instruction stringlengths 5 342 | input stringlengths 18 558 | output stringclasses 7
values | context stringlengths 31 6.57k |
|---|---|---|---|
The input distance of an inclined plane is always greater than the output distance. | (A) true (B) false | A | The man in Figure 16.14 is using a ramp to move a heavy dryer up to the back of a truck. The highway in the figure switches back and forth so it climbs up the steep hillside. Both the ramp and the highway are examples of inclined planes. An inclined plane is a simple machine consisting of a sloping surface that connect... |
The input force is always applied to the thinner side of a wedge. | (A) true (B) false | B | Imagine trying to slice a tomato with a fork or spoon instead of a knife, like the one in Figure 16.15. The knife makes the job a lot easier because of the wedge shape of the blade. A wedge is a simple machine that consists of two inclined planes. But unlike one inclined plane, a wedge works only when it moves. It has ... |
The center of a wheel and axle is called the fulcrum. | (A) true (B) false | B | A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in t... |
The closer together the threads of a screw are, the harder it is to turn the screw. | (A) true (B) false | B | The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. The force applied by the screw (output force) is always greater than the force applied to the screw (input force). Therefore, the mechanical advanta... |
A wedge is used to cut or split objects. | (A) true (B) false | A | A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This f... |
When you use a hammer to pry a nail out of board, the hammer is a first class lever. | (A) true (B) false | A | Did you ever use a hammer to pull a nail out of a board? If not, you can see how its done in Figure 16.18. When you pull down on the handle of the hammer, the claw end pulls up on the nail. A hammer is an example of a lever. A lever is a simple machine consisting of a bar that rotates around a fixed point called the fu... |
A lever always increases the force applied to the lever. | (A) true (B) false | B | All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with a first-class lever. When both the input and output forces are on the same side of the fulcru... |
When you turn a screw, you apply force along its inclined plane. | (A) true (B) false | A | A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move objects to a greater depth (or highe... |
The wheel of a Ferris wheel turns more quickly than the axle. | (A) true (B) false | A | Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same... |
A lever may or may not change the strength of the applied force. | (A) true (B) false | A | All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with first-class levers. When both the input and output forces are on the same side of the fulcrum... |
The wheel of a wheel and axle turns more slowly than the axle. | (A) true (B) false | B | Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same... |
A single fixed pulley has an ideal mechanical advantage of 1. | (A) true (B) false | A | The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat ... |
A compound pulley always contains at least two fixed pulleys. | (A) true (B) false | B | Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulle... |
A zip-line pulley is an example of a single moveable pulley. | (A) true (B) false | A | Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulle... |
simple machine that consists of a rope and grooved wheel | (A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum | C | A pulley is a simple machine that consists of a rope and grooved wheel. The rope fits into the groove in the wheel, and pulling on the rope turns the wheel. Pulleys are generally used to lift objects, especially heavy objects. The object lifted by a pulley is called the load. The force applied to the pulley is called t... |
type of lever in which the fulcrum is between the input and output forces | (A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum | E | All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with a first-class lever. When both the input and output forces are on the same side of the fulcru... |
simple machine consisting of two connected rings or cylinders that both turn around a single center point | (A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum | F | A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in t... |
simple machine that consists of an inclined plane wrapped around a cylinder or cone | (A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum | D | An inclined plane is a simple machine that consists of a sloping surface connecting a lower elevation to a higher elevation. An inclined plane is one of six types of simple machines, and it is one of the oldest and most basic. In fact, two other simple machines, the wedge and the screw, are variations of the inclined p... |
fixed point of a lever around which the bar rotates | (A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum | G | A lever is a simple machine consisting of a bar that rotates around a fixed point. The fixed point of a lever is called the fulcrum. Like other machines, a lever makes work easier by changing the force applied to the machine or the distance over which the force is applied. How does a hammer make it easier to pull a nai... |
simple machine consisting of a sloping surface that connects lower and higher elevations | (A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum | A | An inclined plane is a simple machine that consists of a sloping surface connecting a lower elevation to a higher elevation. An inclined plane is one of six types of simple machines, and it is one of the oldest and most basic. In fact, two other simple machines, the wedge and the screw, are variations of the inclined p... |
