow the expectation for low grade to have ADC bar looking like intermediate low value. So this could be something else. So we follow it. +[1138.77s -> 1151.34s] Instead of recommend, you know, we stop the surgeon and say, you should wait. And three weeks later, the flare abnormality pretty much resolved. The DWI also resolved, and we are seeing some +[1151.34s -> 1160.93s] of this cortical enhancement, so this subacute infarct. So I just want to make sure that you keep the mimickers. +[1160.93s -> 1171.95s] in mind when we try to diagnose this brain tumor. So in summary, WHO 2021, we have the introduction of +[1171.95s -> 1183.28s] extension of the 2016 criteria with the molecular status but much more refined now and including some of the molecular definition of glioblastoma. +[1183.28s -> 1196.54s] it's going to be much more challenging for us to figure out these high versus low grade. We have advanced imaging tools in some of the imaging science that can help us to figure out these molecular subtypes. +[1196.54s -> 1207.34s] And just keep in mind of the tumor mimickers because that's going to be our most added value as radiologists to tell them this is probably not tumor, something else. Okay, thank you for your attention. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_13.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..231df515dca8062846dc3107e169c402bd0ee145 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_13.mp4.txt @@ -0,0 +1,44 @@ +[0.00s -> 10.30s] in this video we'll talk about eosinophil and its role in immunity eosinophil plays a vital role in terms of immunity against parasites +[10.30s -> 23.44s] It was first discovered and described by Paul Elrich in 1879 and he noticed the unusual capacity of these cells to be stained with acidophilic dyes. They play a vital role +[23.44s -> 37.58s] against parasites and they are involved in modulating allergic response. Eosinophils constitute 1% of the circulating leukocytes whereas the majority are the neutrophils. +[37.58s -> 49.87s] which are more than 50 percent of the time but eosinophils are involved in allergic responses and other infections relatively few mature eosinophils are found in the peripheral blood +[49.87s -> 63.42s] generally they are found in specific locations in the gut and other locations where they maintain the homeostasis. Let's talk about the development of the eosinophil. Eosinophil is formed from the hematopoietic +[63.42s -> 76.38s] pluripotent stem cell which give rise to myeloid progenitor and from the myeloid progenitor eosinophils are generated. Once generated they are secreted into the bloodstream but inside the bloodstream they only stay for about 18 hours. +[76.38s -> 88.53s] They move to tissues like thymus or the GI tract and they play vital role in these particular locations. So let's talk about some cellular features of eosinophil. +[88.72s -> 101.70s] So first of all, let's talk about the microscopic features. So in hematoxylin eosin stain, we can see these eosinophils to be stained with this kind of pink stain. +[101.70s -> 106.86s] you can see characteristic bilobed nucleus and a lot of cytoplasmic granules. +[106.86s -> 116.80s] If we look at the ultrastructure of the eosinophil, we can also appreciate the bilobed nucleus and the electron-dense cytoplasmic granules. Question is, what is there inside these cytoplasm? +[116.80s -> 124.32s] cytoplasmic granules, what is the content of these granules. In a moment we would get to know that. So let's talk about the molecular features. +[124.32s -> 136.93s] so first of all let's talk about these granule contents because granules constitute a majority of the cytoplasmic content in eosinophil so there are many proteins such as major basic protein mbp1 and 2 +[136.93s -> 148.14s] eosinophil cationic protein ECP, eosinophil peroxidase EPX and eosinophil derived neurotoxin EDN. So these are the four major components +[148.14s -> 157.10s] the cytoplasmic granules. Other than that there is cytokine, there is other CLC gal10 protein and +[157.10s -> 168.94s] in response to many stimuli these contents are actually released but what we have to understand these four major proteins are really important in terms of eosinophils function +[169.14s -> 182.02s] subsequent slides we would understand why they are important let's talk about the surface receptors a little bit but before that let me tell you other than these cytotoxic granules there are +[182.02s -> 196.00s] proteins such as cytokines various interleukins are secreted by these eosinophils there are growth factors which are secreted by eosinophils chemokines and enzymes are also present in these +[196.00s -> 206.29s] eosinophils. In terms of the surface molecule we can see there are different categories of surface receptors such as cytokine receptors +[206.48s -> 213.87s] such as pattern recognition receptors, various TLRs and PRRs are there. FC receptor is also there. +[213.87s -> 223.98s] Adhesion receptors such as integrin receptors are present on the surface. There are chemokine receptors and receptors for lipid mediators like leukotrienes, prostaglandins, etc. +[224.62s -> 229.01s] Now there are also primary granules and lipid bodies. +[229.46s -> 240.82s] Let's talk about the immune function of eosinophil. Eosinophil as mentioned before plays vital role in terms of destruction of parasites. They also play +[240.82s -> 252.64s] allergic response i mean they also play vital role in modulating the overall allergic response along with mast cells and other responses so all the eosinophil derived proteins +[252.64s -> 258.19s] are involved in various kind of immune response against various kinds of pathogens such as +[258.19s -> 270.69s] if we think about antihelminth response, antibacterial response, antiviral and immune modulatory response, we would see that EPX, ECP and MBP, these +[270.69s -> 285.04s] three proteins which are the major constituents of the cytoplasmic granules they are involved in anti-helminth or anti-parasite response now for antibacterial response ecp and mbp +[285.04s -> 296.19s] responsible for antiviral response ECP and EDN are responsible similarly there are many components which can modulate immune cells and also +[296.19s -> 308.05s] there are components which can activate epithelial cells and change their homeostasis. So eosinophil level goes down in various situations such as Cushing syndrome. +[308.30s -> 319.57s] usage of corticosteroids and in bacteriomia. And eosinophil levels goes up in situations like asthma, allergy, parasitic infection, etc. +[319.89s -> 327.63s] So let's try to understand the role of eosinophil in disease or eosinophilia or increase in eosinophil number in context of disease. +[327.63s -> 340.34s] so the normal number is 0 to 500 beyond that it is eosinophilia and beyond 1500 cells per microliter is basically hyper eosinophilia so +[340.34s -> 354.34s] in allergic rhinitis eosinophilic esophagitis food allergy we can see there is a eosinophilia like situation that means the number goes beyond 500. same condition goes for asthma atopic dermatitis bolus +[354.34s -> 367.20s] etc but in case of nasal polyposis eosinophilic gastritis in these cases the eosinophilia is pretty severe and almost it reaches the hyper eosinophilia stage +[367.20s -> 377.17s] And this is true for chronic helminth infection as well. In case of several cancers such as eosinophil leukemias, we can see hyper eosinophilia-like situation. +[378.16s -> 392.48s] Now, eosinophil has a huge role in terms of immune modulation because eosinophil can interact with various immune cells such as macrophages, neutrophil, dendritic cells, B cells, mast cells and Th2 cells. +[392.48s -> 402.58s] And eosinophil derived factors such as MBP can modulate neutrophil and activate neutrophil to secrete several other stuff. +[402.90s -> 416.53s] Also, it can modulate dendritic cell and lead to dendritic cell activation. So, that is why eosinophil derived factors are really important in context of overall immune modulation. +[416.53s -> 426.42s] So this is a function that is beyond fighting the parasites or getting involved in allergy. So it has a bigger implication in terms of biology. +[427.18s -> 438.42s] So in summary, we learned these eosinophils are usually linked with allergic responses such as asthma or any kind of atopic dermatitis allergy. +[438.42s -> 449.20s] they contain acidophilic granules which are filled up of specific proteins we looked at the names their functions etc so eosinophil level changes in disease they could go up +[449.20s -> 460.37s] or they could go low in specific diseases we looked at them and eosinophils interaction with immune system brings out the bigger implications and biology of the eosinophils function +[460.37s -> 474.64s] so you can get many flashcards and notes in my facebook page so all the links are provided in the description also follow me on instagram you can get these kind of notes and flashcards in instagram as well you can support my channel using a patreon paypal +[474.64s -> 488.42s] or you can click on the super thanks option by clicking on the super thanks option you can pay via net banking paytm paypal or upi your small contribution means a lot for me it would help me to bring out more quality content +[488.42s -> 498.13s] for free education you can get get connected with us using social media all the social media links are provided in the description see you in the next video diff --git a/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_15.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..98096066f24a21a8a6e5791d4b1a2c06cb66bc70 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_15.mp4.txt @@ -0,0 +1,136 @@ +[5.58s -> 7.82s] Intraventricular hemorrhage. +[12.08s -> 25.81s] My name is Anne Hansen, and I'm going to talk to you today about the most common neurologic complication of prematurity, namely germinal matrix and intraventricular hemorrhage. I'm going to use the abbreviation GMH-IVH. +[26.03s -> 38.29s] This information will be helpful in both minimizing risk factors for GMH-IVH and providing accurate information for parents, who usually prioritize knowledge about potential neurologic concerns. +[38.77s -> 48.51s] During this lesson, we are going to discuss the incidence, pathogenesis, and risk factors, presentation and diagnosis, management, +[48.51s -> 58.54s] neuropathic consequences, and outcome of patients who develop an intraventricular hemorrhage. Incidents of germinomatrix intraventricular hemorrhage. +[59.25s -> 72.43s] First, let's talk about incidence. Germinal matrix and interventricular hemorrhage is the most common neurologic complication of prematurity. It occurs in somewhere between 15% and 20% of preterm infants. +[72.43s -> 81.52s] If you spend time working in a neonatal intensive care unit, it won't be long before you take care of a baby with a germinal matrix intraventricular hemorrhage. +[82.00s -> 91.18s] Before we talk further about GMH-IVH, try to imagine what the brain of a profoundly preterm infant actually looks like. +[92.53s -> 105.04s] This is a photo of the brain of a 24-week gestation infant who died of complications of prematurity. It's helpful to keep this image in mind as you learn about GMH-IVH. +[105.04s -> 114.54s] While the external appearance of a premature infant is obviously immature, the brain, though not visible, is equally underdeveloped. +[114.64s -> 123.98s] The germinal matrix is a neuronal and glial cell precursor site that's located in the subappendimal region in the caudothalamic groove. +[124.11s -> 129.65s] Bleeding within the germinal matrix is called a germinal matrix or sub-appendimal hemorrhage. +[130.29s -> 144.13s] The blood in the germinal matrix can extend into the lateral ventricles, causing an intraventricular hemorrhage. The germinal matrix is a fetal structure that spontaneously involutes starting at about 24 weeks gestation. +[144.13s -> 157.14s] It's pretty much gone by about 34 weeks gestation. Term babies don't have a germinal matrix. That's why germinal matrix and intraventricular hemorrhage are almost exclusively a complication of preterm infants. +[158.00s -> 162.42s] pathogenesis and risk factors for GMH-IVH. +[163.18s -> 173.52s] Germinal matrix and interventricular hemorrhages are caused by bleeding that typically originates in the extremely vascular, fragile, and friable germinal matrix. +[173.52s -> 179.25s] Abnormal coagulation or cerebral blood flow can contribute to GMH-IVH. +[179.89s -> 194.13s] Many preterm infants are particularly vulnerable to alterations in cerebral blood flow because they have a pressure passive circulation, meaning that they cannot regulate their cerebral blood pressure to protect against fluctuations in systemic blood pressure. +[194.13s -> 208.11s] These are all important considerations in thinking about the risk factors for GMH-IVH. What puts a patient at risk for intraventricular hemorrhage? The following story describes a mock patient named Sarah. +[208.11s -> 220.30s] and serves to illustrate the risk factors for IVH and how they commonly arise during a preterm infant's hospital course. Sarah was born at 25 weeks gestation at a community hospital. +[220.30s -> 232.06s] because her mother presented in preterm labor with a fever, foul-smelling amniotic fluid, and uterine tenderness concerning for choreoamnionitis. There was no neonatologist at her delivery. +[232.06s -> 246.83s] and it was quite a challenge for the pediatric staff to stabilize her until the transport team arrived to pick her up. The transport team intubated her and gave her a dose of surfactant based on a chest x-ray that was consistent with respiratory distress syndrome. +[247.06s -> 259.06s] They put her in the ambulance and on her way back to the tertiary care hospital, she developed a tension pneumothorax. The pneumothorax reduced her cardiac output and she developed hypotension. +[259.09s -> 271.58s] Once she arrived in the neonatal intensive care unit at the tertiary referral center, the admitting team evacuated the pneumothorax and corrected her blood pressure. The following morning, they obtained a head ultrasound. +[271.58s -> 278.51s] what would you be concerned that this head ultrasound might show? It showed an intraventricular hemorrhage. +[278.96s -> 292.82s] In a moment, we'll discuss how to describe or grade her intraventricular hemorrhage. But first, let's go back to the risk factors to be sure that we understand each of the items on the list. To complete this list, we need to add asphyxia, +[292.82s -> 300.91s] patent ductus arteriosus, and coagulopathy. The risk factors are closely linked to the pathogenesis of intraventricular hemorrhage. +[301.10s -> 309.90s] Besides the coagulopathy, which speaks for itself as a risk factor for intracranial hemorrhage, what do you think that all of the things on this list have in common? +[310.32s -> 316.88s] Each of the items on this list causes either an increase or a fluctuation in cerebral blood flow. +[316.91s -> 327.18s] It's important to remember that many of the ways in which we provide care for newborn premature infants can cause either an increase or a fluctuation in cerebral blood flow. +[327.47s -> 340.85s] We increase cerebral blood flow when we provide a volume expander. Therefore, it is extremely important to avoid the infusion of colloid or hyperosmolar fluids when possible and when they must be given. +[340.85s -> 342.99s] to infuse them slowly. +[343.50s -> 357.68s] Cerebral blood flow also increases when we let a patient be hypercarbic, anemic, or hypoglycemic, or when we perform procedures that cause the patient to have a valsalva response, which can increase cerebral blood flow. +[358.29s -> 372.34s] We see fluctuation in cerebral blood flow in the setting of a pneumothorax, for example, if it is evacuated and then recurs or during seizures or if we perform an exchange transfusion on a premature infant. +[372.85s -> 386.13s] Keeping all of this in mind, trying to normalize and stabilize cerebral blood flow, especially in the first few days after the birth of a preterm infant, can help to minimize the risk of GMH-IVH. +[386.86s -> 390.61s] presentation and diagnosis of IVH. +[391.41s -> 404.72s] The presentation of intraventricular hemorrhage is most commonly silent. You may feel a full fontanelle and the patient may demonstrate anemia on blood testing, but the most common presentation is silent. +[404.72s -> 412.21s] In the literature, you may read about a saltatory or catastrophic presentation, but these are quite rare. +[412.34s -> 426.74s] The saltatory presentation describes a change in consciousness, hypotonia, and abnormal eye movements. The catastrophic presentation involves rapid neurologic deterioration, stupor, tonic posturing, +[426.74s -> 441.04s] and profound hypotension. Since the presentation of intraventricular hemorrhage is largely silent, we rely on screening head ultrasounds to make the diagnosis. We obtain coronal and sagittal views. +[441.17s -> 449.74s] Cranial ultrasound is an ideal technique because it is high resolution, portable, and does not cause any radiation exposure. +[450.03s -> 464.69s] We usually order head ultrasounds according to a schedule based on the patient's chronologic age. When do you typically order a head ultrasound for a prematurely born baby? Please leave us your answer in the comments section of this video. +[465.58s -> 469.79s] Of course, there's some variation from institution to institution. +[469.79s -> 484.34s] But a fairly typical routine for babies born at less than 32 weeks gestation, or less than 1,500 grams, is to get a head ultrasound at 7 to 10 days after birth, with an earlier study about 3 days after birth for the most high risk. +[484.34s -> 488.56s] patients. This timing is based on data like this. +[489.07s -> 503.49s] 50% of intraventricular hemorrhages occur in the first day and 90% within the first three days, according to a study by Dr. Volpe. Essentially 100% of GMH-IVH has occurred +[503.49s -> 511.78s] by one week after birth, according to a study by Dr. Paneth that involved over 1,000 infants weighing less than two kilograms. +[511.78s -> 526.29s] So if a baby does not have a GMH-IVH diagnosed by about one week of age, it's most likely that that will not be a complication of prematurity that this baby will suffer. The Papil Grading System. +[527.09s -> 534.32s] Now we're going to talk about the Papil grading system for IVH. This grading system is very problematic. +[534.64s -> 542.74s] but it's also used extensively, especially in follow-up literature, because it provides a quantitative scaling for neurologic injury. +[543.02s -> 550.38s] I'm going to go through the four papil grades of IVH. I will also describe why some of these grades are problematic. +[550.90s -> 564.02s] First is the grade one or germinal matrix hemorrhage. You might also hear it called a sub-appendimal hemorrhage. This is not an intraventricular hemorrhage. It's only a hemorrhage in the germinal matrix region. +[564.53s -> 576.27s] Next is a grade 2 intraventricular hemorrhage. This is a perfectly fine term. It refers to an intraventricular hemorrhage without enough blood to cause any ventricular dilation. +[576.66s -> 588.02s] Next, we have a grade 3 hemorrhage. This is intended to refer to an IVH that has enough blood introduced into the ventricle to cause the ventricle itself to dilate. +[588.02s -> 601.86s] It often is confused with a grade 2 IVH, in which there is CSF buildup due to post-hemorrhagic hydrocephalus and ventricular enlargement on that basis. That should actually be called a grade 2 IVH with secondary +[601.86s -> 608.58s] post hemorrhagic hydrocephalus. The most problematic term is a grade IV IVH. +[608.58s -> 618.24s] Like a grade 1 IVH, a grade 4 IVH does not refer to an actual IVH. A grade 4 IVH refers to parenchymal bleeding. +[618.24s -> 627.28s] We now understand that this parenchymal blood is much more likely to be a venous infarction than an extension of a grade 3 IVH. +[627.79s -> 634.26s] Let's go over some pathological samples and some head ultrasounds of various grades of IVH. +[634.70s -> 642.80s] Here you can see on the left a germinal matrix that is normal and on the right a germinal matrix that has a hemorrhage in it. +[642.93s -> 655.12s] On the head ultrasound, you can see on the left a germinal matrix that is slightly echogenic, and on the right a germinal matrix that's echogenic with blood that's extended into the ventricle. +[655.73s -> 666.53s] On this pathologic sample, you can see an intraventricular hemorrhage with ventricular dilation. Because there's not actually very much blood in this ventricle, most likely... +[666.53s -> 671.28s] This ventricular dilation is on the basis of post-hemorrhagic hydrocephalus. +[671.92s -> 683.57s] In the head ultrasounds, you can see blood in the ventricles bilaterally with enough blood that the ventricles are dilated. These would be grade three intraventricular hemorrhages. +[683.57s -> 694.54s] And here you can see pictures of parenchymal hemorrhages. In the pathologic sample, you can see on the right that there's parenchymal bleeding and that there's also blood in the ventricles. +[695.31s -> 706.96s] And on the head ultrasound findings, you can see on the right that there's echogenicity extending into the parenchymal region that would also be read as a grade four or a parenchymal hemorrhage. +[707.50s -> 714.16s] We used to think that the parenchymal blood extended from the ventricles into the tissue of the brain. +[714.58s -> 725.50s] But what we now understand is that these are periventricular hemorrhagic infarctions that are probably of venous origin due to obstruction of blood flow in the terminal vein. +[725.50s -> 736.88s] In this picture, you can see that as the ventricle fills with blood, the parenchyma of the brain can become compressed and obstruct the venous drainage on the side of the IVH. +[737.04s -> 743.55s] If you think back to the gelatinous picture of the brain at 24 weeks gestation, it would be easy to imagine +[743.55s -> 756.08s] how the non-muscularized venous system would easily be obstructed and how that could cause a secondary venous infarction. This is what we now understand is the basis of what we've been calling +[756.08s -> 762.35s] grade four or parenchymal hemorrhages. Management of IVH. +[762.83s -> 777.15s] The management of intraventricular hemorrhage is largely supportive. We try to maintain stable cerebral perfusion, normal blood pressure, normal electrolytes, and normal serum glucose levels. We also treat anemia. +[777.15s -> 789.87s] thrombocytopenia, and coagulopathy. Neuropathic consequences and outcome. What are the neuropathologic consequences of developing a germinal matrix or intraventricular hemorrhage? +[790.29s -> 801.78s] A germinal matrix hemorrhage can cause destruction of glial cell precursors. And this area is replaced with a hematoma, or cyst, as can be seen on these head ultrasounds. +[802.16s -> 814.11s] The other neurologic consequences of an intraventricular hemorrhage is post-hemorrhagic hydrocephalus. This occurs when there's impairment of cerebrospinal fluid absorption by the arachnoid villi. +[814.11s -> 820.66s] or mechanical obstruction of CSF flow. Post hemorrhagic hydrocephalus. +[821.23s -> 833.58s] Post-hemorrhagic hydrocephalus occurs in approximately one third of all patients with intraventricular hemorrhages. Of that one third, two thirds of the infants actually have spontaneous arrest. +[833.58s -> 847.47s] or resolution of the hydrocephalus within a month of onset. Please note that of that two-thirds who recover spontaneously, about 5% will develop progressive hydrocephalus again up to one year later. +[847.47s -> 858.58s] But of that one third of patients with IVH who develop post-hemorrhagic hydrocephalus, one third of them will go on to develop long-term problems with post-hemorrhagic hydrocephalus. +[858.99s -> 871.28s] How do we diagnose and monitor post hemorrhagic hydrocephalus? The most basic approach to monitoring is to take a plain tape measure and measure head circumference on a daily basis. +[871.50s -> 881.17s] It can be difficult to determine what is an appropriate head circumference growth for a preterm infant. Typically, we say that one centimeter a week is normal. +[881.17s -> 891.12s] However, if a patient is having poor overall somatic growth and not gaining well in weight or length, one centimeter a week may be excessive. +[891.41s -> 900.18s] On the other hand, if the patient is gaining weight very well and having good catch-up growth, more than one centimeter a week may be appropriate. +[900.18s -> 914.13s] So it's a good idea to put together the head circumference measurements with weight and length measurements to get an overall assessment of what would be expected. In general, growth of more than two centimeters a week is excessive. +[914.86s -> 929.46s] In addition to our head circumference measurements, we also look at vital signs and clinical status, things such as lethargy, feeding intolerance, and apnea bradycardia events. And finally, our gold standard is serial head ultrasounds, which... +[929.46s -> 932.05s] we typically obtain at least weekly. +[932.53s -> 946.62s] The resistive index can be a useful non-invasive measurement obtained during a head ultrasound that can guide the management of post hemorrhagic hydrocephalus. It is defined as systolic blood flow velocity +[946.62s -> 957.50s] minus diastolic blood flow velocity over systolic blood flow velocity, as measured by Doppler ultrasound, typically of the anterior cerebral artery. +[957.50s -> 961.94s] If there is not a non-neurologic etiology of elevated RI, +[961.94s -> 976.27s] as seen with large PDA or high frequency ventilation. Then either an elevated RI or a significant change in RI with gentle compression of the fontanelle by the ultrasound probe raises concern that the patient's degree of intracranial pressure +[976.27s -> 982.32s] elevation is a risk of ischemic brain injury and should have CSF removed. +[982.90s -> 994.00s] Our therapy for post hemorrhagic hydrocephalus is aimed at reducing intracranial pressure by removal of CSF. Generally, we start with serial lumbar punctures. +[994.80s -> 1001.39s] This is an effort to remove CSF in bulk. It is a temporizing measure to safely buy time. +[1001.39s -> 1015.74s] while determining if a patient with post hemorrhagic hydrocephalus is going to be in the two-thirds that gets better group or the one-third that needs long-term therapy. If a patient is determined to be in the one-third that needs long-term therapy group, +[1015.74s -> 1030.10s] They need more definitive treatment. One bridging therapy can be a subgaleal shunt. This is a shunt that starts in the ventricular space and allows fluid to flow up into the subgaleal space. +[1030.42s -> 1044.86s] When assessing whether a subgaleal shunt is functioning or not, it's not important to palpate the area where the subgaleal shunt is present underneath the skin. Instead, you want to do what you always do to assess for elevated intracranial pressure. +[1044.86s -> 1050.32s] feel the fontanelle, follow the head circumference, and look at the patient's clinical status. +[1050.74s -> 1063.98s] The definitive treatment for post-hemorrhagic hydrocephalus is typically a ventriculoperitoneal shunt. Patients are generally big enough for a VP shunt when they reach 1.5 to 2 kilograms. +[1064.30s -> 1075.06s] This is a picture of a patient with a ventriculoperitoneal shunt. It starts in the ventricle. It tracks out to just underneath the skin. You can generally feel it in the neck. +[1075.06s -> 1084.30s] and then there's redundant length of the shunt in the abdomen so that the baby can grow up to be six feet tall and have the shunt still end in the peritoneal space. +[1084.66s -> 1092.69s] Ventricular peritoneal shunts come with their own set of complications, including a risk of both infection and obstruction. +[1092.69s -> 1104.69s] Parents who have a baby with a ventricular peritoneal shunt need to be sure to have the shunt assessed for those potential complications, especially in the setting of fever or neurologic signs and symptoms. +[1104.69s -> 1113.10s] Some centers now perform a procedure called an endoscopic third ventriculostomy with choroid plexus cauterization. +[1113.49s -> 1124.48s] This is an alternative to a VP shunt and avoids the complications of shunt infections and obstructions. The best candidates for an ETV CPC +[1124.48s -> 1133.94s] are patients in whom the aqueduct is obstructed and who do not have scarring of the prepontine cistern. Prevention. +[1134.80s -> 1148.14s] And fortunately, we don't have very many ways of preventing intraventricular hemorrhage. If we could prevent premature birth, we would prevent intraventricular hemorrhage because this is primarily a complication of preterm babies. +[1148.82s -> 1162.06s] We've looked at many different potential antenatal pharmacotherapies to decrease IVH rates, and the one agent that is clearly effective is maternal receipt of a complete course of antenatal steroids. +[1162.19s -> 1168.56s] In utero transport certainly helps, as well as optimal management of labor and delivery. +[1169.20s -> 1182.77s] Researchers have also looked at the potential for postnatal pharmacotherapy to decrease risk of IVH in preterm infants. The only agent that is effective in decreasing the IVH risk is indomethacin. +[1183.66s -> 1196.08s] Based on the most recent Cochrane meta-analysis updated in 2010, the use of prophylactic indomethacin reduces symptomatic PDA and severe IVH, but does not +[1196.08s -> 1203.06s] either benefit or harm longer term outcomes, including neurodevelopment. Additionally, +[1203.06s -> 1217.36s] Indomethacin is accompanied by its own set of risks, including that of intestinal perforation, especially when given in close proximity to systemic steroids. Therefore, the use of prophylactic indomethacin remains controversial. +[1217.36s -> 1231.50s] and must be individualized based on clinical circumstances, local IVH rates, and personal preference. Some centers use publicly available IVH calculators to tailor the decision for specific patients. +[1232.21s -> 1246.77s] Now I'll talk about outcome of patients with IVH. This is where the Papil grading system, despite all of its problems, is useful because it allows us to categorize the hemorrhages into more severe and less severe. +[1247.34s -> 1261.94s] Outcomes. Patients with grade 1 and 2 IVH overall have only a minimal increased risk of adverse neurologic outcome compared to very low birth weight infants with no intraventricular hemorrhage. +[1262.38s -> 1276.98s] As developmental testing becomes more refined, there are reports of an increased risk of cognitive impairment and cerebral palsy, but it is difficult to sort out the effects of the IVH and that of white matter injury, which often coexists in this patient. +[1276.98s -> 1280.62s] population and can be missed by head ultrasound. +[1281.87s -> 1296.46s] In general, we can assure parents that if their baby develops either a germinal matrix or intraventricular hemorrhage without ventricular dilation, we would expect them to have approximately the same outcome as babies matched by birth weight, gestational age, and +[1296.46s -> 1299.63s] severity of illness with negative head ultrasounds. +[1300.08s -> 1312.46s] By contrast, patients with IVH resulting in ventricular dilation and those with periventricular hemorrhagic infarction have a markedly increased risk of impaired neurodevelopment. +[1313.04s -> 1324.78s] About one-third of patients with a grade 3 IVH, that is to say an IVH with ventricular dilation on the basis of the amount of blood that's in the ventricle, will have a major handicap. +[1324.85s -> 1334.83s] and about three-fourths of babies with parenchymal hemorrhages will have a major handicap. These patients are also at risk for visual impairment and seizures. +[1335.54s -> 1345.89s] If they have associated white matter injury, they may develop spastic diparesis as well as cognitive delays. If the injury is extensive and bilateral, +[1345.89s -> 1354.70s] especially if also associated with periventricular leukomalacia, it can result in quadriparasites and severe cognitive deficits. +[1355.44s -> 1368.69s] The patients with post-hemorrhagic hydrocephalus are the ones with the most severely affected outcomes. About 90% of them will have neurodevelopmental impairments. 56% of them will have multiple impairments. +[1369.26s -> 1380.40s] 14% will have seizures that require medical therapy, 9% will have severe vision problems, and 6% will have sensorineural hearing loss. +[1381.04s -> 1395.14s] The characteristics associated with the porous prognosis are bilateral involvement, persistent ventricular enlargement, parenchymal involvement, periventricular ecodensity or echolucency, which is PVL. +[1395.14s -> 1409.41s] or low gestational age. It's important to note that persistent ventricular enlargement can be on the basis of blood, as in the setting of grade 3 IVH. It can be due to CSF buildup due to post-hemorrhagic hydrocephalus. +[1409.41s -> 1415.92s] or it can be due to an ex vacuo hydrocephalus due to actual volume loss of the parenchyma. +[1416.75s -> 1428.14s] The reason that low gestational age is on this list is that profoundly preterm infants often have multiple complications of prematurity, each one making it more difficult to compensate for the other. +[1428.37s -> 1435.81s] For example, if a patient has an interventricular hemorrhage, that would predispose them to, for example, a learning disability. +[1435.81s -> 1446.61s] and the patient also has retinopathy of prematurity and therefore has visual difficulties, the visual difficulties make it more difficult to compensate for the learning difficulties. +[1447.34s -> 1460.98s] I hope that this lesson has helped you to understand the assessment and management of intraventricular hemorrhage and post-hemorrhagic hydrocephalus, including the importance of rigorous attention to the cerebral perfusion, blood pressure, +[1460.98s -> 1471.38s] electrolytes, glucose, hematocrit, platelet, and coagulation factors in the first week after the birth of infants born under 32 weeks gestation. +[1471.98s -> 1485.23s] I also hope you now feel more confident in answering parents' questions about what to expect with their preterm baby in terms of potential neurologic complications and their prognostic implications. Thank you. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_4.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..90fa31f2720bbd08174c0306a0e85140d6061428 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_4.mp4.txt @@ -0,0 +1,59 @@ +[0.40s -> 13.65s] Hello everyone, today we will be discussing a rare tumor sub-ependymoma. Outline of today's talk includes introduction, clinical features, imaging +[13.65s -> 26.54s] findings of sub-ependymoma and its differential diagnosis, macroscopic and microscopic findings, immunoprofile, genetic profile and prognosis. +[29.20s -> 43.70s] Coming to introduction, sub-appendymoma is a glioma characterized by clustering of uniform to mildly pleomorphic tumor nuclei in an abundant febrile matrix. +[43.70s -> 49.87s] prone to microcystic change. This tumor corresponds to CNS-WHO grade 1. +[50.45s -> 63.89s] Localization. Fourth ventricle is the most common site and it accounts for almost 50 to 60 percent of cases. 30 to 35 percent of cases occur in the lateral ventricle. +[63.89s -> 74.86s] followed by third ventricle. Now the cases in the spinal cord are rare and these arise as eccentric masses in the cervicothoracic segment. +[75.34s -> 88.99s] epidemiology. These are rare tumors and account approximately for 8% of ependymal tumors and less than 1% of the intracranial neoplasms. +[88.99s -> 99.95s] The peak incidence is in the adults. Age group ranges from 40 to 84 years and it shows slightly male predominance. +[100.91s -> 111.60s] Coming to clinical features, these patients are often asymptomatic and the tumor is discovered only incidentally on neuroimaging. +[111.60s -> 124.90s] for some unrelated reasons or at the time of autopsy symptomatic intracranial cases are associated with ventricular obstruction raised ict and +[124.90s -> 138.32s] occasionally intratumoral or intraventricular bleed or hemorrhage. Intramedullary tumors manifest as sensory motor deficits indicative of myelopathy. +[140.53s -> 154.82s] Coming to the etiology, examples have been well documented in the monozygotic twins associated with trichorhinophalangeal syndrome type 1 and +[154.82s -> 159.95s] germline TRPS1 mutation. +[161.39s -> 171.44s] So let's have a look at our case. Now this is a 69 year old man who presented with headache, blurred vision and +[172.59s -> 187.25s] MRI revealed a supratentorial intraventricular space occupying lesion within the frontal horn of the lateral ventricle, which measured 4.3 x 3.3 x 2.5 cm. +[187.25s -> 199.92s] The mass appears dumbbell shaped in configuration with foramen of Monroe, third ventricle and anterior horn of left lateral ventricular components. +[199.92s -> 206.96s] The T2 weighted images appear mildly hyper intense and T1 appear hypo intense. +[211.79s -> 226.29s] So coming to imaging findings of sub-appendymoma. These are sharply demarcated lobular non-enhancing intraventricular mass which is hypo to iso-intense on T1. +[226.29s -> 238.29s] and hyper intense on t2 weighted images some ependymomas exhibit calcification cystic taint hemorrhage hosai of contrast enhancement may be seen +[238.29s -> 252.56s] these are typically one to two centimeters in size and they may enlarge to grow as much as more than five centimeters and those larger in size appear symptomatic +[253.97s -> 266.75s] Coming to the differential diagnosis on imaging. The first is ependymoma which is commonly found in younger patients. Ependymoma is a heterogeneously enhancing mass. +[266.75s -> 279.66s] With edema, it is typically found in the fourth ventricle with hydrocephalus and often parenchymal component may be present when it is supratentorial. +[279.66s -> 282.91s] The second DD is the central neuropsychoma. +[282.91s -> 297.33s] the common age group in this central neurocytoma is 20 to 40 years and these are typically bubbly appearance or the soap bubble appearance and calcification is commonly found the location +[297.33s -> 311.20s] is lateral ventricle and central neurocytomas are attached to the septum pellucidum and they show moderate to strong enhancement the next differential diagnosis on imaging is the sub +[311.20s -> 325.49s] ependymal giant cell astrocytoma sega. Now this is an enhancing mass at foramen of Monroe. Calcifications are commonly found and these patients may have other features of tuberous sclerosis. +[325.49s -> 334.74s] such as sub-appendymal nodules, cortical tubercles and white matter lesions. +[339.76s -> 349.71s] The next DD is the choroid plexus papilloma. Now this is common in the pediatric tumors. Lateral ventricle is commonly affected when it comes to the adults. +[349.71s -> 362.61s] It is found in the fourth ventricle and these are enhancing papillary masses with hydrocephalus. Next is the metastasis. Primary is oftenly known. +[362.61s -> 372.88s] Now, these may also show multiple lesions at the gray-white junctions and typically involve choroid plexus when the tumor is intraventricular. +[372.88s -> 380.62s] And a remote possibility of a cavernous malformation should also be taken into consideration. +[382.74s -> 396.24s] So this is what we received in lab. Now the tumor measured almost 3.5 into 2.5 into 2 centimeters. This tumor was operated by +[396.24s -> 409.33s] Dr. Harish Chandrapa from Shimoga, Karnataka and he sent this tumor to us. Now this tumor is a appendimoma. +[409.33s -> 421.55s] is form gray and circumscribed and it may bulge in ex in exophytic fashion into the ventricles histopathology +[421.58s -> 430.83s] Clustering of small euchromatic and round to oval nuclei resembling those of sub-appendymal glia. +[430.83s -> 444.91s] Microcysts and calcification are common particularly in the lateral ventricular subappendymomas. Rarely nuclear pleomorphism and proliferative micro abnormalities may be found. +[444.91s -> 450.03s] Mitotic activity and non-palysidic necrosis is rare. +[450.35s -> 464.74s] Some ependymomas may focally manifest perivascular pseudorosites. Mixed histologic pattern may be present such as sub-ependymoma, predominant neoplasms, +[464.74s -> 477.73s] With nodules of classic ependymoma, the terminology is mixed ependymoma, sub-ependymoma are also well recognized. Secondly, sub-ependymoma +[477.73s -> 492.02s] with elements of fibrillary astroglial or rarely gemistocytic morphology may be found. Exceptionally rare melanotic pigmentation or sarcomatous change may be noted. +[492.85s -> 499.54s] Sclerotic and ectatic blood vessels, hemorrhage and hemocydrine deposits are common. +[501.97s -> 515.73s] Coming to immunoprophy, GFAP is diffusely strongly positive. Some exceptional cases may show olig positivity or even synaptophysin positivity. +[515.76s -> 528.46s] Clustering of focal dot like EMA positivity is noted. KTRX is retained. Now we need to rule out central neuropsychoma in this case. +[528.46s -> 540.85s] which is done seen by synaptophysin and ttf and immunonegativity and the proliferation index mib one is usually less than one percent +[541.58s -> 547.66s] So, we rendered a diagnosis of sub-ependymoma CNS-WHO grade 1. +[548.69s -> 561.42s] Coming to diagnostic molecular pathology, sub-ependymomas in the supracentorial, posterior fossa and spinal cord have a distinct DNA methylation profile. +[561.55s -> 575.92s] Chromosome 19 loss and partial chromosome 6 loss is found in the infratentorial cases and TRIPS1 that is TRPS1 mutation is also found. +[577.58s -> 591.78s] Coming to prognosis, sub-appendymomas exhibit excellent prognosis, recurrence is rare even after subtotal resection, cytological pleomorphism, occasional mitosis. +[591.78s -> 605.47s] and necrosis have not proved prognostically significant in tumors with mixed ependymoma sub-ependymoma component behave aggressively depending on the histology +[605.47s -> 616.50s] of the ependymoma however the study is going on and we're just not sure whether to consider this point +[616.94s -> 628.51s] So take home message. Sub-ependymoma is a glioma characterized by clustering of uniform to mildly pleomorphic tumor nuclei. +[628.51s -> 634.48s] Set an abundant February matrix prone to microcystic change. You must know the grade. +[634.48s -> 645.90s] It's CNS, WHO CNS grade 1. On imaging, these are sharply demarcated lobular non-enhancing intraventricular masses commonly found in the fourth ventricle. +[645.90s -> 660.16s] These are T1 hypo to iso intense and T2 hyper intense masses. Macroscopy, these are firm gray white circumscribed masses which may bulge into the ventricles in the exophytic. +[660.16s -> 672.34s] fashion cystic change and calcification is commonly found coming to microscopy these are clusters of small euchromatic round to oval +[672.34s -> 681.47s] nuclei set on the fibrillary matrix and mitotic activity, microvascular proliferation, necrosis is absent. +[681.47s -> 695.54s] Immunoprofile is GFAP and EMA positive and the KI-61 index is less than 1%. Molecular pathology, distinct DNA, methylation profile. +[695.54s -> 710.38s] has been found in the supratentorial, infratentorial and the spinal cord subappendymomas and the prognosis is excellent irrespective of subtotal excision. +[712.37s -> 726.03s] So thank you very much. If you have any queries, you can write a comment in the comment box or communicate to me on my email ID. Thank you very much. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_6.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..712911a0b39edb0c683c0dafcca33dbfe1a668df --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Diagnostics_and_Laboratory_Medicine_6.mp4.txt @@ -0,0 +1,74 @@ +[7.09s -> 9.23s] Hello and welcome. +[9.52s -> 23.79s] σε αυτήν την κλειστή σεσόν της κανονικής ραδιογραφικής ανατομικής του κανονικού θόρου. Ονομάζομαι Πιτ Μάντις και στις επόμενες λεπτόμερες λεπτόμερες θα παρακολουθήσουμε πώς οι διάφορες οργάνες στον θόρου παρακολουθούν. +[23.79s -> 36.50s] και πώς μπορούμε να χρησιμοποιήσουμε κάποια κατάσταση των χαρακτήρων για να γίνουμε πιο πιθανοί στην αποφάση μας αν είναι μεγαλύτερο, μικρότερο, σωστό ή ασφαλό. +[37.81s -> 51.90s] Συνήθως, όλοι γνωρίζουμε ότι ο θόρακτος είναι τελικά λουσινό και ο μυαλός είναι τελικά λουσινό και περιέχει βασίλες και μπρόγχη που δίνουν αυτή την οπασίτηση. Όλοι καταλαβαίνουμε ότι πρέπει να βλέπουμε και το λατρελό και το βιντεο και το διβι. +[51.90s -> 62.86s] ώστε κάθε φορά όταν κάθε οργάνωμα επεξεργαλείται σε αυτές τις ορθογονικές βιβλίες να γίνει αυτή η τριδιμεσιακή εμφάνιση. +[65.23s -> 76.19s] για να πάρουμε την πλήρη απνορματικότητα και όλοι γνωρίζουμε ότι πρέπει να χρησιμοποιούμε ραδιογραφικά σημαντά, νούμερο, σημαντικότητα, θέση, κατεύθυνση, μαζινότητα και ραδιοοπασία. Εδώ θα πάω... +[76.19s -> 88.18s] Πρώτα στο λατρελό, τότε στο VDDV για να περπατήσουμε τις διάφορες βιβλίες, για να έχουμε μία ιδέα για το πώς βλέπουν σχεδόν σε κάθε βιβλία. +[89.97s -> 96.43s] Θα ξεκινήσουμε με το λατρελό και με το τραχείο. Το τραχείο είναι αυτή η λουσιακή στράξη. +[97.97s -> 112.08s] σχεδόν ενδιαμετρική σε διαμετρικό και τελειώνει στην βιβλιογραφία, η οποία είναι η καρίνα, η μικρότερη, πιο λουσιαστή περιοχή της κοδελής. +[113.01s -> 123.31s] Τώρα, πρέπει να είναι σχεδόν ομορφωμένος, πρέπει να δημιουργείται μία μικρή αγκαλιά με το σπινό του 10-15°. +[123.63s -> 137.84s] ούτε περισσότερο, ούτε λιγότερο. Και ένα μεριόμενο που μπορούμε να χρησιμοποιήσουμε στις adult dogs είναι, πραγματικά, το διάμετρο εδώ, στο διάμετρο του θεραπευτικού σύνολου +[137.84s -> 144.11s] Αν διευκολύνω τη διαμετρία του τραχείου με τη θεραπεία, +[144.75s -> 159.06s] Στις μη βραχυσεφαλικές γυναίκες θα πρέπει να είναι λιγότερο από 0.2, στις βραχυσεφαλικές λιγότερο από 0.16 και στις μη βραχυσεφαλικές γυναίκες θα πρέπει να είναι λιγότερο από 0.5. +[159.06s -> 163.73s] Υπότιτλοι AUTHORWAVE +[164.75s -> 174.16s] πέσει στο 0.07. Είναι κάποιες φορές αυτό που θέλω να ονομάσω το απνορματικό φύλλο. +[174.83s -> 181.14s] Τώρα αυτό είναι για το τραχείο, κάτι που μπορούμε να χρησιμοποιήσουμε όλοι εύκολα. +[181.90s -> 192.56s] Και τότε θα πηγαίνω στο Μιδιαισταϊνό, όπου μπορούμε να δούμε αυτή την περιοχή κάτω. Αυτό είναι το Μιδιαισταϊνό κρανιαλό. +[193.58s -> 205.49s] μόνο κάτω από το τραχείο, όπως μπορείτε να δείτε είναι οπαίκο και δεν μπορούμε να δούμε κανένα σχέδιο μέσα. Περιμένουμε στο καρδιακό σιλουέτο. +[206.26s -> 215.15s] Μπορούμε να δούμε εδώ, για αντιμετωπιστικές λύσεις, αφήνουμε ένα σχέδιο από την Carina στο Apex και μετά... +[215.63s -> 229.41s] Είναι σημαντικό να εγγραφείτε ότι αυτό είναι μόνο για... +[229.41s -> 242.51s] προσπαθώντας να αντιμετωπίσουμε ποιο κύριο είναι μεγάλο, αλλιώς υπάρχει ένα μεγάλο ασφαλείο στην πραγματικότητα και αυτό δεν αντιμετωπίζει την πραγματική πραγματικότητα εκεί. Ένα μεριόμενο που μπορούμε να κάνουμε... +[242.51s -> 255.79s] εύκολα και ειδικά το προτείνω στους παιδιούς, αν δεν έχουμε κανένα συγκεκριμένο βασικό σχέδιο σχεδιασμού με το βασικό σχέδιο του καρδιού, είναι από... +[255.79s -> 268.11s] Αν προσθέσουμε την καρίνα στην αίπεξη, μετρήσουμε την αριθμότητα μεταξύ της αριθμότητας της αίπεξης της αίπεξης της αίπεξης της αίπεξης της αίπεξης της αίπεξης. +[268.82s -> 274.42s] και ανοίγουμε το x 2 τρίτος. +[275.22s -> 289.76s] και αυτό το x στον παιχνίδι θα πρέπει να είναι λιγότερο από τρία μεταξύσταση, ενώ στον μωρό θα πρέπει να είναι λιγότερο από δύο μεταξύσταση. Αυτό είναι ένα γρήγορο ρόλο των χαμπών που μπορούμε να κάνουμε. +[289.76s -> 298.96s] Υπότιτλοι AUTHORWAVE Υπότιτλοι AUTHORWAVE Υπότιτλοι AUTHORWAVE +[299.60s -> 310.13s] και τότε μετρήσουμε τη γλυκότητα, οπότε A και B και τότε ξεκινάμε από T4 παίρνουμε το A +[310.38s -> 321.73s] και το Β και κοιτάξτε πόσο βέρτεβρα συμβαίνουν. Αυτό είναι αυτό που ονομάζεται βερτεβριακό σκόρ. +[321.73s -> 334.26s] το οποίο είναι πολύ χρήσιμο αν έχετε μια επίγραψη για αυτόν τον συγκεκριμένο πλαίσιο, επειδή ο αρχικός 8.5-10.5 δεν μπορεί να εφαρμόζεται σε όλους τους πλαίσους. +[334.26s -> 345.71s] Μπορούμε να το χρησιμοποιήσουμε καλύτερα αν έχουμε μια επίδραση για το φύλλο. Άλλωστε είναι πολύ χρήσιμο όταν σχεδιάζουμε το καρδιακό σιλουέτ σε δύο διαφορετικές περιπτώσεις. +[345.71s -> 357.04s] όταν πάμε να βλέπουμε το καρδιακό σιλουέτ, πραγματικά, αν έγινε μεγαλύτερο ή μικρότερο στο ίδιο άνθρωπο. Αυτό μπορεί να μας βοηθήσει να το αντιμετωπίσουμε. +[357.58s -> 367.20s] Τώρα, το σχήμα του καρδιού είναι διαφορετικό για διάφορες γυναίκες, για παράδειγμα, σε μικρές γυναίκες που πρέπει να έχουν ένα μεγαλύτερο καρδί, ενώ... +[367.20s -> 376.75s] Υπότιτλοι AUTHORWAVE Υπότιτλοι AUTHORWAVE +[377.01s -> 390.56s] στο στερνό, όσο πιο μεγαλύτερο είναι το στερνό. Όλα αυτά, πρέπει να τα καταλαβαίνεις με την εμπειρία, όταν βλέπεις έναν κανονικό ραδιογραφικό αυτού, βλέπεις το φύλλο. +[390.56s -> 398.51s] και πώς είναι η σχέση αυτής. Έχουμε την Κόδα Βινακάβα. +[398.77s -> 409.14s] στο πόδι και αυτή η τριάνγκλα, συνήθως μεταξύ του διάφραμα, το κοδικό ασπίτο της καρδιακής σιλουέτας και του κοδικού Βινακάβα, είναι αυτό που... +[409.39s -> 416.46s] μπορεί να μας δώσει μια ενδιαφέρονση για το πόσο καλά εμφανισμένη είναι η θέση του ραδιογράφου. +[418.48s -> 429.84s] Φυσικά, υπάρχουν πάντα τα τριέδια, αρτέρια, μπρογχούς, κομμάτια, όπου και όταν εξελίξουμε την αριθμότητα του λατρελού. +[431.50s -> 444.82s] Αν έχουμε μία αρτερή ή μία βαίνη, το μεγαλύτερο, θα πάμε στο εξωτερικό τρίτο του τρίτου ρύβου και αυτό θα είναι λιγότερο ή αντίθετο στο εξωτερικό τρίτο του τρίτου ρύβου. +[445.49s -> 455.54s] Ξεκινάμε τώρα στην αόρτα που μπορούμε να βλέπουμε πηγαίνοντας πίσω. Όπως μπορείτε να δείτε είναι βιωσιμό αλλά δεν είναι. +[456.72s -> 471.47s] εξαιρετικά σαφή και μην ξεχνάτε ότι η κόδευση της βυνακάβας, η καρδιακή συλλόγηση και η ταόρτα είναι στρατιωτικά στρατιωτικά. Μετά προχωρούμε στους λόγους του μυαλού. Έχουμε την κράνια, την κοδέυση, την κόδευση. +[472.43s -> 486.32s] και τα αξιολόγητα γλώσσα. Αυτή είναι η σκληρή περιοχή. Μπορούμε πάντα να δούμε τις φυσιολόγικες αριθμίσεις, αν έχουμε σκληρή της πλούρας ή αν έχουμε φλούδι στην πλούρα. +[486.35s -> 499.50s] Τώρα μπορούμε να δούμε ότι οι ΛΑΓΛΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟΠΟ +[504.02s -> 515.76s] Στην δόξα της βεντριακής θερμοκρασίας, ακόμα μόνο μία σχέση για το λάμβριο, έχουμε κρανιό, κορυφό, κορυφό, κορυφό, κορυφό, κορυφό και κορυφό στη δεξιά. +[516.08s -> 527.57s] Το κράνιλ έχει ένα κράνιλο μέρος και ένα κορυφό μέρος στην αριστερά. Απλά έχει να κάνει με τον τρόπο με τον οποίο τα κορυφό και το μπροντινό είναι σχεδόν σε κάθε πλευρά. +[527.57s -> 533.78s] Μπορούμε να το βλέπουμε εδώ, έρχοντας και το διευκολύνουμε στους δύο κομμάτια του μπρόγχου, λίγο στο δεύτερο. +[536.24s -> 547.34s] μπορούμε να δούμε το κράνιλ μηδιεστάινου, το οποίο στην περισσότερη αυτοκτονία, με την εξαρτάσταση των μηδιεστάινων, που έχουν πολύ φαγητό, δεν πρέπει να είναι περισσότερο από 2 φορές. +[548.08s -> 558.10s] τη γλυκότητα μιας θοραστικής βέρτεβας, οπότε A θα είναι λιγότερο ή αντίμετρο από 2B, στο παραδείγμα μας. +[559.92s -> 568.13s] Ακόμα και οι Βουλδόγγες έχουν πολύ λίγο φαγητό και μπορούν να είναι λιγότεροι από αυτά. +[568.13s -> 577.30s] Μπορούμε να δούμε την καρδιακή σιλουέτα και εδώ έχουμε ένα ωραίο μετώναμα. Μετώναμε την αριθμότητα της καρδιακής σιλουέτας. +[577.78s -> 586.42s] και τότε πηγαίνουμε στο 9ο τριμπ, 3, 4, 5, 6, 7, 8, 9, ας πούμε, και το πηγαίνουμε εκεί. +[589.65s -> 601.74s] Στον παιχνίδι, η μεγαλύτερη γλυκότητα του καρδιού στον 9ο κομμάτι πρέπει να είναι λιγότερο από 60% της γλυκότητας του κομμάτου. +[603.92s -> 617.10s] Στον κοτόπουλο, όποτε αυτό είναι κυρίως για τον κοτόπουλο, δεν έχει σκέψη αν προσθέσουμε κάποια πράγματα για τον κοτόπουλο επίσης, είναι περίπου 50%, λιγότερο από 50% της γλυκότητας στο ίδιο επίπεδο. +[620.50s -> 626.38s] Τώρα για το καρδιακό σιλουέτ χρησιμοποιούμε την προσέγγιση του κλωκού, οπότε 12-1 σημαίνει αόρτα. +[626.96s -> 637.79s] 1-2 Pulmonic artery 2-3 Left atrium 3-6 Left ventricle 6-9 Right ventricle +[637.79s -> 644.74s] και το δευτερόλεπτο αριθμό 9-11. Άλλωστε ανάπτυξε πού βλέπουμε τις μπάλες, αφήνουμε ότι είναι... +[644.74s -> 657.36s] μια πραγματική κομμάτια που είναι μεγαλύτερη. Παρακολουθήστε ότι η αριστερή κομμάτια βρίσκεται κάτι σαν αυτό, οπότε αν είναι εξαιρετικά μεγαλύτερη θα έχετε μία μπάλζα στις 7 ημέρα. Αλλά ξανά... +[657.36s -> 670.80s] Η ραδιογραφία δεν είναι η πιο ασφαλής για την επεξεργασία της καρδιακής συλλογής και όσο μπορούμε να δούμε περισσότερα γεγονότα του φαγητού δεν είναι η ιδέα, όλοι γνωρίζουμε την οικοκαρδιογραφία όπως είναι σήμερα. +[670.80s -> 684.51s] Στην βιβλία VDD, πρέπει να παρακολουθείτε την υποστηριασμό της σκαπιούλα, που θα δώσει μεγάλη αυτοκίνηση, ειδικά στις κρανιακές λαμβάνες και την σπινή και την υποστηριασμό βόντων που μπορεί να καθαρίσουν. +[684.51s -> 697.78s] Το κώδος του Βινακάβα βρίσκεται πίσω, μπορούμε να δούμε την αόρτα όταν έρχεται πίσω και βασικά αυτό θα είναι... +[697.78s -> 711.18s] με διάφορες οργάνες. Τώρα, πριν τελειώσω αυτήν την μικρή ανατομική εξελίξη, ας δούμε λίγο για τις προστασίες. Δεν είναι πάντα... +[711.28s -> 725.62s] που είναι δυνατόν αυτοκίνητος θόραξης, αλλά σε περισσότερες περιπτώσεις μπορείτε να δείτε. Οπότε όταν το άνθρωπο βρίσκεται στο δεύτερο πλευράκιο, το κορυφό του διαφράγματος είναι παραλληλό με το άλλο, +[725.62s -> 735.95s] Κόντα Βινακάβα μπαίνει στο πρώτο κομμάτι και το γάσος στο στόμα είναι στο φαντάνι και στο σώμα. Από την αριστερή πλευρά... +[736.50s -> 748.34s] Παραλληλή κορυφή του διαφραμμού, η κορυφή του διαφραμμού εμφανίζεται στην πρώτη, η οποία είναι στην δεύτερη, και το γάσος στο στόμα είναι στο φαντουσιανικό σώμα, ενώ στην αριστερή κορυφή του διαφραμμού, η κορυφή του διαφραμμού δημιουργεί ένα κορυφό, +[748.34s -> 762.37s] Κόντα Βινακάβα μπροστά στον δεύτερο κομμάτι, το οποίο είναι σήμερα. Θυμάστε ότι η ανάπτυξη του κομμάτια είναι πάντα πιο κρανιακή και το γάσος είναι στον πιλόριο, επειδή συνήθως αυτό είναι το μεγαλύτερο. +[762.37s -> 773.07s] Έτσι, αριθμός αριθμός, παραλληλό διαφράγμα, αριθμός αριθμός, διαφράγμα αριθμός, είναι σε ένα κορνό, δημιουργεί ένα κορνό, το κώδωμα είναι το πρώτο κώδωμα, +[773.94s -> 783.38s] το δεύτερο στο δεύτερο και το γάσος στο στόμα είναι στο φάντουσο και το σώμα στο δεύτερο στο πυλούσο στο δεύτερο. +[784.11s -> 793.90s] Και μόλις τελειώνουμε, βέντρο-δόρυσσο-δόρυσσο-βέντρο, όταν είναι δυνατό. Στο βέντρο-δόρυσσο έχουμε τρία μπάλκια του διαφράγματος, το κράσο και το κούπολο. +[794.67s -> 802.40s] την μικη μάουσα, και υπάρχει ένα κομμάτι μεταξύ της απεξης του καρδιού και της... +[802.40s -> 813.06s] Και εδώ μπορούμε να βλέπουμε κάποιες σχέσεις, μια σχέση που είναι η κοδοβέντρολ μυδιαισθινότητας. Αυτή είναι μια απλή σχέση όπως μπορείτε να αντιμετωπίσετε. +[813.06s -> 826.96s] Από αυτό δεν μπορούμε να βλέπουμε πολλά από το μηδιαστέινο, αλλά μπορούμε να βλέπουμε τα μηδιαστέινα όργανα. Στο δόξο του βέντερου, με τον άνθρωπο στο στερνό, το διαφράγμα εμφανίζεται ενδιαφέρουστο, σαν το κεφάλι του Βρετανού. +[826.96s -> 835.76s] η καρδιακή σιλουέτα εξακολουθεί το διάγραμμα. Ένα άλλο πράγμα που μπορείτε να χρησιμοποιήσετε αν υπάρχει αρκετό γάσος στο στόμα, +[835.76s -> 849.07s] είναι ότι στο βέντερο-δόρυσσο, η περισσότερη γάστα θα είναι στο πιλόρους, ενώ αν έχετε γάστα στο βέντερο-δόρυσσο, η γάστα θα είναι στο φάντους. Γιατί, ξεχνάτε, η γάστα πάντα αυξάνεται. +[850.77s -> 854.16s] Ευχαριστώ για την ώρα σας και ελπίζω να απολαύσετε. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_10.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5cea9676e858c0cb0fbaf48522d0cfc281c36e78 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_10.mp4.txt @@ -0,0 +1,52 @@ +[0.18s -> 9.30s] Professor Dave here, let's talk about intermolecular forces. +[9.74s -> 22.78s] what is happening when a liquid boils? why do different liquids boil at different temperatures? to answer these questions we have to learn about intermolecular forces. these are the electrostatic interactions between molecules +[22.78s -> 34.64s] so atoms within a molecule make covalent and ionic bonds with each other but molecules also participate in interactions with other molecules. let's look at the different types +[34.64s -> 46.64s] first we have ion-ion interactions. large ionic solids are held together by these networks of ionic bonds which are the strongest intermolecular force because they involve formal charges +[46.64s -> 52.99s] after that we have ion-dipole interactions. so first we must understand what a dipole is +[52.99s -> 63.52s] the covalent bonds in a water molecule are polar because oxygen is more electronegative than hydrogen and will pull the electrons in the bond towards itself +[63.52s -> 77.23s] because of the bent shape of the molecule when we combine these vectors we see water has an overall dipole or a side of the molecule with some electron excess and a side with electron deficiency +[77.23s -> 91.82s] dipoles can make electrostatic interactions because the partially negative side is attracted to positive charges and the partially positive side is attracted to negative charges. so when sodium chloride dissolves in water +[91.82s -> 105.95s] sodium ions make ion-dipole interactions with the negative side of water's dipole, and the chloride ions make ion-dipole interactions with the positive side of water's dipole. +[105.95s -> 119.42s] each ion can make several of these interactions which store a lot of energy which is why sodium chloride will dissociate in water in the first place. next we have dipole-dipole interactions. as you can guess +[119.42s -> 123.86s] this is when dipoles interact with each other as with pure water +[123.86s -> 136.53s] when in liquid form water molecules will move in such a way so as to always be making electrostatic interactions between the negative end of one dipole and the positive end of another dipole +[136.53s -> 147.94s] in this case these dipole-dipole interactions qualify for a special title, hydrogen bonds. this is when dipoles generated by NH +[147.94s -> 156.94s] OH or FH bonds interact with each other these are just especially strong dipole-dipole interactions +[156.94s -> 170.03s] they are especially strong because these are the most electronegative elements so they will create the most strongly polarized bonds resulting in a very strong dipole and therefore very strong +[170.03s -> 181.07s] dipole-dipole interactions. we can almost think of partial charges as some fraction of a formal charge, so the greater the partial charge the stronger the interaction +[181.07s -> 191.44s] though never quite as strong as interactions between formally charged particles. lastly we have the van der Waals or the London dispersion force +[191.44s -> 205.52s] these names refer to the same force and are completely interchangeable so I will arbitrarily refer to them as van der Waals forces. this is the consolation prize of the intermolecular forces because any substance can do it +[205.52s -> 219.46s] only ions make ion-ion interactions and only covalent molecules with a dipole can make dipole-dipole interactions but absolutely anything can do van der Waals +[219.46s -> 232.69s] for example take a look at helium. helium is a noble gas and due to a full valence shell it does not make bonds with other atoms so a sample of helium is just a bunch of helium atoms. well +[232.69s -> 245.20s] The electron cloud around a helium atom will at any time be slightly lopsided or skewed towards one direction. This will result in something called a momentary dipole. +[245.20s -> 258.86s] this means one side of the atom is ever so slightly partially negative and the other side is slightly partially positive. this is much weaker than a formal dipole but it still exists and can be measured +[258.96s -> 273.55s] If a momentary dipole approaches another atom, it can generate an induced dipole, meaning the slight partial negativity repels this electron density over to the other side of the atom, so it will also +[273.55s -> 283.54s] have a slight dipole, and then there can be a momentary dipole induced dipole interaction that is the van der Waals force. +[283.54s -> 297.46s] this is a weak and fleeting attraction, but this is all that monoatomic species and nonpolar covalent compounds can do, and for very large molecules like some hydrocarbons the force can become significant. +[297.65s -> 309.78s] so the ion-ion force is strongest because it involves interactions between formally charged particles. ion-dipole is next because it involves a formal charge and a partial charge +[309.78s -> 322.85s] then dipole-dipole which is between partial charges, and van der Waals which is between tiny induced dipoles. to see how intermolecular forces dictate phase change let's do a thought experiment +[322.85s -> 332.66s] first recall that a solid's particles are rigidly packed and not moving a liquid's particles are moving but they are still close together and interacting +[333.01s -> 347.55s] gaseous particles are moving and they are far away from each other so compared to liquids they basically don't interact. so let's pretend we have three substances helium, water, and sodium chloride +[347.55s -> 360.93s] we will place them at zero kelvin or absolute zero which is the lowest temperature possible a complete absence of heat energy where there is no energy available for motion here everything +[360.93s -> 374.38s] even helium, is a solid. in order to go from the solid to the liquid to the gas phase heat energy has to go into the sample and overwhelm the intermolecular forces that are occurring +[374.48s -> 379.71s] a liquid there is some energy stored in electrostatic interactions. +[379.71s -> 390.34s] whatever amount that is, that is precisely the amount of heat energy that has to be provided to liberate the molecules into the gas phase +[390.34s -> 400.00s] where they are not interacting and not storing energy, because nature will not tend to go to a higher energy spontaneously. +[400.00s -> 414.10s] so the energy stored in these interactions has to be provided in some other way. this means that the stronger the forces between the molecules, the more heat energy we will have to provide +[414.10s -> 424.80s] to melt and boil the sample so let's take our three substances slowly raise the temperature and see what happens helium +[424.80s -> 434.54s] as it is only participating in incredibly weak van der Waals forces needs only a minuscule amount of heat energy to disrupt these weak interactions. +[434.54s -> 447.54s] that's why helium will melt and boil at barely one degree above absolute zero water on the other hand is participating in strong dipole-dipole interactions called hydrogen bonds +[447.54s -> 462.16s] there is a significant amount of energy stored in these interactions so we will need considerable heat energy to overcome them. water melts and boils at 273 and 373 Kelvin respectively +[462.35s -> 472.99s] lastly sodium chloride is making extremely strong ion-ion interactions so it will take a huge amount of energy to melt and boil this solid +[472.99s -> 487.50s] it melts at 1074 Kelvin which means there's a lot of energy stored in the ion-ion forces. we can use this information to decide which of a given set of compounds might have the highest boiling point +[487.50s -> 501.78s] when we ask this question we are really asking which compound is generating the strongest intermolecular forces. the stronger they are the more heat energy we will need to pull the molecules apart +[501.78s -> 513.30s] put them in the gas phase so they will boil at higher temperatures. we need to be able to look at a molecule and decide what kind of interactions it will make +[513.36s -> 526.27s] if it is a covalent compound with nonpolar bonds it can only do van der Waals. if it is a covalent compound with polar bonds then we must look at the geometry +[526.27s -> 529.07s] to see if there is an overall dipole. +[529.39s -> 543.81s] for example water has a dipole but carbon dioxide does not because even though carbon-oxygen bonds are polar the direction of these polar bonds causes them to cancel each other out +[543.81s -> 556.30s] the molecule is nonpolar overall. similarly compare BF3 with NH3. again the molecular geometry determines that this is nonpolar +[556.30s -> 567.70s] because the vectors precisely cancel each other out, but with ammonia all the bonds point somewhat towards one direction, so ammonia has a dipole. +[567.95s -> 578.90s] CF4 is nonpolar again because of geometry, but CH3F has just one polar bond, so that has a dipole. +[578.90s -> 592.40s] if a molecule has a dipole it can do dipole-dipole interactions. and lastly formally charged ions participate in ion-ion interactions. see which compounds can do what +[592.40s -> 595.73s] and you will be in business. Let's check comprehension. +[625.39s -> 633.97s] thanks for watching guys subscribe to my channel for more tutorials and as always feel free to email me diff --git a/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_12.