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the larger a surface wave is, the more energy the wave has. | (A) true (B) false | A | All waves are the way energy travels through matter. Ocean waves are energy traveling through water. They form when wind blows over the surface of the ocean. Wind energy is transferred to the sea surface. Then, the energy is carried through the water by the waves. Figure 10.11 shows ocean waves crashing against rocks o... |
an ocean wave carries water all the way across the ocean to the opposite shore. | (A) true (B) false | B | Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind through water. The energy of a wave may travel for thousands of miles. The water itself moves very little. Figure 14.9 sh... |
which of the following is not a synthesis reaction? | (A) 2H2 + O2 → 2H2O (B) 2CO + O2 → 2CO2 (C) 3H2 + N2 → 2NH3 (D) Mg + 2HCl → MgCl2 + H2 | D | A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction ... |
the chemical equation 2no + o2 2no2 represents a synthesis reaction. | (A) true (B) false | A | A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+BC In this equation, the letters A and B represent the reactants that begin the reaction, and the letter C represents the product that is synthesized in the reactio... |
the product of a synthesis reaction can be an element or a compound. | (A) true (B) false | B | A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction ... |
examples of synthesis reactions include | (A) 2K + Cl2 → 2KCl (B) Zn + 2HCl → ZnCl2 + H2 (C) Cl2 + 2KBr → 2KCl + Br2 (D) two of the above | A | A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction ... |
physical constraints on technological design include | (A) scientific laws (B) ease of use (C) safety (D) cost | A | Technological design always has constraints. Constraints are limits on the design. Common constraints include: laws of nature, such as the law of gravity. properties of the materials used. cost of producing a technology. Ethical concerns are also constraints on many technological designs. Like scientists, engineers mus... |
technology can have both positive and negative effects on people. | (A) true (B) false | A | Important new technologies such as the wheel have had a big impact on human society. Major advances in technol- ogy have influenced every aspect of life, including transportation, food production, manufacturing, communication, medicine, and the arts. Thats because technology has the goal of solving human problems, so n... |
how did the industrial revolution affect society? | (A) New cities grew up around factories (B) Living conditions in cities improved (C) Average income decreased (D) Population size decreased | A | Few technologies have impacted society as greatly as the powerful steam engine developed by Scottish inventor James Watt in 1775 (see Figure 1.1). Watts steam engine was soon being used to power all kinds of machines. It started a revolution in industry. For the first time in history, people did not have to rely on hum... |
thermal conduction occurs more quickly in certain solids and liquids than in gases. | (A) true (B) false | A | Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soo... |
good thermal conductors include | (A) aluminum (B) plastic (C) wood (D) two of the above | A | Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soo... |
when you wear a down jacket, it prevents the transfer of cold from the outside air to your body. | (A) true (B) false | B | One way to retain your own thermal energy on a cold day is to wear clothes that trap air. Thats because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they dont bump into each other or into other things as often as the more closely spaced particles of l... |
good thermal insulators include | (A) air (B) Styrofoam (C) iron (D) two of the above | D | One way to retain your own thermal energy on a cold day is to wear clothes that trap air. Thats because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they dont bump into each other or into other things as often as the more closely spaced particles of l... |
only matter that feels warm has thermal energy. | (A) true (B) false | B | The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an obje... |
the thermal energy of matter depends on its | (A) mass (B) temperature (C) number of particles (D) all of the above | D | The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an obje... |
an object with a lower temperature always has less thermal energy than an object with a warmer temperature. | (A) true (B) false | B | Something that has a high temperature is said to be hot. Does temperature measure heat? Is heat just another word for thermal energy? The answer to both questions is no. Heat is the transfer of thermal energy between objects that have different temperatures. Thermal energy always moves from an object with a higher temp... |
which choice has the least thermal energy? | (A) cup of hot cocoa (B) bathtub full of warm water (C) swimming pool full of cool water (D) all the water in Earth’s oceans | A | Thermal energy and temperature are closely related. Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter. Does this mean that matter with a lower temperature has... |
the faster the particles of matter are moving, the greater their kinetic energy is. | (A) true (B) false | A | The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. |