type of lever in which input and output forces are on the same side of the fulcrum | (A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum | B | All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with a first-class lever. When both the input and output forces are on the same side of the fulcru... |
how greatly a machine increases the applied force | (A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors | B | Many machinesincluding inclined planes such as rampsincrease the strength of the force put into the machine but decrease the distance over which the force is applied. Other machines increase the distance over which the force is applied but decrease the strength of the force. Still other machines change the direction of... |
Simple machines in a pair of scissors include | (A) two levers (B) two wedges (C) one wheel and axle (D) two of the above | D | Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum li... |
how well a machine deals with friction | (A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors | F | Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than s... |
Compound machines include all of the following except a(n) | (A) chisel (B) bicycle (C) automobile (D) wheelbarrow | A | A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. You can read below about two examplesthe wheelbarrow and corkscrew. Other compound machines, such as bicycles, consist of many simple machines. Big compound machines such as cars ma... |
An axe is a compound machine that consists of a wedge and a(n) | (A) screw (B) inclined plane (C) first class lever (D) third class lever | D | A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This f... |
example of a third class lever | (A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors | C | You may be wondering why you would use a third-class lever when it doesnt change the direction or strength of the applied force. The advantage of a third-class lever is that the output force is applied over a greater distance than the input force. This means that the output end of the lever must move faster than the in... |
any machine that consists of more than one simple machine | (A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors | A | A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. You can read below about two examplesthe wheelbarrow and corkscrew. Other compound machines, such as bicycles, consist of many simple machines. Big compound machines such as cars ma... |
A compound machine tends to be less efficient than a simple machine because a compound machine | (A) produces more work (B) exerts a greater force (C) has more moving parts (D) none of the above | C | Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it ma... |
example of a wheel and axle that works as a pulley | (A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors | E | Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same... |
Which of the following machines has the greatest mechanical advantage? | (A) mountain bike (B) inline skate (C) roller skate (D) tricycle | A | The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of... |
machine consisting of a wheel and axle and a lever | (A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors | D | Look at the wheelbarrow in the Figure 1.1. It is used to carry heavy objects. It consists of two simple machines: a lever and a wheel and axle. Effort is applied to the lever by picking up the handles of the wheelbarrow. The lever, in turn, applies upward force to the load. The force is increased by the lever, making t... |
machine consisting of two levers and two wedges | (A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors | G | A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This f... |
A wheel and axle is an example of a compound machine. | (A) true (B) false | B | A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. For example, a wheelbarrow consists of a lever, as you read earlier in the lesson "Simple Machines," and also a wheel and axle. Other compound machines, such as cars, consist of hun... |
A pulley system that contains a fixed and a moveable pulley is a compound machine. | (A) true (B) false | A | Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulle... |
A single pulley is less efficient than a pulley system that consists of two or more pulleys. | (A) true (B) false | B | The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat ... |
The mechanical advantage of a compound machine is generally less than that of a simple machine. | (A) true (B) false | B | Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it ma... |
Friction tends to be a bigger problem in a compound machine than in a simple machine. | (A) true (B) false | A | Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it ma... |
Simple machines in a bicycle include | (A) wheels and axles (B) pulleys (C) levers (D) all of the above | D | There are six types of simple machines that are the basis of all other machines. They are the inclined plane, lever, wedge, screw, pulley, and wheel and axle. The six types are pictured in the Figure 1.4. Youve probably used some of these simple machines yourself. Most machines are combinations of two or more simple ma... |
Which of the following is a compound machine? | (A) wheel and axle (B) scissors (C) pulley (D) lever | B | A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. For example, a wheelbarrow consists of a lever, as you read earlier in the lesson "Simple Machines," and also a wheel and axle. Other compound machines, such as cars, consist of hun... |
Which of the following machines contains one or more levers? | (A) wheelbarrow (B) scissors (C) fishing rod (D) all of the above | D | There are six types of simple machines that are the basis of all other machines. They are the inclined plane, lever, wedge, screw, pulley, and wheel and axle. The six types are pictured in the Figure 1.4. Youve probably used some of these simple machines yourself. Most machines are combinations of two or more simple ma... |