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..69f840d92ae641fa7e9a6bfab2857cacd3d84749 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_12.mp4.txt @@ -0,0 +1,19 @@ +[0.00s -> 10.35s] Welcome to Sergey's Chemistry. Today we are going to look at thermal decomposition of ammonium carbonate. And let's analyze the products of decomposition. +[10.67s -> 25.33s] Ammonium carbonate is a white solid. Let's see what happens to it when we heat it up. As if it melts, but there is no liquid. +[25.71s -> 40.46s] In fact, it decomposes into three gases. Ammonia, water which is gas at this temperature, and carbon dioxide. All three are colorless, as if our ammonium carbonate disappears into nothing. +[41.52s -> 55.12s] But not totally into nothing, in the higher colder areas of the test tube it can reform back again. It's not really sublimation, it's decomposition followed by synthesis. But this method can be used +[55.12s -> 57.62s] to purify ammonium carbonate. +[59.50s -> 73.52s] Now let's check for the presence of ammonia, water and carbon dioxide in the products of decomposition, starting with ammonia first. It's going to be easy, because another name for ammonium carbonate is smelling salt. +[73.52s -> 87.12s] Even at room temperature it decomposes strongly to give enough ammonia to provide a knock to a person to bring him to his senses. Now let's heat it up. Definitely there is going to be more ammonia. +[87.50s -> 89.58s] Damn pH paper. +[90.26s -> 102.67s] turns blue, showing the presence of an alkaline gas, ammonia in this case. Now it's turn for water. Let's drive this white liquid closer to the colder opening. +[102.67s -> 114.70s] And let's test it with cobalt to chloride paper. It's blue when it's anhydrous. As soon as water gets on it, it turns pink. Yes, presence of water is confirmed. +[114.70s -> 118.26s] Now for the third one for carbon dioxide. +[119.09s -> 132.10s] The test for it is not going to be that easy. I have to remove ammonia from the mixture. It would otherwise mess up with my lime water test. So you see what I'm doing. I'm putting... +[132.10s -> 137.84s] sulfuric acid in the middle and i'm going to bubble the mixture of the gases through it first +[138.22s -> 150.58s] Ammonia being alkaline would react with an acid and is going to be removed. And carbon dioxide would be left and it's going to bubble through lime water on the extreme left. +[151.15s -> 155.73s] Here, let's run our setup by heating up the white solid. +[157.26s -> 170.83s] we have to wait for a little while because the air have to be driven out through the apparatus also carbon dioxide is slightly soluble in sulfuric acid but sooner or later is going to reach +[170.83s -> 172.53s] lime water on the left +[178.70s -> 192.85s] Yes, it's a success. Lime water turns milky. We have proven the presence of carbon dioxide, third constituent. So we have shown that ammonium carbonate is decomposing, producing at least. +[192.85s -> 205.78s] ammonia water and carbon dioxide thank you for watching please subscribe to the channel and give likes to this video if you want to encourage me to make more see you next time bye diff --git a/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_15.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ace28e7cef1ee636f5b6a36951759da6ae30b318 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_15.mp4.txt @@ -0,0 +1,49 @@ +[0.00s -> 10.38s] Hi everyone, welcome to IGCSE Study Buddy where you can revise chemistry topics from the Cambridge IGCSE syllabus. +[11.86s -> 20.43s] If you are enjoying our videos so far please don't forget to hit the like button and subscribe to our channel. +[21.65s -> 28.98s] In this video, you are going to learn part 1 of topic 4, electrochemistry. +[30.83s -> 43.02s] Electrolysis is the decomposition of an ionic compound when molten or in aqueous solution by the passage of an electric current. +[43.06s -> 51.34s] So basically, electrolysis involves breaking apart ionic compounds using electricity. +[51.60s -> 63.76s] Remember that the ionic compound should be either melted or in water so that they have free ions in order to allow electricity to pass through. +[64.85s -> 68.56s] Let's look at a simple electrolytic cell. +[68.88s -> 82.74s] this is an electrode an electrode is a conductor often a metal or graphite rod that allows electric current to go in or out of an electrolyte +[83.44s -> 90.75s] The electrolyte is the molten or aqueous substance that undergoes electrolysis. +[90.75s -> 99.17s] Molten means heated until it becomes a liquid and aqueous means dissolved in water. +[99.17s -> 109.46s] Now just a quick reminder, if an atom loses electrons, it becomes a positively charged ion known as a cation. +[110.54s -> 123.76s] If it gains or takes in electrons, it becomes a negatively charged ion called an anion. +[123.76s -> 137.55s] atoms, elements and compounds, you might remember this visual representation to remember that cations are positively charged and anions are negatively charged. +[139.06s -> 151.95s] The cathode is the negative electrode. Opposite charges attract so the negative charge on the cathode pulls the positive charged cations towards it. +[152.53s -> 166.10s] so cathodes attract positively charged cations the anode is the positive electrode it attracts the negatively charged anions towards it +[167.47s -> 181.62s] Here's a tip to remember which electrode is positive and which is negative. A cathode attracts cations. That's easy to remember since both start with cat. +[182.00s -> 195.17s] We already learned that a cation is a positively charged ion. Remember this picture where I put the positive sign instead of the T in cation? Remember, +[195.17s -> 204.66s] Opposite charges attract each other. So if a cathode attracts positive ions then it must be negative. +[205.04s -> 214.26s] Likewise, an anode attracts anions. This is also easy to remember since both start with N. +[215.09s -> 224.91s] Anions are negatively charged ions. Remember the word negative when you look at the letter N in anion. +[226.42s -> 237.33s] Opposite charges attract, so if an anode attracts negative ions, then it must be the opposite, which is positive. +[239.82s -> 246.67s] During electrolysis, an electric current is required to flow through the circuit. +[246.96s -> 255.02s] At the power supply it is the electrons that carry this electric charge through the external circuit. +[255.22s -> 269.55s] The electrons move from the power supply to the cathode making it negatively charged. The anode becomes positively charged as it loses electrons. +[270.16s -> 278.32s] The positive cations in the electrolyte move towards the cathode where they gain electrons. +[279.22s -> 293.20s] The negative anions in the electrolyte move towards the anode where they lose electrons. The electrons from the anode move back towards the power supply. +[295.12s -> 303.41s] When the current flows in the electrodes and wires it is the electrons that carry the electrical charge. +[305.58s -> 314.10s] When the current flows in an electrolyte it is the ions that move and carry the electrical charge. +[314.90s -> 324.66s] We should be able to predict the identity of the products at each electrode during electrolysis. As we just learned +[324.66s -> 337.36s] Please remember that the positive ion or cation will always move towards the cathode and the negative ions or anions will always move to the anode. +[337.55s -> 345.46s] The electrolyte can be either a molten compound or an aqueous solution. +[347.73s -> 354.96s] A binary compound is a chemical compound composed of two different elements. +[355.41s -> 365.49s] Molten compounds are in a liquid state due to being heated to a high temperature, typically above their melting points. +[365.58s -> 380.18s] So, if the electrolyte is a binary molten ionic compound, we know that once it undergoes electrolysis, the ions in the electrolyte will be just the two elements that make up the compound. +[380.18s -> 389.90s] compound. Example, in NaCl, the ions present will be Na plus and Cl minus. +[391.41s -> 397.33s] During electrolysis, we mainly look at how electrons move. +[397.78s -> 406.93s] When ions touch the electrode, electrons are either lost or gained creating neutral substances. +[408.98s -> 415.63s] These neutral substances are then released as products at the electrodes. +[416.53s -> 429.55s] At the anode, negative ions lose electrons. This is oxidation. So oxidation is when something loses electrons. +[430.00s -> 442.16s] And at the cathode, positive ions gain electrons. This is reduction. So reduction is when something gains electrons. +[442.19s -> 455.60s] An easy way to remember this is the mnemonic oil rig. Oxidation is loss of electrons and reduction is gain. +[455.60s -> 466.58s] of electrons we use ionic half equations to show these processors making sure the charges are balanced +[466.77s -> 475.63s] For example, for the electrolysis of molten sodium chloride, these will be the ionic half equations. +[475.92s -> 487.82s] At the anode, two chloride ions lose two electrons to form Cl2 gas. So it's rearranged to be written like this. +[489.26s -> 502.54s] At the cathode, sodium ions gain an electron to form sodium. That concludes part 1 of topic 4, Electrochemistry. +[503.50s -> 514.37s] are you enjoying our videos are they helping you here's a way you can show your appreciation and support our continued efforts +[514.37s -> 519.44s] You may use YouTube Super Thanks to send us thanks. +[523.66s -> 530.19s] Hope this video helped you. Please share your thoughts and suggestions in the comment section. +[530.19s -> 539.31s] Thank you for watching and please don't forget to subscribe to IGCSE Study Buddy for more revision videos. Bye-bye. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_2.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_2.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d0faa3f2f7f9bd411fa9e6567eae798260a770e5 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_2.mp4.txt @@ -0,0 +1,14 @@ +[0.00s -> 13.92s] Welcome to MedCentral. In this video we are going to look at the pharmacology of the muscarinic receptor antagonists. Muscarinic receptor antagonists. These are used to treat COPD, emphysema, asthma, +[13.92s -> 24.53s] bronchiectasis and chronic bronchitis. In these conditions, increased parasympathetic activity via the vagus nerve results in increased secretion of ACH. +[24.69s -> 36.59s] High levels of ACH act on bronchial smooth muscle and submucosal glandular cells, resulting in increased bronchial inflammation, mucus plugging, and bronchial smooth muscle constriction. +[36.72s -> 44.90s] Muscarinic receptor antagonists block the surge of the ACH on muscarinic receptors of the bronchial smooth muscles of the airway. +[44.90s -> 58.77s] Muscarinic receptor antagonists function by competitively blocking the binding of ACH to muscarinic receptors, resulting in an anticholinergic response. There are five different receptors M1, M2, M3, +[58.77s -> 70.16s] m4 and m5 the m1 m4 and m5 receptors are in the central nervous system m2 receptors lead to increased heart rates +[70.29s -> 84.35s] M3 receptors are in the smooth muscles of the GI tract, urinary tract, airway and blood vessels. Muscarinic receptor antagonist binding to M3 receptors reduces intestinal peristalsis and bladder contraction. +[84.35s -> 97.62s] reduces salivary and gastric secretions reduces bronchial secretions and increases bronchodilation mainly m3 antagonism less lipid soluble than atropine minimal systemic absorption +[97.62s -> 109.58s] Muscarinic receptor antagonists are divided into two categories by the duration of the action. Short-acting muscarinic receptor antagonists. Long-acting muscarinic receptor antagonists. +[109.58s -> 123.38s] Iprutropium is a short-acting muscarinic receptor antagonist, quick relief of symptoms in asthma and COPD. Root of administration is metered dose inhalers, dry powder inhalers, and nebulizers. +[123.38s -> 134.21s] Tyatropium is a long-acting muscarinic receptor antagonist, it is used as maintenance therapy for COPD. Root of administration is dry powder inhalers. +[134.21s -> 147.86s] There are some adverse effects of muscarinic receptor antagonists. Dry mouth, throat irritation, midriasis, and photophobia. Contraindications. Acute asthma, myocardial infarction, hyperthyroidism. +[147.86s -> 159.22s] paralytic ileus, benign prostatic hyperplasia, urinary retention, narrow angle glaucoma, and myasthenia gravis. Thank you for watching. If you are interested in pharmacology, +[159.22s -> 166.03s] check out our pharmacology playlist and subscribe our channel to get notified when new videos are out. Thank you. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_4.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_4.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a5ff10bd43ec0ebe4f50b34de8dfc80bb3cd9cbb --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_4.mp4.txt @@ -0,0 +1,12 @@ +[0.00s -> 14.05s] let's talk about law of definite proportions or it's sometime called law of constant proportions now this law states this law states that in any in any chemical substance the elements are always present in definite +[14.05s -> 26.03s] proportions by mass now instead of proportions we can call them ratio to make to make the definition simpler so we can see that the elements are always present in definite or constant ratio by mass +[27.15s -> 39.90s] Let's try to understand this with the example of water. So we know that water is H2O and if we apply this rule to water, it says that water as a compound is always formed from the same ratio of hydrogen and oxygen. +[39.90s -> 53.49s] And specifically, we can see that water is formed from two atoms of hydrogen. So this is two atoms of hydrogen and one atom of oxygen. So this will always be the ratio of hydrogen to oxygen atoms in any sample of water. +[53.49s -> 67.04s] Doesn't matter if it is tap water or water in an ocean or a lake. The ratio of hydrogen and oxygen atoms in that sample of water will be 2 is to 1. Now this rule also extends to mass. So we know that every atom has a mass of its own. +[67.04s -> 75.94s] And we know that one atom of hydrogen weighs one atomic mass unit. So that will be two atoms will be two atomic mass units. So let me write two amu. +[75.94s -> 89.87s] one atom of oxygen has an atomic mass of 16 amu so that will be 16 amu 16 atomic mass units and now from here i can say that the mass ratio of oxygen to hydrogen will be 16 is to 2 +[89.87s -> 93.14s] And this can be simplified to 8, 8 is to 1. +[93.58s -> 107.86s] This is a ratio of oxygen to hydrogen by mass. And what this really means is that in any sample of water, either a drop or water in a glass or water in an ocean, doesn't matter if you take 50 liter, 10,000 liters, or even just one ml of water. +[107.86s -> 122.24s] the mass of oxygen present in that sample will be eight times the mass of hydrogen that is present in that sample and this is the law of definite proportions it holds true for every other chemical substance even for carbon dioxide so you see carbon dioxide +[122.24s -> 134.75s] being formed when organic matter burns, you also exhale carbon dioxide. And doesn't matter how much carbon dioxide you take, the ratio of oxygen to carbon atoms or the mass of oxygen to carbon +[134.75s -> 138.19s] will always be the same in any sample of carbon dioxide. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_8.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..442cfae1d04bb40f86c8e195bf30ba01f990e442 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Pharmacy_8.mp4.txt @@ -0,0 +1,43 @@ +[0.00s -> 8.62s] Hey it's Professor Dave, let's talk about acids and bases. +[9.14s -> 19.89s] we've probably all heard the terms acid and base, but what do these words mean on the molecular level? let's discuss the rigid definition according to a few different models +[20.11s -> 26.29s] most often when we talk about acids and bases we are referring to the Bronsted-Lowry definition +[26.70s -> 35.22s] according to this model an acid is something that donates a proton and a base is something that accepts a proton +[35.22s -> 47.25s] an H plus ion is a proton because if a hydrogen atom loses an electron all that is left is the proton that comprises the nucleus. proton transfer is a big part of chemistry +[47.41s -> 61.79s] an acid and base will react to form a conjugate acid-base pair. the thing that gives up a proton is the acid, the thing that accepts it is the base, and on the product side the base has become the conjugate acid +[61.79s -> 75.28s] the acid has become the conjugate base because the thing that gained the proton could potentially lose it again acting as an acid and the thing that lost the proton might gain it back acting as a base +[75.28s -> 88.82s] the Bronsted-Lowry definition only applies to protic species or molecules with hydrogen atoms that can be lost as protons but there are aprotic species that also display acidity and basicity +[88.94s -> 100.64s] this is what the Lewis definition entails. under the Lewis definition a base is something that donates a pair of electrons and an acid is something that accepts electrons +[100.64s -> 115.31s] a Lewis base is indistinguishable from a Bronsted-Lowry base, but the acids differ in the sense that a Bronsted-Lowry acid must have at least one hydrogen atom. a Lewis acid just needs some partially positive atom +[115.76s -> 129.82s] species that can act as both a Bronsted-Lowry acid and base is said to be amphoteric. water is amphoteric because it can behave as an acid losing a proton to become hydroxide +[129.82s -> 144.05s] or it can act as a base, gaining a proton to become a hydronium ion. in a sample of water a tiny fraction of molecules transfer a proton from one to another which we call an acid-base reaction +[144.94s -> 155.50s] this is an equilibrium and is shown here. we can write an equilibrium expression by showing the concentrations of the products over the concentrations of the reactants +[155.50s -> 169.17s] we will only include gases and aqueous substances so here it will look like this at room temperature this equals one times 10 to the negative 14 or 1 100 trillionth +[169.30s -> 173.78s] that's the fraction of water molecules that are ionized at any moment +[174.10s -> 187.90s] as temperature increases Kw increases. hydronium concentration which is essentially proton concentration if above one times 10 to the negative seven gives an acidic solution +[187.90s -> 200.34s] if below it's basic, if equal it's neutral. when looking at conjugate acid-base pairs we must understand that a strong acid is something that will very readily lose a proton +[200.34s -> 214.21s] if something is a strong acid it means its conjugate base is very stable that's why it's so willing to lose a proton. a strong acid will have a weak conjugate base since the conjugate base will be very stable +[214.21s -> 226.54s] meaning it isn't dying to pick up a proton. a weak acid, something that isn't very willing to lose a proton, will have a strong conjugate base, something that will very easily gain a proton +[226.93s -> 239.07s] so if the strength of an acid is proportional to the stability of the conjugate base we have to be able to predict the stability of conjugate bases in order to tell how strong an acid will be +[239.07s -> 252.03s] whichever atom is losing a proton the larger it is the more stable the conjugate base will be. comparing the acids made by combining a hydrogen with a halogen we can see that HI is the strongest +[252.03s -> 264.74s] this is because when the proton leaves we are left with an iodide ion. this is much larger than a fluoride ion and therefore can diffuse the negative charge around a greater volume +[264.74s -> 278.58s] thereby stabilizing itself. fluoride is much smaller with a very localized charge and is therefore less stable so hydrofluoric acid is a much weaker acid than hydroiodic +[278.64s -> 284.85s] also the more electronegative an atom the better it is at accommodating a negative charge +[284.85s -> 294.29s] so an oxygen atom can more readily lose a proton than a carbon atom which is why something like water is far more acidic than say methane +[294.51s -> 299.95s] acids are also stronger when their conjugate bases are resonance stabilized +[300.91s -> 310.77s] a carboxylic acid is about a trillion times stronger an acid than water even though both of them leave an oxyanion after deprotonating +[310.77s -> 322.67s] this is because the conjugate base of the carboxylic acid can share the burden of the negative charge between two oxygen atoms by resonance while hydroxide can't +[322.80s -> 335.49s] these resonance structures don't actually exist but rather the composite resonance structure does which shows delocalized pi electron density distributed about this portion of the molecule +[335.49s -> 350.10s] more on this in organic chemistry. there can be monoprotic acids which can only lose one proton or polyprotic acids which can lose several. polyprotic acids become less acidic with each deprotonation +[350.61s -> 364.40s] in an acid-base equilibrium the side with the weaker acid-base pair will always be favored this is because the stronger acid or base will have a greater tendency to react and generate the weaker species +[364.40s -> 374.91s] we can tell acid strength by looking at an acid's pKa. the lower the pKa the stronger the acid. strong acids deprotonate completely +[374.91s -> 388.88s] transferring every acidic proton to molecules of solvent or other things in solution. weak acids only deprotonate partially generating some of the conjugate acid but won't react completely. the weaker they are +[388.88s -> 400.64s] the less completely they will react. once again the hydronium concentration measures the degree to which an acid transfers protons to water molecules and therefore the strength of the acid +[400.64s -> 410.99s] but hydronium concentrations have inconvenient exponents which can be cumbersome to list so we have developed a more convenient way to describe acidity +[411.18s -> 420.72s] the pH of a solution is the negative log of the hydronium concentration. logarithms are the inverse operations of exponents +[420.72s -> 431.20s] so the reason why a negative log is useful here is that it takes an annoying number like 10 to the negative 7 and it turns it into 7 which is much tidier +[431.20s -> 443.15s] so a solution with a pH of 7 has a hydronium concentration that is considered neutral. we can also measure the basicity of a solution by calculating the pOH +[443.15s -> 456.69s] this is because a strong base will generate hydroxide ions in aqueous solution by stealing protons from water molecules. just like pH, pOH is the negative log of the hydroxide concentration +[456.69s -> 467.54s] another way to calculate pH and pOH is by using the formula for Kw. from this we see that pH plus pOH must equal 14 +[468.05s -> 481.62s] between these relationships we can relate pH, pOH, hydronium concentration, and hydroxide concentration and we should be able to get from one to any of the others using this chart +[481.62s -> 483.57s] Let's check comprehension. +[512.94s -> 520.98s] thanks for watching guys subscribe to my channel for more tutorials and as always feel free to email me diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_10.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..bef8620af06224aca522bea5a245095a41fb68ad --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_10.mp4.txt @@ -0,0 +1,23 @@ +[0.05s -> 14.11s] Okay, welcome back to epidemiology. In this tutorial, we're going to discuss attributable risk. Now attributable risk is the amount of risk that occurs because of the exposure. +[14.11s -> 21.18s] calculated the relative risk based on benzene exposure +[21.18s -> 35.92s] and the development of cancer and we came up with 2.82 relative risk, which told us that those who were exposed to benzene were 2.8 times more likely to develop cancer than those who didn't have benzene exposure. +[36.37s -> 49.14s] However, we didn't talk about how much cancer occurred just because benzene exposure occurred. Now, if we got rid of all benzene exposure, we'd still have cancer. +[49.14s -> 52.66s] So we need to somehow define. +[53.42s -> 66.35s] how much risk is directly attributed to the exposure. And that's what attributable risk calculations give us. Now with attributable risk, we are able to +[66.77s -> 76.69s] determine that amount because we can get a ratio of the risks. +[76.94s -> 88.21s] If we looked at the risk of disease of cancer on a bar chart here, and this was our exposed group, now we'd still have some cancer even in the population. +[88.21s -> 102.99s] So even if people weren't exposed to cancer, there would be some amount of risk of disease if we put this on some kind of chart here. Now, what we want to know is how much here +[104.11s -> 118.34s] How much of the disease here is because of benzene? We need to calculate that percentage based on that column of exposed risk. +[118.34s -> 132.10s] So the way we do that is taking this risk amount, subtract this risk amount, and then we divide that by the whole thing. So the calculation is the risk +[132.10s -> 146.32s] in the exposed minus the risk of the in the unexposed all over that total column which was the first one which is the risk +[146.58s -> 156.64s] in the exposed group. So we take our 2x2 table that we've created from our word problem before. We had 40 people who were +[156.64s -> 169.98s] had cancer in the exposed group to benzene 18 that had cancer that were not exposed to benzene and we simply put it into the calculation if you remember 40 divided by 212 is +[169.98s -> 183.66s] 18.87%. Those, the amount of risk in the unexposed group was 6.64%. +[186.93s -> 197.81s] and all of that over .1887 and that will give you a total of 64. +[198.54s -> 202.99s] Point eight one percent +[205.07s -> 219.62s] Now what does that 64.81% mean? Well, that's a very good question. It means that 64% of that group, the risk in the exposed group, so 64% of the disease in the exposed group, +[219.62s -> 226.51s] is because of the exposure so if I were to articulate this in an interpretive words I would say +[227.28s -> 238.93s] 64.81% of the disease among those who were exposed is directly attributed to the exposure. +[239.22s -> 251.41s] One more time, 64%, 64.81% of the disease in the exposed group occurs because of that exposure. +[251.41s -> 259.04s] And that's all there is to attributable risk. So it's the top portion of that graphic distribution. +[259.04s -> 271.00s] description of the risk and the exposed that we're trying to calculate what percentage of that column is because of the exposure and that's 64.81 percent in this case. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_11.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..faff8853e04365e3732fa8d998b9ac16a42b281d --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_11.mp4.txt @@ -0,0 +1,39 @@ +[0.11s -> 11.98s] Hi everyone and welcome to our video on basic epidemiologic terms and concepts, measures of association, odds ratio and attributable risk. +[14.29s -> 27.22s] The learning outcomes of this presentation are to 1. Understand two of the more meaningful measures of association, an odds ratio and attributable risk. +[27.22s -> 40.70s] Understand how each measure of association is calculated generally and how each seeks to establish strength of association between varying levels of cause and effect. And 3. +[40.70s -> 52.11s] Understand how each type of measure effectively contributes to the diverse human and clinical science fields, from health promotion to surveillance in epidemiology. +[54.38s -> 65.33s] To begin, an odds ratio, or OR, is a measure of association between a behaviour and an outcome. Most frequently, +[65.33s -> 78.19s] ORs seek to quantify risk between a behaviour and risk for a specific disease or health outcome. Common examples include associations between smoking and lung disease, +[78.19s -> 91.25s] and sexual behaviors and risk for contracting a sexually transmitted infection in contrast attributable risk or ar quantifies the difference between incidence rates +[91.25s -> 103.54s] rates of new cases for a specific disease between two groups of people people being exposed to a given risk factor such as cigarette smoke to those not exposed +[104.08s -> 118.61s] Attributable risk is sometimes referred to as the risk difference. It refers to the difference in incidence rates between people exposed to some risk factor versus people who are not exposed to the risk factor. +[118.61s -> 129.65s] Examples commonly cited are cancer and smoking cigarettes and cardiovascular disease in smokers versus non-smokers. +[130.80s -> 145.39s] One of the main caveats in gaining a more thorough understanding of the difference between ORs and ARs is to remember odds ratios most commonly seek to quantify the strength of association between an individual +[145.39s -> 154.80s] behaviour and that behaviour's connectivity with a specific morbidity or sickness. In contrast, attributable risk +[154.80s -> 166.80s] looks at and quantifies risk of exposure among groups of people and a condition, those exposed to a condition compared to those not exposed to a condition. +[168.88s -> 181.20s] To calculate an odds ratio we must examine the associations between behavioral exposure as they compare to the result of having a given disease or not. In essence +[181.20s -> 191.90s] we are examining the odds between a case performed a given behaviour and contracting a disease as it compares to those not performing a given behaviour. +[191.90s -> 201.62s] and the presence or absence of having that disease or condition. For an illustration refer to the figure in the upper right corner of this slide. +[201.62s -> 214.30s] we then look at the difference between these two groups mathematically by simple division the quotient of this division is a number along a continuum of positive to negative +[214.30s -> 224.50s] A positive number greater than 1.0 indicates risk in order of magnitude between a behaviour and likelihood of contracting a disease +[224.50s -> 233.71s] while a number less than minus 1.0 indicates that that behaviour is associated with decreased risk for disease. +[236.37s -> 248.58s] This slide highlights the numeric associations previously discussed in the previous slide between a given behaviour and risk for a specific condition. For example, +[248.58s -> 259.66s] If we have an OR of 2.3, then we interpret that to mean that engaging in that behaviour will result in 2.3 times more risk. +[259.66s -> 272.78s] or be more likely of contracting that disease or condition in contrast an or of minus 2.3 can be interpreted to mean that if we engage in that specific behavior +[272.78s -> 286.86s] we are 2.3 times less likely of contracting that disease or condition. Basically, numbers greater than 1.0 indicate harmfulness, while numbers less than 1.0 indicate +[286.86s -> 295.89s] protectiveness finally numbers between 1.0 and minus 1.0 such as 0.55 +[295.89s -> 304.46s] indicate that a given behaviour is not statistically associated with any type of risk for a given disease or condition. +[306.58s -> 319.26s] In contrast to odds ratios, the mathematics of attributable risk involves subtracting the risk of a non-exposed group of people from the risk of an exposed group of people. +[319.26s -> 332.62s] To perform this mathematical operation, we have to add the rows of both positive and negative exposure as seen in the graphic on the lower right portion of this slide. After we get these row totals, +[332.62s -> 343.57s] we then add those values to individual cases of those engaging in a given behaviour such as smoking with those not engaging in the behaviour. Finally, +[343.57s -> 354.45s] we divide positive risk cases from a row total and subtract the negative cases over that row's total. The mathematics of this operation +[354.45s -> 368.94s] yields a percentage when multiplied by 100 and we then get a percentage of risk association for example smoking is associated with a 26 increase for developing bladder cancer +[371.31s -> 382.98s] This slide highlights general comparisons between odds ratios and attributable risk. Both measures quantify strength of associations between behavioral risks +[382.98s -> 397.12s] and the likelihood of developing or resulting in a specific disease or condition. Both of these measures are quantified calculations, meaning that they are represented by numbers each expressing that association. +[397.12s -> 411.12s] For an odds ratio, that number expresses times more or less likely in getting a disease or condition based on a given behaviour, while attributable risk yields a percentage of risk +[411.12s -> 421.26s] between condition and exposure. Both of these measures yield invaluable trends and connections between behaviour or exposure to a given disease. +[421.26s -> 431.66s] Public health professionals can analyze these trends and allow them to guide public health policy as well as health educational and health promotional programming. +[431.66s -> 441.71s] Examples of which can include such things as safety, restraint, belt usage and risk or severe auto accidents up to and including death. +[444.08s -> 458.75s] A more contemporary example of measures of association like odds ratios and attributable risk includes mask and social distancing guidelines that have become synonymous with life in the COVID-19 era. +[458.75s -> 468.64s] Such recommendations were formed from looking at measures of risk between wearing or not wearing a mask and contracting COVID-19. +[468.64s -> 482.16s] as well as analysing distances or airflow between proximal bodies and risk for contracting COVID-19. Thank you for watching and have a great day. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_12.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6b36611f7d9693da207578f47eafa76b688b51a0 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_12.mp4.txt @@ -0,0 +1,32 @@ +[4.24s -> 17.10s] Hello, and welcome to this video where we'll be taking a look at sensitivity and specificity. We'll take a look at what they are, how they're calculated, and two related measurements, positive and negative predictive values. +[17.26s -> 25.58s] Tests are important tools that can help us identify the presence or absence of a disease. But they're not always perfect. +[25.58s -> 36.37s] Sensitivity and specificity are measures that can be used to determine how good a test is at correctly identifying the presence or absence of disease. Let's take a closer look. +[36.69s -> 42.64s] Let's use a table of the outcome of the test and disease status to learn about some of the terms that are used. +[43.22s -> 55.78s] There are people with a disease and those without the disease. When we do a test on someone, it can be either positive or negative. If the test is positive, it should mean that the person has the disease. +[55.78s -> 70.03s] This is called a true positive. It correctly identifies a person with the disease. Similarly, if a test is negative, it should mean that a person does not have the disease. This is called a true negative. +[70.03s -> 83.86s] It correctly identifies a person without the disease. However, because tests are not always perfect, a test can be positive even though the person does not have the disease. This is called a false positive. +[84.30s -> 94.74s] This is not ideal because it could lead to further testing or treatment that's not necessary, negative psychological impacts, and may come with an economic cost or added risk. +[95.18s -> 108.64s] On the other hand, a test can sometimes be negative even though the person has the disease. This is called a false negative. Again, this is not ideal because the test has not picked up the person despite them having the disease. +[108.64s -> 115.78s] This may lead to delays in diagnosing the disease, and therefore, delays in treatment, which could lead to a negative health outcome. +[115.78s -> 127.33s] An incorrectly negative test may also lead to a false sense of security and the continuation of risky behaviors that may worsen the disease or even place others at risk in the case of a communicable disease. +[127.33s -> 131.25s] Missing a diagnosis may also have legal consequences. +[131.70s -> 144.14s] Using these terms, we can calculate the sensitivity and specificity of the test. These are indicators of how good a test is and guides us on how to determine the appropriateness of a test and interpret its outcome. +[144.56s -> 156.72s] Sensitivity is the proportion of people with the disease who test positive for it. A high sensitivity means that the proportion of true positives is high and the proportion of false negatives is low. +[157.33s -> 170.30s] Specificity, on the other hand, is the proportion of people without the disease who test negative for it. A high specificity means that the proportion of true negatives is high and the proportion of false positives is low. +[170.30s -> 184.24s] Let's work through an example. Let's say we have a group of 600 people. Let's assume that 100 people have a disease and 500 people do not. First, we'll focus on the 100 people who have the disease. +[184.30s -> 196.64s] Let's say that we do a test on people with the disease. Now, if that test was perfect, we would have 100 positive tests. However, let's assume that the test is positive in only 90 people. +[196.64s -> 208.83s] In other words, there are 90 true positive cases. This leaves us with 10 people with the disease who have a negative test result. These are false negatives. We know that the sensitivity of the test +[208.83s -> 218.99s] is a proportion of people with the disease who test positive for it. Therefore, in this example, the sensitivity of the test is 0.9, or 90%. +[219.57s -> 233.02s] Now let's do the test on the 500 people without the disease. Ideally, we will have 500 negative results. But let's assume that the test was negative in only 400 people. These are true negatives. +[233.02s -> 246.32s] This would mean that in 100 people without the disease, the test was positive. These are false positives. We know that the specificity of the test is the proportion of people without the disease who test negative for it. +[246.32s -> 251.73s] So in this example, the specificity of the test is 0.8 or 80%. +[252.05s -> 263.66s] And that's how sensitivity and specificity are calculated. Tests with high sensitivity are good for screening tests because the proportion of false negatives is low. On the other hand, +[263.66s -> 276.54s] Tests with high specificity are good for confirmatory tests because the proportion of false positives is low. The perfect test will have a sensitivity of 100% and a specificity of 100%. +[276.54s -> 285.01s] The closer a test's sensitivity and specificity is to 100%, the better the test is in confirming or excluding the disease. +[285.65s -> 297.52s] Finally, let's have a quick look at two related measurements, positive predictive value and negative predictive value. It uses the same information but looks at it from a testing point of view. +[298.29s -> 302.16s] Let's use the same values we used in our previous example. +[302.90s -> 314.88s] There are 190 people who test positive and 410 people who test negative. The positive predictive value is the proportion of people with a positive test who actually have the disease. +[314.88s -> 328.61s] In this example, the positive predictive value is 47.4%. The negative predictive value is the proportion of people with a negative test who do not have the disease. In this case, the negative predictive value +[328.61s -> 340.66s] is 97.6%. Positive and negative predictive values depend on the prevalence of disease, or in other words, how much disease there is in the population. In general, +[340.66s -> 349.01s] An increase in disease prevalence is associated with an increase in positive predictive value and a decrease in the negative predictive value. +[349.42s -> 356.98s] And that's an overview of sensitivity and specificity and a quick look at positive and negative predictive values. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_14.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cc970efe87ac4c4ef399075ba79bbf90f10ffa84 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_14.mp4.txt @@ -0,0 +1,27 @@ +[0.00s -> 13.97s] Welcome back. My name is Greg Martin. We're going to be talking about risk, rate and odds. These are concepts and terms that we use in public health and epidemiology. People often get them confused. By the end of this video, I promise you, you're going to understand them completely. So let's get into it. +[14.13s -> 25.87s] So let's start by talking about risk. Risk really is what you think it is. Risk is the chances of a person getting sick or getting some other health outcome that you're interested in within a certain period of time. +[25.87s -> 36.93s] to calculate risk we really just need three things firstly we need a defined population that we consider to be at risk right so we need that group of people secondly we need a defined period of time during which we consider them to be at risk +[36.93s -> 44.16s] And thirdly, we need to count up the number of new incidents of this disease or this health state that we're interested in that happens during that period of time. +[44.16s -> 58.58s] now if you've watched my video on incidents and prevalence you'll notice that the way i've described risk is very similar if not exactly the same as the way i would have described incidents if we have 10 people and we look at them over a period of one year and three of them develop cancer within that year we would have said the risk of getting cancer +[58.58s -> 72.70s] is three over 10, which is 30%. Now let's talk about rate. Rate is a very similar concept to risk, but there's a small difference. In the case of rate, we divide the number of new cases by something we call the person time. +[72.70s -> 77.33s] And I'm going to explain what that means in just a second. To explain this, I'm going to use an example. +[77.33s -> 89.63s] Let's imagine, for example, that we had a study that we were doing and we were following 10 people over 10 years. And we wanted to count the number of them that got cancer or some other disease during that period of time. During the study, however... +[89.63s -> 98.19s] not everybody would stay in the study all the way to the end. Some people might drop out of the study and other people may die even during the study. +[98.19s -> 109.46s] Not everybody in the study contributes a full 10 years in terms of the period of time within which they might get sick. And so what we could do, and in fact this is what we do. +[109.46s -> 118.03s] is we take the time contribution of each individual that they spent in the study, and we add them all together, and we get a cumulative +[118.03s -> 132.30s] person time of the entire study and we use that as the denominator in other words the three or four people that got cancer whatever disease at the beginning that's the numerator we divide that by the cumulative person time as the denominator and we get +[132.30s -> 144.32s] rate. Now let's talk about odds. Odds is slightly less intuitive. Odds are the number of events divided by the number of non-events or the probability of something happening divided by the probability of it not happening. +[144.32s -> 156.16s] if the odds of an event are more than one then it is more likely to happen than not if they're less than one in other words between zero and one then they're less likely to happen than not and if they're exactly one +[156.16s -> 167.31s] then it's as likely to happen as it is not to happen. To understand the difference between odds and risk, I'm going to use an example. And just so that you know, this channel is sponsored by Nested Knowledge. +[167.31s -> 180.51s] That's a platform that supports systematic literature review and meta-analysis. They're absolutely amazing. Check out the link in the description below. And with that, on with the lesson. Imagine that you've gone to the movies, right? And there's a hundred people in the cinema. One person sneezes. +[180.51s -> 185.47s] The risk of sneezing in that time period is 1 over 100, right? The number of people that... +[185.47s -> 197.14s] had the health outcome, in this case, sneezing over the number of people at risk at the beginning, which is 100. So it's 1 over 100. That's the risk of sneezing. The odds of sneezing is slightly different, right? Now it's 1. +[197.14s -> 208.62s] that's the numerator the number of people that had this health outcome divided by the number of people who didn't have the health outcome not the number of people at risk at the beginning but the number of people who didn't have that outcome in this case it's 99. +[208.62s -> 218.70s] okay because 99 people didn't sneeze so you might say to yourself look the risk of sneezing and the odds of sneezing in that movie are very very similar and that's true +[218.70s -> 225.94s] When you're talking about risk and odds at low incidence, they are very similar, almost indistinguishable. Where this becomes... +[225.94s -> 238.83s] it becomes more apparent the difference between them is when the incidence is higher so let's change the scenario slightly let's imagine that 55 people in this movie sneezed during the time of the film right now +[239.18s -> 252.53s] The risk of sneezing is 55 over 100. So 55, the number of people who sneezed, divided by 100, the number of people at risk of sneezing at the beginning of the movie. So 55%. The odds of sneezing, however... +[252.53s -> 262.58s] are 55 over 45, right? 55 the number of people who sneezed, 45 the number of people who didn't sneeze, right? And that's 1.2. +[262.58s -> 274.10s] now we said about odds if the odds are more than one then it's more likely that you sneeze than you didn't and that's true in this case the odds are 1.2 so it's for any person going to that cinema for that period of time +[274.10s -> 285.57s] it's more likely that they would have sneezed than they wouldn't have. Now stay and watch another video. The next video that I want you to watch is a video that's going to be on understanding the difference between a case control and a cohort study. +[285.57s -> 297.62s] Thanks for tuning into the Global Health YouTube channel. Please subscribe if you haven't before. Hit the bell notification so you get notification of future videos. I really enjoy feedback, so put comments in the comment section below. Stay well, don't do drugs, always do your best. Speak to you soon. Bye. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_15.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cc970efe87ac4c4ef399075ba79bbf90f10ffa84 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_15.mp4.txt @@ -0,0 +1,27 @@ +[0.00s -> 13.97s] Welcome back. My name is Greg Martin. We're going to be talking about risk, rate and odds. These are concepts and terms that we use in public health and epidemiology. People often get them confused. By the end of this video, I promise you, you're going to understand them completely. So let's get into it. +[14.13s -> 25.87s] So let's start by talking about risk. Risk really is what you think it is. Risk is the chances of a person getting sick or getting some other health outcome that you're interested in within a certain period of time. +[25.87s -> 36.93s] to calculate risk we really just need three things firstly we need a defined population that we consider to be at risk right so we need that group of people secondly we need a defined period of time during which we consider them to be at risk +[36.93s -> 44.16s] And thirdly, we need to count up the number of new incidents of this disease or this health state that we're interested in that happens during that period of time. +[44.16s -> 58.58s] now if you've watched my video on incidents and prevalence you'll notice that the way i've described risk is very similar if not exactly the same as the way i would have described incidents if we have 10 people and we look at them over a period of one year and three of them develop cancer within that year we would have said the risk of getting cancer +[58.58s -> 72.70s] is three over 10, which is 30%. Now let's talk about rate. Rate is a very similar concept to risk, but there's a small difference. In the case of rate, we divide the number of new cases by something we call the person time. +[72.70s -> 77.33s] And I'm going to explain what that means in just a second. To explain this, I'm going to use an example. +[77.33s -> 89.63s] Let's imagine, for example, that we had a study that we were doing and we were following 10 people over 10 years. And we wanted to count the number of them that got cancer or some other disease during that period of time. During the study, however... +[89.63s -> 98.19s] not everybody would stay in the study all the way to the end. Some people might drop out of the study and other people may die even during the study. +[98.19s -> 109.46s] Not everybody in the study contributes a full 10 years in terms of the period of time within which they might get sick. And so what we could do, and in fact this is what we do. +[109.46s -> 118.03s] is we take the time contribution of each individual that they spent in the study, and we add them all together, and we get a cumulative +[118.03s -> 132.30s] person time of the entire study and we use that as the denominator in other words the three or four people that got cancer whatever disease at the beginning that's the numerator we divide that by the cumulative person time as the denominator and we get +[132.30s -> 144.32s] rate. Now let's talk about odds. Odds is slightly less intuitive. Odds are the number of events divided by the number of non-events or the probability of something happening divided by the probability of it not happening. +[144.32s -> 156.16s] if the odds of an event are more than one then it is more likely to happen than not if they're less than one in other words between zero and one then they're less likely to happen than not and if they're exactly one +[156.16s -> 167.31s] then it's as likely to happen as it is not to happen. To understand the difference between odds and risk, I'm going to use an example. And just so that you know, this channel is sponsored by Nested Knowledge. +[167.31s -> 180.51s] That's a platform that supports systematic literature review and meta-analysis. They're absolutely amazing. Check out the link in the description below. And with that, on with the lesson. Imagine that you've gone to the movies, right? And there's a hundred people in the cinema. One person sneezes. +[180.51s -> 185.47s] The risk of sneezing in that time period is 1 over 100, right? The number of people that... +[185.47s -> 197.14s] had the health outcome, in this case, sneezing over the number of people at risk at the beginning, which is 100. So it's 1 over 100. That's the risk of sneezing. The odds of sneezing is slightly different, right? Now it's 1. +[197.14s -> 208.62s] that's the numerator the number of people that had this health outcome divided by the number of people who didn't have the health outcome not the number of people at risk at the beginning but the number of people who didn't have that outcome in this case it's 99. +[208.62s -> 218.70s] okay because 99 people didn't sneeze so you might say to yourself look the risk of sneezing and the odds of sneezing in that movie are very very similar and that's true +[218.70s -> 225.94s] When you're talking about risk and odds at low incidence, they are very similar, almost indistinguishable. Where this becomes... +[225.94s -> 238.83s] it becomes more apparent the difference between them is when the incidence is higher so let's change the scenario slightly let's imagine that 55 people in this movie sneezed during the time of the film right now +[239.18s -> 252.53s] The risk of sneezing is 55 over 100. So 55, the number of people who sneezed, divided by 100, the number of people at risk of sneezing at the beginning of the movie. So 55%. The odds of sneezing, however... +[252.53s -> 262.58s] are 55 over 45, right? 55 the number of people who sneezed, 45 the number of people who didn't sneeze, right? And that's 1.2. +[262.58s -> 274.10s] now we said about odds if the odds are more than one then it's more likely that you sneeze than you didn't and that's true in this case the odds are 1.2 so it's for any person going to that cinema for that period of time +[274.10s -> 285.57s] it's more likely that they would have sneezed than they wouldn't have. Now stay and watch another video. The next video that I want you to watch is a video that's going to be on understanding the difference between a case control and a cohort study. +[285.57s -> 297.62s] Thanks for tuning into the Global Health YouTube channel. Please subscribe if you haven't before. Hit the bell notification so you get notification of future videos. I really enjoy feedback, so put comments in the comment section below. Stay well, don't do drugs, always do your best. Speak to you soon. Bye. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_6.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..af141c6c5e0fe51a72fb857731e52a437b58c3a5 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_6.mp4.txt @@ -0,0 +1,59 @@ +[0.91s -> 6.38s] Hello everybody. In this video, we are going to see about choice of right statistical test. +[6.83s -> 20.35s] So here are the five steps in choosing the right statistical test. Number one, what is your hypothesis? Number two, are the samples independent of each other? Number three, what are the types of variable? +[20.35s -> 34.59s] 4. Are they normally distributed? 5. Apply the right statistical test and find p-value. So for this fifth step of this presentation, we have to understand the first four bases to apply the test. +[34.59s -> 48.06s] First step is, we should understand about our hypothesis. That is, what is null hypothesis? What is alternate hypothesis? Suppose if our research objective is estimating ... +[48.06s -> 62.19s] that is estimating a mean or proportion then you need not rather cannot calculate p-value. So if you are doing some association that is you want to study an association between two variables +[62.19s -> 76.27s] then you need to use this hypothesis that is the null hypothesis says that there is no difference between those variables alternate or the research hypothesis says that there is a difference between variable +[76.27s -> 86.48s] What is p-value here is p-value is the probability of rejecting null hypothesis when it is actually true. It is kept at an arbitrary level. +[86.48s -> 95.76s] of 0.05 this is called a statistical significance this does not mean everything in research there is also called clinical significance +[95.76s -> 110.26s] i.e. the difference should be assessed clinically, how important it is, how useful in our settings. So that is more important while calculating this p-value and statistical significance. So that is about knowing our hypothesis. +[110.26s -> 124.21s] The second step here is to know whether the two variables which we are associating are independent of each other or paired samples. That is when the measurements are repeated on the same individual then they are +[124.21s -> 131.63s] not independent they are called paired samples paired observations like pre and post test +[131.63s -> 143.17s] before and after an intervention like a drug then that will be called as paired observations this paired observations and independent observations are important while applying statistical test +[143.17s -> 147.54s] because both follow different set of statistical tests. +[148.34s -> 160.94s] Then the next step is what type of variable which we are dealing with. In type of variable we have four types that is nominal, ordinal, interval and ratio. Nominal is just a name. +[160.94s -> 170.88s] ordinal has an order that is mild moderate severe will become an ordinal interval and ratio interval does not have an absolute zero +[170.88s -> 180.30s] but ratio will have an absolute zero for statistical analysis purpose we can club this nominal and ordinal into categorical variables +[180.30s -> 193.57s] interval and ratio into continuous variables so the third important step here is we have to look at these variables and identify whether it is a categorical variable or continuous variable +[193.57s -> 201.54s] then the next important thing is we need to identify which variable is dependent variable which variable is independent variable +[201.54s -> 210.35s] or otherwise which variable is the predictor variable which variable is the outcome variable suppose if you are studying antenatal care and low birth weight +[210.35s -> 222.13s] low birth weight cannot be a predictor variable for antenatal care it is it should be the vice versa that is antenatal care should be the predictor variable for the outcome variable low birth weight +[223.02s -> 232.48s] then the fourth important step is are the variables distributed normally why this is important is when these variables are normally distributed +[232.48s -> 241.01s] then we apply parametric test when these variables are not normally distributed then we apply nonparametric test +[241.94s -> 254.99s] So why we need to find this normal distribution? Only with normal distribution we can apply this parametric test. That is parametric test assume normal distribution. If the variable is normally distributed for the sample population, +[254.99s -> 268.43s] then the statistical conclusion which we make for the whole population will be valid or more accurate so that is why we want the data to be normally distributed in order to generalize our +[268.43s -> 273.49s] study results and also parametric tests yield stronger results. +[274.51s -> 289.07s] What are all the reasons we don't get normally distributed data is the presence of some outlier and low sample size, nature of the data itself. For example, usually income will be always will not be normally distributed. +[290.45s -> 304.37s] And how to check for this normal distribution? We use two statistical tests for testing the normality of the data. Shapiro-Wilk when the sample size is less than 50, Kolmogorov-Svinav when the sample size is greater than 50. +[304.37s -> 314.99s] But for smaller samples with the sample size less than 20, the tests are unlikely to detect non-normality and for the larger sample size, that is, +[314.99s -> 324.53s] Sample size is greater than 50. The tests can be too sensitive. They are also sensitive to outliers. So use histograms or Q-Q plots. +[324.53s -> 337.31s] the easiest way to check for normality is the visual inspection of the histogram and if there is a bell-shaped curve then the data is normally distributed and also the mean median mode should coincide +[337.31s -> 346.03s] and assume normality of data distribution if mean is greater than two standard deviation. Now the fifth and the last step is the choice of statistical test. +[346.03s -> 358.80s] This is the very important slide of this presentation, that is after understanding the basis of selecting the statistical test, we are now going to select the statistical test for our analysis. +[358.80s -> 372.46s] to understand this flowchart we start from here if your outcome variable is categorical that is cured or not cured if your exposure variable is between two groups that is between +[372.46s -> 386.26s] a drug received and drug not received then we need to use chi-square test which is exact test or logistic regression chi-square test is a simple test here it cannot be used when the +[386.26s -> 398.48s] expected cell values are less than 5 in more than 20 percent of the cells then we need to use fischer's exact test logistic regression can be used when we want to find out +[398.51s -> 412.61s] The prediction of one variable by the other variable. The same way if your categories are more than two groups then the test remains same. Chi-square test which is the exact test on logistic regression. +[412.61s -> 425.73s] If the categories are paired, that is, the observations are on the same individual, then we need to use McNemar's test. Kappa statistic will be for agreement. When the outcome variable is continuous. +[425.73s -> 436.40s] and the data is normally distributed then we need to use two sample t test when the data is not normally distributed we need to use man whitney u test +[436.40s -> 450.53s] when the data is paired that is before and after intervention then we need to use paired t-test and the corresponding not normal distribution statistical test is wilcoxon signed rank test more than two groups +[450.53s -> 464.56s] you want to find out the difference between the effect of drug A, B, C on the fever, then you need to use one-way ANOVA test if the data is normally distributed and Kruskal-Wallis test if it is queued. +[464.56s -> 476.75s] for continuous variable that is you are looking at a continuous variable like age versus temperature then we need to use Pearson's correlation in case of normal distribution. +[476.78s -> 486.45s] Spearman's correlation in case of skewed data. If you want to see the prediction of one variable with the other variable then you can use linear regression. +[488.62s -> 502.30s] This slide shows choice of statistical test from paired or matched observations. When we have two categories that is pass and fail, before and after, then we need to use McNamara's test. +[502.30s -> 512.08s] we have more than two variables pass fail or withheld then we need to use cochrane queue when the data is ordinal variable +[512.08s -> 525.49s] mild moderate severe before and after intervention then we need to use wilcoxon signed rank test quantitative discrete or non-normal distribution then also we need to use wilcoxon signed rank test +[525.49s -> 537.39s] quantitative normally distributed we need to use parity test more than two measurements on the same subjects and it is normally distributed then we need to use repeated measures anova +[537.39s -> 544.72s] more than two measurements on the same subject and it is not normally distributed then we need to use friedman's test or f test +[546.42s -> 557.79s] Suppose if we want to find out how much one variable predicts the other variable or how much one factor predicts the other factor, then we need to use this regression. +[557.79s -> 571.81s] Comparison of multiple independent factors with one factor can be done. When we do comparison of one to one then it is called as simple regression. Example maternal weight affecting birth weight. +[571.81s -> 586.02s] Many to one, it is called as multiple regression. For example, maternal anthropometry factors affecting birth weight. When the outcome is continuous, it is called linear regression. When the outcome is categorical, it is called as linear regression. +[586.02s -> 591.82s] logistic regression when we are using agreement +[592.24s -> 602.24s] The commonly used statistical test is Kappa statistics. In healthcare settings, we use this Kappa statistics to compare the findings between two procedures. +[602.24s -> 616.18s] So as it is close to 1, there is a complete agreement. As it is close to 0, there is no agreement. There are other agreement statistical tests, intraclass correlation coefficient and Cronbach's alpha. +[617.39s -> 630.02s] You need not remember the statistical test. So how to approach this is if we type our search term for statistical test for continuous independent variable and categorical dependent variable, the answer will appear here. +[630.02s -> 641.02s] So you need not remember or memorize the choice of statistical test. Once you start applying this statistical test, automatically it will be remembered. So what next? +[641.02s -> 654.16s] Either you can do manual calculation of all these tests. For chi-square t test, it is going to be very easy. So you can try calculating the test value and p-value manually. +[654.16s -> 665.95s] You can also use online calculators for t-test and chi-square which is exact test it is available. But the easiest way to apply all the statistical test is using softwares. +[665.95s -> 679.34s] So after applying the softwares, you will get a test value. When you are doing a manual calculation, you need to match with the probability table and calculate the p-value. But in softwares it will calculate the exact p-value. +[679.60s -> 681.87s] Thank you for watching this video. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_8.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..cbb6a5fb3746d3114a61751a0d56fa1b6595f532 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_8.mp4.txt @@ -0,0 +1,18 @@ +[0.91s -> 15.50s] Hey, everybody. It's F. Perry Wilson from the Yale School of Medicine here. Excited this morning about new news out of Pfizer about vaccine efficacy. And I thought it'd be a great time to talk to everyone about how we actually calculate vaccine efficacy. +[15.50s -> 22.72s] using some of the numbers we got so let's just walk through this here what I've +[22.72s -> 35.04s] Created here is what's called a contingency table. Sometimes it's called a two-by-two table or an epidemiologist table. And it lets us do some of the math for vaccine efficacy. So let's fill in some numbers here. So first of all, +[35.04s -> 46.43s] We know that there were 44,000 people in this randomized controlled trial and that there was about 22,000 people who received the active vaccine and 22,000 people who received placebo. +[46.43s -> 60.75s] So far, so good. Now, from reporting from The New York Times and other outlets, we know that 170 of those people developed COVID-19. So a small percentage because, you know, there hasn't been that much time that the trial has been going on, but enough to do some calculations. +[60.75s -> 74.78s] We also know that 162 of those 170 were in the placebo group compared to just eight in the vaccine group. So right away, right? Like you can tell something's going on here. But let's figure out how we get to 95% efficacy. +[74.78s -> 89.10s] So knowing this, we can now do some simple arithmetic to fill in the other numbers. So we know that if there's 22,000 people total in the vaccine group and eight developed COVID-19, that means 21,992 did not develop COVID-19. +[89.10s -> 102.06s] And we can do similar math in the placebo group. And now we have all the information we need to calculate vaccine efficacy. So first question, what percent of the vaccinated group developed COVID-19? +[102.06s -> 113.71s] Well, this is pretty easy. It's just 8 out of 22,000, which turns out to be 0.036%. It's a pretty small number. +[113.71s -> 126.96s] How about in the placebo group? Well, that's 162 out of 22,000, which is 0.74%. Now, I've put a little line in between these because I can compare +[126.96s -> 140.18s] the relative risk of getting COVID-19 in the vaccine group to the placebo group by taking 0.036 divided by 0.74%. And that gives me 0.049. +[140.18s -> 147.66s] In other words, people in the vaccine group have about 5% of the risk of developing COVID-19. +[147.66s -> 161.97s] in this trial as people in the placebo group did. That is a relative risk, not an absolute risk reduction. We talk about the difference in my free online course on Coursera, Understanding Medical Research. Your Facebook friend is wrong. Please join us. But when it comes +[161.97s -> 174.86s] to vaccine efficacy, we really are interested in that relative risk reduction because we want to know sort of on a population level how much we can reduce the rate of COVID-19 infection. +[174.90s -> 189.49s] Okay, so 0.049 relative risk reduction. To get to vaccine efficacy, we just do a simple one minus. Okay, it's just one minus the relative risk. So in this case, one minus 0.049, which is 0.951. +[189.49s -> 202.98s] or 95.1%. So that is how we are getting to this idea that the vaccine reduces the risk of COVID-19 infection by 95.1%. +[202.98s -> 215.33s] So I hope that makes it all clear. Really good, exciting news. This, as many people have said, just an outstanding efficacy number for a vaccine, any vaccine, frankly, but especially great in the COVID-19 pandemic. +[215.33s -> 224.31s] So thanks for joining me. And we do stuff like this and a lot more on the Coursera course. So come visit us there. diff --git a/VideoMMMU_ASR_large/Medicine/validation_Public_Health_9.mp4.txt b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..6b36611f7d9693da207578f47eafa76b688b51a0 --- /dev/null +++ b/VideoMMMU_ASR_large/Medicine/validation_Public_Health_9.mp4.txt @@ -0,0 +1,32 @@ +[4.24s -> 17.10s] Hello, and welcome to this video where we'll be taking a look at sensitivity and specificity. We'll take a look at what they are, how they're calculated, and two related measurements, positive and negative predictive values. +[17.26s -> 25.58s] Tests are important tools that can help us identify the presence or absence of a disease. But they're not always perfect. +[25.58s -> 36.37s] Sensitivity and specificity are measures that can be used to determine how good a test is at correctly identifying the presence or absence of disease. Let's take a closer look. +[36.69s -> 42.64s] Let's use a table of the outcome of the test and disease status to learn about some of the terms that are used. +[43.22s -> 55.78s] There are people with a disease and those without the disease. When we do a test on someone, it can be either positive or negative. If the test is positive, it should mean that the person has the disease. +[55.78s -> 70.03s] This is called a true positive. It correctly identifies a person with the disease. Similarly, if a test is negative, it should mean that a person does not have the disease. This is called a true negative. +[70.03s -> 83.86s] It correctly identifies a person without the disease. However, because tests are not always perfect, a test can be positive even though the person does not have the disease. This is called a false positive. +[84.30s -> 94.74s] This is not ideal because it could lead to further testing or treatment that's not necessary, negative psychological impacts, and may come with an economic cost or added risk. +[95.18s -> 108.64s] On the other hand, a test can sometimes be negative even though the person has the disease. This is called a false negative. Again, this is not ideal because the test has not picked up the person despite them having the disease. +[108.64s -> 115.78s] This may lead to delays in diagnosing the disease, and therefore, delays in treatment, which could lead to a negative health outcome. +[115.78s -> 127.33s] An incorrectly negative test may also lead to a false sense of security and the continuation of risky behaviors that may worsen the disease or even place others at risk in the case of a communicable disease. +[127.33s -> 131.25s] Missing a diagnosis may also have legal consequences. +[131.70s -> 144.14s] Using these terms, we can calculate the sensitivity and specificity of the test. These are indicators of how good a test is and guides us on how to determine the appropriateness of a test and interpret its outcome. +[144.56s -> 156.72s] Sensitivity is the proportion of people with the disease who test positive for it. A high sensitivity means that the proportion of true positives is high and the proportion of false negatives is low. +[157.33s -> 170.30s] Specificity, on the other hand, is the proportion of people without the disease who test negative for it. A high specificity means that the proportion of true negatives is high and the proportion of false positives is low. +[170.30s -> 184.24s] Let's work through an example. Let's say we have a group of 600 people. Let's assume that 100 people have a disease and 500 people do not. First, we'll focus on the 100 people who have the disease. +[184.30s -> 196.64s] Let's say that we do a test on people with the disease. Now, if that test was perfect, we would have 100 positive tests. However, let's assume that the test is positive in only 90 people. +[196.64s -> 208.83s] In other words, there are 90 true positive cases. This leaves us with 10 people with the disease who have a negative test result. These are false negatives. We know that the sensitivity of the test +[208.83s -> 218.99s] is a proportion of people with the disease who test positive for it. Therefore, in this example, the sensitivity of the test is 0.9, or 90%. +[219.57s -> 233.02s] Now let's do the test on the 500 people without the disease. Ideally, we will have 500 negative results. But let's assume that the test was negative in only 400 people. These are true negatives. +[233.02s -> 246.32s] This would mean that in 100 people without the disease, the test was positive. These are false positives. We know that the specificity of the test is the proportion of people without the disease who test negative for it. +[246.32s -> 251.73s] So in this example, the specificity of the test is 0.8 or 80%. +[252.05s -> 263.66s] And that's how sensitivity and specificity are calculated. Tests with high sensitivity are good for screening tests because the proportion of false negatives is low. On the other hand, +[263.66s -> 276.54s] Tests with high specificity are good for confirmatory tests because the proportion of false positives is low. The perfect test will have a sensitivity of 100% and a specificity of 100%. +[276.54s -> 285.01s] The closer a test's sensitivity and specificity is to 100%, the better the test is in confirming or excluding the disease. +[285.65s -> 297.52s] Finally, let's have a quick look at two related measurements, positive predictive value and negative predictive value. It uses the same information but looks at it from a testing point of view. +[298.29s -> 302.16s] Let's use the same values we used in our previous example. +[302.90s -> 314.88s] There are 190 people who test positive and 410 people who test negative. The positive predictive value is the proportion of people with a positive test who actually have the disease. +[314.88s -> 328.61s] In this example, the positive predictive value is 47.4%. The negative predictive value is the proportion of people with a negative test who do not have the disease. In this case, the negative predictive value +[328.61s -> 340.66s] is 97.6%. Positive and negative predictive values depend on the prevalence of disease, or in other words, how much disease there is in the population. In general, +[340.66s -> 349.01s] An increase in disease prevalence is associated with an increase in positive predictive value and a decrease in the negative predictive value. +[349.42s -> 356.98s] And that's an overview of sensitivity and specificity and a quick look at positive and negative predictive values. diff --git a/VideoMMMU_ASR_large/Science/dev_Biology_3.mp4.txt b/VideoMMMU_ASR_large/Science/dev_Biology_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..d1bc8e1bd44a17f98388d62557cc081de46c49fe --- /dev/null +++ b/VideoMMMU_ASR_large/Science/dev_Biology_3.mp4.txt @@ -0,0 +1,36 @@ +[0.30s -> 12.61s] Let's get into monosaccharides. So first, let's expand on the definition of a monosaccharide that you put in your 20.1 notes. +[12.61s -> 24.94s] In addition to everything that I've already said about monosaccharides, let's expand our definition to say that it is either a ketone or an aldehyde. +[27.60s -> 35.95s] with three to six carbon atoms. And I told you that six is the most common. +[38.51s -> 50.19s] And in this monosaccharide, every one of the carbon atoms is going to have either +[51.38s -> 60.94s] a double bond to an oxygen, so carbon-oxygen double bond, and that will be the ketone part or the aldehyde part. Or if it doesn't have that, +[60.94s -> 74.99s] it has a bond to an OH. So every single carbon atom has an oxygen on it. Monosaccharides can be called, they can be classified as either an aldose, +[76.43s -> 79.31s] Or a ketose. +[85.55s -> 96.78s] In the aldose molecules, the aldose monosaccharides, the carbon-oxygen double bond is on the first carbon, carbon number one. +[96.78s -> 101.39s] of our chain and so it is an aldehyde. +[103.92s -> 117.20s] And we'll draw a picture of that. In the ketose molecule, the carbon-oxygen double bond is on carbon number two. And so it is going to be a ketone. +[120.50s -> 135.47s] So let's draw a couple of pictures. Now remember when we drew one of these before, when we draw monosaccharides, we draw them up and down vertically, which takes up a lot of space. +[136.91s -> 147.92s] So this is going to be a four carbon chain. The carbon on the top, carbon number one, is going to have the carbon-oxygen double bond. +[149.14s -> 163.73s] And even though in section 20.1 I told you that down here at the end of the chain we normally draw this part of the monosaccharide in condensed notation, I'm expanding it out in this particular section. +[163.73s -> 178.72s] drawing. So this would be an aldose with our carbons. When we number them, we start at the top and we number down to the bottom like this. So our carbon oxygen double bond is on number one. It's an aldehyde and it's an aldose. +[178.72s -> 191.79s] let's draw a ketose. So again, we're going to have a carbon chain. This one's going to be a five carbon chain. And since we're drawing a ketose, we want to put the double bond on carbon number two. +[191.79s -> 200.30s] We'll fill those numbers in in a second. And every other carbon atom has to have an OH. So we'll fill those in. +[200.69s -> 207.98s] And then we'll add hydrogens as we need to to make sure that every carbon has four bonds. +[208.78s -> 223.02s] And let's put numbers on our carbons. There's one, two, three, four, five. I left a hydrogen off of carbon number five. So there's our ketose with the carbon oxygen double bond on carbon number two. +[223.92s -> 238.70s] So in addition to classifying a monosaccharide as an aldose or a ketose, we can also classify it based on how many carbon atoms it has. So if it has three carbon atoms, +[240.56s -> 253.04s] Whether it's an aldose or a ketose, three carbon atoms, we are also going to call it a triose. Ose is the suffix for sugar. +[253.04s -> 265.36s] or carbohydrate. So triose, tri meaning three, and the ose telling us that we're looking at a sugar molecule in general. If we have four carbon atoms +[266.61s -> 281.10s] we will call that a tetros, where T-E-T-R is going to be our prefix meaning four, and os is our suffix telling us that it's a saccharide. If we have five carbon atoms, +[282.29s -> 291.09s] We can also call it a pentose, pent for five. And if we have six carbon atoms, +[291.79s -> 305.25s] We can call it a hexose. And these names, triose, tetrose, pentose, hexose, they apply to both the aldoses and the ketoses. So for our two... +[305.25s -> 319.57s] um molecules like in looking at this guy right here if we wanted to describe this we could call it an aldose and that would be correct and it would be kind of a generic name because when we say aldose +[319.57s -> 333.17s] The only thing that we're communicating in that name is the position of the carbon oxygen double bond. If we wanted to be more specific, we could call it an aldo. +[334.16s -> 335.92s] Tetros. +[337.58s -> 349.62s] The aldo tetros name, the aldo part is telling us that it is an aldose, and the tetros part is telling us that it is a total of four carbons. +[350.48s -> 363.17s] So this name is a little bit more specific, but it's still not really all that specific. It's still kind of a generic name. Looking at our other molecule over here. +[363.17s -> 369.95s] If we wanted to classify this molecule, we could say that it is a ketose. +[369.95s -> 383.44s] When we say that it's a ketose, all that we're really saying is that we have a carbon-oxygen double bond on carbon number two. We're not saying anything about the entire molecule. We could also call it a keto. +[383.82s -> 393.10s] pentose. This name is a little bit more specific. Keto means that it's a ketose. +[393.84s -> 402.56s] And the pentose part is telling us that it has a total of five carbons. So that name is even more specific. However... +[402.56s -> 416.85s] These names, these four names that we've come up with, the ketose, the aldose, the aldotetrose, the ketopentose, those names are also still pretty generic because there are multiple ways in which we could draw a ketopentose. +[416.85s -> 431.06s] by changing the position of the OH groups in this molecule, whether we're drawing the OH group on the right-hand side like we did here, or we could also draw it over on the left-hand side. So as we get more specific... +[431.06s -> 441.44s] with our molecules, we'll come up with even more names to be able to describe them more accurately. But these are the generic classifications of monosaccharides. diff --git a/VideoMMMU_ASR_large/Science/dev_Geography_5.mp4.txt b/VideoMMMU_ASR_large/Science/dev_Geography_5.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..822e5365ab61468f542f9e00374812c17c0d999b --- /dev/null +++ b/VideoMMMU_ASR_large/Science/dev_Geography_5.mp4.txt @@ -0,0 +1,92 @@ +[0.34s -> 6.10s] Hi guys, I've put this presentation together for solving problems in a transformer circuit +[6.10s -> 20.37s] It's not fixing or maintaining a transformer, it's more about calculating the relationship between what's going on on the primary windings and what's happening on the secondary windings. So it's a relationship between the two different circuits, the primary circuit and the secondary circuit. +[20.37s -> 33.30s] not getting your hands dirty fixing the transformer okay so the objective of this presentation is using the supplied formula we're going to solve problems in the transformer circuit +[33.62s -> 38.77s] so um what have we got okay so in your +[38.77s -> 51.23s] Test or exam you're going to receive sort of like a question that's going to look something a little bit like this But the values are going to be be different, but the principle for solving or completing the problem +[51.23s -> 59.89s] is the same so uh what you're gonna get so you're gonna get the um the transformer equation okay and you're gonna have your um +[60.34s -> 75.02s] Formula will here. Okay, so just a recap on this. So what you want to find is in the center Okay, so if you're looking for watts, okay, you go into this quarter here power and once you go in this quarter here volts this quarter here +[75.02s -> 82.45s] Ohms and resistance in this quarter here and amps for current which is in this quarter here +[82.86s -> 93.36s] so again this is this presentation is all about finding out solving the transformer sort of like looking at what we have okay and trying to work out +[95.34s -> 104.05s] what we don't know effectively okay so we're looking for the relationship between what's on the primary and what's on the secondary winding okay +[104.66s -> 115.06s] So let's have a just quick recap of the terminology and some of the abbreviations that we're using. So what are we looking for and what do we have? +[115.76s -> 130.03s] When you start your question the ideally what you need to do is sort of write down what you have Sort of break it down into sort of primary and secondary winding so you could say like the one sorry VP IP +[130.10s -> 143.78s] RP, NP, and PP. So V is voltage, I is current, R is resistance. N is the number of turns on the coil. So NP would be the number of turns on the primary coil. +[143.78s -> 154.32s] NS would be the number of turn on turns on the secondary coil P is the power in watts and the way we sort of +[154.83s -> 168.94s] identify between the difference between primary and the secondary winding is we have a subscript okay so you'll have a capital N and then down here you'll have a little tiny P or a little tiny s okay that is just to indicate that there's you know +[168.94s -> 174.96s] What part of the transformer we are working to or working with? Okay +[176.05s -> 184.50s] So the problem okay, we've been given a problem like this So what we need to do is you'll probably end up having to calculate so we're going to calculate the number of turns +[184.82s -> 196.85s] the primary okay and now the current on the primary the resistance on the primary and the power on the primary coil so that's all relating to this part of the transformer here +[198.54s -> 212.56s] On the secondary coil, we've already got the watts, the ohms, and the number of turns. So what we're going to be looking for on the secondary coil is the voltage and the current. So we're looking for voltage and current on the secondary. +[212.56s -> 215.70s] okay so you know +[216.69s -> 230.86s] and seven items that we need to find okay so how are we going to do that so firstly I would write down okay everything you have or everything you need to find and everything that you have and lay it out in a logical order so like you've got +[230.86s -> 244.14s] your primary on one side and your secondary on another side and then start putting in the information that you've got so you can populate the details and just use that as a master reference so every time you work something out +[244.14s -> 255.02s] pop the new value in there okay so what do we have and what can we find out okay so +[256.37s -> 268.75s] We've got our formula wheel up here. Okay, and we've got our transformer Equation over here. Okay. So at the moment we know the number of turns on the primary. That's why not number turns the voltage on the primary +[269.04s -> 271.76s] Okay, we know the number of turns on the secondary +[272.82s -> 287.60s] But that's about it. Okay, so we can't really use that one because we haven't got enough detail Okay, so what we need to do is now need to look at our formula wheel Okay, and we can look at what we've got and what we need to find. Okay with this formula wheel +[287.98s -> 297.26s] With the formula wheel you can't mix them up so you can't use the voltage on the primary and the resistance on the secondary. +[297.90s -> 311.82s] okay to work out for example the current okay so they must if you're using this wheel they must be related on each side you can only use what the information you have on each side of the coil you can't mix +[313.10s -> 327.57s] Primary and secondary information. Okay, so it must must remain, you know So say for example if you want to work out the current on this one, for example We've got the voltage and we've got the resistance. We've got the voltage on the primary and the resistance on the secondary +[327.57s -> 333.97s] We can't mix those because one's on the primary, one's on the secondary. So we need to look at what other information we have. +[336.46s -> 350.24s] So therefore, so looking at what we've got, so we've got number of turns, okay? We can't use number of turns with this formula wheel, so let's scratch that out. But we do have power on the secondary in watts and resistance on the secondary in ohms. +[350.24s -> 363.07s] okay so with that we can actually use that to find out either our current or our voltage okay so if we look at the power and the resistance okay so we look for if we're looking for voltage +[363.07s -> 374.82s] we could use so this is the voltage so we've got the power and resistance so we could square root power times the resistance okay and that would give us our voltage or we could use the +[374.82s -> 387.63s] Power divided by the resistance square root that a square root power divided by the resistance to give us our current Okay, so we've got two options there. So there's two different pathways you can go Okay, so +[387.82s -> 401.34s] What we have there, so we've got We're going to use this one here So we're going to use this to find out our current so we're going to work out current on the secondary first So that's our formula. Okay, so when you do this, don't forget to do the square root. Okay, so do this in the +[401.34s -> 415.34s] inside the square root first or in the root first okay so do p divided by r and then square root the answer okay otherwise if you do this part so 50 divided by 8 i think you end up with like 6.25 +[415.34s -> 429.42s] okay so what we need is to make sure that you square root the answer and then you end up with our 2.25 amps okay so that's our current on the secondary so once you've worked that out then just pop that in there okay +[430.58s -> 441.68s] like so and then we can start looking at our next stage as well okay so we can now we can use we could use our current +[442.00s -> 450.54s] And our resistance okay to work out our voltage so we can do I times R or R times I Okay, so we can do +[452.27s -> 466.48s] Our resistance times our current equals our voltage, which would be 8 ohms times 2.5 amps. And that gives us 20 volts. So that's our voltage sorted on our secondary coil. +[471.92s -> 480.85s] how far can we go now okay so if we look at what we've got so we've got we've completely solved all of our unknowns on our secondary winding +[481.36s -> 494.67s] and so now what we need to do is we now need to start concentrating on our primary winding okay so at the moment we've only got 240 volts on the primary okay +[495.09s -> 510.06s] so what we need to do is we can't use our formula wheel okay so we're going to have to go across and we're going to have to use this formula here okay so we're going to use +[510.38s -> 513.74s] This formula, okay +[514.80s -> 529.39s] to get the marks okay so the easier if the information is there okay the assessor can can mark it if you just put the answer then you know and you get it wrong obviously then you get score zero marks a lot of the the points for the exam +[529.39s -> 539.55s] actually in the working so showing your workings out so actually providing the right answer is quite low well I will only produce like one or two points but demonstrating you can actually +[539.55s -> 544.98s] Carry out the task to do the correct formula layout accurately okay is +[545.49s -> 558.67s] That's where the points are won and lost, if you know what I mean. So with this formula here, so VP over VS equals NP over NS equals IS over IP. +[558.67s -> 571.39s] Now, we don't necessarily have to use VP over VS equals NP over NS. We can use VP over VS equals IS over IP. We can use NP. +[571.39s -> 585.07s] over NS over NS NP over NS or equals IS over IP I'm tripping myself up here okay so we don't necessarily need to use it from left to right we can actually you know we can use those two +[585.07s -> 592.59s] and those two we can use those two and those two or we can use these two and these two okay +[592.88s -> 605.92s] So the first thing I would do is write the formula down, and then underneath that or next to it, write in the values that you've got. And this way we can actually look at what we have. +[605.92s -> 619.73s] and what we need to find okay and this will actually help us in selecting the formula that we need to actually find our unknowns so we're going to look for +[619.73s -> 633.14s] NP so we've got because we know VP we know VS and we know NS so we're going to find NP okay so but you could but you could if you wanted to you could go +[633.14s -> 635.82s] VP over VS, okay? +[636.69s -> 649.74s] over is over ip okay so you could use these two and find ip but at the moment we're going to find np okay so i've transposed this formula okay +[649.74s -> 663.71s] Transposing sounds like a horrible word, but all it is is just moving the formula around. I'm not going to go into it now because it's a whole other hour of PowerPoint, if you know what I mean. So what we're going to do is I'm just going to give you the formula. +[663.71s -> 676.30s] So this is the formula we're going to use so effectively that goes up there, so it's going to be VP times NS over VS equals NP so then what we can do with that is we can then punch in our values +[677.17s -> 691.10s] Okay, like so, so 240 times 120, divide by 20, okay, and that gives us 1,440, okay, and that's n, so that's the number of turns. So that tells me... +[691.10s -> 698.91s] okay that the primary coil has 1440 turns on it okay +[698.91s -> 713.90s] And the secondary has 120. So you can tell that that is going to be a step-down transformer. Or we can say that anyway, but it's a step-down transformer. So the primary now has 144. +[714.22s -> 720.88s] 144, 140, I'm trying to get my words out, 1440 turns on it +[723.50s -> 729.74s] So the next step is to then look at we're still back on this formula. Okay, but now we've got +[730.03s -> 744.48s] All we've got left is the IP to find okay, so That's the formula we're going to use so it's going to be NS times is over NP and that equals IP So then we punch in our room +[744.48s -> 756.53s] the data that we have so it's going to be 120 times 2.5 over 1440 and that gives us a current on the +[756.72s -> 768.85s] primary coil of 0.2083 okay so it's quite low current so that's like 208 milliamps so as you can see the higher the voltage +[769.01s -> 776.59s] Okay, so if the if the voltage is higher on the primary than on the secondary the the current will be lower +[777.26s -> 789.97s] on the primary okay and higher on the secondary okay so lower voltages generally higher currents higher voltages generally lower currents okay so that's our +[790.06s -> 794.64s] current on our primary +[795.76s -> 809.82s] So now what we've got is we've now exhausted this formula here So we can't use that anymore because we know all of the values So what we're then going to have to do is turn back to our formula world. Okay, and we're going to use +[809.82s -> 823.12s] our formula will and only the information that we have on the primary to solve for our other two unknowns okay so we need to find the power and the resistance okay so +[823.25s -> 836.86s] We're going to look for the resistance. OK, so resistance from our even from our own law triangle is V divided by I equals our resistance. OK, so voltage divided by the current equals our resistance. +[836.86s -> 839.44s] And from there we punch in our values that we know. +[839.73s -> 854.03s] So it's going to be 240 volts divided by 0.2083 and that gives us a resistance on the primary of 1152.18 ohms. +[854.03s -> 864.69s] quite high resistance okay and that's another value found okay so punch that into your master table so you can keep track of all your values +[866.16s -> 877.10s] then the next step okay we've got the last thing to do is the power okay as a rule okay the power on the primary +[877.10s -> 882.61s] okay equals the power on the secondary and vice versa so whatever the power is on the primary +[882.86s -> 894.50s] Will be on the secondary. Okay. So in our case that we have got 50 watts on the secondary Okay, we will have 50 watts on the primary. Okay, but we're going to +[894.50s -> 904.61s] We're just going to prove that theory. So we're now going to do voltage times the current, and that equals power in watts. +[904.61s -> 910.26s] okay so then we punch in what we know so 240 volts times 0.2083 +[910.51s -> 924.24s] and that equals 49.992 watts okay and the chances are the only reason why it's not bang on 50 is because we rounded our current +[925.07s -> 938.67s] okay so that's where that comes from so then now you can punch that into our master table and we have completed the problem that is it done nothing more to do okay +[938.83s -> 948.59s] We found all our unknowns, okay, and we can see We can see what values we have on either the primary or the secondary +[948.91s -> 958.13s] There is one more step that we can do and it's more of a sanity check just to make sure that our values are correct. +[958.86s -> 971.79s] What we've got here so 240 divided by 20 will have a value 1440 divided by 120 will have a value and 2.5 divided by zero point +[972.69s -> 984.53s] two zero eight three will have a value as well and they should all equal the same okay so if you divide that by that actually that will equal 12 now by that that should equal 12 +[984.53s -> 988.78s] And that by that should equal 12. So they all equal the same. +[989.55s -> 1003.62s] And so we're just going to just check that mathematically. Okay, so I've done 240 divided by 20 is 12. Okay, 1440 divided by 120 is 12. Okay, and +[1003.62s -> 1017.31s] 2.5 divided by 0.2083 is 12.00192 and again the reason why that doesn't add up exactly to 12 is because we would have rounded this one +[1017.31s -> 1021.55s] Okay, so we would have rounded our current on the primary +[1022.99s -> 1034.77s] That's fine. That is fine if you come up with that and you've got that and you're getting these values It's all good. Okay, so I would be happy with that and it's that is purely just down to +[1034.77s -> 1046.02s] I'm not rounding error but just the way we've rounded okay so thanks for watching I hope this helps and if you have any questions now please see me in class have a good diff --git a/VideoMMMU_ASR_large/Science/test_Geography_114.mp4.txt b/VideoMMMU_ASR_large/Science/test_Geography_114.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3677d56e50b36f1d78083906ef99cceaffd45022 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/test_Geography_114.mp4.txt @@ -0,0 +1,41 @@ +[0.00s -> 14.26s] Hello there Geographers and welcome back to the Mr. Sin channel. Today we're going to be going into Unit 6, Topic 5. We're going to be talking about the internal structures of cities. This video is going to be jam-packed full of a bunch of different city models. And it's going to be important that you stick around to the end because at the end... +[14.26s -> 28.46s] the video we're going to be practicing these models to make sure you really understand this concept also if you find value in any of these topic review videos don't forget that subscribe button it's a great way to support the channel and also make sure that you get notified when i post the future topic review videos now before +[28.46s -> 42.67s] Before we get started, I want to quick review a concept that we talked about in Unit 5 when we were looking at intensive and extensive agriculture and also von Thunen's model of land use. And that's the bid-rent theory. Remember, the bid-rent theory looks at the relationship of +[42.67s -> 56.88s] prices of land to the market or an urban area the further we go away from a large city the cheaper land will be and that's because there's more land available our population density is lower meaning demand for that land is less +[56.88s -> 58.35s] So the price goes down. +[58.35s -> 72.62s] This is going to be important for us to understand when we're looking at the spatial layout of different cities, especially when we're trying to understand the location of different commercial, industrial, and residential zones. We can see that large retail stores and specialized services that make more money are more... +[72.62s -> 86.83s] likely to locate near the central business district, or CBD for short, where industrial zones that require a lot of workers but do not need to be right next to that central business district are located farther out, with residential zones +[86.83s -> 101.06s] often located after that. This is to minimize costs and to maximize their productivity. By understanding the bid rent theory, we can see the spatial layout of our cities. Now, one thing that bid rent theory doesn't do a good job of is predicting where people might live. +[101.06s -> 115.28s] based on income at least. And that's because sometimes people will rent. They'll rent a multifamily unit. They'll be renting an apartment or maybe even a condo. So the price of land isn't factored into it since they're not purchasing it. Instead, they're renting from a landlord. So we've reviewed the- +[115.28s -> 129.49s] a little bit, now we're gonna move into Burgess' concentric zone model. And this is gonna be our first urban city model. It was developed in the 1920s based off the city of Chicago. This model focuses on the different socioeconomic statuses of individuals and homes. +[129.49s -> 143.70s] within a city. Traditionally, this model has older homes located closer to the central business district, with newer development happening further out. Lower income residents and industries are often located in the zone of transition. +[143.70s -> 157.90s] this is more for the United States. We can actually see in countries in Europe that more of the wealthy individuals are located closer to that CBD. Now parts of this model are starting to change and quite frankly it's becoming a little outdated and that's due to globalization. +[157.90s -> 172.11s] changes in the production of our goods and services gentrification and also urban renewal policies all of this is starting to change where we're living the price of homes and also the location of different industries the next model is the hoyt sector model and this +[172.11s -> 186.32s] This model still uses the CBD as the center point of the model. However, this model doesn't develop in a series of rings. Instead, we can see it develops in a series of wedges or sectors. This is based off different economic and also environmental factors. +[186.32s -> 200.53s] For example, industries we can see will actually align near transportation systems, highways and railroads. This will allow them to be able to export their goods quicker and also be able to connect with their consumers. Now, just like our previous model, this model is also experiencing change. +[200.53s -> 214.74s] and it's starting to feel a little dated. And that's because of changes in our transportation system and also infrastructure. People are living now farther away from cities, which means businesses are moving with them. So we're seeing some changes in the location of different people. +[214.74s -> 228.94s] also businesses. The next model we have is the Harrison-Ullman multinuclear model. This model was created around 1945 and it focuses on trying to account for the changes in technology and also transportation that society was seeing. We can see when +[228.94s -> 243.15s] looking at the model that it has multiple central business districts now we still have our original CBD but this city now has multiple CBDs each around their own purpose we can see that the CBDs will have unique economic opportunities +[243.15s -> 257.36s] residents in that city. And these CBDs will act as nodes within the city. They'll attract certain industries, people, and organizations based on what's offered in those CBDs. Hence why we have multiple central business districts. They all serve- +[257.36s -> 271.57s] For example, CBDs or nodes of the city that focus on manufacturing are more likely to see the workers of those factories live within that area. On the other hand, though, we could also see certain CBDs of the city or nodes repel others. +[271.57s -> 285.78s] For example, again, if we go back to our manufacturing part of the city, it's more likely that the more wealthy individuals of a community aren't going to want to live near that CBD, and they're more likely to live by a CBD that focuses on their way of life. So we can see that... +[285.78s -> 299.98s] that the city actually can become kind of segregated. That could be kind of an issue based on economics, but also based on the opportunities provided throughout the different cities. Continuing off of our multinuclear model, we can go into the next model, which is our galactic model. +[299.98s -> 314.19s] This was made around the 1960s, and it tried to address the changes in the economy. No longer are we seeing cities that are focused on manufacturing. Now we're past post-industrialization. Cities now are focusing on more services. +[314.19s -> 328.40s] advancements in transportation and also our new robust infrastructure systems, we can see that people are now living farther away from that central business district. This model has edge cities which we can see are connected by a beltway or a highway. +[328.40s -> 342.61s] allows these edge cities to offer more specialized services as they're connected to other edge cities if you need more information on the edge cities the beltways check out my video on 6.2 it goes into edge cities boom burbs experts and all these different concepts +[342.61s -> 356.82s] apply to this specific model. Now so far we've been talking about city models that focus on the United States and North America. The next three city models we go into though are going to focus on different regions around the world with the first being the Latin American city model. This model +[356.82s -> 371.02s] takes aspects of the concentric zone model and also our sector model. And we can see the influence of colonization on this model as well. Here the CBD is still located in the center of the model with a spine which goes to the mall. +[371.02s -> 385.23s] and the spine has most of the high-wealth residents. In this model, we can see the division between different socioeconomic classes, with some parts of the city living in extreme poverty. This is known as the disamenity zone. In some cases and in some parts of the city, unfortunately, we'll... +[385.23s -> 399.44s] see areas that lack basic infrastructure things like water power and sewage and also in this model we'll see squatter settlements starting to form these traditionally are happening on the outside of the model and it's due to this increased urbanization +[399.44s -> 413.65s] that's happening as these countries develop we're starting to see more people be drawn into the city unfortunately that's putting further pressure on these urban areas and they're not able to provide services for all of the people if we move over to Africa we can see the subset +[413.65s -> 427.86s] African city model. These models have a significant amount of influence from their European colonizers. These cities often have three CBDs, a traditional CBD, a CBD built by European colonizers with more of a grid-like pattern. +[427.86s -> 442.06s] their streets and multi-story buildings resembling the architecture of european countries and lastly an open market cbd infrastructure in these cities is more robust near the city center similar to the latin american city +[442.06s -> 456.27s] model, we start to see shanty towns and squatter settlements form on the outskirts of the city. This is because as countries continue to develop and advance in the demographic transition model, we start to see more urbanization. As more job opportunities focus +[456.27s -> 470.48s] these larger cities we see people migrate from rural areas into urban centers lastly we could also look at the southeast asian city model here again we can see some influences from the sector model and also our concentric zone model however one thing that's very +[470.48s -> 484.69s] very different here is there is no CBD here we can see the impact of the colonial era as we have the port as kind of the focus point of this model during the colonial era many Western countries wanted to trade with these port cities these cities often have special +[484.69s -> 498.90s] economic zones which are created to encourage trade and development from western countries and they have special zones for chinese merchants government zones and also residential zones but the one thing to notice here is that the hub of activity is located around +[498.90s -> 513.10s] port all right geographers hopefully right now your head isn't spinning i know we just talked about a ton of different models and concepts the important thing here is to understand the spatial layout of these different models understand how the historical connections to them shape the cities +[513.10s -> 527.31s] we live in today and also understand how changes in technology transportation and globalization are continuing to reshape the spatial layout of our city now comes the time to practice geographers answer the questions on the screen and check your answers +[527.31s -> 541.52s] down in the comment section below and when you're down there don't forget to hit that subscribe button and also consider sharing the video it's a great way to support the channel and allows me to make more videos in the future plus by subscribing you make sure that you don't miss out on any of the future topic review videos and if you +[541.52s -> 552.40s] are struggling in your AP Human Geography class, consider checking out my Ultimate Review Packet. It is a great resource that covers all seven units, and it'll make sure you can get an A in your class and a 5 on the national exam. +[552.40s -> 559.54s] All right, Geographers, I'm Mr. Sin. That's all the time we have for today. And until next time, I'll see you guys online. diff --git a/VideoMMMU_ASR_large/Science/test_Geography_14.mp4.txt b/VideoMMMU_ASR_large/Science/test_Geography_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..378821654c26cbe73ba8c1bfcd4bd4794267c1b2 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/test_Geography_14.mp4.txt @@ -0,0 +1,24 @@ +[2.16s -> 12.50s] This video is going to be about the Latin American city model as we look at the different growth models for U.S. cities, primarily the concentric. +[13.07s -> 26.77s] the Hoyt or sector model, and then also the multiple nuclei. The Latin American city model is, or the Ford-Griffin model, is something that kind of combines both concentric and the sector models together with some +[26.77s -> 40.22s] infusing the traditional Latin American culture and some of the elements that we took from previous models to help understand what's actually happening here. +[40.22s -> 52.38s] Generally speaking, when we look at Latin America, we see a lot of primate cities, Mexico City being a primary example of this, where you have a very high population, highly dense population. +[52.38s -> 64.54s] population surrounded oftentimes by slums or the outskirts become places where the poor come +[64.54s -> 72.88s] congregate or come to the urban centers looking for opportunity and a better life. The other elements that we see +[72.88s -> 85.52s] Is this within the central business business district is that the surrounding areas unlike? American models or the three models we looked at previously the poor or the +[85.52s -> 96.22s] less desirable place to live are on the outskirts. That the traditional markets and the more central housing is +[96.22s -> 102.19s] kind of transitions into the high end, being closer to that central business district. +[102.48s -> 113.58s] Where a lot of the market that the natural markets exist? You know as we look at the transition zone is sort of a hybrid of of some of the things that are happening there +[115.41s -> 124.22s] If you look at the spine, one of the main identifying characteristics is the spine that kind of heads between... +[124.22s -> 131.65s] um the central business district out to the outskirts where you have a mall generally another commercial area where you might find +[131.65s -> 145.95s] access for, especially those that are in the most impoverished. And you can see along those lines the elite residential sector, or basically the wealthy. It's the most stable, it's the most economically active. +[145.95s -> 158.50s] Generally speaking, we see the highest or the upper class residing along in those zones. Again, if you're taking a look at Mexico City, oftentimes the density is incredibly... +[158.50s -> 172.54s] The infrastructure is minimal. Oftentimes they're shanty type housing, sometimes put together by scrap material that they have found. Squatter settlements, sanitation tends to be very poor in the most undeveloped. +[172.54s -> 185.97s] places or the LDCs. So as we look at that, you know, it's very similar in some ways to the sector model, you know, if we look at transportation or access into these areas. +[185.97s -> 198.40s] But as you move away from it, the industrial park moves in the opposite direction as the spine, leading to some of the more wealthy. +[198.40s -> 212.66s] neighborhoods and then in that zone of maturities you see this in some cases you often see a place of gentrification or a sort of a rebirth of a particular area near that central business. +[212.66s -> 217.04s] District and so it's kind of constantly renewing itself over time +[217.04s -> 229.81s] And generally speaking, those migrant workers, again, coming from the rural areas, the least maybe the marginalized, the poor, they tend to be on the outskirts of this particular model. +[232.43s -> 244.30s] So again, another element to this is really that idea that most of these places tend to be a primate city because the urban system is so desirable, or at least the potential for opportunity. +[244.30s -> 258.32s] That we see that that impact on the surrounding areas that but there's a disproportionate population that tends to go to these cities and you know establishing those squatter districts are basically the +[258.45s -> 273.42s] The further away you get from the CBD, the poorer the conditions tend to be, which if you compare it to the concentric model, we see a very different picture in the United States. +[273.90s -> 284.08s] So, hopefully this is a quick tutorial that helps you better understand the Latin American city model. diff --git a/VideoMMMU_ASR_large/Science/test_Geography_8.mp4.txt b/VideoMMMU_ASR_large/Science/test_Geography_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ed279fa77050df75bb641cf5df79cb7b141feb09 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/test_Geography_8.mp4.txt @@ -0,0 +1,115 @@ +[0.69s -> 12.54s] Hey guys, Ms. Peterson here, and today we're going to be talking about PV diagrams. I'm not going to lie, this is one of those concepts in AP Physics 2 that was one of the hardest concepts for me to internalize. +[12.54s -> 27.06s] once I started teaching this class. So hopefully this makes it so it's not as difficult for you guys. So basically what a p-v diagram is is just a graph of the pressure versus the volume. +[27.06s -> 41.42s] typically for a closed sample of gas and how it changes in volume and pressure. It's used a lot in the fields of engineering when they're analyzing engines or pneumatics or anything like that. They're also used a lot in the metal +[41.42s -> 51.15s] field to look at how the blood is pumping in the heart or how your lungs are expanding and contracting so that's what they're for +[51.15s -> 64.98s] There are four main type of processes, four kind of vocabulary terms that you guys should know. There is isothermal, exactly what it sounds like, constant temperature. On a PV diagram, +[64.98s -> 74.99s] there are these hyperbolic lines that show that inverse relationship between pressure and volume at constant temperature. +[74.99s -> 87.18s] So these will normally be drawn in for you guys or defined as an isothermal line. They're called the isotherms. There's also isobaric processes, which happen at a constant pressure. +[87.18s -> 98.27s] On a PV diagram, those are gonna be straight lines at a constant pressure, okay? Isovolumetric, also called isochoric. Ooh, I spelled that wrong. +[98.27s -> 109.84s] But those are ones with a constant volume. It's actually spelled like this. So the volume stays constant. It's going to be a vertical line on your PV diagram. Then there's also adiabatic. +[109.84s -> 124.27s] Adiabatic means it's an insulated system. There's no exchange of heat energy, this Q term in our main equation for PV diagrams. We'll get into the internal energy heat and work in the following slides. +[124.27s -> 136.82s] but adiabatic they're typically a little steeper than the isotherms but there's no exchange of heat with the surroundings note that means that it does change temperature +[136.82s -> 146.48s] Okay, you can change temperature without exchanging energy with the surroundings. You can compress something really fast and heat it up, things like that. +[147.15s -> 155.73s] okay so first we're gonna talk about work okay so work is the work +[155.73s -> 166.18s] done on a gas it's most closely related to volume so if the volume increases we define that as negative work because the gas is using its energy +[166.18s -> 178.77s] to expand, whereas the volume decreases because that positive work, because the surroundings or something else is doing work and compressing the gas, giving it more energy. There are two ways to find it. +[178.77s -> 190.42s] If it's a constant pressure system, you can use this equation here. Negative P times delta V, okay? Note if delta V is always final minus initial. So if the final is... +[190.42s -> 198.86s] bigger this will be a positive number so your work will be negative meaning the volume increased okay +[198.86s -> 210.48s] Note, this is also the same if you have a constant pressure or an isobaric process. It is the area under that curve, P times delta V. Now, if it's not... +[210.48s -> 224.75s] at a constant pressure, this equation obviously won't really work. In that case, you would have to find the area under the curve. In AP Physics 2, because we are not calculus based, it will be just a simple triangle or something like that that you have. +[224.75s -> 237.98s] find the area under but the work is the area under the curve okay now the work is zero for iso volumetric processes okay if it doesn't change in volume it +[237.98s -> 248.14s] doesn't do any work, okay? Okay, so again, it's from the shape of the graph. If the line travels to the right, okay? +[248.14s -> 260.66s] that means the volume is increasing, so it's going to be negative work. If the line travels to the left, that means the volume is decreasing, that's going to be positive work. So let's go ahead and test that out. +[261.78s -> 276.56s] Okay, which of these PV diagrams show positive work? Okay, so for positive work, that is when it is compressing, when it's doing energies on it. So that would be one, okay? +[277.20s -> 284.43s] And so we're looking for lines moving to the left. Okay, here's eight. +[285.26s -> 299.07s] Okay. Now negative work. That is when it is expanding. It's doing work. So it loses energy. Negative work. So that's going to be two and seven. +[299.07s -> 304.14s] And three. And then we have these two. +[304.53s -> 318.32s] vertical lines here those are going to be the ones where the work is zero it is not expanding or compressing so no work is being done okay cool okay cool +[318.32s -> 324.53s] Let's go into internal energy, delta U. Now, basically... +[324.82s -> 339.06s] For our purposes, if we're talking about a monatomic ideal gas, the internal energy is the sum of all the kinetic energies. That's where this... +[339.06s -> 353.52s] equation comes into play. This equation is for the kinetic energy of one atom of a monatomic ideal gas. So really specific there. If it is not a monatomic ideal gas, it will give you likely +[353.52s -> 366.45s] another equation. But from this equation, if we multiply it by the number of atoms, okay, then we get this equation, n times three halves kb times t. +[366.45s -> 381.14s] which n times kb can also be rewritten as the number of moles times the gas constant. So that's where those two equations come from that are actually not on your equation sheet, but kind of helpful to know. +[381.14s -> 395.70s] So you'll notice in the equation, the energy is directly proportional to temperature, the internal energy only related to temperature. So internal energy directly proportional to temperature. +[396.18s -> 409.07s] Now, where's temperature on a PV diagram? Well, we know it has those isothermal lines. So the temperature is proportional to PV, okay? +[409.07s -> 422.75s] the pressure times the volume. This is the ideal gas law. When we're talking about one sample of a gas, the number of moles isn't changing. The gas constant is just that, a constant. So you can say temperature is proportional to PV. +[422.75s -> 429.15s] Therefore, the PV is also proportional to the internal energy. +[429.15s -> 443.78s] So if the temperature increases, we call that a positive change in internal energy. And if the temperature decreases, we have a negative change in internal energy. And if we have an isothermal process, then there's no change in internal energy. +[443.78s -> 457.04s] So let's go ahead and put this to the test. Which of these PV diagrams shows an increase in internal energy, positive delta U? Decrease, no change. +[457.04s -> 469.47s] Let's go ahead and start with positive delta U. Note that these PV diagrams have those isothermal lines. So if we're looking for positive internal energy, we're going to look at one moving up, moving to a higher. +[469.47s -> 483.86s] temperature so it's not going to be this one uh it is not going to be this one this one is moving to a higher temperature so that will have a positive delta u this one is moving to a higher temperature positive delta u +[483.98s -> 497.33s] That one's moving to a lower. This one's moving to a higher, positive delta U. And this one's an isothermal. Both of these are isothermal. So let's just go ahead and write delta U equals zero for those. +[497.90s -> 510.58s] And then you'll notice all of these are moving from T2 to T1. It is a negative delTU, negative change in internal energy. Okay, cool? +[510.86s -> 518.45s] Okay, cool. Now the last one. The last term we're going to talk about is Q, which is... +[518.45s -> 530.16s] heat now this one is one of the most confusing ones on a pv diagram because there's no way to determine it directly it also often gets confused with temperature we think if we say heating it up +[530.16s -> 540.03s] we mean the temperature is increasing, but that's not always true. You might remember back to chemistry class when you learned that boiling water is always at the same temperature, okay? +[540.03s -> 553.54s] Because that happens. Its volume is increasing. It's doing other things. There can be other things that that heat energy can be doing other than increasing the temperature. So heat is not directly related to temperature, okay? +[553.54s -> 558.67s] But it is related to its interaction with the surroundings, okay? +[558.67s -> 569.81s] So while internal energy and work have to do specifically with what the sample of gas is doing, if it's expanding or contracting, if its temperature is increasing or decreasing. +[569.81s -> 583.38s] This one has to do the most, I think, with what's going on outside the gas. Is heat going in or is heat flowing out? Is energy coming in or is energy going out? Okay, so if energy goes in, we call that a positive Q. +[583.38s -> 594.21s] If energy is removed, we call that a negative Q. Now, unfortunately, we can't determine that directly from a PV diagram. Instead, we have to infer it. +[594.21s -> 605.36s] by figuring out delta u and w okay and we'll show you that on the next slide um q is zero for adiabatic processes now remember adiabatic +[605.36s -> 616.99s] The definition is no exchange of heat. This can happen either in a really insulated system or if you have a super fast process where there's not time for that exchange of heat energy. +[616.99s -> 622.85s] Often also in AP Physics 2, they will ask you, how does that change? +[622.85s -> 636.67s] How does that energy travel? And what it actually is, is the collisions of the molecules with the walls of their container. So when they collide with the walls of their container, their energy, their momentum is changing, thus... +[636.67s -> 648.08s] um they are transferring some of that energy to the surroundings or they're receiving some of that energy from the collisions but it's all about the collisions okay +[648.08s -> 661.76s] Actually, for everything in gases. It's all about the collisions. Pressure, internal energy, temperature, force, and heat. If you have to explain it, talk about the collisions between the particles. +[661.76s -> 674.91s] 80 back like we said are the q equals zero ones so i went ahead and oops on this slide you guys will see that i wrote for all of them what we had already said about +[674.91s -> 686.10s] delta U and W. So those are already there from our previous slides. And we have to use those to infer what Q is because delta U equals Q plus W. +[686.10s -> 700.53s] so in this one if the internal energy if the temperature decreases but it's compressed okay picture that the temperature is going down but it's being compressed normally when you compress something you heat it up you're giving it more you're like squishing it down the temperature +[700.53s -> 714.35s] tends to rise, but this temperature decreased. That means a lot of heat energy must have been removed from the system. Also, to make a positive plus something equal a negative, this must be a bigger negative number. So Q there is negative. +[714.45s -> 721.79s] For this one, delta u is negative and work is negative, so q could be positive, but... +[721.79s -> 733.02s] see this shape right here that's kind of your clue that it's an adiabatic process it would actually have to tell you that and you guys do a little bit more calculations to assume that but +[733.02s -> 746.70s] I'll tell you guys, this is an adiabatic one. So Q is zero. Same with this guy right below it. Now for these ones. How do we get a positive number from something plus a negative number? Well, that means he must be... +[746.70s -> 758.77s] added okay if the pressure doesn't change beer increasing in the volume the particles are gonna be moving around more you want them moving around and hitting the walls the same amount so you need to add heat in okay this one +[758.77s -> 772.80s] positive and zero so q must be positive you must have heated it up to cause that increase in pressure this one temperature decreased or the internal energy decreased no change in volume so you must have +[772.80s -> 786.43s] cooled it down okay you can actually try that process take a balloon throw it in the freezer well now that its volume would change so that never mind okay but no change in volume negative heat negative q +[786.43s -> 797.39s] We already did number six. Let's look at seven. We have no change in internal energy and work is negative. So we must need a positive Q. And same for this one. +[797.39s -> 811.52s] Internal energy is negative. The work is positive. So to cancel out that work, we must need a negative Q. Okay, all coming back to this relationship. Delta U equals Q plus W. Okay, cool? +[811.52s -> 826.11s] Okay, cool. So just to summarize it, if you're talking about internal energy, you're thinking about temperature, temperature increases, positive delta U, negative, temperature decreases, and it's zero when the temperature is constant. +[826.11s -> 839.47s] For heat, you're thinking about the interactions with the surroundings. If it absorbs energy, it's positive. If it releases energy, it's negative. And it's zero when you have an insulated system or a fast process, aka an adiabatic process. +[839.54s -> 846.93s] If you're talking about work, you're thinking about volume. If the volume decreases or you see that compression word. +[846.93s -> 859.18s] That means it's positive. If the volume increases or the gas expands, that is negative work. And if the volume is constant, an isochoric or isovolumetric process, then the work is zero. +[859.41s -> 868.26s] And most of these things that you can kind of figure out conceptually too, if you just picture the closed sample of gas, okay? +[868.26s -> 882.22s] picture what's going on in there and how those are all related. You can also always apply the ideal gas law to help kind of conceptualize all of this. Okay? Okay. +[882.22s -> 895.81s] So now let's get into an application problem. We have a cylinder with a movable piston containing 0.1 mole of a monatomic ideal gas. So we're pretending this gas is perfect. The gas initially at state A +[895.81s -> 906.70s] can be taken through either two cycles either a b c a or a b c d a okay so either this +[907.06s -> 919.87s] cycle right there, or the whole square. And then we know the system Q from C to A is 685 joules along the curved path. +[919.87s -> 933.62s] So it's absorbing heat energy along the CA path. Work C to A is negative 120 joules along that path. Makes sense that it's negative because the volume is expanding. Delta U. +[933.62s -> 939.02s] From B to A is 450 joules. Makes sense. It's gaining energy. +[939.02s -> 950.13s] along that line, and then the work from A to B to C is 75 joules. So A to B is going to be no work, and then B to C. +[950.13s -> 963.58s] is going to be 75 joules okay so we can kind of picture that right there is your 75 joules okay okay so first question we're going to find delta u from c to a +[963.58s -> 976.72s] This one's super easy because we have Q from C to A and the work from C to A. So, delta U from C to A equals Q. +[977.55s -> 987.18s] c to a plus the work from c to a so we have i'm gonna go ahead and +[987.57s -> 1001.55s] That's 685 plus, oops, minus 120. And we get the answer of 565. +[1001.55s -> 1002.80s] Cheers. +[1003.06s -> 1016.78s] 565 joules. Okay, cool? Okay, cool. So I'm just going to go ahead and erase that work so I keep myself a little bit neater here. So this is 500. +[1016.78s -> 1029.14s] and 65 joules. Okay, now Q, from A to B to C. Okay, so from A to B to C. +[1029.17s -> 1042.32s] We're looking for the heat energy added. Now we know the work done from A to B to C. And overall, we're going from A to C. +[1042.32s -> 1046.29s] So we can relate that to the... +[1046.80s -> 1057.58s] to the change in internal energy from C to A. The change in internal energy there is going to be opposite. +[1057.58s -> 1071.60s] from a to c because it's based on temperature we're still looking at that same difference in temperature so we can use that number to answer the next one so i'm going to go ahead and do the work over here again it's delta u +[1071.60s -> 1084.96s] equals q plus w and if we're looking for q then we're going to have delta u minus w for that path okay equal +[1084.96s -> 1091.73s] the Q so from A to C the Q is going to be negative +[1091.73s -> 1103.09s] The delta U is going to be negative 565 joules. To go from C to A, it was increasing in temperature. To go from A to C, it's decreasing in temperature. +[1103.09s -> 1114.45s] And then they already told us the work along that path as 75. So minus 75 joules. And we get... +[1115.47s -> 1128.24s] 565 plus, oops, negative 565 minus 75. I got 640 joules, negative 640 joules. +[1130.99s -> 1144.53s] Okay, cool? Okay, cool. So again, I'm going to erase my work and then put my answer right there for you guys. Okay. +[1145.39s -> 1155.52s] So now the work from C to D to A. Okay, well notice that the work from C to D is... +[1155.52s -> 1169.76s] an isochoric or isovolumetric process so the work from c to d is equal to zero so really we're just looking at the work from d to a okay +[1169.76s -> 1182.80s] Now from D to A, we have a convenient thing in that it's at the same volume. So we're just going to do negative P times delta V. So we have... +[1182.83s -> 1194.13s] Don't forget the units. Watch your units on your axes when you're plugging in these numbers. Otherwise, your numbers will turn out a little funky and off by an order of magnitude. So we have... +[1194.83s -> 1206.58s] I'm going to actually write this over here. So negative 6 times 10 to the 5th pascals times the change in volume. So the final volume, 1. +[1207.47s -> 1215.70s] minus the initial volume, 0.75, and these are both times 10 to the negative 3. +[1217.36s -> 1228.69s] So we plug that into our calculator. Negative 6 times 10 to the 5th times, putting in your parentheses, +[1228.69s -> 1240.54s] 1 times 10 to the negative third minus 0.75 times 10 to the negative third. And we get negative 150 joules. We expect it to be... +[1240.54s -> 1249.26s] um negative because it is expanding so that checks out negative 150 joules okay cool +[1249.74s -> 1262.96s] Okay, cool. So, again, I'm going to erase my work so that we can make room for all of this. Okay, it is negative 150 joules. +[1263.98s -> 1277.39s] And last but not least, Q from C to D to A. But on this one, we don't actually have enough information to figure it out quantitatively. We have the work, but we don't have the... +[1277.65s -> 1289.12s] Do we have the change in internal energy from C to A? Oh yeah, we do. So if we have the change in internal energy and we have the Q, we could probably solve this out. +[1289.12s -> 1298.24s] Let's actually go ahead and do that. In the actual AP problem that I stole this from, it only asked for qualitatively. +[1298.24s -> 1312.00s] Let's go ahead and know that first. We have delta U equals Q plus W. Now from C to D to A, it increases in temperature. So we have positive delta U. In fact, we have... +[1312.00s -> 1325.84s] Positive 565 joules. Q is what we're looking for. The work done is the same as the work from D to A. That's what we found here. So negative. +[1326.10s -> 1339.34s] It is negative, specifically negative 150 joules. So Q must be positive, and it must be equal to... +[1339.34s -> 1352.85s] 565 plus 150, 715 joules. Yep, 750 joules, and it is positive. +[1353.58s -> 1368.43s] It's not letting me write positive. Positive, okay? Okay, cool? So that's how we can solve out PV diagrams quantitatively. Okay, cool? Okay, cool. diff --git a/VideoMMMU_ASR_large/Science/validation_Biology_15.