the slower the particles of matter are moving, the lower their temperature is. | (A) true (B) false | A | No doubt you already have a good idea of what temperature is. You might say that its how warm or cool something feels. In physics, temperature is defined as the average kinetic energy of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so their temperature is higher. W... |
thermal energy is the total kinetic energy of moving particles of matter. | (A) true (B) false | A | The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an obje... |
examples of thermal radiation include thermal energy traveling through | (A) the air from a campfire to you (B) empty space from the sun to Earth (C) a metal pan to water inside the pan (D) two of the above | D | Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This i... |
no matter is required to transfer thermal energy by | (A) conduction (B) convection (C) radiation (D) two of the above | C | Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This i... |
only very hot objects radiate thermal energy. | (A) true (B) false | B | Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This i... |
life on earth depends on thermal energy radiated from the sun. | (A) true (B) false | A | Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. |
thomson won a nobel prize for his discovery of protons. | (A) true (B) false | B | John Dalton discovered atoms in 1804. He thought they were the smallest particles of matter, which could not be broken down into smaller particles. He envisioned them as solid, hard spheres. It wasnt until 1897 that a scientist named Joseph John (J. J.) Thomson discovered that there are smaller particles within the ato... |
thomson knew that the particles he discovered were smaller than atoms because of their | (A) charge (B) color (C) mass (D) volume | C | John Dalton discovered atoms in 1804. He thought they were the smallest particles of matter, which could not be broken down into smaller particles. He envisioned them as solid, hard spheres. It wasnt until 1897 that a scientist named Joseph John (J. J.) Thomson discovered that there are smaller particles within the ato... |
thomson thought that the positive charges in an atom were | (A) concentrated in the nucleus (B) clumped into small clusters like plums (C) spread throughout the atom (D) none of the above | C | Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like a plum pudding, which has plums scattered through it. Thats why Thomsons model of the atom is ... |
thomsons research proved daltons earlier claim about the smallest particles of matter. | (A) true (B) false | B | John Dalton discovered atoms in 1804. He thought they were the smallest particles of matter, which could not be broken down into smaller particles. He envisioned them as solid, hard spheres. It wasnt until 1897 that a scientist named Joseph John (J. J.) Thomson discovered that there are smaller particles within the ato... |
all atoms are neutral in electric charge. | (A) true (B) false | A | Atoms are neutral in electric charge because they have the same number of electrons as protons. However, atoms may transfer electrons and become charged ions, as illustrated in Figure 23.5. Positively charged ions, or cations, form when atoms give up electrons. Negatively charged ions, or anions, form when atoms gain e... |
the formation of charged matter always depends on the transfer of electrons. | (A) true (B) false | A | Like the formation of ions, the formation of charged matter in general depends on the transfer of electrons, either between two materials or within a material. Three ways this can occur are referred to as conduction, polarization, and friction. All three ways are described below. However, regardless of how electrons ar... |
ways that matter can become electrically charged include | (A) conduction (B) convection (C) radiation (D) all of the above | A | Like the formation of ions, the formation of charged matter in general depends on the transfer of electrons, either between two materials or within a material. Three ways this can occur are referred to as conduction, polarization, and friction. All three ways are described below. However, regardless of how electrons ar... |
conduction occurs when you | (A) touch a van de Graaff generator (B) rub a balloon on your hair (C) reach toward a metal doorknob (D) two of the above | A | To understand how conduction works, you need to think about the tiny particles that make up matter. The particles of all matter are in constant random motion, but the particles of warmer matter have more energy and move more quickly than the particles of cooler matter. When particles of warmer matter collide with parti... |
polarization occurs only when there is direct contact between two objects. | (A) true (B) false | B | Polarization is the movement of electrons within a neutral object due to the electric field of a nearby charged object. It occurs without direct contact between the two objects. You can see how it happens in Figure 23.8. When the negatively charged plastic rod in the figure is placed close to the neutral metal plate, e... |