The fulcrum in a pair of scissors is always located | (A) between the input and output points (B) closer to the input point (C) closer to the output point (D) two of the above | A | Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum li... |
The mechanical advantage of a compound machine equals the | (A) sum of the mechanical advantages of all its simple machines (B) product of the mechanical advantages of all its simple machines (C) highest mechanical advantage of all its simple machines (D) average mechanical advantage of all of its simple machines | B | The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of... |
The way friction is reduced in a compound machine such as a car is with | (A) fans (B) heaters (C) lubricants (D) none of the above | C | Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than s... |
Some compound machines consist of thousands of simple machines. | (A) true (B) false | A | A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. You can read below about two examplesthe wheelbarrow and corkscrew. Other compound machines, such as bicycles, consist of many simple machines. Big compound machines such as cars ma... |
The output force is exerted by the handle ends of the levers in scissors. | (A) true (B) false | B | Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum li... |
Scissors change the direction of the input force. | (A) true (B) false | A | Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum li... |
The fulcrum in a fishing rod is at the center of the rod. | (A) true (B) false | B | The fishing rod with reel shown in Figure 16.25 is another compound machine. The rod is a third-class lever, with the fulcrum on one end of the rod, the input force close to the fulcrum, and the output force at the other end of the rod. The output distance is greater than the input distance, so the angler can fling the... |
Compound machines have more moving parts than simple machines. | (A) true (B) false | A | Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it ma... |
The fewer simple machines a compound machine contains, the greater its mechanical advantage. | (A) true (B) false | B | The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of... |
Compound machines have more friction to overcome than do simple machines. | (A) true (B) false | A | Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it ma... |
energy stored in an object because of its position or shape | (A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy | G | Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its o... |
A leaf hanging motionless on a tree has | (A) no energy (B) elastic energy (C) kinetic energy (D) potential energy | D | Did you ever see a scene like the one in Figure 17.4? In many parts of the world, trees lose their leaves in autumn. The leaves turn color and then fall from the trees to the ground. As the leaves are falling, they have kinetic energy. While they are still attached to the trees they also have energy, but its not becaus... |
stored energy due to an objects shape | (A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy | F | Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its o... |
When a moving bat hits a ball, what happens to the kinetic energy of the bat? | (A) All of it becomes potential energy (B) Most of it is transferred to the ball (C) All of it is used up and gone (D) Most of it changes to heat | B | What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo ... |
use of force to move matter | (A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy | D | Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matteryou. Any matter that is moving has energy just because its moving. The energy of moving matter is called kinetic energy. Scientists think that ... |
A 40-kilogram boy is running at a velocity of 3 m/s. What is his kinetic energy? | (A) 180 J (B) 120 J (C) 43 J (D) 13 J | A | Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg 50 m/s = 2.5 kg m/s Note that the SI unit for moment... |
Lana, who weighs 400 newtons, is about to dive from a 10-meter diving board. Her gravitational potential energy is | (A) 40 J (B) 2000 J (C) 4000 J (D) 40 (E) 000 J | C | Potential energy due to the position of an object above Earths surface is called gravitational potential energy. Like the diver on the diving board, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see another example of people with gravitational potential energy in ... |
energy of moving matter | (A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy | B | Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matteryou. Any matter that is moving has energy just because its moving. The energy of moving matter is called kinetic energy. Scientists think that ... |
stored energy due to an objects position | (A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy | E | Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its o... |
Energy is converted from kinetic energy to potential energy when you | (A) ski down a hill (B) climb a mountain (C) run around a level track (D) two of the above | B | Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. |
ability to do work | (A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy | A | What explains all of these events? The answer can be summed up in one word: energy. Energy is defined as the ability to do work. Doing anything takes energy. A campfire obviously has energy. You can feel its heat and see its light. |
process in which energy changes from one type or form to another | (A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy | C | Energy often changes from one form to another. For example, the mechanical energy of a moving drumstick changes to sound energy when it strikes the drumhead and causes it to vibrate. Any form of energy can change into any other form. Frequently, one form of energy changes into two or more different forms. For example, ... |