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Biology_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b3a28bab17fe2a8701111fb8301dc923517cd149 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Biology_15.mp4.txt @@ -0,0 +1,46 @@ +[0.00s -> 14.22s] This video was sponsored by Kenhub. More on them at the end of the video. Hello and welcome. My name is Patrick, and in this video, I'll teach you some of my tips and tricks for remembering all of the skeletal muscles of the pelvis that you would see in an anatomy class. +[14.22s -> 25.71s] and more manageable for beginners, I'll present the list in smaller chunks of 4-8 muscles. You can find a list of the sections and timestamps in the description below. With that out of the way, let's get into the muscles. +[25.84s -> 40.43s] So this is going to be the shortest video in the muscle series. And while there are only a few muscles to learn, I made this one its own unit because I imagine the pelvic muscles slightly differently than the muscles of the arms and legs, for instance. Like, instead of a clear elbow flexion, +[40.43s -> 54.64s] or spinal extension muscle, you have muscles that support the pelvic floor or that promote blood flow during sexual arousal. And that's really cool to me. The pelvis has skeletal muscles that interact with the urinary, digestive, and reproductive systems, which makes... +[54.64s -> 58.27s] these muscles seem like magical and mysterious, but at the end of the day, +[58.27s -> 72.56s] They're still muscles, and like most of the muscles we've seen before, the name of the muscle usually tells us what the muscle does or where it is. But since the pelvis is a big bone, anatomists refer to certain parts of the pelvis by their bony landmarks. +[72.56s -> 86.77s] So let's review. While the whole thing is called the pelvis, we refer to these big wings as the ilium or ilia. If you're putting your hands on your hips, you're not actually putting them on your hip joint, you're putting them on your ilia. In the front, you have two pubic bones, which are jointed. +[86.77s -> 94.03s] by a piece of soft tissue called the pubic symphysis. Posteriorly, you have these hollowed out bumps called the ischium, +[94.03s -> 108.30s] Colloquially, I've heard these called the sitz bones as well. Then this big centerpiece is the sacrum, the base of your spinal column. And hanging off the tip is one of the remnants of our evolution, the ancestral tailbone called the coccyx. Once you know those bony lan- +[108.30s -> 122.51s] marks, you can start putting terms together. So this joint is the sacroiliac joint, since it's the meeting place between the sacrum and the ilium. And that same strategy works for many of these muscles. This first chunk of muscles is collectively called the levator anigra- +[122.51s -> 136.72s] group, which counterintuitively doesn't lift the anus necessarily, it keeps your organs from falling out of your pelvis. Yes, you have some connective tissue there, but these muscles are the floor of the pelvis, hence pelvic floor muscles. +[136.72s -> 150.40s] which connects the pubic bones in front with the coccyx in the back. It forms like a hammock-esque muscle with some important cutouts for anus and genitals here and here. This little divot posteriorly isn't a cutout. +[150.40s -> 164.69s] It's arched so that it can connect with more surface area on the bone. Hanging out within that muscle is the puborectalis, which originates on the pubic bones and forms this structure called the puborectal sling around the rectum. If you've heard about the +[164.69s -> 173.84s] squatty potty and how squatting makes it easier to poop, the puborectalis is the muscle that supposedly puts a kink in the colon. That's a whole other video though. +[173.84s -> 188.14s] The last muscle in the levator ante group needs a bit of introduction. Now, I've spent the last hour of video telling you about how intuitive these names are, how if you just know the bony anatomy or directional terms, then you're set. But here, with less than 10 muscles to go, +[188.14s -> 202.35s] The iliococcygeus is the crack in the sidewalk that's tripping us up over the finish line. It starts off intuitive, it's easy to see where it inserts on the coccyx, but its origin is this broad sheet of connective tissue called the internal obturator. +[202.35s -> 216.56s] fascia, not the ilium. It's fine, anatomy, I'm not mad, I'm just disappointed. If we move on, we'll see another important pelvic floor muscle, the ischio-coccygeus, a long sheet of muscle that spans from each ischium to the coccyx in the center. Although +[216.56s -> 221.17s] Fair warning, some textbooks just call this muscle the coccygeus, which +[221.42s -> 236.02s] I'm rapidly losing faith in traditional naming conventions for this group of muscles. Just do your best. Something else to keep in mind. You'll almost always get quizzed on these muscles from a superior or top-down view. And from this angle, you'll see some of the other hip muscles, like the piriformis posterior. +[236.02s -> 250.22s] anteriorly, and the obturator internus anteriorly. So if possible, identify what those muscles attach to, because if they attach to the femur, then they're not pelvic floor muscles, and they won't have pubo or coccygeus in their names. But this next group +[250.22s -> 256.56s] perennial muscles requires the opposite perspective, an inferior view. Also, how do I put this? +[256.56s -> 270.99s] If you're watching this in public at a coffee shop or something, just be aware of who's looking over your shoulder, because the images I'm about to show you are going to get a little spicy. From this inferior view, we can see some of the structure of the perineum, the area between the genitals and anus. +[270.99s -> 285.65s] And a few of the muscles in this area use the perineal region in their names. For instance, take a look at the superficial transverse perinei. You already know superficial, it's closer to the surface, and you already know transverse, it runs side to side instead of front to back. +[285.65s -> 299.95s] The perinei points to its location, between the urethra anteriorly and anus posteriorly. Deep to that is the deep transverse perinei, with the same naming conventions. Also in the perineal area, you can find muscles that plug into the genital +[299.95s -> 314.16s] but have different presentations depending on what kind of plumbing we're working with. The first, the ischiocavernosis, originates at the ischium and connects with the genitals. If it's attached to a penis, it inserts on the crus, or crura, of the penis. +[314.16s -> 328.37s] part that attaches to the ischial rami, while the rest of the shaft, mostly the corpus cavernosum, dangles off. For people with vaginas, the ischiocavernosis actually inserts on the clitoris. And remember, the clitoris is much bigger than the small piece that you see on +[328.37s -> 336.48s] external diagrams. As far as how to remember this muscle, the ischio root is easy enough to remember, but the cavernosis relates more to its function. +[336.48s -> 350.80s] I'll explain. During sexual arousal, blood flows into the penis or clitoris, enlarging either. When the ischiocavernosis contracts, it squishes blood towards the distal part of the genitals and compresses some of the veins that drain blood from the genitals. +[350.80s -> 356.94s] which helps maintain an erection or the swelling of the clitoris. And that's a fun fact that you can bring up if you're ever like +[356.94s -> 371.39s] in that situation, but we still need to remember it for our exam. I remember ischiocavernosis because it connects the ischium to caverns of blood, hence ischiocavernosis. Another muscle in that same area is the bulbospongiosis, which no, is +[371.39s -> 372.53s] Not a Pokemon. +[372.53s -> 386.80s] When it accompanies a vagina, the pair of muscles runs from the pubic bone in front along the sides of the vagina. Around penises, it circles the bulb of the penis, which is close to the base. I remember this one because it plugs into the spongy tissue that gets erected. +[386.80s -> 401.01s] during sex. Bordering the perineum, you have two different tubes regardless of the sex of your model, an anus and a urethra. Obviously we don't want anything leaking out of those tubes involuntarily, so we have some muscles that squeeze those tubes shut. These ring +[401.01s -> 412.11s] like muscles are called sphincters, and we have a few. The internal sphincters are actually smooth muscle under involuntary control, but the external sphincters, one around the anus and one around the urethra, +[412.11s -> 426.38s] are skeletal muscles and are controlled voluntarily. So when you're trying to hold in your poop, you're actively contracting the external anal sphincter. Most of the time, your smooth muscle internal sphincter does the trick on its own though. So why do we have two? Well, +[426.38s -> 436.48s] smooth muscle is much richer in mitochondria, so it can contract for long bouts of time without fatiguing. We only use the external sphincter when we're really trying to hold back the floodgates. +[436.48s -> 450.96s] That's gross. What makes this muscle weird, though, is how it doesn't anchor into any bone. It kind of blends in with the other pelvic and perineal muscles, but as far as the scope of this video, just look for the bullseye. It's easy to find. On the other hand, +[450.96s -> 465.17s] The external urethral sphincter will surround the urethra. For people with penises, the external urethral sphincter is right below the prostate at the base of the penis. For people with vaginas, they have shorter urethras. So there will be an internal urethral sphincter. +[465.17s -> 479.38s] right below the bladder, and then right below that is going to be the external. But no matter what kind of genitals you have, the internal sphincter is right below the bladder, almost like you're pinching a water balloon shut. So now we've built a solid foundation for the pelvic organs to sit in, but +[479.38s -> 493.58s] But there are still some genital-specific muscles to consider. If you have testicles, you have a cremaster muscle, a thin layer of muscle that lines the scrotum and tucks the testicles into the body. If it's too cold, this thing contracts and brings them towards body heat. +[493.58s -> 507.79s] I remember this one because its main job is to turn up the heat on the testicles. It's kind of like the cremaster is trying to cremate the testes. That's my memory device, but I'm sure someone's already typing their little jokey jokes into the comments section. Now, these are... +[507.79s -> 522.00s] just the tricks that I personally use to remember these muscles, but if you want another great resource for learning anatomy, then you need to check out Kenhub. I use them all the time when researching and writing these videos, and for this series in particular, they're written articles and Atlas of +[522.00s -> 536.21s] muscles have been extremely helpful in refreshing my knowledge of some of those deeper, smaller muscles. They've also got an enormous library of in-depth videos about muscles, histology, vasculature, nerves, and everything else you'd need to know in anatomy class. +[536.21s -> 550.42s] All those beautiful illustrations that you saw in this video came from them, and in addition to their library of content, I also love Kenhub's quiz feature. They allow you to build custom quizzes with different difficulties, and they give you feedback so you can figure out where your weaknesses are. +[550.42s -> 564.62s] Most of Kenhub's features for free, but if you want full access to all of their learning content and quizzes, then go to khub.me slash corporus to get 10% off your subscription. They've also got a no questions asked seven day money back guarantee. So you can try out the premium version for seven. +[564.62s -> 576.37s] days, and if you don't like it, get your money back. If you want to see the next video in the muscle memorization series, then check out this playlist here. Otherwise, subscribe, leave a like on the video, have fun, be good. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Science/validation_Biology_17.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Biology_17.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..960dd6572fcd41f65f3f1fd81f6fc743d3ced758 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Biology_17.mp4.txt @@ -0,0 +1,11 @@ +[0.00s -> 9.26s] Hello and welcome to Two Minutes of Anatomy. I am Dr. Donald Rosello of Championship Chiropractic in Las Vegas, Nevada. Mastication is the act of... +[9.26s -> 23.06s] chewing the four primary muscles of mastication are the masseter muscles the temporalis muscles the lateral pterygoid muscles and the medial pterygoid muscles all the primary muscles +[23.06s -> 36.51s] mastication attached to the ramus of the mandible and help to move the mandible. The primary muscles of mastication move the mandibles into depression, elevation, +[36.51s -> 49.18s] protrusion, retraction, and side to side motions. Again, the primary muscles of mastication are the masseters, the temporalis, the medial pterygoids, and the lateral. +[49.18s -> 60.45s] pterygoids. The four primary muscles of mastication attach to the rami of the mandible. The mandible is the medical name for the jaw and function to move the mandible. +[60.45s -> 68.85s] The mandibular motions of mastication are elevation, depression, protrusion, retraction, and side-to-side movement. +[68.85s -> 82.00s] the muscles of mastication move the mandible in a side to side motion to assist in the grinding of food the muscles of mastication also function to approximate the teeth the platysma muscle +[82.00s -> 95.78s] assist in depression of the mandible against resistance. The primary and accessory muscles of mastication work in a coordinated fashion to produce mandibular movement for chewing food. +[95.78s -> 104.53s] The accessory breathing muscles of mastication are the buccinator, the suprahyoid muscles, which are the digastric muscle. +[104.53s -> 118.24s] the myelohyoid muscle, and the geniohyoid muscle, and the infrahyoid muscles, which are the sterohyoid, the sterothyroid, the thyrohyoid, and the omohyoid muscle. +[118.24s -> 131.47s] Again, mastication is the act of chewing, and the four primary muscles of mastication are the masseters, the temporalis, the medial pterygoids, and the lateral pterygoids. diff --git a/VideoMMMU_ASR_large/Science/validation_Biology_21.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Biology_21.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..1296a84919e9910495d43092f524dd08e8285fe9 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Biology_21.mp4.txt @@ -0,0 +1,60 @@ +[0.88s -> 15.18s] In this video, we're going to do a basic review of the cell and the things inside of the cell, like the organelles, the tiny organs of the cell. So first, we have the nucleus, which is right there. +[15.18s -> 26.16s] And the nucleus is basically the command and control center of the cell. It tells the cell what to do, how to grow, what proteins to make, what lipids to produce, and things like that. +[26.64s -> 40.29s] Now, in the nucleus, in this region, you have long strands of DNA known as chromatin. And the DNA is basically the instruction manual or the blueprint of the cell. +[40.29s -> 52.85s] it stores the genetic information of the cell. And so within the DNA you have the instructions on how to make the proteins, how to make the individual organelles of the cell, and what they need to do. +[53.84s -> 66.80s] Now, inside of the nucleus, we have this ball right here, and that is the nucleolus. Now, the nucleolus, it creates ribosomal RNA to make ribosomes. +[66.90s -> 70.10s] and ribosomes, you can see these little +[71.31s -> 84.91s] spheres floating in the cytosol and the ribosomes, they make proteins. Now the ribosomes consist of ribosomal RNA and proteins, but they manufacture proteins. +[85.10s -> 99.76s] Now, the way the nucleus makes proteins is that it sends mRNA, or messenger RNA, which carries the instructions to the ribosome to make the specific type of protein that's needed for the cell. +[100.05s -> 114.43s] Now the nucleus is surrounded by a membrane known as the nuclear envelope and on this membrane you'll find these holes on it which are known as nuclear pores. +[114.43s -> 122.96s] and they allow stuff to go into and out of the cell. So the messenger RNA comes out of the nucleus through those nuclear pores. +[123.34s -> 137.65s] Now let's talk about the ER, the endoplasmic reticulum. There are two types. The first one is the rough ER, which is all of this in that region. And the second... +[137.65s -> 151.12s] the smooth ER which is right here. Now what do you notice about these two? What is the difference between them? The rough ER contains ribosomes. +[151.66s -> 162.54s] The smooth VR does not contain any ribosomes. So the rough VR, it assists in the production of proteins because ribosomes, that's what they do, they make proteins. +[162.83s -> 177.17s] Because the smooth ER doesn't have any ribosomes, it does not make any proteins. However, it does produce lipids, cholesterol, and hormones. It also assists in detoxification. +[177.46s -> 189.46s] which means it breaks down toxins. And the way it does so is by making these molecules more water-soluble so that they can be easily removed from the body or excreted through the urine. +[190.10s -> 203.71s] Now let's go back to the rough ER. So once the rough ER, by means of the ribosomes, once they make the proteins, the proteins are enclosed in a vesicle, and those vesicles... +[203.71s -> 207.63s] get transported to the Golgi body, which is right there. +[208.43s -> 221.46s] Now the Golgi body it receives the vesicles and it modifies the proteins that are in the vesicles and the way it does so is by adding lipids and carbs to the proteins and it can also +[221.46s -> 229.17s] fold the protein. It can give it the proper shape because the function of a protein is dependent on its shape. +[229.46s -> 236.78s] So once it modifies and processes the proteins, it exports the proteins out of the cell. +[237.07s -> 250.70s] So here is a visual illustration of what happens to a protein in a cell. Now granted, my drawing is not the best. This is an educational video and not an artist or... +[250.70s -> 264.29s] a how to draw video. And so the protein, it begins at the rough ER because that's where the ribosomes are. And remember, ribosomes, their job is to make proteins. So the protein, it leaves the rough ER. +[264.29s -> 274.42s] by means of a transport vesicle. And you can see the protein inside of this vesicle. And it goes to the goji body for processing and modification. +[274.86s -> 287.22s] So looking at the protein now, you can see that it has a different shape. At the same time, you can see different colors added to it. So this represents the lipids and the carbs added to the protein. +[287.50s -> 299.82s] So once the protein has been tagged with those extra molecules, it gets exported out of the cell. So it travels to the cell membrane where it leaves the cell to perform the function that it needs to do. +[300.14s -> 314.96s] Now, the transport vesicle that surrounds the protein, it fuses with the cell membrane, and so it becomes part of the cell membrane, causing the membrane to expand, or basically causing the cell to grow. +[315.41s -> 321.30s] Now let's talk about some other organelles that you need to know. The next one is the mitochondria. +[321.87s -> 332.53s] Now the mitochondria has its own separate DNA. It's different from the DNA of the cell. And its job is to perform cellular respiration. +[332.82s -> 344.46s] In that process, it takes the energy stored in fats and carbohydrates and converts it to a molecule known as ATP, adenosine triphosphate. +[344.72s -> 358.10s] Next up we have the lysosome. Now the lysosome, which is here, its purpose is to break down food. It contains digestive enzymes and in white blood cells it can also +[358.32s -> 372.45s] destroy pathogens when a white blood cell engulf a pathogen in a process known as phagocytosis the lysosomes in those white blood cells it can break down those pathogens or disease-causing agents into +[372.45s -> 386.19s] smaller stuff that could be used or recycled by the cell. Next up, we have the cytoplasm. The cytoplasm is basically the jelly-like fluid that is in the cell. +[386.74s -> 401.01s] So all of the organelles, they're dissolved in the cytoplasm. The cytoplasm contains solutes like salts, electrolytes, and other stuff like carbohydrates, lipids, and free-floating ribosomes and things like that. +[401.33s -> 413.71s] now let's talk about the cytoskeleton the function of the cytoskeleton is to maintain the shape of the cell at the same time it also provides structural support +[414.10s -> 422.45s] Now the cytoskeleton consists of a network of three fibers. The first of which is the microtubules. +[422.70s -> 430.58s] The second is the microfilaments, and the third one, the intermediate filaments. Now, how can we identify them in the cell? +[431.50s -> 445.60s] The microtubules is the largest of the three fibers. The microfilaments is the smallest of the three fibers. The intermediate filaments, in terms of size, it's somewhere in between +[445.60s -> 456.53s] the microtubules and the microfilaments. Now this picture really doesn't show it but just know that the intermediate filaments there in between and they provide mechanical support to the cell. +[456.88s -> 465.84s] Now the microtubules, they're made up of a protein called tubulin. And the microfilaments, they're made up of a protein called actin. +[466.10s -> 479.28s] the microtubules their purpose is to provide structural support and transportation services to the cell so vesicles they can move from one part of the cell to another part +[479.34s -> 489.78s] by means of the microtubules. The microfilaments, they're involved in elongation and contraction, so they assist the cell to move. +[490.16s -> 504.22s] Next up, we have the centrioles. And here it is in the diagram. The centrioles are active during cell division. And during that time, they form something known as the mitotic spindle, which consists of +[504.22s -> 513.30s] And what it does is during cell division, it pulls apart the chromosomes, thus allowing the cell to be split into two. +[514.29s -> 527.28s] The chromosomes are basically a condensed version of chromatin, so they form during cell division. Now, here are some other terms that you need to be familiar with. Cilia and flagella. +[528.27s -> 539.79s] These also play a role in the movement of a cell. Now cilia consists of tiny short hair like structures and notice that there's many of them. +[540.08s -> 553.55s] Flagella consists of long, whip-like structures, and there's only a few of them. And so the flagella can propel a cell forward from one location to another. Now these two structures +[553.55s -> 559.79s] they're made up of microtubules so microtubules they're very useful in the movement of a cell +[560.11s -> 573.68s] So far, we've been talking about animal cells. But now let's talk about the plant cell. Because even though they are similar, the plant cell has some characteristics that are not found in the animal cell. +[573.81s -> 588.19s] The first of which is the presence of a very large vacuole. This vacuole stores water and nutrients, and at the same time, it provides structural support to the cell by means of +[588.19s -> 599.09s] the hydrostatic pressure that it generates. Now another organelle that's found in the plant cell, but not in an animal cell, is the chloroplasts. +[599.76s -> 613.98s] Now the chloroplast is green due to a pigment known as chlorophyll, which plays a role in photosynthesis. Photosynthesis is a process by which the plant takes sunlight +[613.98s -> 628.37s] carbon dioxide and water and it produces glucose and oxygen gas. Another feature that's present in plant cells but not in animal cells is the presence of a cell wall. +[628.72s -> 639.15s] Now both the animal cell and the plant cell they both contain a cell membrane the cell membrane consists of a phospholipid bilayer and +[639.41s -> 649.97s] It has a property known as selective permeability, which means that it allows some things to enter while preventing the passage of other things from coming into the cell. +[650.29s -> 664.56s] it has these protein channels now small molecules like oxygen gas and water they can diffuse right into the plasma membrane but large molecules like glucose and +[664.56s -> 672.69s] other stuff they have to go through a protein channel even ions have to travel through channels as well +[672.98s -> 684.72s] And so that's the function of the cell membrane. It's basically like the gate of the cell. It allows some things to enter while blocking the passage of other stuff from going into the cell. +[685.17s -> 692.78s] So that's basically it for this video. If you like it, don't forget to subscribe and click on that notification bell +[693.33s -> 707.97s] Now I do have some other content that might be of use to you. I do have playlists on algebra, trig, calculus, chemistry, physics. So if you're taking one of those courses, or if you plan to take it in the future, +[707.97s -> 715.15s] Feel free to check out my channel and you might find what you're looking for. So that's it for this video. Thanks again for watching. diff --git a/VideoMMMU_ASR_large/Science/validation_Biology_22.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Biology_22.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..7f7cc6cb7ad00d6b083fe6618729a0f4d9908873 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Biology_22.mp4.txt @@ -0,0 +1,59 @@ +[0.78s -> 15.15s] Hello and welcome to Nikolai's genetics lessons and in this video I'm going to talk about coefficient of relationship and I want to give you such a problem imagine family as follows so he is female +[15.34s -> 24.30s] he is a male and this couple has a child and this child is +[24.62s -> 37.97s] married to another female and they also have child. It can be a girl or a boy and now imagine another +[38.77s -> 52.19s] relationship connection here and here we also have another child so try to find coefficient of relationship +[52.19s -> 58.90s] of individual A and B. +[60.02s -> 73.74s] and you may stop video here and try to solve this problem on your oven first but meanwhile I will show you how to solve such problems using different examples and then +[73.74s -> 87.47s] I will return to this example so this time we have also another couple and this couple +[87.79s -> 92.24s] has two children. +[93.26s -> 103.79s] The sex of the children here doesn't matter and it can be two boys or two girls or boy and girl. +[104.46s -> 118.11s] Once again, what is the coefficient of relationship of individual A and B? We can say that both these children have the same +[118.11s -> 128.30s] parents. So 50% of the genome they got from mother's side. +[128.66s -> 139.15s] and another 50% of the genome they got from the father side. And this is true for each child. +[140.91s -> 153.97s] So, each child has 50% of the genome of the mother and 50% of the genome of the father. +[155.09s -> 160.56s] children related to their parents by 50%. +[161.20s -> 172.98s] and in this case because this is not genetically identical twins this brother and sister +[172.98s -> 183.54s] also would be genetically related to each other by 50%. And our calculations would be as follows. Individual A got +[183.79s -> 197.15s] 50% or 0.5 from genetic makeup from the mother side. Individual B also got 0.5 or 50% of the genetic makeup. +[197.15s -> 205.71s] from the mother side and if we multiply these two numbers we can say that individual a and b +[206.26s -> 218.34s] share about 25% of the genetic makeup inherited from the mother side. And once again individual A also got +[218.34s -> 230.22s] 0.5 or 50% of the genetic makeup from the father side. Individual B also got 0.5 or 50%. +[230.22s -> 243.30s] of the genetic makeup from the father side and once again we can expect that about 25% of the genetic makeup that these two individuals +[243.30s -> 254.42s] inherited from the father side they are going to share and as you see if we add these two numbers +[255.60s -> 269.97s] we're going to get 0.5 or 50%. So both individual A and B would share about 50% of their genetic makeup. +[270.10s -> 279.60s] Now let's take a look at the different situation where once again we would have +[280.37s -> 290.16s] family, this time imagine that he is a female, he is a male +[291.28s -> 305.62s] and here's one connection and here's another connection so probably this male married first one woman then another woman and in each marriage +[306.22s -> 308.91s] This male had a child. +[309.71s -> 323.52s] Once again sex of the children is not important so how these two children would be related to each other and in this case +[323.52s -> 330.70s] As you see, they would be related only through their father. So they would share. +[331.54s -> 339.73s] 50% of the genetic makeup that they got from their father and these two children +[340.05s -> 354.70s] wouldn't share any of the genetic makeup of the mothers because they have different unrelated genetically unrelated mothers. So we can say that individual +[354.70s -> 365.71s] so individual A and individual B are going to get zero point +[366.22s -> 380.98s] five or fifty percent of the genetic makeup from their father and individual B also going to get fifty percent of genetic makeup from the father side. +[381.36s -> 395.31s] So we can say that individual A and B would share about 25% of their genetic makeup. So coefficient of relationship between +[395.31s -> 404.46s] these two individuals would be 0.25 or 25 percent. +[405.14s -> 419.02s] And in this example of the family with two children, we can say that coefficient of relationship between individual A and B would be 0.5 or 50%. +[419.02s -> 433.18s] And now let's take a look at our first example. So we see that individual A and B related through +[433.18s -> 434.29s] there. +[434.58s -> 448.74s] in the first example through the grandfather and individual B through his father so this individual +[448.74s -> 462.50s] would be grandfather of individual A and would be a father of individual B so basically this individual would be +[462.50s -> 474.96s] common ancestor and individual A would share 0.25% so 50% would inherit from his father +[474.96s -> 489.10s] and his father would also inherit 50% from his father so individual A would have about 0.25% +[489.23s -> 502.03s] of the grandfather. And individual B would inherit 50% from father. +[502.51s -> 504.94s] five and +[505.49s -> 519.87s] Once again, we have to multiply these two probabilities and we can say that these two individuals would share about 0.125 or +[519.87s -> 524.14s] 12.5 percent of the genetic makeup +[524.56s -> 539.25s] would be the same between these two individuals that they got from their common ancestor and once again individual A and B have +[539.25s -> 547.73s] the same mother and from the mother individual A is going to get zero point. +[547.98s -> 557.94s] five percent or zero point fifty percent of its own genetic makeup and zero point +[558.29s -> 563.66s] 5 or 50% individual B also going to inherit from the mother side. +[564.24s -> 578.03s] So we can say that individual A and B would share about 0.25 or 25% of the genetic makeup inherited +[578.03s -> 592.70s] from the mother side and 12.5% they would have through their common ancestor which is going to be a grandfather of individual A +[592.70s -> 607.06s] father of individual P. And once again we have to add these two probabilities and we are going to get zero point. +[607.15s -> 615.25s] 37.5 or 37.5 +[615.60s -> 628.85s] percent of the common genes or we can say that a coefficient of relationship between individual a and b so +[629.62s -> 644.27s] coefficient of relationship of individual A and B equal to 0.375 or 37.5%. +[644.27s -> 656.98s] Both answers are correct answers, but this answer is given on the scale between 0 and 1 and this answer is given on the scale between +[656.98s -> 670.16s] 0 and 100%. And this is all for today. Thank you for your attention. Please subscribe for my new videos that I post almost every day. Thumbs up if you like this video. Please write your comments, questions if you have any. +[670.16s -> 674.70s] Share this video with your classmates and see you in the next video. Goodbye. diff --git a/VideoMMMU_ASR_large/Science/validation_Biology_7.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Biology_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..979fe1bd9058c27a33ec3fcd73a688470e69c6a5 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Biology_7.mp4.txt @@ -0,0 +1,21 @@ +[0.00s -> 13.20s] Welcome to the part 5 of structure of bacteria series. In this video, we will discuss about structures internal to the bacterial cell wall. The main structures that are present inside the cell wall are +[13.20s -> 25.78s] plasma membrane, ribosomes, cytoplasm, mesosome, genetic material, and plasmid. We have already discussed about plasma membrane in the part 4 video. +[26.10s -> 29.68s] Let's check the other components in this video +[38.19s -> 45.94s] Ribosomes present in all living cells. Ribosomes are made up of several RNAs and proteins. +[46.54s -> 59.63s] They act as site of protein synthesis where mRNA translation takes place. Ribosomes link each amino acid in the order specified by the codons on mRNA to form a polypeptide chain. +[60.34s -> 70.96s] Several ribosomes come together to form polysome during the protein synthesis. The rate of protein synthesis depends on the number of ribosomes. +[71.60s -> 84.91s] The bacterial cell contains about 10,000 ribosomes, and they contribute 30% of total dry weight of the cell. More number of ribosomes provide granular appearance to the cytoplasm. +[85.55s -> 99.25s] Ribosomes are of two types, 70S and 80S. The 80S ribosomes are present in eukaryotic cells. Bacterial cell contains 70S ribosomes. +[99.92s -> 113.87s] Here, the S denotes Svedberg units. Svedberg units indicate the rate of sedimentation during ultracentrifugation. The sedimentation rate depends on size, shape, and weight of the molecule. +[114.54s -> 120.50s] For example, Svedberg value is more for the heavier molecules, than the lighter molecules. +[121.14s -> 134.90s] These units are named after Theodor Svedberg from Sweden, who discovered the principle of ultracentrifugation. He was awarded the Nobel Prize, in 1926. The 70S ribosome is made of two subunits. +[134.90s -> 142.86s] a small and a large subunit. Smaller subunit is of 30s and the larger one is of 50s. +[143.47s -> 154.00s] Similarly, the 80S ribosomes in eukaryotic cell consist of a 40S and 60S subunits. However, we are not discussing about it here. +[154.64s -> 164.46s] The smaller subunit in 70S ribosome has 16S RNA, and comprise of 1540 nucleotides, bound to 21 proteins. +[165.10s -> 176.69s] The larger subunit has 5 sRNA, and 23 sRNA. The 5 sRNA comprise of 120 nucleotides, bound to 31 proteins. +[177.30s -> 183.98s] The 23S RNA comprise of 2,900 nucleotides, bound to the 31 proteins. +[184.62s -> 195.89s] During the protein synthesis, the mRNA binds to the smaller subunit. And the larger subunit links amino acids by providing the peptide bonds to the polypeptide chain. +[196.56s -> 204.02s] The two subunits are combined together. The strength of the attachment depends on the concentration of magnesium ions. +[207.76s -> 222.13s] Cytoplasm, also called as protoplasm, is a jelly-like structure and composed of 80% of water. The other 20% is composed of enzymes, nutrients, metabolites, and cellular wastes etc. +[222.99s -> 234.38s] All the cell components are scattered throughout the cytoplasm. Cytoplasm not only hosts the biochemical reactions in the cell, but also protects the cell organelles from damage. +[235.12s -> 242.10s] That's it for now. Let's see the other cell components in the next video. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_11.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..e88dba66ccce762187e7fd6e3a0b5b40cd1a13a2 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_11.mp4.txt @@ -0,0 +1,43 @@ +[1.49s -> 12.37s] In the simplest terms, a titration curve is basically just a plot of the volume of titrant that you're adding to the analyte versus pH. +[12.37s -> 21.06s] What the general shape of a titration curve looks like is kind of like this. And if you haven't seen my titration stoichiometry, +[21.06s -> 35.95s] a problem video yet, I'd highly recommend that you look at that because in that video I explain how titrations work. So back to this, this is a curve of a strong acid. +[37.17s -> 43.28s] and it is being titrated with a strong base. +[44.94s -> 58.67s] And you can tell that it's starting out with a strong acid because the pH is very low. And remember that the lower the pH is, the stronger the acid is. +[58.67s -> 66.40s] Here we're going to add more and more titrant or more and more of the strong base. And then here you see a big jump. +[66.40s -> 73.71s] up to a very high ph so over here it's extremely basic and here it's very acidic +[74.67s -> 86.96s] And then here is what we call the equivalence point. It's pretty much halfway up this huge jump. So this is the equivalence point. +[88.21s -> 98.93s] All right, and what's happening is we have our acid so let's say HCl because that's a strong acid and when you have it in solution +[98.93s -> 107.92s] it's present as H plus ions and Cl minus ions but when we add a strong base to it let's say NaOH +[108.69s -> 114.00s] That goes into solution as Na plus and OH minus. +[114.00s -> 124.46s] ions. Now here the Na plus and Cl minus are spectator ions because they don't really do anything or change chemically. It's just that these +[124.46s -> 131.89s] H plus and OH minus ions are going to combine to neutralize each other and make H2O. +[132.14s -> 143.60s] So what's happening here is we have a lot of HCl and not that much NaOH yet. So because we have a lot of HCl, which is a strong acid, +[143.60s -> 157.26s] That's causing the solution to be very acidic. Now here, the equivalence point is where the moles of HCl equal the moles of NaOH. +[157.87s -> 161.76s] So as you can see, the equivalence point is at +[161.76s -> 175.04s] a pH of around 7, which is perfect because we have a strong acid and a strong base. When they have equal moles, then the pH is 7 or neutral. And then up here we have +[175.04s -> 182.53s] a lot of NaOH so now NaOH is in excess and it's causing the solution to be basic. +[182.53s -> 192.00s] But let's see what happens when we have a strong acid and a weak base as opposed to a strong acid and a strong base. +[192.00s -> 206.42s] Okay, I'm back and now we're going over a titration curve for a strong acid and a weak base. So here you see that the pH is still really low, meaning that we have our strong acid to start with. So let's go with +[206.42s -> 219.47s] And for our weak base, let's go with NH3, which is ammonia. And we see that our equivalence point is around here. +[219.47s -> 232.75s] Now notice that this isn't at 7 like the other titration curve that we looked at. It's a little below 7, so that means that at the equivalence point, the solution is slightly +[232.75s -> 246.00s] acidic and the reason for that is because we have a weak base instead of a strong one that's uh balancing out the effects of the strong acid and also if we write this out +[246.00s -> 260.91s] the equation for NH3 when it's placed in water is it partially dissociates or ionizes into NH4 plus and OH minus. Now since +[260.91s -> 275.18s] this doesn't go to completion. Some of it stays at NH3 and some of it changes into NH4+. And since NH3 is a weak base, its conjugate acid, NH4+, is pretty +[275.18s -> 288.18s] it's a little stronger than the strength of NH3. So since this is a stronger acid it's also causing the solution to be a little acidic. +[288.18s -> 294.99s] And you'll see something similar to that when we look at the weak acid and strong base titration curves. +[295.28s -> 309.36s] Okay, so we've got the same general shape for a titration curve with a weak acid and a strong base, but notice that the pH isn't as low as what it was before. Before it was like around here. +[309.36s -> 323.02s] So because we're starting out with a weak acid, the pH isn't going to be as low. Plus, when we look at the equivalence point, when we go, let's say it's around here, and +[323.02s -> 335.54s] move over to where it says the pH is, the pH is a little higher than 7 now. So that means that it's going to be a little bit basic. Following the logic that +[335.54s -> 349.58s] uh we used for the strong acid weak base um titration curve when we have a weak acid such as acetic acid so h c2 h3 o2 +[349.68s -> 358.42s] That partially dissociates into acetate and H plus ions. +[359.12s -> 372.11s] But remember, it's only partial dissociation. So because acetic acid is a weak acid, its conjugate base is stronger. So since acetate is more of a strong base, +[372.11s -> 379.76s] it's going to accept protons and change back into this. So it's going to +[379.76s -> 394.13s] cause the pH at the equivalence point to be a little higher than 7. Also, I'd like to point out that in here you have what is called a buffer buffer region. +[394.90s -> 405.58s] So what's happening here is when we titrate the weak acid with a strong base, we have a conjugate acid-base pair. +[405.58s -> 418.38s] What's happening is if we have a strong base such as NaOH, it's going to steal the H plus ions from the C2H3O2. +[418.61s -> 432.99s] So what that's going to create is a bunch of acetic acid and a bunch of acetate. And that's going to create a buffer because there are conjugate acids and bases. +[432.99s -> 440.05s] In the middle of the buffer region, which is half of the equivalence point, +[440.34s -> 453.74s] we're actually going to see that the pH is equal to pKa. And remember from the Henderson-Hasselbalch equation, which is pH equals pKa, +[453.74s -> 460.98s] plus log of concentration of the base over the concentration of the conjugate acid. +[461.74s -> 471.89s] that whenever these two are the same, that just simplifies to 1, and the log of 1 is just 0. So what we get from here is that +[471.89s -> 481.73s] pH equals pKa, meaning that the concentration of the conjugate base and the conjugate acids are the same. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_13.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..9815137f693e8dd9fc72ff34ba44c20a28b2c179 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_13.mp4.txt @@ -0,0 +1,31 @@ +[5.01s -> 18.54s] Number 47, determine the molarity of each of the following solutions. And then we have letter C. So in this case, they gave us 0.2074 grams of calcium hydroxide, which is CaOH2. +[18.54s -> 31.18s] And they told us that this was in 40 mils of solution. We need to find out what the molarity is. Formula, guys, it's this right here. Molarity equals moles. +[31.18s -> 40.02s] of solute divided by liters of solution. Most, it's usually broken down by just saying capital M. +[40.50s -> 54.42s] equals moles over liters. So I just say moles divided by liters. But just know that the moles is always the solute and the liters is always the solution. The solute is always the solid. +[54.42s -> 66.90s] that's going to be placed in the solution. So I'm just going to say that overall, my formula is going to be capital M equals moles over liters. +[67.15s -> 79.89s] So if we're trying to solve for the molarity, I need to have the moles and I need to have the liters. But the numbers that they gave me, well, 0.2074, that's in grams. +[79.89s -> 93.78s] That's not a mole value. And they gave me 40 mils. That's not a liter, right? So the first thing is that I have to convert these two values in order to get moles and liters. +[93.90s -> 102.67s] Now let's see. The first thing I'm going to do is let's just go from the grams that they gave me to the moles. +[102.93s -> 112.77s] right? We know how to go from a gram to a mole, right? Here's my little trick down at the bottom. If you're starting off with grams, which is what we have, +[112.77s -> 123.98s] And we want to get to moles. And I put X here, meaning that it's of the same compound. So if you have grams of water, you're going to find the moles of water. If you have grams of... +[123.98s -> 136.53s] calcium hydroxide you're going to find the moles of calcium hydroxide so going from gram to mole we would divide by the molar weight so +[136.53s -> 145.14s] I need to find out what the molecular weight is of CaOH2. We've done that before, guys, right? +[145.84s -> 158.90s] So let's just say, what's the molecular weight of CaOH2? Use your periodic table. I'm just going to do it quickly for you guys here. All right. So I have a periodic table in front of me. Calcium weighs about 40. +[158.90s -> 161.58s] And you can round your numbers. It doesn't matter. +[162.00s -> 176.56s] Um, I'm just going to try to get the most specific one and then let's see where we got the hydrogen. There's two of them. So I get a molecular weight of roughly 74 point. +[176.56s -> 189.82s] 0.096 gram per mole. That's the unit for molecular weight. Now we said before that all we have to do to go from grams to moles is just divide my number by the molecular weight. +[189.82s -> 204.21s] The gram that they gave us was 0.2074. So I'm just going to take 0.2074 and divide it by the molecular weight that we found out, 74. +[204.21s -> 214.26s] .096? What do we get guys? Let's see. .2074 divided by the molecular weight. +[215.38s -> 219.92s] 0.002799. +[221.62s -> 235.66s] Right, 2799, we can cut it off there. That's fine. And that's now in the unit of moles, and that's CAOH2. Okay, so we found out this number. +[237.36s -> 242.99s] We found out 0.002799 is the mole value. +[243.34s -> 257.31s] Now we just got to find the liters. So that's like step number two. They gave me 40 mils, or more specifically 40 point dot dot mils, and I have to convert to liters. Well, +[257.31s -> 271.47s] here's a little trick down here. If you started off with mils and you need to go to leader, right? Here's the mil, here's the leader. I'm going this way. I am dividing by a thousand. +[271.54s -> 282.11s] So all I got to do is just take that number and divide by a thousand. Or you could move the decimal place over to the left three times. It doesn't matter. +[282.11s -> 297.04s] So this would be the same as zero point. We'll do zero for zero, zero, zero, right? One, two, three. Yep. Perfect. And that's in liters. Now I know the bottom number. +[300.66s -> 315.17s] Okay, let's calculate it. Malarity is 0.002799 divided by 0.0400. Malarity... +[315.17s -> 324.85s] is, maybe I'll just make this a little bigger, capital M equals 0.002799 divided by 0.0400. +[326.83s -> 333.68s] I get 0.06998. +[334.74s -> 349.39s] And that's it. The unit for molarity is either a capital M, so I could have just said like a capital M here, or you could do the mole over liter. It doesn't matter. They're both equivalent. +[349.39s -> 363.07s] And that's it. That's the molarity for this answer. Pretty cool. So just know that you know how to get a molecular weight. That was like the extra, you know, add-on here. And just remember all of your conversions because... +[363.07s -> 376.91s] They're coming back. We always got to convert. All right. So hopefully this helped. Let me know in the comments. And thank you so much for viewing this video. I hope I'm helping you out in your chemistry class. Have an awesome day. You guys rock. See you later. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_15.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..4e12590313490b96fda0c6679bba0125c5df888e --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_15.mp4.txt @@ -0,0 +1,49 @@ +[0.11s -> 8.05s] Hydrochloric acid is an example of a strong acid and sodium hydroxide is an example of a strong base. +[8.05s -> 17.66s] Let's say we are titrating an unknown concentration of hydrochloric acid with a known concentration of sodium hydroxide. Let's say it's 0.20 molar. +[17.66s -> 27.62s] Because we know the concentration of sodium hydroxide, we call that the titrant. And because we don't know the concentration of hydrochloric acid, we call that the analyte. +[27.62s -> 38.42s] And when our strong acid hydrochloric acid reacts with our strong base sodium hydroxide, the products are an aqueous solution of sodium chloride and water. +[38.42s -> 52.88s] As a quick review of how to write the overall or the complete ionic equation for a strong acid-strong base reaction, remember that sodium hydroxide, being a strong base, dissociates completely in aqueous solution to form sodium cations and hydroxides. +[52.88s -> 67.09s] anions. Hydrochloric acid being a strong acid will ionize completely in aqueous solution to form H plus ions and chloride anions. Sodium chloride is a soluble salt so in aqueous solution we would have sodium +[67.09s -> 71.36s] cations and chloride anions and of course we'd also have water. +[71.36s -> 85.94s] When writing the net ionic equation, we cross out these spectator ions. So since we have sodium cations on the left and on the right, we can cross out the sodium cations. And the same with the chloride anions. So both of those are the spectator ions. What we're left with is our... +[85.94s -> 97.25s] net ionic equation. So one way to write the net ionic equation for a strong acid, strong base reaction is hydroxide anions plus H plus cations form water. +[97.25s -> 105.44s] And our goal for the strong acid, strong base titration is to find the concentration of hydrochloric acid using a titration curve. +[105.44s -> 119.73s] Let's say we do our titration and we come up with this as a titration curve. For titration curves, you put the pH on the y-axis and the titrant on the x-axis. So in this case, we're adding base to our solution of hydrochloric acid. +[119.73s -> 128.21s] And before we use our titration curve to find the concentration of hydrochloric acid, let's go through the titration curve and look at some particulate diagrams. +[128.21s -> 141.52s] And as we look at particulate diagrams, keep in mind they're just to help us understand what's going on in the actual solution. So they're just a representation. And we're also gonna leave out water molecules for clarity purposes. +[141.52s -> 155.79s] So let's think about this point on our titration curve. So that's zero milliliters of base added, meaning we're starting only with hydrochloric acid. So there are two H plus particles and there are two chloride. +[155.79s -> 157.34s] anion particles. +[157.34s -> 171.82s] Next, we add in some sodium hydroxide. So the sodium cation is this purple sphere right here, and the hydroxide anion is over here as well. So we add in some sodium hydroxide to our solution of hydrochloric acid, and for the hydroxide anion, +[171.82s -> 186.02s] and that's neutralized by one of the H plus ions that's present. So the OH minus and the H plus react to form H2O, and since we're leaving H2O out of our particulate diagrams, we don't see it in this second particulate diagram. +[186.02s -> 198.78s] What we do see in this second particulate diagram are the chloride anions that were initially present, so here they are, and the other H plus ion that was initially present, and the added sodium cation. +[198.78s -> 205.73s] And since there's still an H plus cation left in solution, we haven't neutralized all of the acid that was initially present. +[205.73s -> 214.02s] So next we add some more sodium hydroxide. So here we're adding a sodium cation and we're also gonna add this hydroxide anion to our solution. +[214.02s -> 227.04s] The added hydroxide anion will be neutralized by the H plus ion that's already present. They will form water, and since we're leaving water out of the particulate diagrams, we don't see water in this third particulate diagram. +[227.04s -> 239.02s] What we do see in our third particulate diagram here are the two chloride anions that have always been with us in the titration. We had one sodium cation already present and then we added one more sodium cation. +[239.02s -> 253.39s] So this third particulate diagram represents the equivalence point of our titration. All of the acid that we initially had present has been neutralized by the added base, and we're left with an aqueous solution of sodium chloride. +[253.39s -> 256.72s] only sodium cations and chloride anions in solution. +[256.72s -> 271.12s] At 25 degrees Celsius, the pH of water is equal to seven. And since neither the sodium cation nor the chloride anion will react with water to change the pH, the pH at the equivalence point of a +[271.12s -> 274.72s] strong acid, strong base titration is seven. +[274.72s -> 288.29s] And we can find the equivalence point on our titration curve by going over to a pH of about 7 here, and if we draw a little dashed line, wherever that dashed line hits our titration curve represents the equivalence point. +[288.29s -> 302.64s] So the first particulate diagram was before any base was added, so that's this point on our titration curve. The third particulate diagram is meant to represent the equivalence point, so this point on our titration curve. And our second +[302.64s -> 311.47s] this particulate diagram was when we haven't neutralized all of the acid that's present. So that's in between those two points on the titration curve. +[311.47s -> 325.68s] Also notice how steep the graph is around the equivalence point of this titration. Therefore, adding very small amounts of base around the equivalence point causes large changes in the pH of the solution. +[325.68s -> 340.11s] Let's go back to our particulate diagram at the equivalence point and let's add some more sodium hydroxide. So we add one more sodium cation and one more hydroxide anion. This time, since there's no more acid to neutralize the... +[340.11s -> 349.55s] added hydroxide anion. In our fourth particulate diagram, here's our hydroxide anion, and one of these sodium cations is the one that we just added. +[349.55s -> 363.89s] and we still have the chloride anions and the sodium cations that were present at the equivalence point. So this fourth particulate diagram represents the titration after the equivalence point when we're adding excess base. +[363.89s -> 370.62s] And we can see on our titration curve, as we continue to add excess base, the pH keeps increasing. +[370.62s -> 382.54s] Now that we've gone through the particulate diagrams for our strong acid, strong base titration, let's get back to our original problem, which was to find the initial concentration of hydrochloric acid. +[382.54s -> 396.88s] And we can do that by figuring out how many milliliters of base were added to get to the equivalence point. So if we just drop down here on our titration curve, we can see that after 50 milliliters of base have been added, +[396.88s -> 398.77s] equivalence point has been reached. +[398.77s -> 413.20s] Therefore, it took 50 milliliters of our 0.20 molar solution of sodium hydroxide to completely neutralize the hydrochloric acid that was originally present. And if we know the initial volume of the hydrochloric acid solution, +[413.20s -> 421.22s] let's say it was 100 milliliters, we can calculate the concentration using the MV is equal to MV equation. +[421.22s -> 435.70s] So for our equation, let's think about acid being on the left side. So we don't know the concentration, the molarity, so we make that x. And for the volume of the acid, it's 100 milliliters, so we plug that into our equation. On the right side, let's think about this being +[435.70s -> 449.90s] the base. So we know the molarity of the base, it's 0.20 molar, and we also know the volume of base that was necessary to reach the equivalence point, which is 50 milliliters. Solving for x, we find that x is equal to 0.10 +[449.90s -> 455.74s] So that was the initial concentration of our hydrochloric acid solution. +[455.74s -> 469.26s] And notice on our titration curve, remember we started with only hydrochloric acid, so we start with a very low pH if we're titrating a strong acid with a strong base. As we add more and more of the strong base, the pH increases. +[469.26s -> 481.18s] We've just looked at the titration curve of a strong acid with a strong base. Let's compare that titration curve to this one, which is the titration of a strong base with a strong acid. +[481.18s -> 492.58s] Since we're starting with a strong base, notice how the initial pH is very high. And since we're adding acid, notice down here in the x-axis, it now says milliliters of acid added. +[492.58s -> 502.40s] As acid is added, we can see the pH dropping slowly. And as we approach the equivalence point, we see a large drop in pH with small additions of acid. +[502.40s -> 516.82s] However, the pH at the equivalence point is still equal to seven. So if we find a pH of seven on the y-axis and go over to our titration curve, this point represents the equivalence point. And we could drop down to the x-axis and we would see +[516.82s -> 528.10s] It took 20 milliliters of acid to neutralize the base that was initially present. Finally, once we go past the equivalence point, we can see as we add more and more acid, the pH keeps getting lower. +[528.10s -> 539.04s] So this titration curve of a strong base with a strong acid is essentially the reverse of the first titration curve that we saw, which was the titration of a strong acid with a strong base. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_16.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_16.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fc8da42f6c364db85809470bf7a26879404bc136 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_16.mp4.txt @@ -0,0 +1,32 @@ +[0.00s -> 8.21s] Hey it's Professor Dave, let's talk about molecular geometry. +[9.23s -> 18.72s] we begin to learn more about molecules, it's important to understand the way molecules are arranged in three-dimensional space, because this will affect how the molecule does chemistry. +[18.72s -> 30.83s] a model we can use to analyze molecular geometry is called the VSEPR model which stands for valence shell electron pair repulsion. this is how we will predict the shape of a molecule +[30.83s -> 39.18s] atoms are surrounded by clouds of negatively charged electrons and when you have atoms in a molecule together these electron clouds repel each other +[39.18s -> 48.62s] because of this a molecule will automatically adopt a particular geometry so as to allow all the atoms to be as far away from each other as possible +[48.62s -> 62.82s] think of these electron clouds as magnets of like charge. the closer you push them together the more potential energy they have. things want to be at the lowest energy possible so if you let go they will push apart lowering their energies +[62.82s -> 73.90s] atoms will do the same thing. take carbon dioxide for example. the carbon atom has two electron domains or areas of electron density extending from it +[73.90s -> 84.26s] in order to participate in these bonds the carbon takes an s orbital and a p orbital and hybridizes them forming sp hybridized molecular orbitals +[84.26s -> 97.26s] for now we can just count the number of electron domains and use that many atomic orbitals to describe the hybridization of the central atom in a molecule. for each energy level there is one s, three p's, +[97.26s -> 103.94s] and five Ds, so here we just need one S and one P for these two electron domains. +[103.94s -> 118.29s] anything that is sp hybridized is going to show linear electron domain geometry because the furthest these two oxygen atoms can be from each other while still being bound to carbon is this shape which involves a 180 degree bonding +[118.29s -> 132.30s] look at a molecule like BF3. boron has three valence electrons so it can make three bonds. that means that there are three electron domains surrounding the boron atom. that makes the boron sp- +[132.30s -> 145.63s] anything that is sp2 hybridized will exhibit trigonal planar electron domain geometry. this is the furthest the three florians can be from each other while connected to the boron +[145.63s -> 155.10s] trigonal planar molecules have 120 degree bond angles. once we get to four electron domains around a central atom we will need to utilize the third dimension +[155.10s -> 161.44s] the carbon and methane is sp3 hybridized so it has tetrahedral electron domain geometry +[161.44s -> 172.19s] these 109.5 degree bond angles put the hydrogens as far away from each other as they can be making a shape that would have four sides if we connected the points +[172.19s -> 183.82s] atoms with five electron domains are sp3d hybridized and have trigonal bipyramidal electron domain geometry, basically two pyramids connected at the base +[183.82s -> 197.74s] these complexes have both 90 and 120 degree bond angles and atoms with six electron domains are sp3d2 hybridized and have octahedral geometry resembling an eight-sided figure +[197.74s -> 210.13s] all the bond angles here are 90 degrees. so in order to figure out the electron domain geometry of a molecule you just count up the electron domains. the number will tell you the hybridization and therefore the geometry +[210.13s -> 215.66s] Besides covalent bonds to other atoms, lone pairs also count as electron domains. +[216.02s -> 225.34s] take ammonia for example. the three hydrogens and one lone pair make nitrogen sp3 hybridized so it has tetrahedral electron domain geometry +[225.34s -> 236.14s] but the lone pair doesn't take up as much space as a bond to another atom so it has a slightly different shape from methane and we assign it a different molecular geometry +[236.14s -> 246.80s] molecules that are sp3 hybridized but have one lone pair are said to have trigonal pyramidal molecular geometry. the oxygen atom in a water molecule +[246.80s -> 259.79s] also sp3 hybridized because it makes two bonds and has two lone pairs for a total of four electron domains but the two lone pairs mean this molecule has a bent molecular geometry +[259.79s -> 269.14s] it is very important to understand how molecules like carbon dioxide and water have completely different shapes even though they contain the same number of atoms +[269.14s -> 282.42s] the lone pairs on oxygen are pushing away the electron clouds on the hydrogens just like an atom would, which is why it has tetrahedral electron domain geometry, but the shape or the molecular geometry +[282.42s -> 292.48s] bent because the lone pairs don't take up as much space as a bond to another atom. in CO2, carbon doesn't have any lone pairs, just bonds to oxygen. +[292.48s -> 301.98s] so to summarize the number of electron domains surrounding an atom be they covalent bonds or lone pairs determines the hybridization of the central atom +[301.98s -> 312.22s] the hybridization should contain as many letters as there are electron domains. the hybridization correlates with a particular electron domain geometry +[312.22s -> 322.48s] within each electron domain geometry there can be multiple molecular geometries as we replace bonds with lone pairs. +[322.48s -> 333.07s] when asked to assign these geometries always start by drawing the correct Lewis dot structure and then just count up the electron domains. let's check comprehension +[362.64s -> 370.67s] thanks for watching guys subscribe to my channel for more tutorials and as always feel free to email me diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_17.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_17.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..0ec166cf1ff14cb568996c488cd5a09b1f737e31 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_17.mp4.txt @@ -0,0 +1,44 @@ +[0.00s -> 6.11s] If you're anything like me, then whenever you see a molecule in 3D, you go like, yes! +[6.11s -> 20.46s] But the chances are you're not like me and the words like Newman projections or chair confirmations or anything to do with stereochemistry makes you want to run away as fast as possible and as far as possible. Well, if that +[20.46s -> 34.67s] the case then this is exactly the video you'll need to watch because I can promise you that at the end of it you're going to be drawing the Newman projections like a pro. And the best way to illustrate how to deal with the Newman projections is of course with them. +[34.67s -> 48.88s] example, so let's jump into it right away. Well, first of all, we are always going to indicate how exactly we are looking at the molecule. Typically, your instructor will show the eye and the direction in which we are looking at the molecule. +[48.88s -> 55.39s] Personally, I like to use little stick guys over here. I think it kind of looks a little bit more fun. +[55.39s -> 69.68s] Alternatively, your instructor might say something like look at carbons two and three or between carbons three and four or something like that, indicating which two atoms we need to align in order to make the Newman projection. We're always going to show +[69.68s -> 83.89s] the front atom as a dot, while the back atom is going to be a large circle with a dot inside. Next, I'm going to add a couple of helper tools to the structure. Those are the plane of paper which is +[83.89s -> 98.10s] my blue line and the horizon, which is my red line. Those are going to be our mental aids. You don't want to be actually drawing those on your Newman projections, but they will help us figure out where exactly the groups are in our mind. +[98.10s -> 112.30s] molecule. So why do I need those? If I rotate my molecule just a little bit to align the bond we are looking at through the horizon, we are going to have a very clear picture of which groups should be above the horizon. +[112.30s -> 117.94s] and which groups should be below the horizon in the Newman projection, just like so. +[117.94s -> 132.29s] Now, remember how particular I always am about proper drawing of your dashes and wedges. I'll remind you, we always draw our dashes and wedges away from the point in the bond line structure. +[132.29s -> 140.75s] If this is my point, then my dashes and wedges should be right over there. If you draw them on the opposite sides like this. +[140.75s -> 155.02s] It brings ambiguity and ultimately may cost you points on the test as you can easily misinterpret where the groups actually are. Alright, so the next step is to look at our dashes and wedges. The way how we look at the molecule is +[155.02s -> 169.23s] super important here. If we look at our molecule from left to right, like what I have on this example, then our wedges are going to be on the right side of the paper line in the Newman projection, and likewise the dashes will +[169.23s -> 171.92s] be on the left. Like this. +[171.92s -> 186.22s] And if we're looking at our molecule from right to left, it's going to be the other way around. The dashes are going to be on the right, while the wedges are going to be on the left. So now we know all the tricks. +[186.22s -> 199.97s] we can actually go ahead and build our molecule. So first I'm going to start with the dot. Then the back atom is my circle. Then the OH group is above the horizon. +[199.97s -> 207.23s] and it's to the right. The hydrogen atom is above the horizon and it's on the left. +[207.23s -> 222.08s] The CH3 group is in the plane of paper below the horizon. Now, moving to the back atom, in the back, we have the phenyl group, which is in the plane of paper above the horizon. +[222.08s -> 234.43s] The chlorine atom is below the horizon to the right. And finally, the propyl group is below the horizon and to the left, just like that. Easy, right? Now. +[234.43s -> 249.04s] Before we look at a few more examples, I want to go over a few variations of the Newman projections that you'll see in your class. We're going to see two versions of the staggered conformation, the one that looks like a peace sign, so... +[249.04s -> 263.41s] this one, and the one that looks like a Y shape, so like that. You'll be making those when you see your molecule making a typical zigzag, so when your molecule is zigzagging around, that is when you're going to +[263.41s -> 268.10s] be making regular Newman projections in staggered conformations. +[268.10s -> 282.42s] We'll also see the two versions of the Eclipse confirmation. In those confirmations, the groups are right behind each other, so drawing them will always be a little bit awkward. So you're going to be kind of squishing them together. +[282.42s -> 296.62s] right next to each other. And since we cannot realistically show two groups one behind the other one, we'll have to offset the back atom just a little bit. Make sure that you are doing it very carefully and your structures are even. +[296.62s -> 310.83s] easily distinguishable. If I cannot distinguish your eclipse structure from your staggered structure, I can guarantee your instructor is going to take points from that. You will immediately know that you have an eclipse conformation if your molecule looks more like +[310.83s -> 317.41s] a U shape, something like this, or something like that, rather than just a regular zigzag. +[317.41s -> 330.45s] All right, so now we are ready for some examples. For each of those examples, pause the video, work on your structure, and then check your answer. The first one is already on the screen, so go. +[332.56s -> 346.59s] First, I'm going to add my implicit hydrants so I don't forget to draw them in my Newman projection. Next, this is going to be an eclipsed conformation so I'm going to draw the corresponding shape for it. +[346.59s -> 358.80s] Finally, I'm going to add my groups to where they belong. And since it's an eclipsed confirmation, drawing the groups is always going to be somewhat awkward, so do your best. We have +[358.80s -> 372.03s] oxygen and bromine on our bottom right, so below the horizon on the right side. We have both of our implicit hydrogens below the horizon. +[372.03s -> 385.25s] On the left side, we have the methyl group in the plane of paper looking up, and we have this butyl group over here again in the plane of paper. +[385.25s -> 389.58s] looking up over there. Next, how about this molecule? +[391.47s -> 405.97s] You ready to check it your numeral projection should look something like that since we're looking from the right side I'm going to have my dashes the hydrogen and OH be on the right side the corresponding +[405.97s -> 418.32s] OH is going to be below the horizon while the hydrogen is going to be above the horizon just like that. My CH3 group +[418.32s -> 429.36s] and my ethyl group are in the plane of paper. They're on the plane lines. CH3 is above the horizon while the ethyl group is below the horizon. +[429.36s -> 441.50s] Then the aldehyde group from this perspective is going to be on the left side and it is above the horizon. The implicit hydrogen is on the right and above the horizon. +[441.50s -> 456.30s] As I've already mentioned, the ethyl group is going to be below the horizon and it's going to be looking straight down in the plane of paper. Well, how about this molecule? You have your structure? Let's check it. +[456.30s -> 470.58s] This one is also going to be an eclipse confirmation like the one on top of this page. So the back atom will have to be hiding its groups right in the background. So I have my line of the horizon. So anything above that line. +[470.58s -> 483.02s] is going to be above my horizon. So the OCH3, my hydrogens, my methyl group, all of those guys are above the horizon. So OCH3 is above the horizon to the right. +[483.02s -> 492.26s] The methyl group is above the horizon to the left. My hydrons in the back are hiding right there. And of course I have... +[492.26s -> 500.34s] two more groups in the plane of paper below the horizon looking just like that. So what do you think? Easy? +[500.34s -> 514.67s] For as long as you follow this algorithm, I can guarantee that you'll make a correct Newman projection every single time with almost no effort. And once you practice a little bit, you'll also be able to do it really, really. +[514.67s -> 528.66s] really fast. And talking of practice, check the links below or visit organicchemistrytutor.com for more practice problems and other tutorials. Tell me your questions and feedback in the comments below and I'll see you in the next video. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_19.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_19.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..3c43cb8e75acd18af932647a64d6aca2103cd501 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_19.mp4.txt @@ -0,0 +1,50 @@ +[2.93s -> 13.23s] Hi guys, in this video we're going to look at what optical isomers are, the properties of optical isomers, chiral centres, and then finally we're going to summarise. +[14.10s -> 25.07s] If you've watched our video on stereoisomerism of complex ions in the transition metal section of the course, we introduced the idea of optical isomerism. +[25.07s -> 36.06s] Let's define it again here by saying that optical isomers are non-superimposable mirror images of each other. Let's take a closer look at what we mean by that. +[36.06s -> 47.84s] We'll illustrate the point with this carbon which is the central grey atom shown here and it has four different groups attached shown by these +[47.84s -> 62.13s] balls of different colours and sizes. What we've done with the molecule on the left to create the molecule on the right is reflect it through a mirror plane between the two objects. If you imagine the +[62.13s -> 72.24s] reflection of this molecule in the mirror we're still going to have this big green one closest to the mirror the smaller green one pointing up +[72.24s -> 85.81s] And then we're going to reflect the other two. So we have the red one closest to us and the maroon one furthest away. Now we've created this molecule. +[85.81s -> 93.06s] by reflecting the other one, let's rotate it to try and match it up with the original molecule. +[93.06s -> 107.34s] So what we've done here is rotated this carbon to try and line it up with the other one. But as we've turned it round to put the green atoms on the same side, so they're both pointing +[107.34s -> 117.87s] to the right, our pinkish maroon atom is now pointing out towards us whereas in the other one it's pointing away from us. +[117.87s -> 126.35s] As you can see, it's impossible to realign these two different isomers, and the name we give them is enantiomers. +[126.35s -> 133.01s] Another way of getting your head around this concept is thinking about the macroscopic example, which means +[133.01s -> 146.88s] the sizes we're used to in the real world, which is our hands. We have a left hand and a right hand, and although they are basically identical, they are mirror images of each other. +[146.88s -> 161.17s] if you try now you will not be able to turn one hand so that it is exactly the same as the other. The thumb will be on the wrong sides and the fingers will go in different directions. This is why when we have gloves we must +[161.17s -> 175.04s] put the right glove in the right hand or indeed the left glove in the left hand because if we tried to put a wrong hand in the wrong glove then we're not going to get a fit +[175.04s -> 183.28s] So now we've recapped what optical isomerism is, let's have a look at the properties of these different isomers. +[183.28s -> 197.55s] Both of them have exactly the same chemical properties, and they tend to have similar physical properties, although we'll look at a difference in physical properties in a little while. The main thing about optical isomers that... +[197.55s -> 211.76s] interesting is that they have drastically different biological properties so limonene is a good example of this we have two different optical isomers of the limonene where you can see +[211.76s -> 225.97s] here that one of the isomers has this carbon bond coming out towards us whereas the other has it going into the page. If we turn this over so they were pointing in the same direction this part of the +[225.97s -> 238.13s] molecule would no longer match up with the other side. One of these isomers smells to us like oranges whereas the other smells like pine trees. These aren't scents that you would +[238.13s -> 248.08s] count as particularly similar but they come from more or less the same chemical just with a different orientation in space and we smell them so differently. +[248.08s -> 262.35s] An infamous example of this type of isomerism acting differently in biology is thalidomide. You may have heard of thalidomide, which was a drug that was developed and tested for treating +[262.35s -> 272.53s] in pregnant women. One of the isomers was safe, however the other isomer was incredibly dangerous. With the +[272.53s -> 286.80s] other isomer birth defects were caused and even if mothers were given the safe isomer the bodies converted it back into a mix of the two so there was no escaping the fact and lots of +[286.80s -> 291.55s] were given this drug which caused birth defects. +[291.55s -> 305.84s] A main difference in physical properties, although we said they are largely similar, is that one isomer will rotate plane-ponarised light clockwise, whereas the other will rotate it anticlockwise. Now remember, light... +[305.84s -> 315.44s] is made up of lots of different oscillations in many different directions. However, we can pass it through this sort of polarising filter. +[315.44s -> 322.94s] And this restricts the direction of oscillation to in this case just up and down. +[322.94s -> 337.09s] Now, if we take this polarized light and pass it through our samples of the different isomers, one of them is going to rotate it anticlockwise and one of them is going to rotate it clockwise. +[337.09s -> 345.04s] An interesting effect of this is if we have a 50-50 mix where we have equal amounts of each of the isomers, then +[345.04s -> 359.31s] the effects will cancel each other out and the light will not be rotated at all. It will pass through unhindered. We call this type of mixture, where it's 50-50, a racemic mixture. So... +[359.31s -> 373.18s] If we passed plane polarized light through an even mix, we would not see any effect. When we introduced isomerism in this video, we gave the example of a carbon with four different +[373.18s -> 387.54s] groups attached to it and in fact this is a necessity to form something that has an optical isomer. We must have a carbon with four different groups attached in organic chemistry and we +[387.54s -> 395.76s] call these carbons the chiral centres of the molecule. So if we look at the example here, we can see +[395.76s -> 407.55s] that this carbon has a 1, 2, 3 propyl group attached and a methyl group attached as well as a hydrogen and an NH3 group. +[407.55s -> 420.58s] This means that it has four different groups and therefore will have an optical isomer. These molecules are quite simple and small but we can have large molecules +[420.58s -> 426.64s] with more than one chiral centre involved. Chiral centres are +[426.64s -> 440.91s] asymmetrical and so we cannot have symmetry in a molecule that is going to have a chiral carbon. We'll label chiral carbons with a star and this is a very common thing to do. So in this molecule here +[440.91s -> 447.78s] because of the double bond making it asymmetric along this line, this carbon +[447.78s -> 462.19s] Shown by the star here has effectively four different groups attached it has a CH3 a Hydrogen and then if you go in different directions around this ring you will encounter different groups in different +[462.19s -> 472.98s] orders so this contains a chiral carbon however if we removed this double bond from the molecule like so we now have the +[472.98s -> 487.28s] carbon attached, the hydrogen, but if you go in different directions round this ring there is no difference. It has a line of symmetry down the middle because you encounter the same groups either way round. +[487.28s -> 501.49s] This means that there is no chiral carbon. One example of molecules that often contain chiral carbons is amino acids. And in fact, with the exception of glycine, they all have a chiral carbon. +[501.49s -> 511.63s] centre and are usually made in labs in racemic mixtures which remember means that we have 50% of each type of isomer. +[511.63s -> 525.44s] So on the left here we show glycine which is where the extra group on the carbon is also a hydrogen so we do not have four different groups so this has no chiral centre. +[525.44s -> 530.06s] But then all other amino acids have a different group. +[530.06s -> 540.61s] than the hydrogen attached to the carbon so they will have four different groups and therefore this central carbon will be chiral +[540.61s -> 553.58s] so we will have at least one chiral centre. There could be more chiral centres in the R group of the molecule, but unless we specify the amino acid, we don't know what that is. +[553.58s -> 555.90s] Hey guys, I hope you enjoyed the video. +[555.90s -> 569.26s] If you're looking for an amazing A-level chemistry resource, join me today in my series of engaging bite-sized video tutorials. Just click the Snap Revised smiley face and together let's make A-level chemistry a walk in the park. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_20.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..49208c60d05281cd103095fcfed31c3b478aa458 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_20.mp4.txt @@ -0,0 +1,18 @@ +[0.00s -> 7.23s] A chiral center is an atom that is attached to four different groups. We represent a chiral center with an asterisk. +[7.23s -> 21.65s] When an atom has a double or triple bond, it cannot be a chiral center since there are not enough groups. For example, this carbon is not a chiral center because there are only three different groups and we need +[21.65s -> 35.65s] four different groups for this to be a chiral center. Let's identify the chiral centers in these two examples. Looking at this carbon, we will see if there are four different groups surrounding the central carbon. We have OH, +[35.65s -> 45.94s] this carbon chain, a totally different carbon chain with an OH group, and a hydrogen. So both of these carbons are our chiral centers. Note. +[45.94s -> 58.35s] An achiral molecule can still have chiral centers as shown here. This entire molecule does have a line of symmetry, and both parts are the same, making it achiral. +[58.45s -> 68.48s] In this example, there are actually no chiral centers because there are two methyl groups. And remember, all of the groups have to be different. Note. +[68.48s -> 77.58s] A chiral molecule does not have to have a chiral center. There is no line of symmetry within this molecule making it chiral. +[77.58s -> 90.32s] Okay, to make sure you fully understand everything we just covered, try these two questions and we'll go over the answers in just a little bit. For question one, identify the chiral centers. +[95.34s -> 108.13s] To finally answer to question one, let's check each carbon and see if there are four different groups. Nope, not enough groups. Not enough groups for the next carbon. +[108.13s -> 121.95s] This carbon has one, two, three, four different groups, so yes, this is a chiral center. Next, remember double or triple bond will never be a chiral center, so this one is not a chiral center. +[121.95s -> 135.25s] This next carbon doesn't have enough groups. The next carbon has one, two, three, and four different groups, so yes, this is another chiral center. And this n-carbon is a common mistake. +[135.25s -> 148.70s] It has enough groups, but there are two of the same groups, our methyl groups. But we need all four groups to be different, so this is not a chiral center. There are only two chiral centers in this molecule. +[148.70s -> 153.23s] For question two, label each molecule as chiral or achiral. +[156.88s -> 170.77s] To find the answer to question 2, remember we are looking for lines of symmetry. If there is a line of symmetry within the molecule, then it's achiral like this first one is. Here is another hidden line of symmetry. +[170.77s -> 182.42s] We can count the number of carbons on either side and see that we can cut this molecule in half and it would be the same. Since there are one, two, three carbons on the left, +[182.42s -> 196.40s] and one, two, three carbons on the right, making this molecule achiral. Now for the remaining molecules. There is no line of symmetry. No matter how we try to cut them down the middle, they are never the same. +[196.40s -> 198.82s] So these both are chiral. +[198.82s -> 213.42s] You can find other helpful videos right here. And if you would like additional homework help, tutoring, or other resources, you can find that all in the description box. And remember, stay determined. You can do this. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_6.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ef8f3a29181b9b28d54e91ffb6dba2985d9a56f3 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_6.mp4.txt @@ -0,0 +1,35 @@ +[0.00s -> 12.91s] Hey guys, Michael from Conquer Chemistry. In today's video we'll be talking about all things phase diagrams. We'll be talking about what phase diagrams are used for, what all the different points are, and how to read a phase diagram. +[12.91s -> 16.13s] A face diagram is just to show +[16.13s -> 30.67s] what phase will be will exist at a particular pressure and temperature so on the y-axis you have pressure and that typically is in ATMs and on the x-axis you'll have temperature and that's usually in degrees Celsius or it could be +[30.67s -> 41.26s] degrees kelvin and then typically you'll see three lines like this and it separates into the three phases now if you have an empty phase diagram an easy way to know which +[41.26s -> 53.23s] to label as what phase is to go from left to right and it will always be solid, liquid, and gas from left to right. And then once you have the phases labeled +[53.23s -> 67.01s] you can use that to determine what phase the compound or substance will be at a particular temperature and pressure. So for example, if you're asked about what's the phase at this particular pressure, +[67.01s -> 76.62s] and this particular temperature, you just trace it and you get a dot and that dot is in the solid region. So that's how you know this is going to be a solid. +[76.62s -> 90.66s] Or if you were asked about what phase exists at this particular pressure in this particular temperature, then you'll be at this point and that's in the gas region. So that means that that compound will be a gas at that. +[90.66s -> 104.90s] pressure and that temperature. Some other points that you need to know, we have the triple point right here, which is the intersection of the three lines. And the triple point, that's the point in which all three +[104.90s -> 117.95s] phases exist at equilibrium. That means that at this particular pressure and that particular temperature, all three phases, solid, liquid, and gas will exist. +[117.95s -> 124.94s] Another point that's useful to know is this point right here. And that blue point, this is called the critical point. +[125.65s -> 140.14s] The critical point can be broken down into the critical, if you trace it down here, this would be the critical temperature. And if you trace it over here, that would be the critical pressure. +[140.14s -> 153.17s] Then if you bring the points up and then bring the line over then you get this region right here. So what's so special about the critical point is that just in this region above the critical point you no longer can differentiate. +[153.17s -> 158.06s] So you no longer can differentiate between +[158.38s -> 170.54s] the liquid phase and the gas phase. Instead, they sort of combine to become a new phase called the supercritical fluid. +[170.96s -> 185.14s] So that's another point that's important to know. And then lastly, you need to know all the phase changes that can occur. If you're going from a solid to a liquid, that's just called melting. +[185.90s -> 192.53s] And then if you're going from the liquid to the solid, that is called freezing. +[192.82s -> 207.54s] If you're going from the liquid phase to the gas phase, that's called boiling or also called vaporization. And then if you're going from the gas phase to the liquid phase, that is called condensation. +[212.37s -> 226.13s] And then if you're going from a solid to a gas that is called sublimation. And lastly if you're going from a gas to a solid that is called deposition. +[228.11s -> 241.01s] Now let's take a look at some practice problems to apply what we've learned. Here we have a face diagram with A, B, and C. The states aren't labeled, so let's first label states. We know that to label states... +[241.01s -> 254.11s] We go from left to right and that will be solid, liquid, and gas. So C is a solid, B is a liquid, and then A is a gas. So the first question asks, at 30 ATM... +[254.11s -> 267.31s] the boiling point of the substances so we're at 30 atm and boiling occurs when a liquid becomes a gas so we just trace that over and then and then trace that down so that'll be 50 degrees celsius +[267.31s -> 281.04s] and that would be the boiling point at 38 degrees atm the second question asks if the temperature of the substance is held constant negative 15 degrees celsius the phase change that would occur when the pressure goes from one atm to 30 atm is +[281.04s -> 294.58s] so we're given a temperature of negative 15 degrees celsius and it asks what's the phase change that will occur when it goes from one atm to dirty atm so we're starting at one atm we're going to dirty atm so you're going upwards +[294.58s -> 308.43s] And you can see that's going from the liquid. A is a liquid. And then C is a gas. So it's going from a gas to a solid. A is a gas and C is a solid. So gas is solid. That would be deposition. +[309.87s -> 321.46s] Then the next question asks, what is the temperature and pressure of the triple point? So we know that the triple point is the point where all three lines intersect, and that's going to be this point. +[322.48s -> 334.10s] Pressure will be 6 atm and then the temperature will be negative 15 degrees Celsius. So 6 atm and negative 15 degrees Celsius. Next question. +[334.10s -> 346.58s] A phase change that occurs from B to A is known as, so now we're going from B to A, and B to A is just a liquid going to a gas, so that's just known as boiling, or we can say vaporization. +[346.58s -> 358.10s] And then lastly, at STP the substance can exist as. So STP is 0 degrees Celsius and 1 atm. So let's trace that. 1 atm. +[358.10s -> 362.83s] 0 degrees Celsius, that's at this point, and that's A, and A is a gas. +[364.82s -> 376.05s] And that's how you read a phase diagram and what essentially phase diagrams are used to help you determine what phase a substance will be at a particular temperature and pressure combination. +[376.05s -> 384.54s] The other points that you need to know are the triple point and the critical point. And then you also need to know all the phage changes that can occur. If you want to learn +[384.54s -> 392.61s] how to ace chemistry if you want to learn what's the best way to study for this class if you want to learn some neat tricks and tips to take into your exam and do better on them +[392.61s -> 404.83s] then you should head over to my website and get this free guide, 12 Secrets to Ace in Chemistry. You can head over to www.conquerchemistry.com slash chemsecrets. I'm going to include a link in the description below. +[404.83s -> 412.66s] Check it out. I think it's really going to help you and you're going to like it. Until next time, keep working hard and continue the good work. diff --git a/VideoMMMU_ASR_large/Science/validation_Chemistry_9.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Chemistry_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..335f02d0ff5e5998934e4b8b74f9d5de0db30d07 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Chemistry_9.mp4.txt @@ -0,0 +1,33 @@ +[0.40s -> 12.75s] Let's compare Markovnikov and entire Markovnikov addition, which are the addition across unsymmetrical double bonds. First of all, let's talk about Markovnikov addition. +[12.75s -> 26.83s] According to the modern definition of Markovnikov rule, the Markovnikov addition is stated as addition of an unsymmetrical or polar reagent across unsymmetrical double bond under polar conditions to yield more stable ion. +[26.83s -> 35.89s] There are certain points in this definition which must be understood, like the substrate in Markovnikov addition must be an unsymmetrically double bond, +[36.24s -> 48.88s] Attacking reagent must be polar or unsymmetrical and the reaction conditions must be maintained polar. Consider this reaction the addition of HBr into an unsymmetrical alkene. +[48.88s -> 61.30s] the reaction proceeds via the stepwise mechanism and whenever a stepwise mechanism proceeds there must be a transition state and in this reaction the transition state is a carbocation +[61.52s -> 73.17s] When HBr, a polar or unsymmetrical reagent adds into an unsymmetrical alkene, it can yield secondary carbocation or a primary carbocation. +[73.36s -> 86.19s] And we know that secondary carbocation is more stable than the primary carbocation. And according to the definition of Markovnikov rule, the Markovnikov addition prefers more stable iron. +[86.19s -> 97.04s] so far markovnikov addition the secondary carbocation will be favored because it is a more stable let's discuss the mechanism of the reactions first of all the polar conditions +[97.04s -> 110.67s] ionize the hbr yielding h positive and br negative ions the double bond which is electron enriched attacks on the proton yielding either primary carbocation or secondary carbocation +[111.54s -> 120.29s] This secondary carbocation or primary carbocation is then attacked by negatively charged species, which is BR-negative in this case. +[120.29s -> 131.50s] as secondary carbocation is more stable so the product formed by secondary carbocation will be formed in markovnikov reaction while there will be no product +[131.89s -> 146.51s] formed by the primary carbon pattern. In other words, we can say that in Markovnikov addition, the negative part of the attacking reagent goes to that carbon which contains greater number of substitutions. +[146.51s -> 161.46s] As secondary carbocation is further attached with two carbon atoms while primary carbocation is attached with one carbon, so secondary carbocation will be favored and it will produce the Markovnikov product. +[161.97s -> 166.83s] The other reactions proceeding via my comic of addition are +[167.22s -> 180.18s] The addition of water or addition of HX, which are the polar reagents and the polar conditions as I have discussed earlier, it can be the acid catalyzed addition across olefinic block. +[180.78s -> 193.86s] Now let's talk about the anti-Markovnikov addition. It is the addition across unsymmetrical double bond in the presence of peroxides and non-polar conditions. The anti-Markovnikov addition is antagonistic to the +[193.86s -> 205.36s] Markovnikov addition. Here the attacking reagent should be a peroxide and the reaction condition should be maintained non-polar like in the presence of THF. +[205.71s -> 215.63s] The reaction proceeds via free radical mechanism. This is the overall reaction. The same reaction I have again considered. +[215.63s -> 230.11s] non-polar conditions and with peroxides. When HPR adds into the unsymmetrical alkene, the less substituted product forms. Going to the mechanism, as free radical mechanism starts with initiation, +[230.11s -> 239.09s] first of all the peroxides undergo the homolytic cleavage homolytic cleavage means the bond between two atom breaks equally +[239.47s -> 248.35s] single headed arrow will be written for homolytic cleavage it will generate this species and when this species attacks on +[248.35s -> 260.11s] hbr it generates an alcohol along with bromine free radicals these bromine free radicals then attack on polyphenic bond +[260.11s -> 269.10s] again causing the homolytic cleavage of the double bone the bromine free radical can add at secondary carbon or primary carbon but +[269.42s -> 283.30s] In anti-Markovnikov tradition, they always add at less stable position. Or in other words, we can say that the negative part of the attacking reagent goes to that carbon with high number of +[283.30s -> 294.00s] hydrogen or with less substitution this fishy contains less substitution the carbon is attached to further one carbon and this carbon is attached to further two carbon so +[294.00s -> 300.94s] The carbon with less substitution will be favored in anti-Markovnikov radiation and this red colored product will not form. +[301.68s -> 314.14s] And the free radical goes onto this carbon. Now this free radical then again attacks on HBR taking the hydrogen from it and again generating the free radical. +[314.14s -> 325.42s] this br3 radical again causes the homolytic cleavage of other olefinic bonds and the process goes on these two steps are propagation steps determination steps +[325.42s -> 337.97s] we usually do not discuss for this reaction because they usually involve the joining of waste products that we are free radical joins with this we are radical creating br2 +[337.97s -> 348.70s] The free radical mechanism can also proceed at high temperature or in the presence of light. In a nutshell, Markovnikov addition and anti-Markovnikov addition differ in +[348.70s -> 359.18s] their attacking reagents and the reaction conditions. Under polar conditions and polar reagents, the Markovnikov addition will proceed while +[359.18s -> 369.87s] and dimer cognac of addition will proceed if the reagent is peroxide and the reaction is maintained at non-polar conditions or you are using the thf as a solvent +[369.87s -> 378.93s] This was all about the difference between Markovnikov and anti-Markovnikov addition. Like, share and subscribe to my YouTube channel. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Science/validation_Geography_1.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Geography_1.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..97753154aea2dc2877622d5c94062f6ecb657f1a --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Geography_1.mp4.txt @@ -0,0 +1,50 @@ +[0.18s -> 14.00s] Torsion is the twisting of an object caused by a moment acting about the object's longitudinal axis. It is a type of deformation. A moment which tends to cause twisting is called torque. +[14.61s -> 22.19s] A common example of an object subjected to torsion is the transmission shaft, which is used to transmit power by rotation. +[22.99s -> 35.09s] This could be the driveshaft and axles used to transmit power from the engine of a car to the wheels, for example. Or the shafts used to transmit power from the blades of a wind turbine to its generators. +[36.34s -> 45.81s] Let's explore what happens when we apply torque to a circular bar. We can see that the applied torque causes the bar to deform by twisting. +[46.10s -> 60.43s] An interesting thing we can observe is that individual cross-sections of the bar do not get distorted by the twisting. We can imagine that the bar is made up of multiple individual discs, which rotate relative to each other when the torque is applied. +[60.43s -> 68.50s] but do not deform. This is only true because the cross section of the bar is axis symmetric. +[70.64s -> 81.02s] A bar with a rectangular cross section is not axis symmetric, and so torsion results in warping of the bar cross sections. This warping is complex. +[81.02s -> 87.47s] So in this video, we will keep things simple and only consider torsion as it relates to circular bars. +[88.21s -> 97.33s] Let's fix our bar at one end, and track how a line between point A and point B deforms as we apply a torque to the other end. +[98.90s -> 112.40s] The applied torque causes the free end of the bar to rotate by an angle phi. This is called the angle of twist. It varies linearly from zero at the fixed end of the bar to phi at the free end of the bar. +[113.20s -> 117.23s] We can calculate the angle of twist using this equation. +[118.77s -> 132.13s] It is a function of four parameters, the length of the bar L, the applied torque T, the shear modulus G, which is material property, and J, which is the polar moment of inertia. +[132.13s -> 141.87s] So what is the polar moment of inertia? It defines the resistance of a cross-section to torsional deformation due only to the shape of the cross-section. +[142.19s -> 152.05s] The polar moment of inertia for a hollow bar with an outer radius RO and an inner radius RI can be calculated using this equation. +[153.07s -> 157.90s] Setting the inner radius to zero gives us the equation for a solid bar. +[160.21s -> 172.99s] One neat thing about the equation for the angle of twist is that it gives us a way to determine a material's shear modulus, g, experimentally. If we apply a known torque to a bar of known length and cross-section, +[172.99s -> 179.70s] and measure the resulting angle of twist, we can use that information to calculate the material shear modulus G. +[185.01s -> 197.14s] Torsion generates stresses and strains within the bar, which we need to be able to calculate so that we can make sure our bar won't fail. To figure out how to calculate these stresses and strains, +[197.14s -> 208.05s] We can start by observing how a small rectangular element on the surface of our bar deforms. The element is initially rectangular, but when the torque is applied it gets distorted. +[209.33s -> 218.18s] Let's take a closer look. Because the bar is axis symmetric, we know that individual cross sections will rotate but won't get distorted. +[218.18s -> 232.03s] so the sides CF and DE of the element will only move vertically along the lines shown here. After the torque is applied, the angles of the element are no longer 90 degree angles. This gives rise to a shear strain. +[232.03s -> 234.93s] which corresponds to the angle you can see here. +[235.31s -> 249.74s] We can calculate the shear strain by considering only the geometry of the bar in the deformation. It corresponds to this angle between AB and AB'. We can use trigonometry to derive an equation for shear strain. +[249.97s -> 260.14s] For small angles, gamma will be approximately equal to the tangent of gamma, which makes it equal to the length BB' divided by the length AB. +[260.78s -> 273.46s] AB is the length L of the bar. We can calculate the length BB' by realizing that it is the arc length of a circle with a radius r, covering an angle equal to the angle of twist theta. +[273.46s -> 287.30s] So the shear strain is equal to the radius of the bar multiplied by the angle of twist divided by the length of the bar. This is actually only an equation for the shear strain on the surface of the bar. But what about inside it? +[287.30s -> 300.72s] It turns out that the shear strains increase linearly with the distance from the center of the cross section. So, if we define ρ as the radial distance from the center of the cross section, we can replace r in this equation with ρ. +[300.72s -> 311.92s] to give us an equation we can use to calculate shear strain due to torsion at any point within the bar. That's shear strains covered. But what about shear stresses? +[316.24s -> 329.44s] Like the shear strains, shear stresses increase linearly with the distance from the center of the cross section, with the maximum shear stress occurring on the outer surface, as you can see here. This is true for a solid bar. +[329.44s -> 343.22s] but also for a hollow bar. This is useful to know because it means that hollow bars are way more efficient at carrying torsional loads, since the central part of a solid bar is only resisting a small part of the total load. +[345.39s -> 358.88s] Let's consider a small element within our cross section that has an area equal to dA and is located at a distance rho from the center of the cross section. The internal force acting on this element is equal to its area. +[358.88s -> 367.57s] dA multiplied by the shear stress tau. We can use this information to work out an equation for calculating the shear stresses. +[368.02s -> 381.97s] The moments caused by the internal forces acting on all of the elements within the cross-section must sum up to be equal to the torque T. Otherwise, equilibrium is not maintained. We can represent that mathematically by this integral. +[382.13s -> 396.30s] We know that the quantity tau divided by rho is a constant, because the shear stress varies linearly with the distance from the center of the cross-section. So we can rearrange the terms and move tau over rho out of the integral. +[396.37s -> 408.75s] It turns out that the integral we now have on the right is actually the definition of the polar moment of inertia, so we can replace it with the letter J, and we can rearrange this to get an equation for shear stress. +[413.42s -> 423.79s] The shear stress is a function of the torque T, the distance rho from the center of the cross-section, and the polar moment of inertia J. It's quite a simple equation. +[423.86s -> 438.83s] So, we now have equations that allow us to calculate the shear strains and shear stresses. We also have the equation for angle of twist that we talked about earlier. These three equations tell us everything we need to know about a circular bar which is under torsion. +[441.01s -> 449.87s] So far we have only talked about a uniform bar fixed at one end with a single applied torque, but shafts are often loaded by multiple torques. +[450.19s -> 462.86s] This shaft, for example, which is supported by bearings at both ends, is driven by a gear at point B, and in turn drives two gears at points A and C. It is loaded by three torques. +[463.34s -> 477.49s] Before we can use the equations for shear stress, shear strain, and angle of twist that we just developed, we need to figure out the internal torque at each location along the shaft. The process for doing this is similar to calculating the shear force along a beam. +[477.49s -> 490.61s] which I covered in a separate video. First, we draw a free body diagram. Then we make imaginary cuts and use the concept of equilibrium to determine the internal torque at different locations along the shaft. +[498.74s -> 503.15s] This will give us an internal torque diagram that looks something like this. +[508.91s -> 518.19s] The maximum shear stress will occur in the section of the shaft with the largest internal torque, and can easily be calculated using the equation we derived earlier. +[519.66s -> 533.90s] I want to end the video by talking about failure due to pure torsion. If we have two bars, one made of a ductile material and one made of a brittle material, and we apply the same torque to both bars, we will observe that they fail differently. +[533.90s -> 546.19s] The ductile bar fails at an angle perpendicular to its axis, but the brittle bar fails at a 45 degree angle to its axis. We can explain this by remembering that ductile materials tend to fail in shear. +[546.19s -> 557.55s] and so fracture along the plane of maximum shear stress. But brittle materials are weaker in tension than in shear and so tend to fracture along the plane of maximum tensile stress. +[560.98s -> 564.21s] Moore's circle for pure torsion looks like this. +[568.34s -> 577.49s] We can see that when our stress element is oriented this way, the shear stresses are at their maximum values and we have no normal stresses. +[578.13s -> 591.57s] There is a 90 degree angle on Moore's circle between maximum shear stress and maximum normal stress, which means that normal stresses are at a maximum when our stress element is rotated by an angle of 45 degrees. +[591.95s -> 605.71s] This explains why brittle and ductile materials fail in different ways due to pure torsion. That's it for now. Thanks for watching, and don't forget to subscribe if you haven't already. diff --git a/VideoMMMU_ASR_large/Science/validation_Geography_10.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Geography_10.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..869769859216aff01ad4cdec014ead1d94368823 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Geography_10.mp4.txt @@ -0,0 +1,48 @@ +[0.00s -> 14.26s] all right so this is the first video on a series with bending stress and moment of inertia and this is kind of the most basic as it gets all right so we have two shapes and with these two shapes we're told to first find the moment inertia about the principal x-axis so that's +[14.26s -> 28.46s] this middle line axis that passes right through kind of the center of gravity of this thing so if you can picture you know where the center of gravity of this thing is the principal axis is going to pass right through there so what we're going to do is find the moment inertia and the maximum bending stress +[28.46s -> 39.87s] the section resists a bending moment of 10 kilonewton meters. Okay, so our general formula for bending stress is bending stress equal to moment times C, and we'll get to this, but this is the... +[39.87s -> 54.16s] The distance that's farthest from the neutral axis, that's in tension or compression. So, you know, distance farthest from neutral axis. And I'll put neutral axis as NA. Right, the neutral axis is this, you know, principle XX axis here. This is... +[54.16s -> 66.58s] neutral axis for the bending there so that's what we're going to start with i again is the moment of inertia and that's why we need it is so that we can find the bending stress and obviously in this question m is the moment so i is the moment of inertia +[66.58s -> 69.98s] And we'll write it down here, but M, right, is the moment. +[69.98s -> 84.34s] and we need two other formulas here the moment of inertia of these basic shapes so we have a circle right here's our circle and here's our rectangle and our rectangle has you know a base b and a height h you know our circle has a has a diameter d so +[84.34s -> 98.54s] So I'll just write those in here. But for the moment of inertia of a circle, Ix equals pi times d to the fourth over 64. And for the rectangle, we have Ix equals bh cubed over 12. +[98.54s -> 108.46s] So this is always the base, the bottom part that's parallel to the neutral axis, the dimension parallel to the neutral axis, times the dimension that's perpendicular to the neutral axis. +[108.46s -> 122.74s] cubed all over 12. so that's our those are our two formulas and right now all we have to do now is come and plug in chuck so this is cool we have our numbers and if you want to use this as a test see if you get the same thing you know pause the video try and plug these in and see if you get it +[122.74s -> 133.28s] but I'll write them out here. So for the circle, we have ix equals pi times our diameter of 100 millimeters to the fourth all over. +[133.28s -> 145.76s] uh 64. and you might be wondering well this isn't solid and you're absolutely right so in this case if it's not solid we have to subtract off right the inside so we're going to do pi times +[145.76s -> 158.26s] well the inside the diameter is this this is tricky sometimes but it's 100 minus the thickness of eight minus the thickness of eight again so it's twice the thickness so a hundred you know millimeters +[158.26s -> 165.41s] Minus two times the thickness or two times eight millimeters and what are we gonna get there? You know, it's gonna be +[165.41s -> 177.34s] um this is going to work out to 84. when we do that out right we get a value of something really big it's two four six four eight one eight +[177.34s -> 182.93s] millimeters to the fourth so that's a lot of millimeters and I'm just gonna label this because we're working on the circle now +[183.09s -> 197.68s] okay so once we have that that's good right the next thing that we need right to finish our bending stress formula here is this value c and for a circle the c is the distance that's farthest from the neutral axis and hopefully you can see this +[197.68s -> 211.02s] but that distance C here is just gonna be the distance farthest from the neutral axis, which is just gonna end up really being the radius. So C equals R in a circle. So for this circle we have 100 millimeters. +[211.02s -> 222.26s] Divide by two equals 50 millimeters. And then we can solve for our bending stress, right? So our bending stress is just gonna be MC over I, this formula over here. So our moment is 10. +[222.26s -> 234.64s] kilo newton meters and i'm going to want to convert everything here so that i get mpa in the end and to do that what i'm going to do is i'm going to multiply by a thousand newtons per kilo newton and multiply by a thousand +[234.64s -> 245.42s] millimeters per meter all over you know what do we have here for a moment of inertia this big long number two four six four eight one eight +[245.42s -> 259.82s] millimeters to the fourth and you might be wondering where c ended up this is all just moment and c we still have to we can't forget about c 58 millimeters okay so that's our big long equation and the thing that i like to do is i like to get it all into newton's meters if possible because i know +[259.82s -> 273.60s] know one MPA equals you know one Newton per millimeter squared so let's see if that's what we end up with we cross out our kilonewtons we cross out our meters so we're ending up with a Newton and millimeter on the top +[273.60s -> 275.18s] Millimeter times millimeter. +[275.18s -> 289.46s] oops, I forgot my parentheses, is a millimeter times millimeters, a millimeter squared, divided by millimeters to the fourth. So we get a newton per millimeter to the, you know, a newton per millimeter squared, which is going to equal an MPA. And when we do this out, we get 200, about 203. +[289.46s -> 297.90s] mpa okay and that's really that's it right so all we had to do here was we had to go in plug in +[297.90s -> 310.27s] our formula for our circle find c you know substitute in make sure we get our conversions correct and we end up with 203 megapascals so what i'm going to do next is i'm just going to +[310.27s -> 315.38s] Delete this out and we're gonna do the same thing for the rectangle. So let's do that +[315.70s -> 328.05s] All right, so for the rectangle, what we're going to do is we are going to basically do the same thing. We're going to first find our moment of inertia, which is just going to be ix, which is, you know, in this case, I'm just going to write this out. It's going to be bh cubed over... +[328.05s -> 335.71s] 12 and this is like for the outside, you know outside minus BH cubed +[335.71s -> 350.03s] right over 12 for the inside so we're going to subtract off all the area that's on the inside of this thing to get the total moment of inertia so we can plug the numbers in so our base is 100 millimeters our height is you know +[350.03s -> 353.52s] 120 millimeters, that gets cubed. +[353.52s -> 367.82s] all over 12, and that's the outside moment of inertia, and then we wanna subtract off this inside moment of inertia, this inside section here, to get our total moment of inertia for the actual. +[367.82s -> 376.80s] section the blue section here so let's do that and we'll subtract now we need to know what our b is so b in this case again if we have +[376.80s -> 391.50s] thickness of 15 our 100 millimeters needs to be subtracted by 15 on one side and 15 on the other so 15 and 15 is 30 and i'll just write it like this our base is 100 millimeters minus 2 times 15 millimeters +[392.02s -> 405.47s] and our height is gonna be similar. It's gonna be 120 millimeters minus two times eight millimeters, because we have two times the thickness here. You know, two times the thickness here. We have to cube all that. +[405.47s -> 419.28s] Divide it by 12 the big long equation and hopefully your calculator skills work If not, you know try them out see see how you do. So what I get here is 7 8 3 8 2 9 3 millimeters to the fourth and +[419.28s -> 424.98s] So we're coming back to our bending stress formula. We have I. We need to look at C. +[424.98s -> 439.25s] So when we find the distance from the neutral axis for the rectangle, what we're going to do is we're going to take this distance and go straight up. This is anywhere perpendicular to the neutral axis. This distance is going to be our distance c, which +[439.25s -> 451.70s] which is just gonna equal essentially the height, the total height over two. So C is gonna equal 120 millimeters over two, which is gonna be 60 millimeters. I'll write that down here as well, but we have C equals +[451.70s -> 464.56s] the height, which is 120 millimeters, divided by 2, which is 60 millimeters. And then we can just plug into our last equation here. So I'll move this up a little bit so that we have a little bit of room. But the bending stress is just going to equal... +[464.56s -> 477.95s] m which is 10 kilonewton meters and again i'm just going to multiply this by a thousand newtons per kilonewton and a thousand millimeters per meter that's our moment times our c which is 60 +[477.95s -> 489.60s] millimeters divided all by our moment of inertia which is 7838293 millimeters to the fourth and when we do this when we solve for it +[489.60s -> 500.27s] We're going to get about 76.5 megapascals. So there you have it, right? Basically, all we did is we took our basic bending stress formula. +[500.27s -> 507.97s] We apply that by first finding the moment of inertia, then finding C, the distance from the neutral axis to the farthest. +[507.97s -> 516.98s] point that's in stress and then we just plugged and chugged right so hopefully that makes sense and if you have a problem like this one of the hard things might be getting this moment this moment +[516.98s -> 529.55s] and this problem was given to you, but you might have to go through a shear moment diagram. So feel free to check out how to do that. But otherwise, it's making sure you know how to use your calculator, getting the right conversions, and putting it all in. So hope this helps. +[529.55s -> 534.62s] If you have any questions feel free to drop a comment. Otherwise keep working hard and moving onward and upward. diff --git a/VideoMMMU_ASR_large/Science/validation_Geography_3.