electrons are transferred whenever there is friction between materials that differ in their ability to give up or accept electrons. | (A) true (B) false | A | Another way electrons may be transferred is through conduction. This occurs when there is direct contact between materials that differ in their ability to give up or accept electrons. For example, wool tends to give up electrons and rubber tends to accept them. Therefore, when you walk across a wool carpet in rubber-so... |
of all known elements, transition metals make up about | (A) 80 percent (B) 60 percent (C) 40 percent (D) 20 percent | B | Transition metals are all the elements in groups 3-12 of the periodic table. In the periodic table pictured in Figure known elements. In addition to copper (Cu), well known examples of transition metals include iron (Fe), zinc (Zn), silver (Ag), and gold (Au) (Copper (Cu) is pictured in its various applications in the ... |
transition metals include | (A) aluminum (B) barium (C) cobalt (D) all of the above | C | Transition metals are all the elements in groups 3-12 of the periodic table. In the periodic table pictured in Figure known elements. In addition to copper (Cu), well known examples of transition metals include iron (Fe), zinc (Zn), silver (Ag), and gold (Au) (Copper (Cu) is pictured in its various applications in the ... |
which of the following is not a property of most transition metals? | (A) malleability (B) ability to conduct electricity (C) ability to conduct heat (D) low melting point | D | Transition metals are superior conductors of heat as well as electricity. They are malleable, which means they can be shaped into sheets, and ductile, which means they can be shaped into wires. They have high melting and boiling points, and all are solids at room temperature, except for mercury (Hg), which is a liquid.... |
transition metals are high in density and very hard. | (A) true (B) false | A | Transition metals are superior conductors of heat as well as electricity. They are malleable, which means they can be shaped into sheets, and ductile, which means they can be shaped into wires. They have high melting and boiling points, and all are solids at room temperature, except for mercury (Hg), which is a liquid.... |
most transition metals are dull and brown in color. | (A) true (B) false | B | Groups 3-12 of the periodic table contain transition metals (see Figure 6.11). Transition metals have more valence electrons and are less reactive than metals in the first two metal groups. The transition metals are shiny. Many are silver colored. They tend to be very hard, with high melting and boiling points. All exc... |
a mechanical wave is a wave that travels through matter. | (A) true (B) false | A | The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the med... |
the matter a mechanical wave travels through is called the medium. | (A) true (B) false | A | The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the med... |
examples of transverse waves include the wave that travels through a | (A) guitar string when you pluck it (B) spring toy when you shake it from side to side (C) bungee cord when you shake it up and down (D) all of the above | D | A transverse wave is a wave in which the medium vibrates at right angles to the direction that the wave travels. An example of a transverse wave is a wave in a rope, like the one pictured in Figure 19.2. In this wave, energy is provided by a persons hand moving one end of the rope up and down. The direction of the wave... |
earthquake waves travel in all directions away from the disturbance that causes the earthquake. | (A) true (B) false | A | Seismic waves are the energy from earthquakes. Seismic waves move outward in all directions away from their source. Each type of seismic wave travels at different speeds in different materials. All seismic waves travel through rock, but not all travel through liquid or gas. Geologists study seismic waves to learn about... |
s waves travel through underground rocks. | (A) true (B) false | A | Transverse waves called S waves occur during earthquakes. The disturbance that causes an earthquake sends transverse waves through underground rocks in all directions away from the disturbance. S waves may travel for hundreds of miles. An S wave is modeled in the Figure 1.3. |
types of friction include | (A) static friction (B) sliding friction (C) rolling friction (D) all of the above | D | Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction: static, sliding, rolling, and fluid friction. Static, sliding, and rolling friction occur between solid surfaces. Fluid friction occurs in liquids and gases. All four types of friction are described bel... |
static friction prevents you from slipping when you walk on a sidewalk. | (A) true (B) false | A | Static friction acts on objects when they are resting on a surface. For example, if you are walking on a sidewalk, there is static friction between your shoes and the concrete each time you put down your foot (see Figure 13.12). Without this static friction, your feet would slip out from under you, making it difficult ... |
sliding friction is stronger than static friction. | (A) true (B) false | B | Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. Thats why its easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example... |
factors that affect the amount of friction against an object moving through the air include the objects | (A) speed (B) weight (C) temperature (D) two of the above | A | Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If youve ever tried to push your open hand through the water in a tub or pool, then youve experienced fluid friction between your h... |