The atoms of matter have kinetic energy. | (A) true (B) false | A | Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. |
An objects velocity affects its kinetic energy more than its mass does. | (A) true (B) false | A | The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass velocity2 This equation shows that an increase in... |
A heavier object has less gravitational potential energy than a lighter object at the same height. | (A) true (B) false | B | Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly tha... |
Compressing a spring gives it potential energy. | (A) true (B) false | A | Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its o... |
Energy conversions cannot be reversed. | (A) true (B) false | B | The law of conservation of energy applies to energy conversions. Energy is not used up when it changes form, although some energy may be used to overcome friction, and this energy is usually given off as heat. For example, the divers kinetic energy at the bottom of his fall is the same as his potential energy when he w... |
The ability to cause a change in matter is one definition of | (A) work (B) force (C) energy (D) motion | C | Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter you. The energy of moving matter is called kinetic energy. |
Forms of energy include | (A) mechanical energy (B) electrical energy (C) chemical energy (D) all of the above | D | Energy, or the ability to cause changes in matter, can exist in many different forms. Energy can also change from one form to another. The photo above of the guitar player represents six forms of energy: mechanical, chemical, electrical, light, thermal, and sound energy. Another form of energy is nuclear energy. Q: Can... |
What is the kinetic energy of an object that has a mass of 10 kg and a velocity of 1 m/s? | (A) 100 J (B) 10 J (C) 5J (D) 1J | C | The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass velocity2 This equation shows that an increase in... |
What is the gravitational potential energy of an object that has a weight of 12 N and is 3 m above the ground? | (A) 108 J (B) 36 J (C) 15 J (D) 4J | B | Potential energy due to the position of an object above Earths surface is called gravitational potential energy. Like the diver on the diving board, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see another example of people with gravitational potential energy in ... |
Which statement is false about objects with kinetic energy? | (A) They are in motion (B) They are doing work (C) They are moving matter over a distance (D) They are using up their energy by moving | D | What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo ... |
The SI unit for energy is the | (A) joule (B) newton (C) newton meter (D) two of the above | D | Because energy is the ability to do work, it is expressed in the same unit that is used for work. The SI unit for both work and energy is the joule (J), or Newton meter (N m). One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. For example, suppose the boy in the Figure 1... |
Which type(s) of energy does a person have when jumping on a trampoline? | (A) kinetic energy (B) elastic potential energy (C) gravitational potential energy (D) all of the above | D | There are many other examples of energy conversions between potential and kinetic energy. Figure 17.7 describes how potential energy changes to kinetic energy and back again on swings and trampolines. You can see an animation of changes between potential and kinetic energy on a ramp at the URL below. Can you think of o... |
Most forms of energy can also be classified as kinetic or potential energy. | (A) true (B) false | A | If you think about different sources of energysuch as batteries and the sunyou probably realize that energy can take different forms. For example, when the boy swings his tennis racket, the energy of the moving racket is an example of mechanical energy. To move his racket, the boy needs energy stored in food, which is ... |
If the mass of an object doubles, its kinetic energy is only half as great. | (A) true (B) false | B | The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass velocity2 This equation shows that an increase in... |
Kinetic energy and velocity have an inverse relationship. | (A) true (B) false | B | What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo ... |
Clothes hanging motionless on a clothesline do not have any energy. | (A) true (B) false | B | Evaporation explains why clothes dry on a clothesline. Evaporation is the process in which a liquid changes to a gas without becoming hot enough to boil. It occurs when individual liquid particles at the exposed surface of the liquid absorb just enough energy to overcome the force of attraction with other liquid partic... |
Changing the shape of an elastic material gives it potential energy. | (A) true (B) false | A | Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its o... |
If you double the weight of an object, its gravitational potential energy also doubles. | (A) true (B) false | A | Potential energy due to the position of an object above Earth is called gravitational potential energy. Like the leaves on trees, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see examples of people with gravitational potential energy in Figure 17.5. Gravitational... |
The higher above the ground you are, the less gravitational potential energy you have. | (A) true (B) false | B | Potential energy due to the position of an object above Earth is called gravitational potential energy. Like the leaves on trees, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see examples of people with gravitational potential energy in Figure 17.5. Gravitational... |