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Geography_3.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..20134734ffbce0e53cb47e6a3d7a4772298efcf1 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Geography_3.mp4.txt @@ -0,0 +1,78 @@ +[0.00s -> 14.22s] Influence lines, whether you love them or hate them, you've used them all the time, you've never used them before. We're gonna be going full depth with numerous examples and kind of test problems to test the waters and get you feeling more confident about influence lines. They are something that more. +[14.22s -> 28.43s] So bridge engineers use more often than not, but that doesn't mean that we don't use them in buildings and they can't be another great handy dandy tool in the utility belt as a civil structural engineer out there. So buckle up, let's get going. First off, I gave a couple rules for influence. +[28.43s -> 42.64s] lines and then secondly we're going to go through a little test problem going through a couple different scenarios you know doing some different cuts and different locations along this three span beam that i have here then after that we're going to apply it to one with actual values do +[42.64s -> 56.85s] full influence line and then effectively use it to calculate numbers he would in the real world. But what are our rules? Well, just like anything else we solve for in engineering, most of the time you have reactions, you have sheer values, you have moments that +[56.85s -> 71.76s] you're looking for and just like influence lines you have those categories as well and for each category you have a different rule that you're using in order to create your influence line for the first rule you need to impose a unit displacement of one unit +[71.76s -> 86.06s] That one that I put in parentheses is unit less. It's not until later when you actually apply the loading on your system. Well, it actually we use the influence diagram to then spit out an actual value with. +[86.06s -> 98.94s] You know with tips or pounds or whatever displacement of one unit at the reaction in question The deflected shape is the influence line of the three. This is the easiest one you only use this rule +[98.94s -> 113.23s] at your boundary conditions. You know, at A, you have a reaction. B, C, D, we all know this. You can't use the first rule to find, you know, a force or a quote unquote, I'm going to use this incorrectly, a reaction. +[113.23s -> 127.44s] Somewhere along a beam because that's where there's shear and potentially moment present in the beam It's only at a boundary condition. Do you have a set reaction rule number two shear influence line? So this is just determining shear in your beam along +[127.44s -> 135.34s] along your system here. Impose a unit shear deformation of one unit, and I put in parentheses here, this is my little rule, down and up. +[135.34s -> 145.26s] you'll see why later at the point where shear is to be calculated so at that location where you're trying to figure out how much shear demand do i have you know if i go blue do i have +[145.26s -> 159.54s] Here or over here or over here anywhere along your system you can find Sheer demand and you can use the influence line to determine that and then lastly Moment influence line. This one I think is for me personally +[159.54s -> 166.99s] is the most difficult of the three. This is where you impose a unit rotation deformation. That sounds scary, but that's not. +[166.99s -> 177.23s] It's not too bad. Of one unit at the point where the moment's to be calculated. Same freaking thing. If I go in blue, if we want moment here, if we want moment over here. +[177.23s -> 184.03s] Etc, etc. You may be trying to answer the question of why do we even need influence lines? Why can't we just use +[184.03s -> 198.32s] the standard approach and cut our beam and method of sections and stuff like that to determine the shear along our beam, the moment, all that kind of stuff, blah, blah, blah. An influence line is more so used when you have several loading conditions or criteria. +[198.32s -> 202.66s] You might have a distributed load and that distributed load is +[202.66s -> 216.98s] can be you know patterned so it can be on some areas and not on other areas as well as a point load that can occur anywhere along your system and those then adding those two loading criteria together and all of those combinations of where they +[216.98s -> 231.18s] could all be. And someone asks you under those loading criteria, what is the worst possible condition, whether it be a reaction, a shear or a moment anywhere along that beam? If that person's like, what about at sea? How bad is it over there? If I have, you know, some low +[231.18s -> 243.60s] loading on A to B and some loading on C to D and I have a point load right here. Oh, but actually I changed my mind. What if I actually have a point load here and not here and no distributed load? +[243.60s -> 247.18s] Etc, etc, etc. That's like a thousand different ways +[247.18s -> 260.32s] that you'd have to start over and calculate by hand method of sections. This is something that comes up commonly in bridge design, lane loading, all that kind of stuff. And when you have multiple spans of bridges. +[260.32s -> 274.70s] and you know girder spans and then you have lanes several lanes across one span so this is more so where it comes up but you can use this just like you would in bridges on just anywhere you could in buildings as well where you have a situation like this let's start +[274.70s -> 283.02s] by saying we want to find the reaction at point B. And what I would do is I do RB because you're doing reaction. +[283.02s -> 297.36s] At point B, point B is actually a boundary condition. We have our system drawn and just like the rule says, we want to impose a unit displacement of one unit at the reaction in question. I'm going to go blue here. +[297.36s -> 308.66s] Erase the boundary condition from the problem. So now you have the following and you're going to now impose a one unit force. You can think about it like a force. +[308.66s -> 322.96s] because you are displacing this beam upward and in replacement of the boundary condition B. Well, if you take that and you can visualize in your head, if you were to be on the bottom of that beam and you were to point your finger and push up from underneath, what would... +[322.96s -> 337.17s] the deflected shape look like with the boundary conditions that remain? Something like that. And with that quote unquote one, that relays to a total displacement of one unit. And that right there is your deflected shape. +[337.17s -> 351.38s] and that is your influence line for the reaction at B. Well, now let's do R, D. Now we'll erase this blue line or blue circle, and now we're getting rid of that reaction as the rule states, and we replace it with an upward reaction. +[351.38s -> 365.58s] of one unit pushing upward what would be our deflected shape that would look something like this drew it a little funky but it's supposed to cross obviously cross the plane where you have your reactions that's where your curvature of your beam +[365.58s -> 379.79s] reverses at those reaction points because you have a boundary condition pinning that in place. You now have your influence line for reaction D. That displacement is a unit of one. These are some lesser displacements. +[379.79s -> 393.38s] So they would be, you know, 0.4 and 0.4 something. That's not exactly what they are. I'm making that up, but they are less than one because they are, they have less curvature because you can ultimately. +[393.38s -> 407.66s] You can only have your largest displacement of your influence line for reactions of 1.0. That's as large as it can be. All right, so I'm going to erase those. I think we got reactions. Let's move on. What about VE? So now we're in shear. So now I do V. +[407.66s -> 420.66s] because that's the sheer influence line that we're going for. And E is the point of interest. So that's this guy right here, circling blue. And as I've drawn here and underlined, E and G are not pins. So they're... +[420.66s -> 435.02s] They are still continuous members through those points. Those are just points of interest that I've marked. Those are not actual pins. Our rule is to impose a unit shear deformation of one unit down and up, as you'll see here, at the point where the shear is to be calculated. +[435.02s -> 449.23s] And E, we will say for the sake of argument right now, is at mid-span between A and B. So that's a unit shear of 1 down and up. And that total unit shear is 1. +[449.23s -> 461.98s] about your member of interest. It is 0.5 above and 0.5 below. It always equates back to one. You can think of one equaling 100%. And now you need to... +[461.98s -> 474.96s] um picture as if you're taking this member right here and i'll actually draw on red first and you're slicing it with a knife and you're slicing it right through that point of interest +[474.96s -> 480.34s] And now you can think about that member. And if you're pulling down and you're prying up. +[480.34s -> 494.64s] on the opposite piece. Then from there, you take your deformed shape, and that will give you your influence line for sheer. So that's going to look like this. I'll go back to blue. So we're prying down on the left-hand portion of that remainder. +[494.64s -> 508.85s] piece of member but because this is a pinned connection it cannot translate any moment about that point so that member is just going to linearly drop straight down and this +[508.85s -> 521.09s] boundary condition right here. It's a continuous member over top of it. So that does have the ability to flex and translate moment. So that will not be linear. That will be nonlinear. +[521.09s -> 523.89s] And that will look something like that. +[525.26s -> 539.86s] and do something like that. We're just figuring out how to actually draw the influence lines right now. I think this is a great thing for the PE exam. And actually, I've been going through my studies on the SE exam and getting all brushed up on influence lines. And that's why, obviously. +[539.86s -> 548.78s] I'm here today. What about the shear at point G? So if we go back up again, this is not a pin, but now we want to know about point G. +[548.78s -> 555.28s] Let's do it. So point G is right here. Same thing. You're cutting that knife right through point G. +[555.28s -> 569.58s] Fruit Ninja, you're going to go down and you're going to go up. I'm gonna actually say point G is over here and we're gonna give some difference. So let's say this is 10 feet total and let's say it's seven and three. And now we're making that cut through there. +[569.58s -> 583.60s] in blue and it's gonna look something so again that's gonna go down and you're gonna draw your deformed shape now as if you're prying on those two parts that you just cut through and it looks something like that and again this is a total unit +[583.60s -> 597.82s] Bring these dashes out. That right there is a total unit of one. But you may notice that the bottom piece of that cut looks deeper than the top piece. And that's because we are no longer at mid span of the member that we cut. We are now. +[597.82s -> 607.14s] you know more favorite on one side than the other with three feet and seven feet and how that translate is just through basic geometry and ratioing so +[607.14s -> 621.42s] The closer you get to one end, the larger and deeper your influence line is going to be for sheer. This bottom dimension is actually 0.7 because it's 70% because this is 10 feet total. +[621.42s -> 633.15s] So it's seven over 10 of our one unit, which is 0.7, which gets you that. And that means that the top piece is three tenths of our one unit. +[633.15s -> 643.66s] So top portion is 0.3 gang is literally a thousand degrees in here, but let's keep it rolling All right moment influence lines oppose a unit rotation deformation of one unit +[643.66s -> 654.80s] at point where moment is to be calculated so it's the same process as shear except you're applying a unit rotation deformation you're like ah it's you're just yeah you'll see in a second here so let's find +[654.80s -> 667.20s] the moment about point E. Now I go M E because we're looking at moment. And this one I think about like kind of strange, but if you were to, you know, take our knife again and you were to cut like +[667.20s -> 673.90s] 90% of this thing out and then you were to pull up on that piece. So instead of +[673.90s -> 685.71s] uh pulling down on one piece and up on the other piece like we did for the sheer we're going to cut most of it out but now we're going to take both pieces and we're going to pry them up all right so that would ultimately lead to +[685.71s -> 698.62s] you know, something like that happening as you pry up on it. But I still like to think about it like there's still a little piece hanging on there, a little paperclip attached. And, uh... +[698.62s -> 710.38s] Then you draw the influence line based on the deformed shaped by applying that unit rotation. We'd get something like this. Again, there's a pin right here at point A. +[710.38s -> 719.57s] it's not a fixed condition it's pin so there's no moment uh translation right there so you'd have a linear uplift +[720.14s -> 727.20s] but then for the rest same thing that's not linear i know i kind of drew it linear but this has a +[727.20s -> 741.55s] you know a slope to it now i gotta get my butter knife out of the way and that unit rotation is that value equal to one right there so it's it's a it's an angle it's a unit of rotation and ultimately there you go +[741.55s -> 750.14s] Just like that, you have your influence line for your moment at 0.8. That's all that it is. Where it gets tricky for moment is actually determining +[750.14s -> 764.46s] um the values once you start putting loads on them that's the where i say it's kind of the trickier one of the three in my opinion but let's do one more quickly let's say mb b is right here but you're saying wait a minute that's not a reaction what are we supposed to do there well hang on a sec +[764.46s -> 776.22s] you do the same exact thing you do like we talked about you know up here with that kind of that thought of how you're gonna cut most of it away and you're gonna you know pry it upward +[776.22s -> 787.73s] But we have that boundary condition that is holding that in place. So there's no way for like we show up above here. If I go green for M E. +[787.76s -> 797.82s] We show this like displacement right here of our influence line Lifting up the beam and turning it into you know, the blue influence line +[797.82s -> 812.14s] But for this case, that can't be possible. You can't lift the beam up there because you have a boundary condition that has upward and downward capacity. So it's going to hold that thing in place. So does that mean that you can't do anything? +[812.14s -> 823.66s] you can't solve for a moment here no you still can you still need to picture that you're you're bending and prying that thing but you can't actually lift it up but if your two hands are gripped on the side of it +[823.66s -> 828.88s] and you're doing this, ultimately what's going to happen is you're going to get a deflected shape like this. +[833.62s -> 839.10s] and your unit rotation is equal to one. That is your moment influence line. +[839.10s -> 853.52s] for point B. My explanations took a little bit longer today. So unfortunately, I'm saving the full on example problem with numbers until the next video, but I will drop that very soon. So stay tuned. Let me know in the comments down below if you're feeling a little more confident. +[853.52s -> 867.57s] or if you're totally lost with influence lines. I know that I was early on in my career and when I was in school, they scared me a lot and I found them to be really difficult. Ultimately, it's the core rules that you just learn and keep under your belt. +[867.57s -> 881.04s] And you just more so think about the system in the physical world. Think about yourself with a little erector set and you're able to, you know, like I said, cut with a knife and pry those things open. +[881.04s -> 884.56s] um and see how they deform and deflect that is uh +[884.56s -> 898.13s] that's the best way that i was able to wrap my head around this stuff and by the way before i go we are quickly approaching 8 000 subscribers which is so so freaking cool 8 000 engineers from around the world obviously if you like the content like it if you didn't well +[898.13s -> 912.56s] still like it because I'm out here sweating a ton and it's really hot and I'm, you know, trying my best. I don't know. And if you want to consider supporting the channel to create more content for all of you, better, better quality, better explanations, consider joining Team Kastava. +[912.56s -> 914.29s] Siempre. Peace. diff --git a/VideoMMMU_ASR_large/Science/validation_Geography_6.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Geography_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..a99c2d16ace1ffacf95553406ee7f16611ae489b --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Geography_6.mp4.txt @@ -0,0 +1,86 @@ +[0.00s -> 10.24s] Shear force and bending moment diagrams are powerful graphical methods that every mechanical and civil engineer should know how to use to analyze a beam under loading. +[10.24s -> 23.31s] In this video, I'll explain exactly how to master these diagrams, and we will see how they can be used to understand how a beam is loaded. I want to start by explaining what shear forces and bending moments actually are. +[23.31s -> 36.50s] When a beam is loaded, internal forces develop within it to maintain equilibrium. These internal forces have two components. We have shear forces oriented in the vertical direction. +[37.65s -> 50.98s] And we also have normal forces, which are oriented along the axis of the beam. If the beam is sagging, the top of the beam will get shorter, and so the normal forces in the top of the beam will be compressive. +[50.98s -> 65.44s] the bottom of the beam will get longer, and so the normal forces in the bottom of the beam will be tensile. Each of the tensile normal forces has a corresponding compressive force, which is equal in magnitude but opposite in direction. +[65.44s -> 79.39s] As such, these forces don't produce a net normal force, but they do produce a moment. This means we can conveniently represent the internal forces acting on the beam cross section using just two resultants. +[79.39s -> 93.10s] one shear force, which is a resultant of the vertical internal forces, and one bending moment, which is a resultant of the normal internal forces. This is a very common way of representing the internal forces within a beam. +[93.10s -> 107.15s] Drawing the shear force and bending moment diagrams is just figuring out what these internal forces are at each location along the beam. These resultant shear forces and bending moments will depend on the loads acting on the beam. +[107.15s -> 119.22s] and the way in which the beam is supported. Beams can be loaded in a number of ways, the most common being concentrated forces, distributed forces, +[120.62s -> 123.06s] In concentrated moments. +[124.05s -> 136.24s] Beams can also be supported in a number of different ways. They can have pin supports, roller supports, or be fully fixed which each restrain the beam in different ways. +[136.24s -> 149.33s] Pin supports prevent vertical and horizontal displacements, but allow rotation. Roller supports prevent vertical displacements, but allow horizontal displacement and rotation. +[149.55s -> 163.87s] Fixed supports prevent all displacements and rotation. If a certain degree of freedom is restrained at a support, we will have a corresponding reaction force or reaction moment at that location. For example, +[163.87s -> 176.59s] rotations are permitted for a pin support so there is no reaction moment but displacements in the vertical and horizontal directions are prevented so we will have horizontal and vertical reaction forces +[177.07s -> 188.10s] So how do you determine the shear forces and bending moments within a beam? There are three main steps we need to follow. First, we draw a free body diagram of the beam. +[188.10s -> 193.30s] This shows all of the applied and reaction loads acting on the beam. +[193.84s -> 206.48s] The next step is to calculate the magnitude of the reaction forces and reaction moments at all the beam supports. We do this using the concept of equilibrium. To maintain equilibrium, +[206.48s -> 217.86s] all of the forces in the vertical and horizontal directions should cancel each other out. Similarly, all of the moments acting at every point along the beam should cancel each other out. +[217.86s -> 232.24s] This gives us a set of simple equations we can solve to calculate the reaction forces and moments. If we can calculate all of the reaction loads using the three equilibrium equations, the beam is said to be statically determinate. +[232.59s -> 243.23s] For some beam configurations, like this one shown here, we won't be able to calculate all of the reaction loads because we have too many unknowns and not enough equilibrium equations. +[243.23s -> 253.02s] In this case, the beam is said to be statically indeterminate. This beam has four reaction forces, but we only have three equilibrium equations. +[253.02s -> 267.98s] To solve this beam we would need to use slightly more complicated methods and consider boundary conditions. In this video I will only cover statically determinate cases, where we can use the equilibrium equations to calculate all of the reaction loads. +[268.27s -> 279.33s] Once we have calculated all of the reaction loads, the third and final step is to figure out the internal shear forces and bending moments at every location along the beam. +[279.33s -> 293.14s] To do this, we will use the concept of equilibrium again. If we cut our beam at any location, the internal forces and moments need to cancel out the external forces and moments so that equilibrium is maintained. +[293.14s -> 308.11s] This allows us to easily calculate the shear force and bending moment at each location along the beam. All we need to do is start from one side of the beam and move the location of the cut along the beam, calculating the shear forces and bending moments as we go. +[314.96s -> 326.99s] Now is a good time to define the sign convention we will be using. Applied forces will be positive if they are acting in the downwards direction. For shear forces and bending moments, +[326.99s -> 330.51s] The positive sign convention will be as shown here. +[331.25s -> 343.70s] If the beam is on the left side of our cut, shear forces pointing downwards will be positive. If the beam is on the right side of our cut, shear forces pointing upwards will be positive. +[343.70s -> 355.09s] Positive bending moments will be those that put the lower section of the beam into tension. Another way to think about it is that bending moments which cause sagging of the beam are positive. +[355.09s -> 365.74s] and those that cause hogging of the beam are negative. Let's take a look at an example of a beam with pinned and roller supports loaded by two concentrated forces. +[366.99s -> 370.10s] First, we draw the free body diagram. +[371.06s -> 382.74s] We can then use the equilibrium equations to determine the unknown reaction forces at point A and point B. The sum of the forces in the vertical direction is equal to zero. +[382.74s -> 387.47s] So Ra plus Rb is equal to 15 plus 6. +[388.24s -> 400.54s] Because HA is the only horizontal force, it must be equal to zero. We also know that the sum of the moments about any point along our beam must be zero. +[400.54s -> 415.09s] Let's consider the moments about point B. That gives us this equation, which we can solve to determine that rA is equal to 12. By substituting rA into the previous equation, we can deduce that rB is equal to 9. +[415.50s -> 423.25s] Now that all of the external loads acting on the beam are defined, we can draw the shear force and bending moment diagrams. +[428.21s -> 431.54s] We will start from the left-hand side of the beam. +[431.82s -> 444.19s] Let's draw the free body diagram for a location immediately to the right of the 12 kN reaction force. To maintain equilibrium, the shear force must be equal to the reaction force. +[444.19s -> 451.70s] We can draw this on our shear force diagram. The shear force will be constant until we reach the next applied force. +[452.05s -> 465.58s] The bending moment must be equal to the 12 kN reaction force multiplied by the distance x to the reaction force. This gives us the equation for a straight line, which we can draw on our bending moment diagram. +[468.30s -> 482.00s] We then repeat the process by moving the location of our cut further to the right. This time we place the cut immediately after the 15 kN force, and we draw the free body diagram again to determine the shear force and the bending moment. +[489.33s -> 493.78s] We repeat this process until we have covered the full length of the beam. +[505.26s -> 510.03s] We end up with the complete shear force and bending moment diagrams for the beam. +[511.89s -> 525.87s] That example was a fairly simple one for cases with more complex loading drawing the shear force and bending moment diagrams can be more difficult There are relationships between the applied loads shear forces +[525.87s -> 535.73s] and bending moments which will help us better understand what our diagram should look like. Let's consider a beam loaded by an arbitrary distributed force. +[535.79s -> 544.24s] We can zoom in to look at an infinitesimally small segment of the beam with a width equal to dx and draw the free body diagram. +[544.98s -> 558.80s] Over such a short section of the beam, the distributed force can be assumed to be uniform, and we can replace it with an equivalent concentrated force. By applying the equilibrium equations to this free-body diagram, +[558.80s -> 567.47s] It is possible to demonstrate that the following relationships exist between the applied distributed force, the shear force graph and the bending moment graph. +[571.12s -> 582.11s] The quantity dv over dx is the slope of the shear force curve, and at a given point along the beam it is equal to minus the distributed force. Similarly, +[582.11s -> 592.45s] dm over dx is the slope of the bending moment curve and at a given point is equal to the shear force if we integrate the first equation +[592.45s -> 603.26s] we can show that the change in shear force between two points is equal to the area under the loading diagram between those two points. And if we integrate the second equation, +[603.26s -> 611.09s] we can show that the change in bending moment between two points is equal to the area under the shear force curve. +[611.22s -> 620.14s] This is really useful information we can use to help construct or sense check our shear force and bending moment diagrams. Let's take a look at an example. +[620.59s -> 628.46s] This beam has an applied distributed force and a concentrated force. Let's quickly draw the shear force in bending moment diagrams. +[631.86s -> 646.05s] By using the free body diagram method, we can show that the bending moment curve for the section of the beam under the distributed force is defined by the quadratic equation negative 4x squared plus 34x. +[646.05s -> 647.47s] plus 68. +[649.14s -> 662.58s] If we differentiate this equation, we get negative 8x plus 34, which based on the dm over dx equation above, we now know is the equation for the shear force curve in this section of the beam. +[663.79s -> 670.00s] If we differentiate again, we get negative 8, which is the equation for the distributed force. +[670.38s -> 681.42s] This is a great way to sense check your shear force and bending moment diagrams. Another way of checking your diagrams is using the area equations I mentioned earlier. +[681.42s -> 694.13s] The area under the shear force curve highlighted here is equal to 34 times 2, which is 68. This is equal to the change in bending moment over this section of the beam. +[694.32s -> 708.34s] We can also calculate the area under the shear force diagram for the beam section under the distributed force. The total area of this section is equal to 72.3 minus 12.3, which is 60. +[708.34s -> 715.28s] This is equal to the change in bending moment of 60 kNm over this section of the beam. +[718.06s -> 729.62s] Where concentrated forces are applied, there is a sudden jump in the shear force diagram and where concentrated moments are applied, there is a sudden jump in the bending moment diagram. +[729.62s -> 734.58s] These equations will not be applicable across discontinuities in the diagrams. +[734.99s -> 745.97s] One final observation we can make based on these equations is that when the shear force is equal to zero, the bending moment curve will be at a local minimum or maximum. +[748.27s -> 750.77s] Let's look at one last example. +[752.21s -> 765.42s] Here we have a cantilever with an applied concentrated moment of 120 kNm and a distributed force of 6 kNm. Again, we start by drawing the free body diagram. +[765.97s -> 775.34s] Because the support is fully fixed, we have vertical and horizontal reaction forces, RA and HA, and reaction moment, MA. +[775.70s -> 788.66s] Let's look at our first equilibrium equation. The sum of forces in the vertical direction is equal to zero. In this case, the only forces acting in the vertical direction are the reaction force Ra, +[788.66s -> 794.45s] in the distributed force, so RA is equal to 6 times 3, which is 18. +[794.70s -> 804.96s] HA is the only force in the horizontal direction, so it must be equal to zero. Next, we can take the sum of the moments acting at point A. +[804.96s -> 818.29s] In calculating the moment caused by a uniformly distributed force, you can remember that it is equal to a concentrated force located in the middle point of the load. This gives us MA equals 21. +[826.90s -> 833.78s] To calculate our shear forces and bending moments, we will start on the left side of the beam and move towards the right. +[834.16s -> 843.60s] This is our first free body diagram. The shear force calculation is easy, as we only need to consider the reaction force of 18 kN. +[843.89s -> 856.21s] The bending moment needs to take into account the reaction moment and the reaction force. At x equals zero, the bending moment is equal to the reaction moment of 21 kilonewton meters. +[856.21s -> 865.58s] As we move to the right, we also need to consider the moment caused by the 18 kN reaction force. This gives us the equation for a straight line. +[868.11s -> 871.89s] We can then move our cut to the right of the concentrated moment. +[872.14s -> 885.97s] The moment won't affect the shear force, which will remain constant at 18 kN until we reach the distributed force. But it does cause the bending moment to suddenly drop by 120 kNm. +[885.97s -> 895.34s] After the drop the bending moment is again defined by a straight line. Things get a little more tricky when we reach the distributed force. +[897.78s -> 909.17s] We can replace the uniformly distributed force by an equivalent concentrated force with a magnitude of 6 multiplied by the length x over which the force is applied. +[909.17s -> 918.99s] This force is located at a distance of x over 2 from our cut. We can then calculate the shear force and bending moment equations using the normal approach. +[921.46s -> 926.32s] The bending moment in this section of the beam is defined by a quadratic equation. +[926.93s -> 936.82s] No loads are acting on the small 1-meter section to the right of the distributed force, so shear forces and bending moments in that section will be equal to zero. +[938.74s -> 947.66s] Although we can't calculate displacements from these diagrams, we can use the bending moment information to predict the deformed shape of the beam. +[948.18s -> 962.80s] Where the bending moment is positive the beam will be sagging and where it is negative It will be hogging where the bending moment is zero the beam will be straight That will give us a deformed shape that looks something like this +[966.16s -> 975.18s] That's it for this quick look at shear forces and bending moments in beams. I hope you learned something new, and if you enjoyed the video, please don't forget to subscribe. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_11.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..801e1b654b266c714c458e5e4915dc0f59e4dd7d --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_11.mp4.txt @@ -0,0 +1,103 @@ +[21.62s -> 34.42s] Hi, everybody. Hope everybody's having a good day today so far. And I hope everybody is ready to talk about concave and convex functions. Concave, convex functions show up. +[34.67s -> 47.28s] all over the place in economics, especially in microeconomics, and we're going to find out about them today. So let's just get started. We're going to be working, as we have been for some time, +[47.28s -> 58.61s] in a vector space. So we'll say V is a vector space. And we're going to be working in a domain that is a subset. +[58.70s -> 67.66s] of the vector space. And it's going to be a convex domain, a convex set. So x is a convex set. +[69.26s -> 83.47s] And we're going to be working with functions, and so let's just say we're working with a specific, some specific function defined on that convex domain, and it's... +[83.47s -> 97.20s] going to be a real valued function. So this tells us that it's real valued. So let's say f is real valued. +[104.91s -> 117.54s] Okay, so with this setup here, a convex subset of a vector space and a real valued function defined on that convex set. +[117.54s -> 130.29s] Here we have our definition of a convex function, a concave function actually to start with, and then a convex function. +[130.29s -> 141.58s] This tells us that the function is concave if whenever we take two vectors, two points in the domain, +[141.58s -> 153.57s] and we take a convex combination of those two vectors, we have a lambda scalar between 0 and 1, then it's got to be the case that the value of f +[153.57s -> 168.19s] at the convex combination on the left of this inequality is at least as large as, if you like, the convex combination of the values at the two points, which is what's on the right-hand side. +[168.19s -> 180.72s] of this inequality. And then you'll note that if the inequality goes the other way, if the value at the convex combination is always less than or equal, +[180.91s -> 193.15s] less than or equal to the convex combination of the values, then we say the function's convex. And let's also point out that +[193.15s -> 202.94s] We say the function is strictly concave or strictly convex if that's a strict inequality always. +[202.94s -> 212.61s] Let me just write that a little different way because I think that's useful in terms of thinking about this. So what that inequality says, if we use... +[212.61s -> 224.58s] x of lambda, so we've been using x of lambda as our sort of shorthand notation for the convex combination 1 minus lambda x. +[224.58s -> 238.18s] plus lambda y. So this inequality could be written f of x of lambda is greater than or equal to 1 minus lambda. +[238.18s -> 248.18s] times f of x plus lambda times f of y. So writing the left-hand side of the inequality this way, +[248.18s -> 262.45s] We just don't have as much going on in the argument here. And since we kind of know, it's kind of become a habit already, I think, that this represents the convex combination of the two vectors x and y. +[262.45s -> 267.15s] To me, this is an easier way to think about this. +[267.70s -> 282.19s] So we have our definition, and what we need to do now, as we usually need to do when we have a definition of a new concept, is to look at a few simple examples where the definition +[282.19s -> 294.64s] where the definition will actually tell us something. So let's take this off and we will do a couple of examples. +[295.38s -> 309.76s] Okay, let's do an example here. Let's take a specific function, and let's let that function be f of x equals 9 minus x squared. +[309.76s -> 324.05s] And so this is a real valued function, but it's actually a real function, meaning when we say a real function, we mean that the arguments are real numbers also. So in this case, capital X is some subset of R, and let's just let it be all of R. +[324.05s -> 336.98s] So this is a function on the convex domain, all of R. So let's draw a picture here of the graph of this function. +[339.06s -> 350.19s] Should look something like that. And let's draw the y-axis in here. Let's draw the horizontal axis here. +[354.58s -> 365.62s] Okay, so there's the graph of our function. And let's just note that the value is 9 here at x equals 0. +[365.62s -> 379.86s] It's minus 3 and 3 that we're going to have the value of the function being 0. So that's 3. This is minus 3. And let's put the other numbers in here as well. +[380.56s -> 395.38s] So minus 2, minus 1, 1, 2. So there's the graph of our function. And let's look at two points, x and y, in the domain. So let's let x. +[396.62s -> 407.79s] be 2. And let's let y be minus 1. So this is x. This is y. +[409.10s -> 416.18s] Let's let lambda be 1 third. +[418.03s -> 432.06s] So in particular, that means that x of lambda, the convex combination of x and y, is one-third of the way from x to y. And so that would be exactly 1. +[432.06s -> 443.02s] So two-thirds x plus one-third y is going to be 1. So this is x of lambda. +[443.92s -> 449.62s] and that's where lambda equals a third. Well we've already got that down here so we don't really need to do that again. +[453.01s -> 466.96s] And so now let's look at the value of f at these points. Well, lambda is third. Let's actually say that x of lambda here is 1. So what's f of x? +[468.14s -> 480.98s] at 2. We have a 9 minus 4, that's 5. So let's actually go up here. That's 5. +[481.58s -> 494.26s] So this is 5. What about y? f of y. y is minus 1. 9 minus the square of minus 1. 9, that's going to be 8. +[497.52s -> 504.02s] So that's 8. And let's look also at f of x of lambda. +[507.79s -> 522.45s] x of lambda is 1, so f there, if we've got 1 here, this is going to be 8 again, so let's go over here like this. This is 8. +[522.99s -> 533.47s] Okay, so we have the value we have the value of f at the convex combination That's 8 we have the value of f at both x and y +[533.47s -> 543.38s] That's 5. And I left out the value of y here. So let's squeeze that in. That is 8. +[543.82s -> 557.52s] There we go. Okay. And I didn't even write in f of x of lambda. I drew them up here and forgot to come back down here and put them down here numerically. So f of x of lambda is 8. +[559.41s -> 571.15s] And so the only thing left that we have to look at is what's on the right-hand side of this inequality. We want to look at 1 minus lambda. +[571.95s -> 584.37s] f of x plus lambda f of y. That's 1 minus lambda is 2 thirds, so that's 2 thirds of 5. +[584.72s -> 593.97s] plus 1 third of 8. That's 10 thirds and 8 thirds is 18 thirds, so that's 6. +[594.77s -> 606.66s] And we can see that, indeed, in this simple example, the convex combination of the values is 6. +[606.66s -> 615.38s] Value at the convex combination is 8, so the left-hand side here is 8, the right-hand side is 6. Our inequality is satisfied. +[615.38s -> 628.18s] And so that's consistent. Of course, that doesn't tell us the function's concave. It just says that for this particular x and y and this particular lambda, we have the inequality. +[628.18s -> 635.34s] doing the right thing. But of course, to be concave, we have to know the function. +[635.34s -> 647.70s] does this for every x and y in the domain and for every convex combination, for every lambda between 0 and 1. So of course, we're not going to be able to check every one of those. +[647.70s -> 661.62s] directly, arithmetically, but we could prove that this function's concave. Perhaps I'll give that as an exercise. So let's actually do a little more with the +[661.87s -> 669.20s] the diagram here, let's note that if I join up these two points +[669.68s -> 679.34s] And what are those two points? Those two points are 1 is x, f of x. +[680.37s -> 693.30s] That's this point here. x is the value in the domain, and f of x is the value in the target space here. And y... +[693.62s -> 704.30s] f of y, that's this point here, y in the domain and f of y in the target space. So what we're really doing +[704.50s -> 718.59s] Here is we're actually looking at the convex combination of these two points. It's just that it doesn't show up that way in the definition. But you can think of it that way. So what's happening here. +[718.59s -> 732.11s] when we go one-third of the way from here to here is we go right to there. So, we see that the +[732.11s -> 744.56s] convex combination of the two values, that would be the value 8 and the value 5. +[745.94s -> 755.58s] on the vertical axis, which is over here, but I've drawn it over here just to put it next to these numbers. +[755.58s -> 768.46s] The convex combination of these two values, where lambda is a third, is a third of the way from 5 up to 8. A third of the way from 5. +[768.46s -> 782.32s] if you like down here up to eight up here so that it's that convex combination that has to be less than or equal to +[783.76s -> 791.89s] the value of f at the convex combination. So another way of thinking about it, of course, and this is perhaps the way you thought about +[791.89s -> 805.04s] concave or convex functions before if you've seen them, is that whenever we draw a chord or a line segment joining points on the graph, that line segment has to lie below the graph. +[805.17s -> 816.27s] And of course, we can see that with this particular function in this particular graph, that's going to be the case, whatever two points and whatever lambda I choose, I could do this. +[816.27s -> 829.95s] I could do this. It is clearly, intuitively, it is always going to be the case that any line segment joining two points on the graph will lie beneath the graph. Moreover, notice that +[829.95s -> 844.27s] The line segment always lies strictly beneath the graph. In particular here, 6 is less than 8, not equal to 8. So in fact, again, this is not a proof. This is just... +[844.27s -> 850.26s] taking the intuition of the picture here, we can say that this function +[850.32s -> 860.98s] 9 minus x squared is actually strictly concave because we can see that it's always going to be the case that the +[860.98s -> 874.78s] value at a convex combination is going to be strictly less than the convex combination, sorry, the value at a convex combination, that's here, is going to be +[874.78s -> 885.94s] strictly bigger than the convex combination of the two values. So this actually is a strictly concave function. +[886.61s -> 897.52s] Let's note one more thing here, and that is that +[898.96s -> 906.10s] A function is concave exactly if the negative of the function is convex. +[906.10s -> 920.46s] Or you could say it vice versa. You could say a function's convex if it's the negative of a concave function. And the same for being strictly concave and strictly convex. So that tells me that if I take the negative of this, +[920.46s -> 934.70s] this function, well the graph in that case is of course going to look like this. And our axis will be here and the horizontal axis will be here. +[935.22s -> 950.16s] And so this, of course, would be the value 0, and this would be minus 9. So here what we have is let's call this g of x equals minus. +[950.99s -> 964.61s] f of x. So that would be x squared minus 9. Let's just even write that down here. x squared minus 9. And that would look like this. And it's the negative. +[964.61s -> 970.86s] of this strictly concave function, so it's strictly convex. +[972.24s -> 982.64s] Let's note one other thing here before we move on beyond this example, and that's that a linear function +[983.06s -> 996.91s] is both concave and convex. At first, that seems a little bit like, well, how can that be both concave and convex at the same time? But note that a linear function, let's put it a different way. Our function f is linear. +[996.91s -> 1011.06s] If this is not an inequality, but an equation. So a function is linear if whenever we have two points in the domain and we have a +[1011.79s -> 1024.91s] linear combination of those two vectors, it's got to be the case that what's on the left hand side of this inequality is equal to what's on the right hand side. And actually, that's got to be true for any lambda, not just. +[1024.91s -> 1038.72s] lambda is between 0 and 1. But in particular, it will be true for a convex combination. So if I have a linear function so that the left-hand side is always equal to the right-hand side, then obviously +[1038.72s -> 1051.76s] The inequality is satisfied, the weak inequality, so the function's concave, but the weak inequality of the other direction is satisfied too, so it's also convex. So indeed, any linear function... +[1051.76s -> 1061.98s] is both concave and convex and clearly is not either strictly concave or strictly convex because +[1061.98s -> 1071.54s] the inequality here is not going to be a strict inequality. For a linear function, it's always going to be equal. So this is a good starting point. +[1071.54s -> 1085.50s] Let's maybe do one more thing before we move on, and that is let's look at the situation if we have the domain being two-dimensional. So let's suppose... +[1085.50s -> 1096.27s] that our capital X is a subset now of R2. It could be all of R2. That would be fine. Just like here, it could be all of R. +[1096.27s -> 1106.93s] That would be convex. That would be fine. So now our graph isn't going to be like this because it's going to be in three space. The graph is going to be in three dimensions. +[1106.93s -> 1117.20s] two dimension, a plane for the domain, and a third dimension for the value of the function. So the graph is going to be some kind of surface in +[1117.20s -> 1131.12s] R3. And in particular, if we have a concave function, the graph is going to look like what we have down here. The graph is going to be kind of a +[1131.12s -> 1143.89s] It's like a hill like this, sort of the analog of this, but in three dimensions. And if we take the negative of that function, +[1143.89s -> 1156.14s] then its graph is going to be the other way. It's going to be like a bowl, sort of the analog in three dimensions of this two-dimensional diagram here. +[1156.14s -> 1163.36s] Both of these pictures, the concave diagram, the convex diagram, clearly +[1163.36s -> 1176.05s] the functions in those diagrams are actually strictly concave in the one case and strictly convex in the other case because whenever I have two points on the graph, +[1176.91s -> 1188.08s] Whenever I have two points in the domain, an x and a y, and then I join up the corresponding points on the graph at x, f of x. +[1188.53s -> 1199.71s] And at yf of y on the graph, and I draw the line segment between them, in the concave case, that... +[1199.71s -> 1211.47s] line segment will lie strictly below the graph for the graph we have here. And that would be a strictly concave function. And for the convex, +[1211.47s -> 1220.05s] function. The line segment will lie strictly above, so it would be a strictly convex function. +[1220.05s -> 1233.74s] This gives us a good idea of how concave and convex functions work, not just when we have a one-dimensional domain, but when we have a multi-dimensional domain as well. +[1233.74s -> 1246.02s] that in each case, we are talking about a function that is a real valued function, as we said at the outset. We have to be talking about a function f that maps from a +[1246.02s -> 1256.85s] convex domain, that's critical, and it has to be the case that the values are real numbers, a real valued function. Okay, so with all of that, +[1256.85s -> 1269.90s] Let's now take off some of the stuff we have here on the board and we'll look at another somewhat different example with a little more obvious direct important economic. +[1269.90s -> 1273.73s] content to it. Let's take this off. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_12.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..07316068843bf29542147c55e543c4edaab52786 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_12.mp4.txt @@ -0,0 +1,41 @@ +[0.02s -> 5.54s] Now let's see of how to solve linear programming problem using dynamic programming technique. +[5.54s -> 16.18s] So, the problem given us is maximization objective function is 2x1 plus 5x2 subject to the constraints are 2x1 plus x2 less than or equal to 430. +[16.18s -> 26.86s] 2x2 less than or equal to 416 and x1 x2 greater than or equal to 0. In the first step we have to find the state, stage and the objective function. Step 1. +[29.14s -> 34.45s] State will be the number of constraints. Since we have two constraints, it is 2. +[40.11s -> 54.93s] Stage will be the number of variables. The variables used are x1 and x2. So it is also 2. And the objective function is z which is maximization. +[60.05s -> 70.45s] We make an assumption here where we consider two resources which is dependent on the number of constraints. Since we have two constraints here, we use two resources. +[73.90s -> 86.13s] b1 and b2. Using these two resources, we frame a function fi of b1, b2. This i represents the stage. +[88.59s -> 100.98s] Now we have two stages. So let's see two stages separately. Stage 1. So therefore i is equals to 1. So let's frame the function. +[102.77s -> 115.09s] f 1 of b 1 comma b 2 is equals to from the objective function we will be framing the function. So, it is maximum of since it is the first stage. +[115.09s -> 128.34s] we will use only the first variable 2x1 whose limits varies between 0 less than or equal to x1 less than or equal to b. So in this first step we have to calculate the value of b. To calculate b +[130.80s -> 139.86s] The formula used is minimum of b1 comma cx1 comma b2 comma cx2. +[139.95s -> 152.91s] where b 1 and b 2 are the resources and c x 1 is the coefficient of x 1 and c x sorry this is also x 1 and c x 1 this is the coefficient of x 1 of the second constraint b 1 +[152.91s -> 156.69s] will be the right hand side of the constraint number one so which will be +[157.42s -> 171.82s] minimum of right hand side of the constraint number 1 is 430 by the coefficient of x1 of the first constraint which will be 2 comma b2 right hand side of the constraint number 2 460 since there is no +[171.82s -> 184.18s] x1 in the second constraint it will be 0. As we solve this it results in minimum of 215. Anything divided by 0 will result in infinity. So the final value is 215. +[187.76s -> 202.13s] We substitute this b in the function f1 of b1 comma b2 is equals to max of 2x1 where limits varies between 0x1 to 215. +[202.13s -> 211.92s] Now we have to find the value of x1. So to find the value of x1 we have to find it from the constraint. First from the first constraint +[212.43s -> 224.82s] The value of x1 results in x1 is equals to 430 minus x2 by 2. Since we don't have the x1 in the second constraint, from the second constraint the value of x1 will be 0. +[225.26s -> 238.26s] So to find which x1 value to be used the formula used is minimum of x1 from the constraint number 1 and minimum of x1 from the constraint number 2. +[239.79s -> 241.46s] So minimum of +[242.96s -> 257.10s] 430 minus x2 by 2 comma 0. So since 0 is can be ignored the value will be x1 is equals to 430 minus x2 by 2. Now we substitute this x1 value in the function. +[257.26s -> 270.93s] So f1 of b1 value is the right hand side constraint of constraint number 1. So 430 and b2 is right hand side of the constraint number 2 460 equal to 2. +[271.60s -> 282.93s] minimum of x1 value. So minimum of 430 minus x2 by 2. Now let's go to stage number 2. +[285.23s -> 287.34s] Where i's value will be 2. +[287.76s -> 301.63s] The function frames here will be f2 of b1 comma b2 and the equation form will be max of will include both the variables up to second variable. So that will be 2x1. +[301.63s -> 308.94s] plus 5x2. Since we know the value of x1, we can substitute the maximum of +[309.30s -> 320.98s] 5x2 plus 2 into value of x1 from the above equation which will result in minimum of 430 minus x2 by 2. +[321.58s -> 325.20s] So now let's calculate the value of b for x2. +[333.20s -> 346.83s] The formula used is b or b is equals to minimum of b1 of cx2 comma b2 of cx2. This will be the coefficient of x2 from constraint number 1. +[346.83s -> 353.14s] and coefficient of x2 from constraint number 2. So this will result in minimum of +[353.46s -> 367.54s] 430 by 1 comma 430 comma 6. By solving this you will get minimum of 430 comma 230. So the final answer is B is equals to 230. +[368.69s -> 383.06s] sorry this will be 460. Now let's substitute in the function we have known it f2 of so b1 value will be 430 comma 460 is equals to maximum +[383.89s -> 397.97s] The limit varies between 0, x2 less than or equal to 230, 5x2 plus 2 into minimum of 430 minus x2 by 2. +[398.83s -> 407.31s] So to calculate minimum value to calculate this minimum of +[408.34s -> 421.54s] 430 minus x2 by 2. Using this we can calculate the value of x2. So here x2 value varies between 0 and 230. So this can be further simplified as minimum of +[421.54s -> 427.73s] For when x2 is equal to 0, this value will be 430 and when x2 will be 230. +[428.72s -> 437.81s] This results in 100. So, for minimum value will be 100 for which the x2 value is 230. Therefore, x2 value will be 230. +[441.46s -> 455.28s] Using the x2 value we can determine the x1 value. From the first stage we can determine the x1 value where x1 value will be minimum of 430 minus x2 by 2. +[455.28s -> 460.69s] So, substituting the x2 value will result in x1 is equals to 100. +[461.33s -> 476.18s] As we have found the x1 and x2 value we can substitute in our objective function which will be z is equals to 2x1 plus 5x2. x1's value will be 100 and x2 value will be 230. +[476.94s -> 491.09s] 2 into 100 will be 200 plus 5 into 230 will result in 1150. So, therefore the final answer is z is equals to 1350. Thank you. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_15.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c7fb6cd430546384576df85d888db4ba6ae2eda7 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_15.mp4.txt @@ -0,0 +1,69 @@ +[0.91s -> 13.94s] Number 1. A 17 foot ladder is leaning against a building. The foot of the ladder is 8 feet from the base of the building and it's sliding away from the building at 3 feet per second. +[14.13s -> 28.75s] How fast is the top of the ladder sliding down the wall of the building? Well, let's find out. So let's start with a picture. So let's say that's the building. This is the ground. And let's say this is the ladder. +[30.19s -> 40.43s] Now let's call this X Y and let's say the length of the ladder is Z Now let's write down what we know +[41.55s -> 53.78s] So we have a 17 foot ladder, therefore z is 17. The foot of the ladder is 8 feet from the base, so that's the value of x. +[54.77s -> 58.61s] And we don't know the value of y. +[59.50s -> 72.53s] Now, we know that the ladder is sliding away from the building, that is, it's sliding in this direction, at 3 feet per second. So every second, x is going to change by 3 feet. +[73.10s -> 83.76s] So that's dx dt. That's the rate at which x is changing. So let's write that here. So dx dt is 3 feet per second. +[86.35s -> 96.98s] Now we don't have the value for dy dt But in part a that's what we're looking for how fast is the top of the ladder sliding down the wall? +[97.55s -> 111.34s] So as the ladder slides to the right, it's also sliding down the wall. And so y is changing as well. Notice that y is decreasing while x is increasing. Because x is increasing, +[111.34s -> 124.02s] dx dt is going to be positive. And because y is decreasing, we should expect a negative answer for dy dt. So let's go ahead and calculate dy dt. +[124.75s -> 133.55s] So we need an equation that relates x, y, and z. So notice that we have a right triangle. +[134.03s -> 147.98s] And according to the Pythagorean theorem, c squared is equal to a squared plus b squared. Now c is the hypotenuse, so c matches with z. And we can say a is x, b is y. +[148.27s -> 162.48s] So z squared is equal to x squared plus y squared. Now, before we could differentiate both sides with respect to time, we need to calculate the value of y. So z is 17. +[163.28s -> 177.36s] x is 8, what is y? 17 squared, that's 289. 8 times 8 is 64. 289 minus 64 is 225. +[178.19s -> 192.94s] And now we need to take the square root of both sides. The square root of 225 is 15. So now that we have the value of y, +[193.33s -> 204.62s] we should differentiate this equation with respect to time. So the derivative of z squared is what? Is it 2z times dz dt? +[204.94s -> 216.88s] Now, notice that Z is not a variable but a constant. Z cannot change. So therefore, dz dt is 0. So anytime you find the derivative of a constant, it's going to be 0. +[217.23s -> 227.28s] So this is going to be 0. It's equal to 2x times dx dt and the derivative of y squared will be 2y times dy dt. +[228.24s -> 233.49s] So we could divide everything by 2 0 divided by 2 is 0 so we can get rid of this +[235.38s -> 244.11s] x is 8, dx dt is 3, y is 15, and we need to calculate dy dt. +[244.72s -> 257.50s] Now, 8 times 3 is 24, so let's move that to this side. On the left side, it's going to be negative 24, and that's equal to 15 times dy dt. So if we divide both sides by 15... +[257.50s -> 268.66s] we can see that dy dt is negative 24 over 15. But we can reduce that. So let me just reduce it somewhere on the left side. +[269.68s -> 282.29s] 24 is 8 times 3. 15 is 5 times 3. So we could cancel with 3. So therefore, dy dt is negative 8 over 5. +[283.50s -> 285.97s] And that's it for part A. +[291.18s -> 299.09s] Now, let's move on to Part B. How fast is the area formed by the ladder changing at this instant? +[301.62s -> 314.03s] So what is the area of a right triangle? The area of a right triangle is 1 half base times height. In this problem, we can see that the base is x and the height is y. +[314.74s -> 323.57s] Now we have dx dt and dy dt. So in this form, we can go ahead and differentiate this equation with respect to time. +[325.49s -> 338.45s] The derivative of A is going to be dA dt, which is what we're looking for. And then we need to use the product rule. So let's say if we have F times G. +[339.34s -> 346.26s] It's going to be the derivative of the first part times the second plus the first part times the derivative of the second. +[347.28s -> 355.02s] So let's say the first part, f, we're going to say it's 1 half x. And the second part, g, is y. +[356.08s -> 369.42s] So f prime, the derivative of 1 half times x, is going to be 1 half times the derivative of x, according to the constant multiple rule. The derivative of x is 1, but times dx dt. +[369.65s -> 383.34s] And then we need to multiply by the second part, which is g, and g is y. And then plus the first part, which is not going to change, so that's 1 half x, times the derivative of the second part. +[383.89s -> 389.46s] which is g prime, the derivative of y is 1, times dy 18. +[396.21s -> 405.58s] Now all we need to do is plug in the information that we have. So this is going to be 1 half times dx dt, which is 3. +[405.97s -> 418.64s] And then dy dt, I mean not dy dt, but y, that's 15. And then plus 1 half times x, which is 8. And dy dt is negative 8 over 5. +[418.70s -> 428.98s] And I forgot to write the units for dy dt, so let's talk about that. So what's the units for y? x and y have the units feet. +[429.26s -> 437.84s] And then the unit for time is going to be seconds. So dy dt is feet per second. +[439.44s -> 447.76s] Now let's go back to this problem. So we have 3 times 15, which is 45, and half of that, that's going to be 45 over 2. +[449.33s -> 458.45s] Half of 8 is 4, and 4 times negative 8, that's going to be negative 32. So this is negative 32 over 5. +[458.80s -> 464.46s] So we need to combine these two fractions, and so we have to get common denominators. +[465.42s -> 475.92s] The common denominator between 2 and 5 is going to be 10. So we need to multiply the fraction on the right by 2 over 2 and the one on the left by 5 over 5. +[476.53s -> 489.58s] So what's 45 times 5? 40 times 5 is 200. 5 times 5 is 25. So this is going to be 225 over 10. 