when you put on the brakes of your bike, the wheels stop turning. then friction between the wheels and the road slows your bike to a stop. which type of friction is this? | (A) fluid friction (B) static friction (C) sliding friction (D) rolling friction | C | Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. Thats why its easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example... |
some animals use echolocation to find prey. | (A) true (B) false | A | Animals such as bats and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. You can see in the Figure 1.1 how a bat uses echoloca... |
sonar is used to determine the | (A) speed of motor vehicles (B) distance to underwater objects (C) location of approaching storms (D) all of the above | B | Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a re... |
you can calculate distance from speed and time with the equation | (A) Distance = Speed/Time (B) Distance = Time/Speed (C) Distance = Speed x Time (D) none of the above | C | If you know the average speed of a moving object, you can calculate the distance it will travel in a given period of time or the time it will take to travel a given distance. To calculate distance from speed and time, use this version of the average speed formula given above: distance = speed time For example, if a ca... |
the speed of sound waves through ocean water is 1437 m/s. assume that ultrasound waves take 2 seconds to travel from a sonar device on a ship to the bottom of the water and back to the ship again. how deep is the water? | (A) 2874 m (B) 1437 m (C) 718 m (D) none of the above | B | Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a re... |
the use of reflected ultrasound waves to create images of organs inside the body is called ultrasonography. | (A) true (B) false | A | Another use of ultrasound is to see inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patie... |
the smallest alkene is methene. | (A) true (B) false | B | Unsaturated hydrocarbons that contain at least one double bond are called alkenes. The name of a specific alkene always ends in ene, with a prefix indicating the number of carbon atoms. Figure 9.10 shows the structural formula for the smallest alkene. It has just two carbon atoms and is named ethene. Ethene is produced... |
smaller alkenes are gases at room temperature. | (A) true (B) false | A | Unsaturated hydrocarbons that contain at least one double bond are called alkenes. The name of a specific alkene always ends in ene, with a prefix indicating the number of carbon atoms. Figure 9.10 shows the structural formula for the smallest alkene. It has just two carbon atoms and is named ethene. Ethene is produced... |
which statement about aromatic hydrocarbons is true? | (A) They have only single bonds (B) They have branched-chain shapes (C) They have strong scents (D) two of the above | C | Unsaturated hydrocarbons called aromatic hydrocarbons are cyclic hydrocarbons that have double bonds. These compounds have six carbon atoms in a ring with alternating single and double bonds. The smallest aromatic hydrocarbon is benzene, which has just one ring. Its structural formula is shown in the Figure 1.2. Larger... |
alkynes are very common in nature. | (A) true (B) false | B | Unsaturated hydrocarbons that contain at least one triple bond are called alkynes. The name of specific alkynes always end in yne, with a prefix for the number of carbon atoms. Figure 9.12 shows the smallest alkyne, called ethyne, which has just two carbon atoms. Ethyne is also called acetylene. It is burned in acetyle... |
which chemical formula represents an alkyne? | (A) CH4 (B) C2H6 (C) C2H4 (D) C2H2 | D | Unsaturated hydrocarbons that contain one or more triple bonds are called alkynes. The names of specific alkynes always end in -yne and have a prefix for the number of carbon atoms. The structural formula in the Figure 1.3 represents the smallest alkyne, named ethyne, which has two carbon atoms and two hydrogen atoms (... |
earth has north and south magnetic poles like a bar magnet. | (A) true (B) false | A | Imagine a huge bar magnet passing through Earths axis, as illustrated in Figure 24.10. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles and a magnetic field. |
how does earths magnetic field protect the planet? | (A) It holds the atmosphere in place (B) It deflects solar winds (C) It protects Earth’s organisms from radiation (D) two of the above | D | Earths magnetic field helps protect Earth and its organisms from harmful particles given off by the sun. Most of the particles are attracted to the north and south magnetic poles, where Earths magnetic field is strongest. This is also where relatively few organisms live. Another benefit of Earths magnetic field is its ... |
there would be no northern lights without the magnetosphere. | (A) true (B) false | A | When massive solar storms cause the Van Allen belts to become overloaded with particles, the result is the most spectacular feature of the ionosphere the nighttime aurora (Figure 1.1). The particles spiral along magnetic field lines toward the poles. The charged particles energize oxygen and nitrogen gas molecules, ca... |