The energy of a child on a swing changes back and forth between kinetic and potential energy. | (A) true (B) false | A | There are many other examples of energy conversions between potential and kinetic energy. Figure 17.7 describes how potential energy changes to kinetic energy and back again on swings and trampolines. You can see an animation of changes between potential and kinetic energy on a ramp at the URL below. Can you think of o... |
Some of the kinetic energy of the child in question 8 is given off as heat. | (A) true (B) false | A | What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo ... |
Energy conversions are always permanent changes in energy. | (A) true (B) false | B | Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change.... |
energy released when atomic nuclei split apart | (A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy | C | Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. |
The sum of an objects kinetic and potential energy is its | (A) thermal energy (B) chemical energy (C) mechanical energy (D) none of the above | C | Mechanical energy is the energy of an object that is moving or has the potential to move. It is the sum of an objects kinetic and potential energy. In Figure 17.9, the basketball has mechanical energy because it is moving. The arrow in the same figure has mechanical energy because it has the potential to move due to th... |
total kinetic energy of all the atoms in an object | (A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy | 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... |
Which form of energy travels in waves through empty space? | (A) sound energy (B) electrical energy (C) electromagnetic energy (D) two of the above | C | Energy that the sun and other stars release into space is called electromagnetic energy. This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays (Figure 17.14). |
energy stored in chemical bonds | (A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy | A | Energy is stored in the bonds between atoms that make up compounds. This energy is called chemical energy, and it is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. The wood in the fireplace in Figure 17.10 has chemical energy. The energy is released as thermal... |
Which energy conversion occurs in a battery? | (A) electrical energy chemical energy (B) electromagnetic energy light energy (C) chemical energy light energy (D) chemical energy electrical energy | D | Batteries like the one in Figure 23.11 are one of several possible sources of voltage needed to produce electric current. Sources of voltage include generators, chemical cells, and solar cells. Generators change the kinetic energy of a spinning turbine to electrical energy in a process called electromag- netic inductio... |
Energy stored in the nucleus of an atom is called | (A) electromagnetic energy (B) electrical energy (C) thermal energy (D) nuclear energy | D | The nuclei of atoms are held together by powerful forces. This gives them a tremendous amount of stored energy, called nuclear energy. The energy can be released and used to do work. This happens in nuclear power plants when nuclei fission, or split apart. It also happens in the sun and other stars when nuclei fuse, or... |
energy of an object that is moving or has the potential to move | (A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy | F | Mechanical energy is the energy of an object that is moving or has the potential to move. It is the sum of an objects kinetic and potential energy. In Figure 17.9, the basketball has mechanical energy because it is moving. The arrow in the same figure has mechanical energy because it has the potential to move due to th... |
energy that travels in waves through matter from a vibrating object | (A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy | G | 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... |
If two objects have the same mass, which object has greater thermal energy? | (A) The object with larger atomic nuclei (B) The object with faster-moving atoms (C) The object with faster-moving electrons (D) The object with stronger chemical bonds | B | If two objects have the same mass, the object with the higher temperature has greater thermal energy. Temperature affects thermal energy, but temperature isnt the same thing as thermal energy. Thats because an objects mass also affects its thermal energy. The examples in Figure 18.1 make this clear. In the figure, the ... |
kinetic energy of moving electrons | (A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy | B | Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. |
energy that travels in electrical and magnetic waves | (A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy | E | Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electro- magnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation. Electromagnetic waves can transfer energy through matter or ac... |
Stars release electromagnetic energy into space. | (A) true (B) false | A | Energy that the sun and other stars release into space is called electromagnetic energy. This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays (Figure 17.14). |
The energy stored in food is chemical energy. | (A) true (B) false | A | Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in ... |
During photosynthesis, plants change thermal energy to chemical energy. | (A) true (B) false | B | One of the most important series of endothermic reactions is photosynthesis. In photosynthesis, plants make the simple sugar glucose (C6 H12 O6 ) from carbon dioxide (CO2 ) and water (H2 O). They also release oxygen (O2 ) in the process. The reactions of photosynthesis are summed up by this chemical equation: 6 CO2 + 6... |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.