32 times 2 is 64. +[490.86s -> 496.78s] And if we subtract 225 by 64, that will give us 161. +[497.17s -> 511.25s] So, DA over DT is going to be 161 over 10, and the units is going to be square feet, because we're dealing with area, per second. So, this is the answer. +[512.53s -> 513.97s] for Part B +[524.78s -> 536.88s] Now let's move on to Part C. Find the rate at which the angle between the ladder and the ground is changing at this instant. So where is the angle between the ladder and the ground? +[537.42s -> 545.36s] So here is the ladder. Here's the ground. Therefore, the angle between that is right here, which we'll call theta. +[546.22s -> 559.31s] Now, we need to relate theta to x, y, or z, and we can use any of the three trig functions, sine, cosine, or tangent. However, one of them I would not recommend using. +[559.66s -> 565.52s] since it involves a lot of unnecessary work. Now, let's review Sokotoa. +[565.97s -> 579.66s] Hopefully, you remember the principles taught in trig. So let's start with so. This tells us that sine theta is equal to the opposite side divided by the hypotenuse. Opposite to theta is y. +[579.66s -> 591.25s] And the hypotenuse, which is across the box, that's Z. That's the longest side. So sine theta is Y divided by Z. Now, Ka tells us that cosine theta... +[591.73s -> 602.61s] is equal to the adjacent side, adjacent to theta is right next to it, that's x, divided by the hypotenuse, z. And toa, tangent theta, +[603.15s -> 617.39s] is equal to the opposite side, y, divided by the adjacent side, x. Now, keep this in mind. x and y are variables because they're changing. z is a constant. +[618.74s -> 632.80s] Now, for sine, you have a variable and a constant. You could simply use the power rule to differentiate that. And the same is true for cosine. You have a variable and a constant. For tangent, you have two variables. And so you need to use the quotient rule. +[632.80s -> 640.66s] if you're going to use tangent theta. And let's avoid the quotient rule, so let's not use tangent theta. I'm going to use sine theta. +[650.90s -> 665.33s] So sine theta is equal to the opposite side of theta divided by the hypotenuse. So I'm going to rewrite y over z as 1 over z times y. +[666.58s -> 674.26s] So you can see what we have is a constant times a variable. Now let's differentiate both sides with respect to time. +[674.90s -> 688.24s] So the derivative of sine theta is cosine theta. And then, according to the chain rule, we need to differentiate the inside function theta. The derivative of theta is 1 times d theta over dt. +[689.62s -> 701.01s] Now let's use the constant multiple rule. So the derivative of a constant times y is going to be the constant times the derivative of y, which is 1 times dy dt. +[702.77s -> 704.82s] Now, what is cosine theta? +[705.36s -> 719.06s] If you recall, we said that cosine theta is equal to the adjacent side, which is x, over the hypotenuse z. And we have x. x is 8 and z is 17. So therefore, cosine theta... +[719.06s -> 729.30s] is 8 over 17. Our goal is to calculate the rate at which the angle is changing. So we need to calculate d theta dt. +[729.71s -> 742.00s] Z, we have that, is 17. And dy dt is negative 8 over 5. So now let's multiply both sides. +[746.19s -> 748.21s] 17 over 8 +[751.02s -> 761.42s] If we do so, notice that the 8s on the left cancel and on the right will cancel. And at the same time, the 17s will cancel on both sides. +[763.28s -> 775.76s] So just by doing that simple move, we have the answer. So the only thing that's left over is d theta dt. And as we can see, it's equal to negative 1. +[779.18s -> 793.26s] over 5. And that's it. So that's the answer for part c. d theta dt is negative 1 over 5. And let's talk about the units. The unit for d theta dt +[793.90s -> 800.91s] So the angle is in radians, and the time is in seconds. +[802.93s -> 809.74s] And that concludes this lesson. So that's it for this video. Thanks for watching. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_17.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_17.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ecd9cf6a681e36103e6d8a59d09305b864ccff7f --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_17.mp4.txt @@ -0,0 +1,35 @@ +[4.82s -> 19.36s] As always, please pause the video and try the question on your own before moving on. In this question, we are trying to minimize the amount of time it takes for a woman to go across the lake on the boat to point B and then travel by foot over to point C. +[19.36s -> 31.89s] In order to minimize her travel time, it's actually going to be useful to first look at the distances that she's traveling. From A to B, we can represent that distance as just D1 and from B to C, we can represent it as D2. +[31.89s -> 46.42s] And now at this point, a little high school geometry is going to kick in here. What we're going to do is draw a line from BC. And the reason that we do that is because we're going to end up forming a right triangle. We recall from high school geometry that in a circle, if you have... +[46.42s -> 59.18s] an inscribed angle, that's just an angle that touches the edge of the circle. If that inscribed angle is formed with a diameter of the circle, then the angle is 90 degrees. So we do indeed have a right triangle here. +[59.18s -> 72.02s] And since we have a right triangle, all the trigonometric ratios apply. One that's particularly useful here is the cosine. Now of course the cosine of an angle is equal to the adjacent over the hypotenuse. If we look at the right triangle that we just formed, +[72.02s -> 86.42s] In relation to theta, we can see that the adjacent side is marked as d1, and the hypotenuse would be 4 miles. So we can fill those into the cosine. We can easily solve this equation for d1 by multiplying both sides by 4. +[87.15s -> 101.74s] We'll hold on to this representation of D1 and come up with a representation for D2. Now we'll notice that D2 is a curved distance. It's an arc length from B to C. We know that arc length is equal to the radius times an angle. +[101.74s -> 115.90s] The only thing we have to watch out for is that angle. Of course, this right here is marked as theta. We recall from geometry that when you have an inscribed angle that's marked theta, then the arc that it intercepts is actually two theta. +[115.90s -> 129.87s] That's another idea from high school geometry. So, plugging into the arc length formula, we would have the radius of the circle, which was 2 miles, multiplied by the angle that the arc length is represented by, and that, again, is 2 theta, and therefore... +[129.87s -> 143.76s] we get 4 theta for the arc length from B to C. We've called that D2, so in essence, D2 is equal to 4 theta. Now, you might be asking, why do we need representations of the distances? We're trying to minimize the time. +[144.37s -> 158.27s] Well, we recall from perhaps a physics course that time is equal to a distance divided by a speed. So we can come up with an expression for t1, which was the time required to go across the length, by just plugging in that distance. +[158.27s -> 163.86s] D1 over the speed of the woman going across the lake. Now that speed was stated +[164.27s -> 174.22s] as being two miles per hour. So we can plug that in for the speed going across the lake. Remember that D1 was four cosine theta, so we can actually make a replacement here, a substitution. +[175.09s -> 180.02s] And then we can simplify this just a little bit by dividing numerator and denominator by 2. +[180.59s -> 191.41s] So we are left with an expression that represents the time required to go across the lake in the boat We're going to do the same thing for the time required to go along the arc length by foot +[191.44s -> 205.20s] We'll call that time T2. Recall that the distance of walking from point B to point C along the shore was 4 theta. And then the speed that the woman walks with was given to us as 4 miles per hour. +[205.58s -> 216.40s] Now of course this simplifies to just theta. So here is a representation of the time to walk along the arc length. The total time would just be these two times added together, so we can write that out. +[217.10s -> 231.66s] So here is the total time function. We basically have time as a function of the angle equal time 1 plus time 2. Now that we finally have a simplified equation in terms of just one variable, we can proceed in optimizing it. And to do that, we take the derivative. +[232.30s -> 245.87s] Now the derivative of 2 cosine theta will be negative 2 sine theta and then the derivative of theta will just be 1. We can then set the derivative equal to 0. We'll subtract 1. +[246.99s -> 254.67s] Then divide by negative 2 and so now we have the sine of theta equals 1 half. Now it turns out there are two solutions to this equation. We can have +[255.41s -> 266.88s] 30 degrees or 150 degrees Certainly 150 would be too much because if we had an angle that projected out to 150 degrees Then it would look something like this and that would be well +[266.88s -> 276.34s] outside of the bounds of even the circle. So we can confidently reject 150 degrees. We still have to make sure that this angle indeed creates a minimum amount of time. +[277.01s -> 287.50s] And to do that, what we have to do is test the time required at the end points of our interval and also at this critical number. So for example, +[287.50s -> 298.03s] We have the following interval here. The smallest that theta could be would be 0 degrees. The largest, as noted earlier, that it could be is 90 degrees. And then we have a critical number here at 30 degrees. +[298.35s -> 311.71s] Now to find out which one of these values leads to the absolutely minimum amount of time required to travel around the lake, we just plug them in for theta into the time equation. So for example, +[311.71s -> 323.50s] T of zero degrees or zero radians comes out to two hours. T of 30 degrees or pi over six comes out to approximately 2.25 hours. +[324.11s -> 332.32s] And T of 90 degrees, or pi over two radians, comes out to approximately 1.57 hours. Well, +[332.32s -> 340.14s] we're trying to minimize the time that it takes for her to reach her destination. So we can actually see that the correct answer, the correct angle, +[340.14s -> 350.69s] that we should have is the pi over two radians, or 90 degrees. Let's understand what this means in terms of the question by referring back to the picture. So in the original picture, this angle +[350.69s -> 365.07s] doesn't look like 90 degrees in fact it isn't 90 degrees in order to make it 90 degrees we would have to open it up a little bit so let's say we open it up about that much okay that's still not 90 degrees but we're getting closer so she would row her boat across this much of the lake and then she would get off and then walk the rest of the way +[365.07s -> 378.14s] to point C. Well, that wasn't the correct angle, right? This is still a little bit less than 90 degrees. So we'd have to open it up just a little bit more. So perhaps that would look like this if we try to make this angle 90 degrees. She would have to row just a little bit. +[378.14s -> 384.05s] across the lake get off the boat and then walk the remaining portion of the distance all the way to point c +[384.05s -> 398.35s] That angle right there would be the theta, but it's still not quite 90 degrees. The point is, as we open up the angle more and more to try to get to 90 degrees, she's essentially not going to have to go across the lake at all. She's simply going to walk around the perimeter. +[398.35s -> 409.68s] get to point C. And so the correct answer here is having the woman just walk around the perimeter of the lake in order to get to point C. She doesn't have to row at all. An interesting result. +[411.47s -> 420.56s] Thanks again for taking the time to watch this video. If you like it, please subscribe and feel free to send your own question to the following email address and stay tuned for diff --git a/VideoMMMU_ASR_large/Science/validation_Math_18.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_18.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..b9f7c68e07fd7d00d3a7fe48d748f77b475753cf --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_18.mp4.txt @@ -0,0 +1,24 @@ +[0.34s -> 6.48s] In this video, we're going to take a look at how to create a spanning tree using a breadth first search. +[7.06s -> 15.74s] So how will a breadth-first search differ from a depth-first search? Well, if you'll recall, on our last video, we started with +[15.74s -> 30.06s] a root node and then we chose the next vertex and went as far as we could go with that particular vertex and in this case for a breadth first search instead we are still going to add +[30.06s -> 42.35s] whatever our root node is going to be. But then we're going to add all edges incident to that vertex. So in this case, I would add AE. +[42.83s -> 57.52s] and AB. I would add those edges. So I'm going to add B and E to my directed rooted graph, which is of course how we're going to look at the spanning subgraph. +[58.42s -> 72.64s] So starting at a I would connect to B and E now the important thing here is that we have to have some order So you can go with alphabetical order or you can have whatever other order you choose +[72.64s -> 82.99s] But the reason that this is important is I'm going to actually add an edge that wasn't originally in our graph to demonstrate how the algorithm might fail. +[82.99s -> 95.22s] So if I don't have an order, as we can see, E connects to C and B connects to C. And those are my two vertices that I'm dealing with. So the question is. +[95.22s -> 105.74s] According to the algorithm, should B be the one that connects to C or should E? So if you have an order and say, I'm going to use alphabetical order. +[105.74s -> 115.02s] then it's clear to the algorithm that we're going to be starting from B. So from B, I'm going to connect to both C and D. +[118.22s -> 130.67s] And now I've reached each of the vertices in my spanning tree. Whereas if there was no order, it would not be clear should E connect to C or should B connect to C. +[131.70s -> 146.02s] This question may look familiar as we did it in our last video, but we were using a depth-first search rather than a breadth-first search. So we're going to go ahead and do the exact same example, just using a different +[146.02s -> 158.61s] algorithm so this algorithm says we're going to start at a and we're going to connect all of the vertices that are adjacent to a so that would be b and c +[158.99s -> 166.64s] F and I am going to use alphabetical order as my order so I've now connected B and F +[166.64s -> 175.34s] and c again order is important order says now starting from b what can you connect to so i'm going to connect to d +[176.66s -> 189.07s] And I'm not going to continue from D. I'm now going to move over to C. So what can I connect to from C? Well, obviously, I can connect to F, but I'm already there. So I'm going to connect to G. +[189.07s -> 204.05s] So from C, I'm going to connect to G. And from F, I'm going to connect to E. So that is what my breadth-first search spanning tree would look like. +[205.04s -> 216.85s] Here's one last practice for you to try on your own using a breath first search. When you are ready, press play to see how you did. So again, I will start with A. +[218.13s -> 232.27s] And where you start is sort of arbitrary, but we'll start with A. A connects only to one other vertex, which is C. So now I've visited both A and C. C connects to two vertices. +[232.27s -> 235.15s] B and E. +[237.01s -> 248.66s] And so now I've visited both B and E. B doesn't have any other vertices adjacent to it, so E is going to connect to both D and F. +[252.82s -> 266.80s] Again, I'm going to use alphabetical order as my guide. So from D, I can connect only to F, which we've already visited. So I'm now going to branch off of F to visit both G and H. +[270.22s -> 280.43s] G can only connect to H, which has already been visited, so H will connect to I. And that is my spanning tree. +[281.94s -> 296.37s] Up next, we're going to take a look at minimum spanning trees. So these would be a spanning tree for a graph that is weighted with costs or times or so forth. We'll start with Prim's algorithm. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_20.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fa3f80455b451e07c07434a29958844744096712 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_20.mp4.txt @@ -0,0 +1,32 @@ +[0.00s -> 11.44s] Prim's algorithm for minimum spanning tree. Now before we go into the steps of Prim's algorithm, let's first understand what is a minimum spanning tree. +[11.86s -> 25.84s] so given a graph a minimum spanning tree is going to be a subgraph such that all the vertices in the original graph exist in this subgraph the subgraph is connected +[25.84s -> 40.11s] and that there are no cycles in the subgraph. So essentially we are going to construct a tree out of the vertices and edges in the graph such that we cover all the vertices. +[40.66s -> 51.86s] why do we call it minimum spanning tree because the edges we include we want the summation of the weights of those edges to be minimum +[52.56s -> 56.27s] So with this in mind let's take a look at an example. +[96.91s -> 102.13s] so this is going to be the graph that we want to construct the minimum spanning tree for +[105.30s -> 116.08s] So let's see what Prim's algorithm is going to do. The first step in Prim's algorithm is going to be to choose an arbitrary start vertex. +[124.08s -> 137.52s] Let's say I am going to start at A. Now in Prim's algorithm what we are going to do is we are going to keep including +[140.08s -> 154.10s] into our MSD connected edges so let's see what are the connected edges to A +[154.90s -> 168.88s] we have one edge here we have another edge and we have another edge now which of these edges will I choose I'm going to choose the minimum of these edges +[172.24s -> 186.35s] So I am going to choose the edge which has 2. Now that I have included B in my graph, what are the connected edges? The edges connected to B are +[197.52s -> 209.23s] Now I will want to include that shaded edge which is of minimum distance. So I am going to include +[209.62s -> 212.53s] This edge which has a distance of 1. +[219.66s -> 225.78s] Now that I have included D, I am going to see what are the connected edges I can get from that. +[228.78s -> 240.02s] Now, given these shaded edges, I am going to select the edge which has not yet been selected and has the minimum distance. That is going to be 2. +[245.17s -> 250.51s] Now that I have included D, I am going to see what are the connected edges to E. +[254.16s -> 266.13s] Now out of these shaded edges I want to pick that edge which has not yet been included and is the minimum distance. I see that I have a edge which is 3 here. +[266.90s -> 273.42s] But the question arises, can I add this edge? The answer is no. +[273.71s -> 286.69s] why can i not add the edge of 3 because in our minimum spanning tree we do not want any cycles so if we add the edge of 3 here then +[286.69s -> 295.28s] We will be getting a cycle between D, D and E. So we cannot add these three. +[298.45s -> 309.07s] So apart from this 3, what is the minimum edge? We can see that we have a 4 here. I am going to include this 4. +[315.70s -> 321.39s] Now let's see what are the edges that we can get connected to G. +[328.34s -> 336.66s] Now, out of these edges, which is the minimum edge? We can see that we have an edge of distance 1. So, I am going to insert that. +[340.27s -> 347.70s] Now we can see that out of these edges which have not yet been included which is the minimum edge. +[348.05s -> 358.29s] We have an edge of 4 over here. But can we include that edge? No. Why? Because it forms a cycle. So this 4 cannot be included. +[358.70s -> 370.51s] After that, we can see we have a 5 here. Can we include this 5? No, because that will create a cycle between a, b, g and f. So we cannot include this. +[372.82s -> 379.89s] Now we go to 6. Can we include this 6? Yes, because it doesn't form a cycle. +[383.79s -> 391.15s] and with that we have included all the vertices in our subgraph. +[392.02s -> 403.76s] in minprim's algorithm we choose an arbitrary start vertex when we keep including connected edges provided that it does not form a cycle +[406.38s -> 418.77s] And this connected edge should be the minimum. So this is how Prim's algorithm to find the minimum spanning tree of a graph is going to work. +[419.31s -> 429.97s] we can say that the weight of this spanning tree is going to be 6 plus 4 plus 2 plus 2 plus 1 plus 1 which is going to be 16 +[432.37s -> 436.94s] With that, we come to the end of the working of Prim's algorithm. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_23.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_23.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..ca2f9bac8487a68e1d3a9c73777591f49ecf8e7e --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_23.mp4.txt @@ -0,0 +1,65 @@ +[6.51s -> 16.56s] Hi everyone, Physics Ninja here. In the previous problem I looked at a projectile that was launched horizontally and it calculated how long it was in the air, how far it went, and its speed right before impact. +[16.56s -> 28.34s] I now want to consider the same projectile. I'm going to consider the same cliff in the same setup, except this time I'm going to launch it at an angle. So let's try to calculate our same parameters. So how much time is it in the air? +[28.34s -> 38.13s] how far does it go distance from the cliff and also what's its final velocity so we're going to use the same parameters as before my initial velocity is going to be 20 meters per second +[38.58s -> 51.22s] The angle here, let's give it some arbitrary angle, let's say 25 degrees. And the height of the cliff that I'm launching the projectile from is going to be 15 meters. +[55.73s -> 60.75s] all right so question one is how much time is it in the air so this projectile is gonna do some +[61.62s -> 75.20s] Some trajectory like this. It's going to be in the air quite a bit of time So in order to find this equation we're going to proceed with the same approach We did with the previous case is we're going to look at the vertical motion, right? The reason we want to look at the vertical motion +[75.20s -> 89.20s] If you looked at the horizontal motion, you don't know what its horizontal displacement is by the time it gets here at the bottom, but you do know the vertical displacement. So if you look at our equation describing the vertical position of this projectile, +[89.23s -> 96.34s] The general equation is this one. And I'll go ahead and substitute what the acceleration is. +[96.75s -> 106.90s] So we have something like this. y0 is my initial position. Again, I'm going to take the y equals the 0 position right here down at the bottom of the cliff. +[106.90s -> 118.67s] So that would make that my initial position for this problem is 15, and it's positive 15 meters. Now the next term is the initial velocity. However, it's only the initial velocity in the vertical direction. +[119.28s -> 130.35s] So if you have some general velocity here at some angle, v0, the vertical component of that velocity is this one over here. +[131.12s -> 144.69s] This is my initial velocity in the y direction, which for this problem is pretty straightforward. Simply v0, the hypotenuse, multiplied by sine of 25 degrees. +[147.06s -> 159.34s] And then again, minus 1 half little gt squared. Now my final position here, my final position is when I'm going to be down at the bottom. And this is the final vertical position. So this term here is going to be 0. +[159.76s -> 174.11s] So again, rewriting our final equation here, we get 15 plus 20 times sine of 25. That's 8.5. Check that out in your calculator. I forgot the time here in the first expression. +[174.11s -> 188.34s] minus one half nine point eight t squared. So here's equation one. This is a quadratic equation in time. In order to solve this you have to remember what the quadratic equation is. +[188.94s -> 196.18s] remember minus b plus or minus square root of b squared minus 4ac +[197.20s -> 209.33s] divided by 2a. If you substitute these numbers in your calculator, so c is 15, b is 8.5, and the number a, if you group both of those together, will be 4.9. +[209.39s -> 220.56s] You're going to find at the time for this problem. You're going to get two solutions one of them is positive 2.82 and the other one is negative approximately 1.1 +[220.98s -> 228.78s] Now for all these types of problems when you're dealing with physics, we just throw away this solution. We're really only interested in the positive time. +[229.14s -> 236.21s] So here's the solution 2.82 seconds. That's how much time it takes me to go from the top all the way down here to the bottom +[239.50s -> 245.78s] Alright, our next question is how far does it go? So really all they want to know now is how far does this projectile travel? +[246.42s -> 260.21s] Let's call this distance x. My equation of motion for the x direction, and if you look at the previous video, simply the initial velocity, except this time it's the initial velocity in the x direction multiplied by how much time it takes. +[260.21s -> 272.69s] So this is a pretty straightforward problem. Again, if my original projectile was launched here at some initial velocity v0, which is 20, that would make the initial velocity in the x direction +[273.14s -> 284.62s] This component over here. This would be V zero X which in this case would simply be 20 and that's the adjacent side, so that's cos of +[285.01s -> 298.85s] 25 degrees. You substitute everything in the calculator, I think you get approximately 18.1 meters per second for that initial component. So that makes this problem pretty simple. My distance x that I travel +[298.85s -> 312.94s] is simply my initial velocity, which we just calculated, 18.1, multiplied by the total time. The total time was our 2.82. And this gives you approximately 51 meters. +[314.51s -> 316.21s] So that's it for that part. +[318.35s -> 331.79s] Alright, the final question here is what's the final velocity here? We've calculated both components of the initial velocity, but really what I'm asking for now is what's the final velocity when it's right down here, the instant before it hits the ground? +[332.08s -> 343.95s] All right, it's going at some angle over here. Well, and again, if I draw the same vector kind of down over here to make it a little bit bigger, this here has two components. +[344.66s -> 354.70s] All right, it's going to have an x component, a final x component, the x, and it's also going to have a final y component, which is going to be pointing down. +[355.06s -> 359.98s] Vy so if we're able to find both of those components we've solved the problem +[360.62s -> 375.28s] So let's go ahead and do that. So the x component of the velocity, again, since there's no acceleration in the x direction, it's simply the initial component of the velocity. That's easy. That's our 18.1 that we just calculated, meters per second. +[375.60s -> 386.22s] Now the Y direction is a little bit more complicated because in the Y direction, well initially we calculated it was 8.5, but at the top we know that it's zero and then after it turns around. +[387.38s -> 396.40s] So velocity in the y direction is my initial velocity in the y direction. Then there's the acceleration term, minus little g times time. +[396.75s -> 406.29s] So the first term is positive because it's pointing up. And we're going to take that to be positive. Acceleration is pointing down, so our second term here is negative. +[406.61s -> 421.58s] So all you have to do now is just substitute in the values. We get 8.5, positive, pointing up, minus 9.8, multiplied by the time. Again, the time is 2.82 seconds. That's the time we calculated in the first part. +[421.84s -> 432.37s] So the y component, the vertical component of the velocity for this problem ends up being negative 18.9 meters per second. +[432.78s -> 443.50s] So again, if you want to find the total velocity or the magnitude of the velocity, let's use Pythagorean theorem. Vx squared. +[443.86s -> 452.62s] Plus V y squared just plug and play at this point. We're going to get V is +[455.15s -> 468.98s] substitute our numbers here vx was 18.1 squared plus 18.9 squared we get a final velocity of 26.3 +[469.23s -> 481.58s] meters per second. All right, just to finally define the total vector, now we know what the magnitude is, but if you wanted to find the angle, again, you can use tangent here. +[481.90s -> 493.14s] Tangent of this angle is simply going to be Vy over Vx. So the angle theta is the inverse function. +[496.82s -> 509.10s] And substituting all the numbers in here, we know Vy is 18.9 18.1 for Vx and you get 46.2 degrees +[509.20s -> 522.83s] And again, that's the angle with respect to the horizontal, the way I've defined it here in this triangle. All right, here's one more bonus question. Typically another problem that comes up is what is this maximum height here? +[523.86s -> 533.94s] What is y max? It's kind of two approaches to find this one. The first one is just use our equation for the y position. +[534.77s -> 545.07s] All right, if I just rewrite the entire thing, minus 1 half little gt squared. All right, my initial position, well, my initial position we said was 15 meters. +[546.03s -> 550.74s] plus my initial velocity in the y direction was 8.5. +[552.37s -> 566.22s] Multiply that by the time. And minus 1 half. Little g would take 9.8. And multiply by times squared. Now I'm missing the time, right? If I know the time, I can certainly... +[566.22s -> 578.26s] substitute it in this equation and find the height. But I need to know how much time it takes to get to the top. However, one thing at the top that we know is that the vertical component of the velocity is zero. +[579.12s -> 591.09s] So if we know that, we can use our vertical velocity equation, which looks like this one, minus little g times time. This allows me to find the time at the top. +[591.54s -> 597.71s] So at the top we know it's zero. Let me just remind here. Just write this down +[598.22s -> 611.50s] Okay, I know the initial velocity in the y direction. I know little g I can solve for time. Time for this problem is simply the initial velocity divided by little g. And again, it's only the initial velocity in the vertical component. +[611.98s -> 622.64s] Substitute the numbers in here. We get 8.5 over 9.8. This should give us about 0.87 seconds. +[625.39s -> 640.14s] So all you have to do now is substitute the time back in our equation. And if you do that, what you're going to do, you're going to find that my vertical height as measured from the ground is going to be 18.7 meters. +[643.09s -> 656.50s] Now there's another way of doing this. If you remember, there's another kinematic equation. I'll just do it down here at the bottom. Another kinematic equation was this one. V0 squared plus 2AD. +[658.48s -> 667.25s] And again, in this case here, let's simplify this a little bit. Let me just actually write it as the displacement here is going to be in the y direction. +[667.73s -> 681.36s] And instead of writing the acceleration, let me get rid of that, I'm going to substitute little g. However, if I do that, I also have to put the direction in. So I'm going to put minus 2 times little g multiplied by the vertical displacement. +[681.46s -> 690.74s] Now the velocity again, it's going to be the velocity at the top and the velocity at the top now You got to be careful with this equation the velocity at the top is not zero +[691.09s -> 702.80s] Okay, the velocity at the top, there's still some horizontal velocity over there, right? So at the top, we still have v0x squared. +[703.25s -> 717.74s] This equals to the total initial velocity minus 2 times little g times delta y. You substitute in all our values here. What you're going to find is delta y. +[718.61s -> 731.73s] is going to be equal to 20 squared that's the initial velocity squared minus the initial x component of the velocity and divided by twice the +[732.53s -> 747.34s] Acceleration due to gravity. You substitute in all your values over here, you're going to find that delta y is equal to 3.7 meters. Now it looks different from this one, but remember, in this equation here, it gives us the displacement in the y direction. +[747.60s -> 758.96s] Delta y is really my position minus the initial position. So at the end of the day, we're going to get the exact same answer for my final position. +[759.47s -> 773.20s] Because the initial position here is 15 meters. Delta Y is 3.7. Therefore, the final Y has to be 18.7 meters. So kind of two different approaches to solving the same problem. Thanks for watching. +[773.20s -> 780.43s] If you like the channel, please subscribe. If you have any questions, don't hesitate to leave a comment or send me an email. I'd love to help you out. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_6.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_6.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..bb528d12d881eaffe8733c91c65767f0bf70efa1 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_6.mp4.txt @@ -0,0 +1,27 @@ +[0.27s -> 14.86s] Hello, this is Mr. Kinyanola, and I'm going to help you find segment lengths when you have a tangent line. So, if you didn't see the video on tangent lines and radii, it's just a previous video. +[14.86s -> 28.37s] video i suggest you watch it because it's so fascinating um so uh but if you didn't think it's fascinating then whatever i'm not hurt okay so yeah not hurt so but just watch it again +[28.37s -> 42.80s] And again and again. So find the segment length indicated. So this line right here. Assume that lines which appear to be tangent are tangent. So this line right here, it's telling us that this line is tangent. +[42.80s -> 55.31s] So if you guys remember, when a line is tangent to a circle and a radius intersects that tangent line at the point of tangency where the line... +[55.31s -> 66.62s] touches the circle then the radius and the tangent line are perpendicular. Remember perpendicular means that they make right angles so this is a right angle. +[66.62s -> 80.61s] so what do we have here it looks like we have a right triangle it says find this length right here this is the question mark when we have a right triangle and we have at least information about two sides +[80.61s -> 82.93s] we can use the Pythagorean theorem. +[83.15s -> 95.92s] So let's use a Pythagorean theorem. Remember the Pythagorean theorem is C squared is equal to A squared plus B squared. And the C is the hypotenuse. The hypotenuse is the side. +[95.92s -> 107.62s] that is opposite the right angle here's the right angle and it's looking at the hypotenuse right there so this entire side right here is the hypotenuse +[107.62s -> 115.47s] we're trying to just find this but what's the length of this right here do we have any information about this whole thing right here um yeah so +[115.73s -> 129.62s] The length from here to here is 4 because that's the radius. So the length of this, our information about C, is 4 plus question mark. +[129.65s -> 140.62s] The hypotenuse that we have is 4 plus question mark squared. So this is our C right here. +[140.62s -> 150.99s] and we'll set it equal to a squared which is 4 squared plus 4.2 squared so here's our a +[150.99s -> 164.45s] Here's our B or this could have been your A. This could have been your B. Doesn't matter. And then let's just grab our calculator and start scoring some numbers. So four squared. Well, we don't need a calculator for that. Hopefully not. Four squared is not eight. +[164.45s -> 173.52s] It's 16. But what's this decimal square? So 4.2 squared is 17.65. +[173.52s -> 187.79s] four is equal to so now here you're going to be tempted to do some algebra definitely don't be tempted to distribute the square here and here because that's against algebra rules you'll be tempted to +[187.79s -> 198.51s] You might write four plus question mark times four plus question mark because that's real algebra, but don't do that. So just bring this down. +[199.09s -> 210.86s] okay and let's combine these two like terms so 16 uh so we still have the 17.64 plus 16 which is 33 +[211.31s -> 218.69s] Point six four and we'll bring this down four plus question mark squared +[218.69s -> 232.75s] and we want to get this question mark by itself so i want to get rid first i want to get rid of the square right here what's the opposite of scoring something yeah i heard you you said square root yeah good so we're going to square root both sides +[232.75s -> 241.58s] So the square root of 33.64 is 5.8. +[243.12s -> 257.30s] And so now the square and the square roots or the radical cancel each other out. So we just have four plus question mark. And how do we get that question mark by itself? We subtract four from both sides. So the question mark. +[257.30s -> 267.25s] 5.8 minus 4 is 1.8. There aren't any units, so we're just going to write units. +[267.34s -> 277.60s] That looks like a V, so I'm going to write the word out. So units. So there's your final answer. Question mark is 1.8 units. +[277.60s -> 285.10s] and that's how you find a segment length when you have a tangent line and the radius just remember +[285.10s -> 296.24s] that the tangent line and the radius are always perpendicular. And if they make a triangle, they make a right triangle. So just use a Pythagorean theorem. +[296.24s -> 300.23s] And that's it. I hope that helps. Have a great day. diff --git a/VideoMMMU_ASR_large/Science/validation_Math_7.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..12fcb16c2e04072f3c74d4a70466a29ed559cc16 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_7.mp4.txt @@ -0,0 +1,58 @@ +[0.00s -> 12.03s] This video will be a summary based on all the videos in this series, so please watch all these videos first. But here is a quick recap on the concepts in all these videos. +[12.03s -> 24.78s] In the first chapter, instead of using the standard definition using axioms, we introduce groups as symmetries of objects, which lays the foundation for the entire video series. +[29.26s -> 43.60s] as well as making the concept of group actions easier to understand, because symmetries naturally act on the vertices, edges or faces. Then, we derive the orbit stabilizer theorem +[46.03s -> 55.98s] which states that the size of the orbit multiplying the size of the stabiliser of any element in the set X is the size of the group G. +[55.98s -> 64.58s] Next, we discover the fact that the size of the stabiliser divides the size of the group can be argued in a different way. +[64.58s -> 79.50s] And then we extract the properties of the stabiliser we used to define what a subgroup is. Then we discover Lagrange's theorem, which states that the size of a subgroup divides the size of the whole group. +[80.50s -> 90.38s] Then we introduce the concept of conjugation, and figure out its intuition to be just viewing the symmetry being conjugated in another perspective. +[90.38s -> 96.14s] This allows us to introduce the concept of normal subgroups and simple groups. +[97.65s -> 107.82s] which in turn allows us to define what a quotient group is, which is a group of the cosets where we can define a consistent operation. +[114.70s -> 120.35s] The video also consisted of seeing the concept in different perspectives. +[120.35s -> 130.48s] In the sixth chapter, we then introduce the concept of homomorphism, and then understand the three statements of the isomorphism theorem more intuitively. +[137.46s -> 151.60s] Then finally in the last chapter, we discover that group actions can be thought of as a homomorphism. And we also prove Cayley's theorem as a direct application of this change of perspective. +[156.53s -> 165.23s] With all these recaps done, now we are going to see an example that will use all the concepts that we have seen before. +[165.33s -> 178.98s] Suppose G is a simple group with 60 elements, and H is a subgroup of G. By considering an action of G on the coset of H, show that H cannot have two +[178.98s -> 183.86s] three of four cosets. Let's dissect what this means. +[183.86s -> 197.71s] G being a simple group means that its only normal subgroups are the identity and the group G itself. So whatever we need to do, it would somehow be related to normal subgroups. +[197.71s -> 210.35s] groups. Next, we have the number 60. But the only concepts that we discussed that will involve some sort of numbers are the orbit stabilizer theorem and the Lagrange's theorem. +[210.35s -> 221.81s] because they refer to products of something. For the next line, we just note that subgroup is a concept that we have seen in the third chapter. Nothing too special here. +[221.81s -> 230.24s] The next line is quite special, because it specifically tells us what to do. So this should be a useful starting point. +[230.24s -> 242.58s] Just as a reminder of what a coset is, we have this mental picture of the subgroup and its coset, so the cosets are just the rectangles tiling up the entire group G. +[242.61s -> 256.75s] The last line is what we need to prove. And this result is not immediately obvious either. Apparently, it must have something to do with simplicity, and the number 60 somehow. And we are going to figure out +[256.75s -> 270.77s] how these things are connected. The third line provides us with a starting point, and the line of reasoning would be, what if G is simple with 60 elements, but H has 2, 3 or 4 cosets? +[270.77s -> 283.44s] it should have some contradiction with the theorems that we know, then we can show that H cannot have 2, 3 or 4 cosets. Pause the video if you want to have a go yourself. +[283.44s -> 293.71s] The first step is to consider an action of G on cosets of H, which sounds abstract, but the action we will be considering is very straightforward. +[293.71s -> 303.76s] Again, we consider this mental picture we have for this more abstract action. Each dot represents a coset, including the subgroup H. +[303.76s -> 312.62s] Considering the action of G on these cosets, this simple action will transform any coset to some other coset. +[312.62s -> 319.41s] This action will send H to the coset GH, G inverse H to H itself, and so on. +[320.69s -> 334.42s] So we now have a group action of G on the cosets of H, given by this relation where you just stick a G1 in front. We will then have the corresponding homomorphism, say phi. +[334.42s -> 345.02s] from the group G to the symmetric group on the cosets of H. This opens up the possibility of analysing the group action with the isomorphism theorem. +[345.02s -> 353.98s] The isomorphism theorem states three things once we have a homomorphism between two groups. Let's look at the first statement here. +[353.98s -> 367.04s] It is given that G is simple, which means that the kernel can only be the identity set or the group G itself, because these are the only normal subgroups that G has. +[367.04s -> 372.06s] Now consider the case where this kernel is the entire group G. +[372.06s -> 386.69s] Because the kernel is everything that gets mapped to the identity, and in this case, the identity of the symmetric group of the cosets of H would be the identity permutation, which is the permutation where everything stays fixed. +[386.69s -> 396.75s] If the kernel is the entire group G, then for all G in the group, the corresponding permutation would look like this, not moving anything. +[396.75s -> 409.90s] To show this is not possible, consider G acting on H. H would be sent to GH. Now this isn't done yet, because sometimes GH would be the subgroup H itself, +[409.90s -> 415.41s] like when G is actually a member of the subgroup H. But this cannot happen for +[415.41s -> 427.60s] all G inside the entire group, because the only case when all elements of the group G will send H to itself is that there is only one coset to begin with. +[427.60s -> 440.99s] Since our line of reasoning is to assume that H has two, three or four cosets and see what happens, this case when kernel of V is the entire group G is not possible. +[440.99s -> 452.77s] Back to where we were a minute ago. All the discussion just now shows that the kernel can only be the identity set. Next up, we can use the second statement here. +[452.77s -> 464.29s] Since it uses the concept subgroup, we are going to use Lagrange's theorem, which states in this context that the size of the image divides the size of the symmetric group. +[464.29s -> 476.62s] Lastly, from the last statement, all we need to use is the fact that isomorphic groups must have the same size, because the isomorphism has to be 1 to 1. +[476.78s -> 488.56s] then recall from the quotient group video where I explained why it is called a quotient group. The size of the quotient group is just a quotient of the sizes. +[488.56s -> 501.74s] this also just comes directly from Lagrange's theorem. So that means in the last statement, we have the size of the quotient group to be the size of G divided by the size of kernel. +[501.81s -> 515.81s] Since the group has size 60, and the kernel is just the identity set, the size of the image can then be just calculated as 60. So in this second implication that we draw, +[515.81s -> 525.39s] we can replace the size of the image as 60. So far everything is good, but this implication here will be the main punchline. +[525.39s -> 538.90s] Let's rewrite this bit here at the top. The only mystery that we need to tackle is the size of the symmetric group. Let's do this in general. If we want to find out the size of the symmetric group of n things, +[538.90s -> 552.08s] then the first thing under consideration can be put in n different places, including the option to not move. Then, the second thing can be put in n-1 different places, and so on. +[552.08s -> 562.18s] This means that the size of the symmetric group, that is, all the permutations of n things, would be n times all the way to 1. +[562.18s -> 574.08s] because the first thing has n places for choice during permutation, and the second thing would have one fewer choice, and so on. So we apply the result we just discovered. +[574.08s -> 585.97s] If we have only two cosets of H, the size of the symmetric group would be 2 times 1 equals 2. This is not possible because 60 does not divide 2. +[585.97s -> 599.74s] What if there are 3 code sets of H? The symmetric group would then have size 6. Not possible. In a similar fashion, if there are 4 code sets, 60 still does not divide the size of the symmetric group. +[599.74s -> 603.95s] which completely proves the result that we need to show at hand. +[603.95s -> 616.70s] I know that this proof is rather involved because it covers most of the concepts that we have covered in this video series, so feel free to replay the entire proof and pause when necessary. +[616.70s -> 627.89s] If you are ready for some more, it can be shown that there is only one group up to isomorphism that is simple and has 60 elements. The proof of this is way +[627.89s -> 639.18s] way beyond the scope of this video series, but we can show what this group structure looks like. It is precisely the group of rotational symmetries of an icosahedron. +[639.18s -> 653.26s] To link to really all the concepts we have covered, try using the orbit stabiliser theorem to see why this group has 60 elements, and use the intuition of conjugation to see why this group is simple. +[653.26s -> 666.27s] Great thanks to all your support to this group theory video series, and I really hope that you can grasp the intuition to aid your learning, whether you are studying or about to study this interesting field of mathematics. +[666.27s -> 673.33s] If you enjoyed this video, give it a like and subscribe to the channel with notifications on. See you next time! diff --git a/VideoMMMU_ASR_large/Science/validation_Math_9.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Math_9.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..fd3d2466005d6130e043dbc1c3002bc46ca38f02 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Math_9.mp4.txt @@ -0,0 +1,61 @@ +[0.00s -> 14.51s] What are Hamiltonian cycles in graph theory? That's what we'll be going over in today's Wrath of Math lesson. We'll also talk about Hamiltonian paths and Hamiltonian graphs. You might already be familiar with a similar concept. +[14.51s -> 24.88s] of an Euler circuit, which is a circuit that contains every edge of a graph. A similar question you might ask is if a graph has a cycle +[24.88s -> 37.90s] that contains every vertex of the graph. Such a cycle is called a Hamiltonian cycle. That's what we'll be talking about today and we'll begin by looking at a graph and an example of a Hamiltonian cycle. +[37.90s -> 52.38s] So here's a beautiful graph. I've labeled its vertices A through D. So does this graph have a Hamiltonian cycle, a cycle that contains every vertex? Indeed it does, and you might be able to see one yourself. +[52.38s -> 64.94s] Let me draw one. We could start at the vertex A, and then go to the vertex C, then to the vertex D, then to B, and then back to A, where we started. +[64.94s -> 70.58s] This is a Hamiltonian cycle, a cycle that contains every vertex of the graph. +[70.61s -> 85.20s] When we're talking about simple graphs, cycles are most easily defined as sequences of vertices where consecutive vertices are adjacent and no vertices are repeated except for the first and the last, which are +[85.20s -> 99.01s] equal so let's write out this hamiltonian cycle as a sequence of vertices we start at a then we go to c then we go to d then we go to b +[99.01s -> 113.36s] and then we return to A where we started. So that is an example of a cycle. Now for a cycle like this to be Hamiltonian, the sequence has to contain every vertex of the graph. In this case, +[113.46s -> 123.18s] Of course, it does. AA, CC, DD, B, and then we go back to A. We've got every vertex of the graph in that Hamiltonian cycle. +[123.18s -> 132.61s] If a graph has a Hamiltonian cycle, you might be able to guess. We call it a Hamiltonian graph, or simply a Hamilton graph. +[132.61s -> 145.84s] So this is a Hamiltonian graph. If you want to prove a graph is Hamiltonian, you've got to prove that it has a Hamilton cycle. A cycle like this, that contains every vertex of the graph. +[146.19s -> 159.02s] Something interesting you might notice about a Hamiltonian cycle is that if we delete an edge from the cycle, we're left with a neat sort of path. Let's say we delete this edge here. +[159.60s -> 174.22s] Now we've got a path going from D all the way to C. Let's write that out also as a sequence of vertices. We go from D to B to A to C. This +[174.22s -> 186.13s] is a path that contains every vertex of this graph. Such a path as you might be able to guess is called a Hamiltonian path. So this is a Hamiltonian path. +[186.22s -> 197.73s] Whenever we have a Hamiltonian cycle, we can create a Hamiltonian path by deleting one edge from the cycle. The converse is not necessarily true. +[197.73s -> 204.91s] If we have a Hamiltonian path, we may or may not be able to find a Hamiltonian cycle in that graph. +[205.17s -> 214.45s] Here's a very simple example. Any path graph will do. Let's look at the path graph on four vertices. This path graph +[214.45s -> 223.02s] clearly has a Hamiltonian path we could go from if we label these vertices go from vertex 1 to 2 to 3 +[223.02s -> 237.41s] to 4. And that's a path in the graph that contains every vertex. However, there's no Hamiltonian cycle in that graph. Once we get to vertex 4, there's no way that we're going to get back to where we started. +[237.41s -> 242.69s] without passing through vertices and edges multiple times which isn't allowed. +[242.69s -> 256.29s] So if we have a Hamiltonian path, we may or may not be able to get a Hamiltonian cycle in that graph. But if we have a Hamiltonian cycle, we can delete any one edge and end up with a Hamiltonian path. +[256.29s -> 263.09s] Now we mentioned Euler circuits earlier and there is a very nice necessary and sufficient condition +[263.09s -> 277.25s] to know if a graph has an Euler circuit. A graph has an Euler circuit if and only if every vertex in the graph has an even degree. There's no super handy condition like that for Hamiltonian graphs. +[277.25s -> 291.06s] But of course we can talk about some necessary conditions and we could talk about some sufficient conditions. We'll talk about some necessary conditions for a graph to be Hamiltonian in this lesson. So these are conditions that +[291.06s -> 300.56s] If a graph doesn't meet them, then it's not Hamiltonian. If a graph does meet them, it might be Hamiltonian, but we don't know. So let's talk about some. +[300.72s -> 307.97s] One very obvious necessary condition for a graph to be Hamiltonian is that it has to be connected. +[307.97s -> 319.50s] If a graph is disconnected, there's no way it's going to contain a cycle that contains every vertex of the graph, because there's going to be some vertices in another component that you can't get to. +[319.50s -> 331.81s] Another less obvious condition for a graph to be Hamiltonian is that it cannot have any cut vertices. Remember that a cut vertex is a vertex that when deleted +[331.81s -> 345.17s] disconnects its graph so to see why it's necessary that a graph has no cut vertices in order for it to have any chance of being hamiltonian let's come over here and draw a quick diagram +[345.17s -> 359.79s] So suppose we have a graph that has a cut vertex Then we can draw it kind of like this there's some piece of the graph over here and there's some piece over here and they're connected only by +[359.79s -> 373.60s] this cut vertex there might even be you know multiple edges going to that cut vertex but if you delete that vertex cuts the graph leaving two components behind a graph like this certainly cannot be +[373.60s -> 385.89s] Hamiltonian because at some point you're going to have to pass through this cut vertex to get to one piece of the graph and then you're not going to be able to get back to where you started. +[385.89s -> 400.18s] without passing through that vertex again if you start in this piece you're going to have to pass through the cut vertex to get here and then you'd have to pass through it again to get back and that's not allowed if you start at the cut vertex +[400.18s -> 414.16s] and go to either one of the pieces you're going to have a similar problem. So it's another necessary condition a graph needs to have no cut vertices to have any chance of being Hamiltonian. Let's mention one other condition. +[414.16s -> 426.42s] for a graph to be Hamiltonian, one other necessary condition. And actually, before I write out this condition, let's see it in action in this graph here. Let me erase those blue lines. +[426.54s -> 440.80s] And then I'm going to erase this edge that joins A and C. Now what I've just done by erasing that edge is I've reduced the degree of A from 2 to 1. So here's a problem. In a cycle, +[440.80s -> 445.81s] every vertex has to have degree two you got to have one edge going to the vertex +[445.81s -> 457.49s] I say going, you know, informally because we're not talking about directed graphs. But you have to get to a vertex and then you have to leave it and you can't go back. So in a cycle, each vertex has degree two. +[457.94s -> 465.84s] Vertex A in this graph has a degree of 1, so there's no way it's going to be part of a cycle in this graph. +[465.84s -> 473.23s] Thus, there's no cycle in this graph that contains A, and thus there's no Hamiltonian cycle in the graph. +[473.23s -> 483.60s] A vertex with degree one is often called an end vertex or a leaf if we're talking about tree graphs. So this gives us another necessary condition. +[483.73s -> 495.47s] Another necessary condition for a graph to be Hamiltonian is that it can have no vertex v with a degree less than 2. If it has a degree of 1, we've got this situation here. +[495.47s -> 508.78s] If a vertex has a degree of zero, then either the graph is disconnected, which we know is not allowed for it to be Hamiltonian, or it's a trivial graph with just one vertex, which clearly has no cycles. +[509.07s -> 522.48s] So let's quickly, before we go, see a couple examples of families of graphs that are always Hamiltonian. One really obvious one, perhaps the most obvious one, is the family of cycle graphs. +[522.48s -> 532.80s] So here's the cycle graph on three vertices. This very clearly has a Hamiltonian cycle. Go from here to here to here to there. Easy. +[532.80s -> 541.74s] Same thing with if we draw another cycle graph, say the cycle graph on five vertices. Cycle graphs, by their definition, are very clearly +[541.74s -> 552.30s] Hamiltonian. You can find a cycle in this graph that contains every vertex. Now certainly if a graph is Hamiltonian and we add edges to it +[552.30s -> 565.62s] the resulting graph will still be Hamiltonian because whatever Hamiltonian cycle was there before will still exist. Now this leads to the result very easily that all complete graphs +[565.62s -> 577.84s] with at least three vertices are Hamiltonian. Let's add edges to this cycle graph to make it a complete graph. So here's a complete graph on five vertices and you can see clearly +[577.84s -> 589.84s] It's still a Hamiltonian graph because the cycle that was there before is still there. Let me know in the comments if you can think of any other families of graphs that are always Hamiltonian. +[589.94s -> 604.32s] Also let me know if you can think of any more necessary conditions for a graph to be Hamiltonian. It can be as simple and obvious or as complex as you want. I'd be interested to see what you come up with. Now before we go, let me just leave you one... +[604.32s -> 619.26s] example exercise. Oh, and also, I mentioned earlier there are some sufficient conditions as well for a graph to be Hamiltonian. These are conditions that if a graph meets them, we know it's Hamiltonian. But if a graph doesn't meet them, +[619.26s -> 627.70s] we don't know that it's not Hamiltonian. So I'll go over some of those in another lesson. One of them is called Orr's theorem which I'll hopefully have a proof +[627.70s -> 634.67s] I'll have a proof on that theorem out pretty soon. So I hope you'll subscribe so you don't miss that. Now let's see this example problem. +[636.14s -> 649.66s] So here's the question. KMN is the complete bipartite graph where one partite set has M vertices and the other partite set has N vertices. So the question... +[649.66s -> 658.66s] is what must be true about m and n in order for this complete bipartite graph to be Hamiltonian. +[658.66s -> 673.23s] So let me know what you think and justify your response. And you can even write a proof if you want. Let me know down in the comments and I will of course leave an explanation in the description. So I hope this video helped you understand Hamiltonian cycles, graphs, and paths. +[673.23s -> 685.15s] Let me know in the comments if you have any questions, need anything clarified, or have any other video requests. Thank you very much for watching. I'll see you next time, and be sure to subscribe for the swankiest math lessons on the internet. +[685.15s -> 698.00s] And a big thanks to Valo who, upon my request, kindly gave me permission to use his music in my math lessons. Link to his music in the description. +[702.32s -> 711.73s] Too close to be a cop You were so diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_11.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_11.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..8ece63349fb8d13a36372bf6dbba3dd560c54aa1 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_11.mp4.txt @@ -0,0 +1,27 @@ +[5.10s -> 18.22s] Number 73, find the minimum thickness of a soap bubble that appears red. When illuminated by white light perpendicular to its surface, take the wavelength to be 680 nanometers and assume the same index of refraction as water. +[18.22s -> 33.12s] All right, so please review number 71. Talked in detail about this thin film interference, how to think through it, what's going on. Now we're going to start running through, let's say, formulas. All right, so we know that our constructive interference here. +[33.12s -> 44.27s] formula for a thin film interference is this it's going to be equal to two multiplied by the thickness of the film is going to be then a function of basically the wavelength +[44.27s -> 57.57s] in a particular medium, in this case in the soap, divided by then two, or it could have been three halves, basically the wavelength, or it could have been five halves, right? Bah, bah, bah, bah, bah, bah, bah, bah, bah. So... +[57.57s -> 69.42s] what we need to do is we need to find the minimum thickness so basically you can set this equal to this or you can set this equal to this or you can set etc etc now if you notice +[69.42s -> 77.30s] In order to find the minimum of the TC, in order to find the minimum thickness, that gives us constructive interference, by the way. +[77.30s -> 87.66s] should give us then the smallest value on the right-hand side. Now, is this 1 half smaller than 3 halves? Yes. Is then that smaller than 5 halves? Yes, etc. +[87.66s -> 98.38s] So the smallest thickness here will correlate with this first part. In other words, 2 multiplied by the thickness of the film to produce constructive interference should be equal to then the wavelength. +[98.38s -> 111.81s] of the light in the material in the soap divided by two. Now, to find the thickness, this is simple algebraically, this is just a wavelength in the film divided them by four. +[111.81s -> 126.00s] But the thing is, what's the wavelength in the film? Well, if you're seeing red light, that's not the wavelength in the film. That's the wavelength in air. Your eye's in air, unless the soap bubble's in your eye, right? So the... +[126.00s -> 137.84s] wavelength that was given here the 680 nanometers all right is going to be the wavelength in air and again check out number 71 for the concept +[138.48s -> 150.67s] Now, I don't want to know the wavelength in there. I can't plug it in. I've got to plug in the wavelength in the medium, in the soap. So I need to use this formula over here on the upper right-hand side. This says that the wavelength in, let's say, the soap. +[150.86s -> 163.95s] is equal to then the wavelength in a vacuum. Now remember the wavelength in a vacuum is very similar to the wavelength in air because the indices of refraction there are basically one. They're both one, right? Basically. So... +[163.95s -> 176.32s] Divide that then by the index of a fraction of that particular medium. And in this case, that almost looks like soup, right? I'm just looking at it. Soap. Not soup. Soap. +[176.32s -> 189.55s] Mmm, soup sounds good right now. You're like, what? What are you, 98? Anyway, the index of refraction of soap goes down here. All right? So what we need to do now is we need to basically just... +[189.55s -> 193.52s] Plug in the values, right? So this, the wavelength and the soap. +[193.52s -> 206.58s] is going to be equal to the wavelength in air of 680 nanometers. By the way, I'm going to leave it in nanometers, all right? And it told us the index of refraction of the water here, which is the, assume that that is what the index of refraction of the soap is. That's going to be 1.333. +[206.58s -> 219.22s] Right, roughly. So just take the 680, divide it by then 1.333, whatever, or 2, it doesn't matter. The wavelength of then the soap, the wavelength of the light in the soap. +[219.82s -> 227.87s] This is going to equal about 510 nanometers. Now, careful. Write your answers in nanometers. That's okay. That's okay to plug it in, but... +[227.87s -> 242.19s] Just be aware of what units you're using. So now what we're going to do is we can finally now plug in this 510 divided by 4. I'm using the exact value in the calculator. I'm going to divide that exact value by 4. So this works out to be about 127. Now I think it's going to matter. +[242.19s -> 253.74s] by the way, possibly in terms of the rounding, if you went out to, I went out to, in my calculator, I put an extra three here. But let me see if it does make a difference. So 680 over 1.33, then divide that then by four. +[254.06s -> 266.83s] So fortunately it actually won't matter so this still should work out to be about 128 All right, and that's in terms of now nanometers. So that's the minimum thickness of the film. All right in order +[266.83s -> 277.44s] for when light is incident perpendicular to the surface for your eye to detect red. Again, check out number 71 for the concept. Guys, thanks for tuning in. I appreciate it very much. +[277.44s -> 286.19s] Please, if you can help us out, that'd be awesome. Subscribe, like, all right? Maybe even mention us to your classmates if you can. And by the way, we're also covering a lot of other subjects. +[286.19s -> 299.92s] So keep this in mind if you're taking chemistry or precalculus or calculus or biochemistry or statistics. All right. Because we've got a lot of stuff out there solving specific problems. All right. And we usually go through the OpenStax book. +[299.92s -> 313.92s] So, even if you're not using the book, guess what? The problems are basically the same thing in all the textbooks. So, we solve specific problems. I guarantee if you take a look at the book, go to OpenStax, it's free. Download the book, find a problem that is similar to yours. We'll have a video out there for you. +[313.92s -> 319.50s] And then you'll be able to figure out your specific problem. Guys, thanks again. See you soon. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_12.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_12.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..325d77e17707040467505cbaf8131770ec18530c --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_12.mp4.txt @@ -0,0 +1,29 @@ +[1.42s -> 12.27s] What is charging by induction? What is that exactly? Before we answer that question let's talk about charging by conduction. +[12.91s -> 21.17s] so let's say if we have a metal sphere and We have a rod that's charged +[22.86s -> 36.88s] Let's say this is negatively charged and the metal sphere is neutral Now once we bring the metal sphere in contact with the negatively charged rod +[37.65s -> 51.09s] the metal sphere is going to be charged by conduction. Some of the electrons in the metal rod, they're going to move to the metal sphere. And once we separate them, +[53.01s -> 65.94s] the metal sphere will have a net negative charge. So that's charging by conduction. In order to charge an object by conduction, +[67.12s -> 82.00s] the two objects must be in contact. If the two metal objects don't make contact, then you can't charge by conduction. Now, when charging by induction, no contact is involved. +[82.83s -> 96.27s] particularly with a charged object. So this time, the metal rod, it's not going to touch the metal spheres. Now these two metal spheres, initially they're in contact with each other, but they're neutral. +[97.17s -> 108.18s] Once we bring the negatively charged metal rod closer to the first metal sphere, what's going to happen is the electrons in these two metal spheres +[108.46s -> 117.49s] They are going to be repelled by the electrons in the metal rod So the electrons are going to move away from the metal rod +[118.00s -> 124.50s] So what's going to happen is on sphere number two, it's going to develop a net negative charge. +[125.07s -> 137.30s] As for sphere number one on the left, because electrons are leaving that sphere, it's going to develop a net positive charge. Now let's say... +[137.94s -> 151.63s] We take this sphere and move it to the right so we disconnect these two metal spheres and then afterward Once we disconnect them, let's remove the negatively charged metal rod +[152.75s -> 167.66s] Once we do that, the sphere on the left is going to have a net positive charge. The sphere on the right is going to have a net negative charge. And so that is charging by induction. +[168.21s -> 182.13s] We were able to charge these two metal spheres using another charge object, but there was no contact involved between these two metal spheres and the negatively charged +[182.13s -> 196.85s] metal rod so that's charging by induction it's when you have a charge object and you use it to induce a charge in another object without the charge object touching the neutral object +[199.25s -> 206.64s] Now let's consider another example, so let's say we have a neutral metal sphere +[207.92s -> 217.39s] just like before but this time we only have one metal sphere not two and we're going to have a negatively charged metal rod +[219.28s -> 231.47s] Now as we bring this negatively charged metal rod closer to the metal sphere The electrons in the metal sphere they are going to be repelled and so they're going to move to the right +[232.50s -> 242.16s] So on the right side, we're going to have a buildup of negative charge on the left side. It's going to be electron deficient. So the left side is going to have positive charge. +[243.63s -> 255.36s] Overall, the metal sphere is still neutral, but notice that we have separation of charge. One side is positive, the other side is negatively charged. So at this point, it's said that +[255.36s -> 268.50s] It can be said that the metal sphere is polarized due to that separation of charge. Now, what we're going to do at this point is we're going to take a metal wire. +[269.14s -> 272.82s] and attach it to the right side of the metal sphere. +[274.42s -> 288.11s] Now this metal rod is still on the left side so now these electrons they have somewhere to go Because they're still being repelled by the negatively charged rod What's gonna happen is they're gonna move? +[288.88s -> 298.74s] away from the metal rod and to the ground or to the earth. Now, once we disconnect that wire, +[301.55s -> 312.14s] And once we remove the metal rod, so we're going to disconnect the wire first, and then second we'll remove the metal rod. We'll move it away from the metal sphere. +[313.90s -> 325.17s] Now because the metal sphere lost electrons some of the electrons went to the ground The metal sphere now has a net positive charge +[325.46s -> 340.37s] The ground has a net negative charge. And so this is another example of charging by induction. We took a neutral metal sphere and we put a positive charge on it. +[340.72s -> 353.36s] using a negatively charged metal rod, even though that negatively charged metal rod did not make any contact with the metal sphere. So that's charging by induction. +[354.26s -> 360.91s] It's using one charge object to induce a charge on another object without making any contact. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_13.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_13.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..521c3270f8049b6c1bf7e43d786bbea6f5527a48 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_13.mp4.txt @@ -0,0 +1,17 @@ +[0.00s -> 11.66s] You should already know that velocity time graphs look like this, and how we can use them to map out a journey. +[13.07s -> 16.85s] If you're unsure, you may want to watch this video first. +[17.42s -> 28.69s] In this video, we're going to look at the area under these graphs and what they represent. Let's start by looking at a simple velocity time graph. To find the area underneath the line, +[28.69s -> 39.54s] Multiply the value on the horizontal axis with the value on the vertical axis. We are multiplying together the velocity of the object and the time it has travelled for. +[39.79s -> 52.18s] Look at the unit, 80 metres. The area underneath the graph gives us the total distance that the object has travelled. So we have velocity, time and distance. +[52.59s -> 66.48s] The area won't always be quite so simple to calculate. Velocity time graphs more commonly look like this. We can calculate the area underneath the line by cleverly splitting the area into triangles and rectangles. +[66.48s -> 72.94s] Remember that the area of a triangle is the base multiplied by its height divided by 2. +[75.28s -> 87.66s] Can you work out the distance travelled for this velocity time graph? Work out the total area underneath the graph. Pause the video and give it a go. Did you get it right? +[89.52s -> 92.59s] 2,430 meters +[94.32s -> 108.45s] For most velocity time graphs, splitting up the area will be relatively obvious. However, you might come across some more complicated plots. Splitting up an area like this will be less obvious. Whilst it doesn't matter exactly how you split the area up, +[108.45s -> 120.94s] The fewer shapes you have, the fewer calculations you'll have to do. As a general tip, try to include a triangle where you see diagonal lines, and rectangles where there are horizontal sections. +[121.14s -> 128.78s] Give this one a go yourself. Pause the video and work out the distance travelled. Did you get it right? +[130.48s -> 142.02s] This means that for the journey shown by the velocity time graph, the object travelled a total distance of 24 metres. When doing these calculations, just be sure to check the units that you're given. +[142.02s -> 154.56s] because this will affect what unit you will give in your answer for the total distance. For this one, it was seconds and meters per second, so the distance in meters is correct. But for this one, +[154.56s -> 160.02s] It's hours and kilometres per hour, so the distance would be measured in kilometres. +[161.71s -> 171.82s] So there we have velocity time graphs. Velocity on this axis, time on this axis, and the area underneath the graph is the distance. Simple. +[175.02s -> 180.40s] Please like and share our videos with your friends. If you have any questions that you want help with, just comment below. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_14.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_14.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f899cdf72aae4cc984e868d1a18fcb02766428c3 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_14.mp4.txt @@ -0,0 +1,33 @@ +[0.00s -> 13.60s] Let's summarize the ideas of refraction snell's law and refractive index. When light goes from one medium to another, like say from water to glass, it bends and this bending follows a rule. And for that rule, we drop a normal. +[13.60s -> 26.98s] and then if we define this angle as the angle of incidence and this is the angle of refraction and the rule of refraction which is called Snell's law is the sine of the angle of incidence by sine of the angle of refraction is a constant. +[26.98s -> 34.53s] this constant depends upon the two media for example for water and glass it happens to be 1.13 +[34.53s -> 47.38s] as an example but for different different media this will be different different numbers but what's important is that even if i had incident and another ray of light at a different angle i'll have different angle of incidence different angle of refraction +[47.38s -> 60.22s] but sine i by sine r will stay the same. And this term, this constant is called the refractive index. Let's talk more about refractive index. The symbol that we use for refractive index is n. +[60.22s -> 74.21s] Now since refraction is happening in glass, we will use the subscript G, NG. But since the light came from water, we will say this is refractive index of glass with respect. +[74.21s -> 84.80s] to water that's how you read this refractive index of glass with respect to water that is 1.13 +[84.80s -> 96.02s] But what decides this number? Why is this number equal to 1.13? Well, turns out refraction happens due to the change in the speed of light. Speed of light is different in water. +[96.02s -> 105.26s] than in glass and that change is the reason for why light bends and turns out that this refractive index is the ratio +[105.26s -> 119.10s] of the speed of light in the two media. So in this case, the refractive index of glass with respect to water happens to be, this number is actually the speed of light in water divided by speed of light in glass. +[119.10s -> 125.78s] Now something to be very careful about over here, not to get confused between which number comes on top. +[125.78s -> 139.25s] the speed of light of the reference medium see here we are calculating refractive index of glass with respect to water so water is our reference medium the speed of light of the reference medium comes on the top and the speed of light of our +[139.25s -> 151.89s] Refraction medium comes on the bottom. For example, if I asked you what is the refractive index of diamond with respect to say oil, what would that be? +[151.89s -> 166.69s] Well, that would be the speed of light in oil, the reference medium comes on the top, divided by the speed of light in diamond. Does that make sense? Okay, one more question. What if I asked you what is the refractive index of glass? +[166.69s -> 181.14s] With respect to vacuum, what if the first medium was vacuum? Then we don't really write vacuum. Vacuum is special for some reason. We will just write refractive index of glass. If we don't mention the reference medium, +[181.14s -> 190.61s] it automatically means that it's vacuum. That is the convention that we follow. So what is refractive index of glass equal to? +[190.61s -> 203.87s] Well, just like over here, it'll be the speed of light of the reference medium that comes on the top. Since the reference medium is vacuum, speed of light of vacuum comes on the top. And that is C, which you probably know as three. +[203.87s -> 216.90s] times 10 to the power eight meters per second. So, it's the same formula. It will be now speed of light in vacuum divided by speed of light in glass. Okay, now let's quickly check our understanding. +[216.90s -> 226.26s] Suppose I'm given that a rare flight is incident at an angle of 30 degrees undergoes refraction at an angle of 60 degrees into another medium +[226.26s -> 240.62s] We're asked to calculate what is the refractive index of medium B with respect to medium A. Can you try and figure this out using Snell's law? All right, so Snell's law says the sine of the angle of incidence, which is 30 degrees, +[240.69s -> 252.53s] divided by the sine of the angle of refraction. Here the angle of refraction is 60 degrees. That equals the refractive index. Refractive index of which medium? +[252.53s -> 265.89s] where is refraction happening here so refractive index of medium b because this is where the refracted ray is this is where refraction is happening but with respect to which medium with respect to a and +[265.89s -> 277.49s] i can just substitute and solve this so that equals sine 30 which is half divided by sine 60 which is root 3 over 2 +[278.06s -> 291.63s] That gives us 1 over root 3. And there we have it. That is the refractive index of B with respect to A. Now, quick question. What if I had asked you what is refractive index of A? +[291.63s -> 304.51s] with respect to B. What would that number be? Can you pause and think about how would you calculate that? Well now, I want refractive index of A with respect to B, which means I won't consider refraction happening in this medium. +[304.51s -> 317.92s] Well, for that to happen, just reverse this. You can just imagine reversing this, and now refraction happens in this medium. So this now becomes the angle of incidence. This now becomes the angle of refraction. +[317.92s -> 330.34s] So the Snell's law will say sine 60 divided by sine 30, that equals the refractive index of A with respect to B. And if you see, that's basically reciprocal of this. +[330.34s -> 343.49s] So it'll be reciprocal and it's going to be just root 3. So you can see one amazing property that we have found out is that refractive index of B with respect to A is just the reciprocal of refractive index of A. +[343.49s -> 356.58s] with respect to B. And that happens because you can just reverse the ray of light. Pretty cool, right? Okay. Now, we are given the speed of light in this medium is 2 times 10 to the power 8 meters per second. +[356.58s -> 369.95s] What is the speed of light in medium A? How would we find that? Well, now we can use our connection of refractive index with the speed of light. Remember what we saw? We saw that the refractive index of medium B with respect to A +[369.95s -> 383.63s] That is the speed of light in A, remember the reference medium speed comes on top, divided by the speed of light in medium B. Now I have found out what this is, so I'm just going to substitute. +[383.63s -> 397.28s] this happens to be 1 over root 3 that equals VA which I don't know divided by VB which is given to me as 2 times 10 to the power 8 meters per second +[397.28s -> 410.42s] And so from this Va equals 2 times 10 to the power 8 meters per second divided by root 3. And there you go. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_15.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_15.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..5cdab689c50086e0f8f2b58bce4e8ded1f547500 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_15.mp4.txt @@ -0,0 +1,21 @@ +[1.10s -> 3.50s] This is a thin film interference summary. +[5.14s -> 16.83s] So this summary works for nearly vertical rays. If they're at too much of an angle, there's a little more to it. My drawings would be at quite a bit of an angle, but we're going to take it on as if the light was coming in pretty much vertically. So I've got this soap film. +[16.83s -> 31.07s] basically a soap bubble. It's got air on the inside, air on the outside, and I've got soap of some kind of thickness. The light ray is going to come in, it's going to reflect and refract, and then on the bottom it's going to reflect and refract again. And on the top you can see I have those two reflected, bouncing +[31.07s -> 41.42s] light rays and they're going to interact with each other. In fact one of them is going to travel farther than the other one and the distance it's going to travel is twice the thickness of the soap film. +[41.42s -> 55.54s] But notice the variable we're using for the thickness of the soap film. It's not D or L or something that makes sense. It's T. And the only reason why I'm using T is because everyone else seems to want to use T. Usually lowercase T is time, but in this case it means thickness. +[55.54s -> 68.13s] twice the thickness of the soap film because the light goes down and then back up. And so I know that that's the path length difference. Twice the thickness is equal to M lambda, which is the path length difference. But... +[68.13s -> 79.66s] Notice that because the path length is in the film and not in the air or the vacuum, the wavelength is going to differ, and that's what's important. So I need to account for that. So I'll use the wave equation, C equals lambda F. +[79.66s -> 89.71s] and the index of refraction is c over the velocity in the medium, which means that the wavelength in the vacuum, or air, is the same, divided by the wavelength in the medium is equal to the index of refraction. +[89.71s -> 99.79s] When I rearrange that, the wavelength in the medium is equal to the wavelength in the vacuum, which is the same as air, divided by the index of refraction. Now I've got one more little hitch to this. +[99.79s -> 113.33s] Whenever a light ray goes from a low index to a high index, like from air to soap, I get a 180 degree phase change, or lambda over 2 phase change. Whenever a wave goes from... +[113.33s -> 123.33s] a high index to a low the opposite I don't get a phase change there's no phase change there so because it's a phase change usually we know when the path length is equal to m lambda +[123.33s -> 133.62s] I get constructive interference, I get a bright spot. But here, because that lambda over 2 phase length, instead of a bright spot, I get a dark spot. In other words, I get destructive interference. +[133.62s -> 147.31s] twice the thickness is equal to m lambda over n, and my orders are 0, 1, 2, 3, and that's destructive. So these are the frequencies that it's blocking out. And the frequencies that you see, constructive interference, would therefore be m plus 1 half. +[147.31s -> 158.18s] Now just so you know there is an alternative format of writing this equation. You can multiply both sides by the index of refraction and you get two nt's equal to m lambda and two nt's equal to m plus a half lambda. +[158.18s -> 168.21s] But to me, this equation really doesn't tell the story of the fact that you have to change the wavelength in the substance, which is why it's lambda over m. Okay, let's look at a different situation. +[169.01s -> 182.42s] And this time I've got air and soap sitting on top of glass. And you can see how my indices of refraction have changed. So this is the equation that we had before. The light comes in, reflects and refracts, then reflects and refracts. +[182.42s -> 194.86s] all the way down, and I'm going to ignore what happens as it leaves the glass, so the glass is as thick as I want it to be. But when it comes in, the first one, it's going from air to soap, so from low to high, that's going to give me a 180 degree phase change. +[194.86s -> 208.75s] And then when it goes from soap to glass, it does it again, from a lower index to a higher index. So I get a second 180 degree phase change. So now because I have two phase changes instead of just one, they essentially cancel each other out. +[208.75s -> 222.19s] So now, instead of 2t is equal to m-limit over n being destructive, it becomes constructive. The same thing is true at the bottom. Instead of m for the m plus a half equation, constructive interference turns into destructive interference. +[222.96s -> 237.60s] So you've got to remember when things are changing. To help summarize what's going on, I've got this little table. So I've got the equation. I've got my equation. Also in the standard form, the 2nt is equal to m plus a half lambda. With one phase shift, you can see it's constructive. +[237.60s -> 245.23s] The two NTs you can land a one phase shift destructive. And I've got a little picture down there to help you and show you kind of how it works with the phase shifts. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_18.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_18.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..165392957ce07d053887cd98db96270f02d4fcf6 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_18.mp4.txt @@ -0,0 +1,25 @@ +[1.90s -> 12.53s] Okay, so we have a complex circuit, but it's a fairly simple complex circuit. And we know the resistances of everything involved, and we know the total voltage. +[12.53s -> 25.46s] that's being applied to the circuit. And this is sort of a realistic situation, because normally we can look at the resistor and see what the resistance is, or we can measure the resistance of an object. And we can usually control or choose the voltage of a source. +[25.46s -> 38.51s] So now we want to sort of figure out everything else about the circuit. Who knows what the question might be? What's the current on resistor 3? What's the voltage on 4? We're just going to solve the whole circuit and find absolutely everything. +[38.51s -> 52.67s] So, for a simple review, quickly, we've got four resistors here, obviously. One and three. Number one and three aren't connected in series, they're not connected in parallel. I don't know how to describe their connection, so I'm not going to. +[52.67s -> 63.89s] But I do know that 3 and 2 are in parallel. An electron coming here can either go through 3 or it can go through 2. It can't go through both. They're in parallel. 4. +[63.89s -> 78.18s] And this whole group are in series, because if an electron goes through somewhere in this group, it's got to go through four. So they're in series. It's got to go through the battery. It's in series. It's got to go through resistor one. It's all in series. So we've got three and two connected in parallel. +[78.18s -> 88.37s] in series with 1 and 4, and we know the total voltage is 9. The only new piece of information that we're going to use here, which hopefully isn't new for you, is Ohm's Law. +[90.10s -> 95.57s] which, of course, is B equals IR. It's usually written that way. +[97.68s -> 110.86s] I think for historical reasons, I equals B over R is maybe a better way to think about it. But regardless, we're going to use that several times. The nice thing about Ohm's Law, if you ever have B and I, you know R. +[110.86s -> 123.98s] If you ever have R and I, you know V. Each resistor or source has three things, V, I, R. And if you know two of them, you automatically know the third one because of Ohm's Law. And that's all we're going to use it for. We start off. +[123.98s -> 132.21s] not knowing two things about anything, so Omslaught is not going to come into it. But we know all the resistances, so let's calculate the total resistance. +[132.21s -> 145.71s] Looking on this branch, we have two in parallel. Again, I'm starting here because these are the only two that are connected simply in parallel. And looking here, we're going to find the total resistance of sort of this branch of the circuit. +[145.74s -> 158.90s] And that's 1 over 20 plus 1 over 5 equals 4 over 20 plus 5 over 20. But we've got to flip that over. 20 over 5, which equals 4. +[158.90s -> 173.01s] So this thing has an equivalent of 4 ohms. These two together. This guy has 3, 4, 2. They're all in series 3 plus 4 is 7 plus 2 is 9. So my total resistance is 9 ohms. +[173.01s -> 177.84s] Now, I know V and R for the source, so I'm going to use these. +[179.47s -> 192.43s] I'm going to use Ohm's law here. V over R, 9 volts over 9 ohms is obviously 1 amp. So I'll put 1 amp through there. I knew 2, so I knew 3. +[193.01s -> 206.74s] If one amp is leaving the battery, one amp has to go into this resistor. So this also has to have a resistance of one. Hey, I know I and R, so I can find V. One times three is three, so the voltage is three volts. +[207.28s -> 217.54s] One amp goes into this junction, so one amp has to come out. Ooh, that looks confusing. Let's hang off one second. We know for sure that when they come back together, there's going to be one amp. +[217.54s -> 229.58s] If there's one egg here and here, there's got to be one egg through here. So I'm going to go ahead and put that. Again, I know one and two. So Ong's law tells me I know V, which is two volts. +[230.19s -> 243.84s] And now if I think about an electron making a full circuit, it has to lose 9 volts. It loses 3 there, it loses x here, and it loses 2 there. It loses 5, so that means it's got to lose 4 here if it goes this circuit. +[243.84s -> 257.10s] These two are parallel, though, so obviously 2 and 3 have to be the same, so that is also 4 volts. And lo and behold, now I know 2 for both of these. So, what is I? I is V over R. +[259.60s -> 273.26s] 4 over 20, which is 0.2 amps. 4 over 5, which is 0.8 amps. And just to double check, 0.2 plus 0.8 equals 1. So that makes a lot of sense. +[273.26s -> 284.66s] I could have done this directly using my brain and a little math. I could have thought, hey, R3 is four times as resistive as R2, which means that... +[284.66s -> 296.32s] 4 times more current will go through 2 than 3. See how 0.8 is 4 times 0.2? And they add up to 1, so there's really only one option. 4 times compared to 1 times is resistive. +[296.32s -> 311.18s] So 1 fifth the current goes there, 4 fifths of the current goes here. But I didn't need to do that in my head. I was able to figure it out by working backwards as well. Now we can try a harder one. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_19.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_19.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..c5decd077f96e74d08ae60d36cfe33a31dcc8fbb --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_19.mp4.txt @@ -0,0 +1,56 @@ +[0.00s -> 14.29s] In this video, we're gonna change the brightness and the color of the light or the intensity and the frequency of the light and see how that affects the graph of the photoelectric effect. And the reason I have two graphs is because we'll do two cases. Now, before we start, let's quickly. +[14.29s -> 25.04s] recap what this graph was all about on the horizontal we have plotted the voltage of the collector plate and on the vertical we are plotting the current over here +[25.07s -> 39.66s] Now when the voltage of the collector plate is positive and it's increasing it starts attracting more and more electrons and as a result it starts collecting more and more electrons and as a result the current starts increasing but after a point it's +[39.66s -> 50.10s] all the electrons that are emitted and then further increasing the voltage does not increase the current. And that's why we hit a saturation. And so we saw that this is an indicator. +[50.10s -> 63.73s] This current, this saturation current is a direct indicator of how many electrons are coming out per second. So I'll just say hash for number of photoelectrons, we call them. This is the number of photoelectrons. +[63.73s -> 74.18s] coming out per second you can think of this height represents this number and then when we make the voltage on the collector negative by say flipping the battery +[74.18s -> 88.46s] Now, the collector starts repelling the electrons, and so electrons start going back. And as a result, the current starts reducing, reducing, and eventually, eventually it stops. And we know at this point, even the fastest electron, the most energetic... +[88.46s -> 94.10s] electrons have also stopped they're not able to make it and therefore this point is what we call +[94.10s -> 104.08s] this voltage this negative voltage is what we call the stopping voltage or the stopping potential and this is a direct indicator in fact it's equal to in electron volts +[104.08s -> 112.18s] the maximum kinetic energy. And if you need a refresher on this, and we've talked a lot about this in our previous video, so feel free to go back and check that out. +[112.46s -> 124.18s] But now what we'll do is let's change the intensity and the frequency in the first case I'm going to increase or let's say I'm gonna decrease I'm gonna decrease the intensity of the light +[124.82s -> 133.90s] but I'm gonna keep the frequency of the light the same. And I want us to predict what the new graph is gonna look like. +[133.97s -> 148.56s] And I think we've already learned everything that is needed. We've already seen how the intensity and the frequency affect the number of photoelectrons and affects the maximum kinetic energy. Now all we have to do is use that and translate it into drawing what the new graph is going to look like. +[148.56s -> 153.01s] So a great idea to pause the video and see if you can try doing it yourself first. +[153.49s -> 167.41s] All right, let's do this. So let's start with the frequency part. Since the frequency is staying the same, that means the energy of my photons are gonna stay the same. So whatever was the energy of that my photons were, that has not +[167.41s -> 180.22s] changed. Why? Because remember, Planck's equation, E is equal to H into F. And so if the energy of the photons have not changed, that means the energy that we're giving to the electrons have not changed. That means the energy with which the electrons are coming out +[180.22s -> 194.43s] that won't change. And so the maximum kinetic energy will stay the same. So I know that my graph is going to end over here. It has to. I'm going to draw my new graph with green. It has to be over here. Okay. +[194.43s -> 205.04s] Now let's look at what happens over here. And that's all we have to do. We have to look at these two things, how these two things changes. Now let's look at what happens to this one. For that, let's look at the intensity. +[205.33s -> 218.27s] So when I reduce my intensity, what happens? Well, as I reduce the intensity, the number of photons that reduces. So I'm reducing the number of photons that are falling on this per second. +[218.27s -> 226.77s] And if that reduces, the number of electrons coming out would reduce, and that means this current should also reduce. +[226.77s -> 234.26s] And therefore I know that my saturation current, my maximum current has to be smaller because now less number of photoelectrons are coming out. +[234.61s -> 248.78s] And therefore now I can predict what the graph is going to look like. It's going to be similar to this, but now my graph will look somewhat like this. And there we go. All right. Okay. Now you try one. +[248.78s -> 258.99s] In the second case, let's get a little bit more adventurous. Let's increase the intensity of light, let's make this light brighter, but let's decrease the frequency. +[260.27s -> 270.53s] Okay, can you now predict what the new graph is gonna look like? Pause and try. All right, again, let's start with the effect of frequency. If the frequency has become smaller, +[270.53s -> 281.01s] Then now I know from Planck's equation, the energy of the photons should have also become smaller. So these photons have now become very tiny. +[281.01s -> 288.51s] i mean tiny as in like tiny in energy okay they don't have size or anything they become they have less energy now and since they have less energy +[288.51s -> 302.00s] they transfer less energy to the electrons and therefore the electrons will now come out with less energy. Therefore, the maximum energy of the electrons would be smaller and therefore the stopping voltage would be also smaller. So I know in this case, the stopping voltage has to become smaller. +[303.28s -> 317.78s] And when I was studying this, I should try to directly memorize. If frequency decreases, stopping voltage would reduce. If intensity increases, this happens, that happens. It's very boring. It can be very confusing. So please don't do that. Instead, always go back to your basics. +[317.78s -> 330.29s] Frequency decreases, that means the energy of the photons reduced, that means less energy is given to the electrons, and therefore it will be easier to stop them, and therefore smaller stopping voltage. Alright, now what happens due to the increased intensity? +[330.42s -> 341.87s] Well, if the intensity has increased, remember, intensity is an indicator of how many photons are there per second. More intensity means we're getting more photons per second, right? And if there are more photons per second, +[341.87s -> 353.36s] there'll be more electrons coming out per second. And if there are more electrons coming out per second, that means the saturation current should be higher. So I know that in this case, the saturation current should become larger. +[354.38s -> 363.31s] And so now I can predict the graph should go from here to here. The graph has to stick similar to this. So it's going to go like this maybe. And then. +[365.17s -> 376.91s] Isn't it fun to do this logically? Okay, because we're having so much fun, let's do two more bonus graphs. In this graph, we're gonna plot +[377.46s -> 388.08s] the stopping voltage along the vertical, so not the voltage of the collector, but the stopping voltage itself, versus the intensity of light. +[390.06s -> 397.87s] Okay, I want you to predict what this graph is gonna look like provided we keep the frequency same. So we're gonna keep the frequency constant. +[399.86s -> 411.70s] So think about what this graph means, what we're doing with the light, and then predict what this graph is gonna look like. So again, beautiful idea to, sorry, great idea to pause and see if you can try this. +[413.23s -> 424.93s] Okay, first step is trying to figure out what we are trying to do over here. We are changing the intensity, right? So we're keeping the frequency the same and we are making it brighter. Imagine that, we are increasing the brightness. +[424.93s -> 434.96s] Our question is, what happens to the stopping voltage? Or in other words, we're asking, what happens to the maximum kinetic energy of the electrons? What do you think is going to happen? +[434.96s -> 447.60s] Well, as I increase the intensity, I'm increasing the number of photons, right? But the energy of each photon stays the same because the frequency is a constant. Planck's equation, E is equal to HF. +[447.60s -> 459.54s] And therefore, if the frequency stays the same, that means the energy of the electrons coming out stays the same, right? It's exactly this graph, right? I changed the intensity. +[459.54s -> 465.10s] but the stopping voltage did not change. So if I change the intensity, the stopping voltage +[465.10s -> 477.18s] will not change so it's all about just getting what it's looking i mean taking what we have already learned and putting into a graph so whatever was the stopping voltage earlier i don't know what that was so let's say the stopping voltage earlier was i don't know maybe three volt +[477.18s -> 488.69s] Then here, throughout, the stopping voltage will stay 3 volt. That means our graph is going to look like this. So let me use, okay, let me use yellow itself. It's going to look like this. +[489.39s -> 502.03s] Make sense? Okay, one last. One last graph. What if I draw a graph of, this time, again, stopping voltage versus frequency? +[504.02s -> 518.13s] keeping intensity the same. I'm not gonna change the intensity. All right, if I increase the frequency of the light, that means I'm increasing the energy of the photon. +[518.13s -> 531.44s] Planck's equation is equal to HF. So if the energy of the photon is increasing, that means the kinetic energy of the electrons will also increase. That means the maximum kinetic energy will increase. That means the stopping voltage should also increase. +[531.44s -> 542.38s] So we know as the frequency increases, the stopping voltage will increase. But is it going to be a straight line? Is it going to start from zero? Is it going to be a curve? How do I figure that out? +[542.38s -> 556.30s] So that's why this part is a little tricky, maybe a little bit more interesting. For that, we can go back to our equation. There's only one equation that we have for photoelectric effect, that's Einstein's equation. Einstein's equation says that the energy of the photon, which I'll just write as h times f, +[556.37s -> 567.86s] and this is our frequency on the x-axis, that should equal the work function, which is a constant, plus the maximum kinetic energy, which is basically the stopping voltage. +[568.88s -> 581.94s] And what I see is a direct linear relationship. And therefore I know it has to be a straight line. But does that straight line start from zero? +[582.29s -> 584.53s] Think about it. What do you think? +[585.39s -> 599.12s] The straight line can't start from zero because if the frequency is too low, then it's not able to overcome the work function. We will not have any kinetic energy, we will not have any stopping voltage. So if the frequency is zero, +[599.12s -> 606.48s] Nothing happens. If the frequency is a little higher, again nothing happens, right? So, if you start with very low frequency, +[606.80s -> 619.12s] you get no photoelectric effects, so stopping voltage should also be zero until you hit that minimum threshold frequency, maybe somewhere over here. After that, if you now increase the frequency, +[619.12s -> 630.99s] now the this one the maximum kinetic energy would increase dropping voltage would increase and so now there will be a linear relationship so now it'll increase linearly so it's going to be a straight line somewhat like this +[631.76s -> 635.15s] And there we go. This is what the graph would look like. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_20.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_20.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..24f941835fc03d191080c88101f574f052d9d89a --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_20.mp4.txt @@ -0,0 +1,28 @@ +[0.88s -> 15.20s] One of the most common graphs that we come across in the photoelectric effect is the graph of kinetic energy against frequency. What we can see here is that the graph starts out negative as the frequency increases. +[15.20s -> 28.51s] and then eventually becomes positive and continues to increase with the frequency. Now what's important here is that we can use this formula to determine what the x and y-intercepts of this graph mean. +[28.51s -> 40.78s] And the first one, to determine what the y-intercept of this graph means, we rewrite this formula by saying the energy of the photon is the product of Planck's constant and frequency. +[40.78s -> 54.37s] and that's equal to the work function plus the kinetic energy. This is the y-intercept which means at this point the frequency must be equal to zero which means that zero is equal to +[54.37s -> 68.29s] the sum of work function and kinetic energy which then can be rewritten as the work function is equal to negative kinetic energy and this is when frequency is zero so that tells us +[68.29s -> 75.66s] that the y intercept on this graph is the negative work function. +[77.17s -> 91.92s] The second intercept that we would want to find here is the intercept with the x-axis. We know that that is going to happen when the kinetic energy is equal to zero, and we get this by rewriting this equation. +[91.98s -> 106.22s] where the energy of the photon is a product of Planck's constant and frequency. The work function is the product of Planck's constant and the threshold frequency, and in this case the kinetic energy is now zero. +[106.54s -> 119.74s] And so we can then rewrite this or simplify it. Let me write that or leave that as kinetic energy, which leaves us with H times F is equal to H times F0. +[119.74s -> 133.52s] which then simply tells us that the frequency at the point where kinetic energy is zero is our threshold frequency. So what this tells us is that we now have a graph that can tell us where the +[133.52s -> 147.54s] work function is or what the work function is it can also tell us what the threshold frequency is and now this graph makes more sense because it tells us that when the photons have an energy or frequency less than the threshold frequency +[147.54s -> 160.16s] There is no kinetic energy because there are no photoelectrons ejected. We know that once the threshold frequency is surpassed then the kinetic energy of those photoelectrons increases. +[160.16s -> 173.78s] and it increases with a steady gradient and the gradient of that graph is kinetic energy over frequency which we know then is Planck's constant, a constant value. +[173.78s -> 176.40s] for a constant gradient on that graph. +[177.74s -> 190.26s] The second common use of the photoelectric effect or the way that we show it is in an electric circuit that's set up as follows. We have a battery connected to an ammeter connected to a... +[190.67s -> 204.72s] photocell that we can see here essentially breaks the surface where we have a metal over here connected to the negative terminal of the battery and here metal connected to the positive terminal of the battery and what we can see here +[204.72s -> 208.21s] is that by shining a light onto this metal +[208.69s -> 222.99s] If the frequency of the light exceeds the threshold frequency, then electrons will be ejected from the surface of this metal and be attracted towards the positive terminal of the battery, which would then +[222.99s -> 237.33s] register a current on this ammeter. So the first graph that we can draw here is a graph of current versus frequency and what this shows us is that no current would register until the point +[237.33s -> 249.65s] where we reach our threshold frequency and from then onwards a current would register because now electrons are being allowed to bridge that gap which completes the circuit and allows a current to flow. +[250.03s -> 259.60s] This circuit can also be used to demonstrate the fact that intensity changes the number of electrons that are ejected because what we will find here +[259.95s -> 271.02s] is that if instead of plotting current versus frequency, we now plot current versus intensity, we'll find that as we increase the intensity of this light, +[271.76s -> 286.38s] We increase the number of electrons that are ejected and more electrons being ejected means more charge moving across that gap. More charge we know would increase the amount of current because current is the charge. +[286.54s -> 293.14s] over the amount of time. So what we find is that our current versus intensity graph +[293.58s -> 303.70s] will increase for as long as the intensity increases. Again, as long as the frequency exceeds the threshold frequency. +[303.98s -> 317.63s] So once again, these are two different ways in which we can see the photoelectric effect, but both of them show us the same thing. They say that no photoelectrons are ejected until the threshold frequency is surpassed. +[317.63s -> 331.31s] They tell us that the kinetic energy increases once the threshold frequency is surpassed. And they tell us that the intensity affects only the number of electrons ejected. It does not affect... +[331.31s -> 335.09s] whether or not an electron is ejected as a photoelectron. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_21.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_21.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..f213aa45b855eae579ec53fe64ee409809dc54c8 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_21.mp4.txt @@ -0,0 +1,32 @@ +[7.57s -> 21.68s] Over the years of my teaching career I must have taught accounts of thousands of year 10 and 11 students and some of them were very bright and capable physicists but not once was I ever asked, hold on sir, how come the nucleus +[21.68s -> 30.74s] With these positive things packed close together doesn't just go bang. Good question. And that's the subject of this video. +[31.54s -> 41.58s] Imagine two protons which of course we know are both positive. We're going to consider the forces acting on these protons as we try to bring them closer together. +[42.64s -> 55.39s] By convention, we say that repulsive forces are positive. There is an electrostatic repulsive force between these two protons then. If you've had the joy of doing electric fields in year 13, +[55.39s -> 69.60s] You'll know that this follows a 1 over r squared pattern. Don't worry if that didn't mean anything to you, it soon will. But for now, just accept the fact that the force that is repulsive between these two protons grows large rapidly. +[69.60s -> 79.58s] We can show this graphically. As one proton approaches its stationary friend you can see this in the green curve. Notice how quickly the green curve rises. +[79.58s -> 87.60s] Considering how small the mass of a proton is, this repulsive force between these two protons is truly enormous. +[88.05s -> 99.66s] The diameter of a proton is around about give or take roughly to a good approximation 10 to the minus 15 meters. Now we call 10 to the minus 15 a femto. +[99.66s -> 111.98s] And this is easy to remember because both the femto and 15 begin with an F. This point here on the X axis is showing a distance of three femtometers then, which is roughly about three proton diameters. +[111.98s -> 120.78s] Notice all the hand waving that's going on here. We're not really interested in exact measurements but approximations are going to be fine for us. +[121.55s -> 135.89s] Given how large this repulsive force is between these protons, we can see that we've got a bit of a problem developing here. How can a nuclear stay together? Surely the protons should just literally blow each other apart. +[139.25s -> 153.68s] In order to put a lid on the potential problem of the exploding nucleuses, there must be another force at play. Clearly this is the case because, well, we just wouldn't be here, would we? So, enter the strong nuclear force. +[153.71s -> 161.39s] The nature of the strong nuclear force is quite different to any other force that you've met. For starters, it's a short-range force. +[161.68s -> 172.35s] Let's picture the moving proton coming closer to its stationary friend. At large distances, whatever that means, there simply is no strong nuclear force. +[172.35s -> 176.80s] There will, however, still be some electrostatic repulsion. +[176.80s -> 189.25s] As we move closer we find that around about four or five centimeters the strong nuclear force is beginning to slowly increase but overall there is still a larger repulsive force between the protons. +[189.25s -> 201.89s] Moving closer still and arriving at around 3 femtometers, we see that the strong nuclear force starts to increase rapidly in magnitude, peaking at a separation of around 1.5 femtometers. +[201.89s -> 209.66s] Notice though that the strong nuclear force is negative which according to our convention means that it is an attractive force. +[209.66s -> 218.42s] Therefore you can see that at around about 1.5 femtometers the resultant force between the particles is now strongly attracted. +[218.80s -> 232.08s] As we go even closer, the strong nuclear force begins to become rapidly less attractive and at around half a femtometer flips over to being repulsive and continuing to increase rapidly as you get closer. +[232.11s -> 238.67s] Like I said the electrostatic force and gravitational force are nothing like the strong nuclear force. +[239.41s -> 252.74s] So you can see that if you try and push two protons closer than, well, shall we say, I don't know, one femtometer, very quickly the force is going to become extremely repulsive. In other words, you can't get them closer than that. +[252.74s -> 265.52s] and there is a sweet spot round about one and a half femtometers one other important point is that the strong nuclear force applies to all hadrons and naturally that includes neutrons +[265.78s -> 273.49s] And so a proton and a neutron will feel the strong nuclear force if they get close enough, as indeed will two neutrons. +[274.93s -> 289.63s] The neutron is often described as the glue that holds the nucleus together. Let's see if we can see why. I want us to imagine a slice, one row, through a relatively large nucleus. We're going to go proton, neutron, proton, neutron, alternately, just to keep it simple. +[289.63s -> 298.56s] let's pick any two particles that are separated well any two particles that are adjacent to each other obviously we have one proton one neutron so there's going to be a +[298.56s -> 311.25s] strong attractive force between those because their distance between their centers is going to be around about one to one and a half centimeters. However, there'll be no repulsive force, because one of them is neutral, therefore strongly held together. +[311.25s -> 325.81s] What if we take alternate protons? So we go proton, neutron, proton. Well, in this case, we have two positive particles separated at a distance of around about two to two and a half centimeters. And as I'm sure you can see from the graphs earlier, the strong force is beginning to... +[325.81s -> 337.55s] of fall off a bit at this point but we also now have a repulsive force caused by the fact that they are both positively charged so now it's getting a bit more complex we're going to have to look for a resultant force +[337.55s -> 349.14s] probably between those two protons is going to overall be attractive but what happens now if we move out to two protons separated by let's say around about four to five femtometers +[349.26s -> 361.04s] Now in this case the strong force has fallen away basically down to zero but there is still a repulsive force between those particles because well as we know electrostatic force is not a short range force. +[361.90s -> 376.34s] Although we are still firmly in hand-waving territory I think you can begin to see that the neutrons are acting like glue since they attract all of their nearby neighbours without experiencing any repulsive force. diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_7.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_7.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..2a41a0ae4403473241a5929974569cf5b5dab1a3 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_7.mp4.txt @@ -0,0 +1,20 @@ +[3.70s -> 11.63s] Consider our planet Earth in space and these sample positions of an Earth satellite in circular orbit. +[12.59s -> 24.11s] before the idea of inertia was understood people thought that a force in the direction of motion was responsible for motion they imagined angels pushing on the planets +[24.59s -> 36.58s] newton changed all that and taught us that the only force acting on a satellite acts toward the body it orbits that's the gravitational force and what if this force disappeared +[36.58s -> 48.75s] Then the satellite would fly off on a straight line path. No force, no orbital path. Note that each of the force vectors are the same size and point to Earth's center. +[49.01s -> 58.00s] Same size because the satellite circles at the same distance from Earth. Note also that they're perpendicular to the orbital path. +[58.48s -> 71.60s] the ninety degree angle means there is no component of force along the orbital path which further means no change in speed from an energy standpoint that means no change in kinetic energy +[72.14s -> 83.02s] and since distance remains constant no change in potential energy so both kinetic energy and potential energy are constant all along the orbital path +[83.76s -> 97.74s] So a satellite in circular orbit effectively coasts at an unchanging speed all the way around and around and around Now things are different for a satellite in an elliptical orbit +[98.80s -> 113.36s] consider these sample positions for such a satellite since the distances from earth are different the forces are different weaker far from earth and stronger when closer in accord with the inverse square law +[113.68s -> 116.05s] So the speeds are different also. +[118.80s -> 132.02s] kepler was the first to discover the elliptical paths of planets about the sun early in the seventeenth century he discovered that planets travel fastest closest to the sun and slowest farther away +[132.21s -> 143.47s] but he had no explanation as to why just as a projectile tossed upwards slows as it rises and speeds up as it returns so it is with any satellite +[144.24s -> 158.67s] kepler never viewed a satellite as a projectile that planets are projectiles falling around the sun just as our moon is a projectile falling around earth this way of thinking escaped kepler +[160.24s -> 170.35s] let's talk energy conservation the sum of the potential energy and kinetic energy at any point along the satellite path is the same as at any other point +[170.54s -> 184.37s] hence where the kinetic energy is greatest potential energy is least and vice versa we can look at the changes in speed by considering the components of gravitational force along the satellite path +[185.14s -> 196.78s] the component perpendicular to the satellite path shown as a white vector here doesn't affect speed but changes the direction of motion curving it away from a straight-line path +[197.30s -> 209.81s] more interesting is the component along the path which we make purple here that component of force changes speed when in the same direction of motion speed is increased +[210.32s -> 218.26s] But here on the other side, the purple component slows the satellite. That's because the satellite is going against gravity there. +[218.90s -> 231.18s] so for our satellite we see it has the least speed farthest from earth and the most when closest it falls around and around indefinitely i want to leave you with a question +[231.47s -> 246.38s] What becomes of the purple component of force along the satellite's path when the satellite is closest to and farthest from Earth? And more important, why? Until next time, good energy! diff --git a/VideoMMMU_ASR_large/Science/validation_Physics_8.mp4.txt b/VideoMMMU_ASR_large/Science/validation_Physics_8.mp4.txt new file mode 100644 index 0000000000000000000000000000000000000000..290d503ffe20d9186d6f98c6af4eedcbd288c728 --- /dev/null +++ b/VideoMMMU_ASR_large/Science/validation_Physics_8.mp4.txt @@ -0,0 +1,37 @@ +[0.02s -> 8.75s] Professor Dave here, let's discuss angular motion. +[9.84s -> 18.14s] We talked about uniform circular motion, but we need to make an important distinction between spin and orbital motion. +[18.14s -> 31.47s] An object can spin around an internal axis that goes through its center of mass, and it can also orbit around some external axis. This means that the earth will spin on its axis +[31.47s -> 41.78s] but it orbits around the sun. We have discussed spinning objects and the way that tangential speed will vary according to distance from the axis of rotation. +[41.78s -> 56.13s] But this can be a tricky way to view the rotation of something like a ferris wheel, because there is a certain context in which we would like to say that every part of the wheel is spinning at the same speed, since it is one solid object. +[56.13s -> 67.31s] For this reason, when we are looking at a rotating rigid object, rather than looking at translational motion, we will want to discuss angular motion, or rotational motion. +[67.89s -> 72.46s] To do this we can begin to discuss certain angular quantities. +[72.46s -> 83.14s] angular displacement represented by theta will be the angle swept out by any line passing through a rotating body that intersects the axis of rotation. +[83.14s -> 89.28s] This value will be positive if the motion is counterclockwise and negative if clockwise. +[89.28s -> 103.60s] you have a hard time remembering this just remember that in going counterclockwise around the xy plane we will cover quadrants one two three and then four so positive angular displacement correlates with a positive +[103.60s -> 107.92s] increase in the number quadrant that is being traversed over time. +[108.27s -> 122.86s] The SI unit for angular displacement will not be degrees, but rather radians. We will discuss the derivation and importance of the radian in the upcoming mathematics course, but for now, we simply need to know that one +[122.86s -> 137.55s] revolution is equal to two pi radians, so if the rotation completed by the object is a counterclockwise quarter turn, the angular displacement is one half pi radians, or pi over two. +[137.97s -> 148.66s] Angular velocity, as one might expect, is equal to the angular displacement over some time period, just the same way that linear velocity is equal to linear displacement over time. +[148.66s -> 156.05s] average angular velocity, represented by the Greek letter omega, is therefore given as delta theta over delta t. +[156.05s -> 168.19s] The SI unit for this value will be radians per second, although we will frequently encounter other units like revolutions per minute, or RPM. Again, counterclockwise rotation involves +[168.19s -> 181.01s] positive angular velocity and clockwise will be negative. Lastly, angular acceleration, represented by the Greek letter alpha, is equal to the change in angular velocity over some time period. +[181.01s -> 187.12s] This will be equal to delta omega over delta t, with units of radians per second squared. +[187.22s -> 201.81s] Now that we have defined these terms, we can begin to understand that rotational kinematics will utilize equations that are direct analogs of those involved with linear kinematics. We just swap out linear components +[201.81s -> 211.54s] for angular ones. Looking at these familiar equations, if we just exchange displacement for angular displacement, velocity for +[211.54s -> 222.18s] angular velocity and acceleration for angular acceleration, we arrive at a new set of equations that allow us to calculate rotational motion. +[222.18s -> 228.91s] they will apply to any system with rotational motion under constant angular acceleration. +[228.91s -> 242.58s] Depending on the scenario, it may or may not be easier to model rotational motion with these equations rather than with the linear ones, where we have to use tangential velocities that vary according to the radius. +[243.02s -> 249.73s] How can we set a system into rotational motion? We can do this by generating something called a torque. +[249.73s -> 264.05s] Torque is defined as the ability of a force to rotate an object around some axis, whether we are looking at a wheel, a seesaw, or anything else that exhibits this kind of motion, and for now we can just look at a top-down view +[264.05s -> 268.80s] a panel attached to a rod, allowing for free rotation. +[268.80s -> 283.12s] Torque, represented by the Greek letter tau, will be equal to the applied force times the distance over which the force is applied, times sine theta, where theta is the angle between the force vector and the plane of the rotating force vector. +[283.12s -> 297.57s] object. Torque will therefore have units of Newton meters, and torque will be at a maximum when the applied force is perpendicular to the plane containing the object, because the sine of 90 degrees is one. +[297.57s -> 311.89s] Any angle less than 90 in either direction will give a sine value that is less than one, and will therefore diminish the torque, while still producing some motion, until the angle is zero, at which point the whole expression will be equal to zero. +[311.89s -> 324.74s] and no motion can result. By convention we will say that torque is positive if it results in counterclockwise rotation and negative if it results in clockwise rotation, as we are by now familiar. +[324.74s -> 339.06s] This must be the case, because if two different forces act upon this object to produce opposite torques that are equal in magnitude, the object will not move and the sum of the individual torques must be zero. +[339.06s -> 351.42s] to reflect this fact. We must also note that the magnitude of torque will be equal to the magnitude of the applied force times the length of the lever arm, expressed in Newton meters. +[351.42s -> 365.71s] the lever arm, or the +[365.71s -> 376.62s] from the axis of rotation to the point where the force is applied. This sheds light on the quote by Archimedes which is generally reported as some variation of the following. +[376.62s -> 390.21s] Give me a lever long enough, and a fulcrum to place it on, and I will move the earth. This implies that with a long enough lever arm, one could generate such a massive torque so as to move the world. +[390.21s -> 401.36s] Wise words from a wise man, so let's learn about some other things Archimedes said next, but first let's check comprehension. +[427.54s -> 438.32s] Thanks for watching, guys. Subscribe to my channel for more tutorials, support me on patreon so I can keep making content, and as always feel free to email me,