animals that use earths magnetic field for navigation include | (A) loggerhead turtles (B) migratory birds (C) humans (D) all of the above | D | Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural compasses that work just as well. For example, the loggerhead turtle in the Figure 1.2 senses the direction and strength of Earths magnetic field an... |
people have only recently started using earths magnetic field for determining direction. | (A) true (B) false | B | Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural compasses that work just as well. For example, the loggerhead turtle in the Figure 1.2 senses the direction and strength of Earths magnetic field an... |
some birds may be able to sense earths magnetic field lines as a visual pattern. | (A) true (B) false | A | Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural compasses that work just as well. For example, the loggerhead turtle in the Figure 1.2 senses the direction and strength of Earths magnetic field an... |
valence electrons tend to be attracted by the nuclei of other atoms as much as, or more than, the nucleus of their own atom. | (A) true (B) false | A | Valence electrons are the electrons in the outer energy level of an atom that can participate in interactions with other atoms. Valence electrons are generally the electrons that are farthest from the nucleus. As a result, they may be attracted as much or more by the nucleus of another atom than they are by their own n... |
all the elements in the same period of the periodic table have the same number of valence electrons. | (A) true (B) false | B | The number of valence electrons in an atom is reflected by its position in the periodic table of the elements (see the periodic table in the Figure 1.1). Across each row, or period, of the periodic table, the number of valence electrons in groups 1-2 and 13-18 increases by one from one element to the next. Within each ... |
what is the maximum number of valence electrons an element may have? | (A) 6 (B) 8 (C) 10 (D) 12 | B | The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the ne... |
when a group 1 element reacts it | (A) gains two electrons (B) loses two electrons (C) gains one electron (D) loses one electron | D | The halogens are among the most reactive of all elements, although reactivity declines from the top to the bottom of the halogen group. Because all halogens have seven valence electrons, they are eager to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of elec... |
which element would you expect to gain one electron in a chemical reaction? | (A) chlorine (B) oxygen (C) nitrogen (D) carbon | A | It takes energy to remove valence electrons from an atom. The force of attraction between the negative electrons and positive nucleus must be overcome. The amount of energy needed depends on the element. Less energy is needed to remove just one or a few electrons than many. This explains why sodium and other alkali met... |
velocity is a vector. | (A) true (B) false | A | Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow ... |
if you represent velocity with an arrow, the length of the arrow represents | (A) speed (B) distance (C) direction (D) acceleration | A | Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow ... |
the si unit for velocity is km/h. | (A) true (B) false | B | How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. |
the steepness of a line graph is called its slope. | (A) true (B) false | A | In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The ste... |
if a velocity-time graph is horizontal, then velocity is | (A) increasing (B) decreasing (C) not changing (D) accelerating | C | In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The ste... |
in the graph described in question 5, acceleration is | (A) zero (B) positive (C) less than 1 (D) none of the above | A | In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant ... |
in the graph in question 8, acceleration between seconds 2 and 4 is 10 m/s. | (A) true (B) false | B | In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant ... |
a clear image is produced by diffuse reflection. | (A) true (B) false | B | If a surface is extremely smooth, like very still water, then an image formed by reflection is sharp and clear. This is called regular reflection. If the surface is even slightly rough, an image may not form, or if there is an image, it is blurry or fuzzy. This is called diffuse reflection. Both types of reflection are... |
regular reflection occurs when the reflective surface is very smooth. | (A) true (B) false | A | Reflection of light occurs when light bounces back from a surface that it cannot pass through. Reflection may be regular or diffuse. If the surface is very smooth, like a mirror, the reflected light forms a very clear image. This is called regular, or specular, reflection. In the Figure 1.1, the smooth surface of the s... |
when light passes from one medium into another it may | (A) change direction (B) change speed (C) be refracted (D) all of the above | D | Transmission of light occurs when light passes through matter. As light is transmitted, it may pass straight through matter or it may be refracted or scattered as it passes through. When light is refracted, it changes direction as it passes into a new medium and changes speed. The straw in the Figure 1.2 looks bent whe... |
when light is absorbed, it transfers its energy to matter. | (A) true (B) false | A | Light may transfer its energy to matter rather than being reflected or transmitted by matter. This is called absorption. When light is absorbed, the added energy increases the temperature of matter. If you get into a car that has been sitting in the sun all day, the seats and other parts of the cars interior may be alm... |
what happens to light that strikes transparent matter? | (A) It is reflected (B) It is absorbed (C) It is transmitted (D) none of the above | C | When visible light strikes matter, it interacts with it. How light interacts with matter depends on the type of matter. |
matter is opaque if it | (A) absorbs light (B) reflects light (C) transmits light (D) two of the above | D | Matter can be classified on the basis of its interactions with light. Matter may be transparent, translucent, or opaque. An example of each type of matter is pictured in the Figure 1.4. Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and c... |
the sclera is the opaque, white, outer covering of the eye. | (A) true (B) false | A | The human eye is an organ that is specialized to collect light and focus images. The structures of the human eye are shown in the Figure 1.1. Examine each structure in the diagram as you read about it below. The sclera, also known as the white of the eye, is an opaque outer covering that protects the eye. It keeps ligh... |
the lens is the only structure in the eye that focuses light. | (A) true (B) false | B | The human eye is an organ that is specialized to collect light and focus images. The structures of the human eye are shown in the Figure 1.1. Examine each structure in the diagram as you read about it below. The sclera, also known as the white of the eye, is an opaque outer covering that protects the eye. It keeps ligh... |
which of the following statements about the cornea is false? | (A) It is transparent (B) It helps focus light (C) It helps protect the eye (D) none of the above | D | The human eye is an organ that is specialized to collect light and focus images. The structures of the human eye are shown in the Figure 1.1. Examine each structure in the diagram as you read about it below. The sclera, also known as the white of the eye, is an opaque outer covering that protects the eye. It keeps ligh... |
which structure controls the amount of light that enters the eye? | (A) retina (B) lens (C) pupil (D) none of the above | C | The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye... |
the membrane lining the back of the eye is the | (A) cornea (B) sclera (C) retina (D) optic nerve | C | The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye... |
rods are nerve cells that sense different colors of light. | (A) true (B) false | B | The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye... |
the vision problem called myopia is also called farsightedness. | (A) true (B) false | B | Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can ... |
in myopia, images focus | (A) in front of the retina (B) behind the retina (C) above the retina (D) on the retina | A | Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can ... |
the vision problem called hyperopia is also called nearsightedness. | (A) true (B) false | B | You probably know people who need eyeglasses or contact lenses to see clearly. Maybe you need them yourself. Lenses are used to correct vision problems. Two of the most common vision problems in young people are myopia and hyperopia. You can compare myopia and hyperopia in Figure 20.13. To learn about astigmatism, anot... |
in hyperopia, the eyeball is | (A) longer than normal (B) shorter than normal (C) smaller than normal (D) larger than normal | B | Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure 1.2). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia... |
all waves that travel through matter are called | (A) longitudinal waves (B) mechanical waves (C) transverse waves (D) surface waves | B | The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the... |
the matter a wave travels through is called the material of the wave. | (A) true (B) false | B | The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the med... |
the more energy a wave has, the farther the particles of matter move. | (A) true (B) false | A | Waves that travel through mattersuch as the fabric of a flagare called mechanical waves. The matter they travel through is called the medium. When the energy of a wave passes through the medium, particles of the medium move. The more energy the wave has, the farther the particles of the medium move. The distance the pa... |
the position of a particle of matter in the absence of a wave is called the | (A) trough (B) midline (C) resting position (D) normal location | C | In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as propertie... |
a wave with greater energy has a larger amplitude. | (A) true (B) false | A | A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles. The ripples are low- amplitude waves with very little energy. Now imagine throwing a big boulder into the pond. Very l... |
in all mechanical waves, particles of the medium move up and down when the wave passes through them. | (A) true (B) false | B | The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the med... |
a wave with a higher frequency has a longer wavelength. | (A) true (B) false | B | The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude... |
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