H. Physics Chapter 6 Test
1. Which of the following equations can be used to directly calculate an object's momentum, p? a. p=mv c. p=FΔt b. d. Δp=FΔt
A
1. Which of the following has the greatest momentum? a. a tortoise with a mass of 275 kg moving at a velocity of 0.55 m/s b. a hare with a mass of 2.7 kg moving at a velocity of 7.5 m/s c. a turtle with a mass of 91 kg moving at a velocity of 1.4 m/s d. a roadrunner with a mass of 1.8 kg moving at a velocity of 6.7 m/s
A
11. A billiard ball collides with a second identical ball in an elastic head-on collision. What is the kinetic energy of the system after the collision compared with the kinetic energy before the collision? a. unchanged c. two times as great b. one-fourth as great d. four times as great
A
11. Two large objects move separately after colliding, and both the total momentum and total kinetic energy remain constant. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
A
11. Two objects with different masses collide and bounce back after an elastic collision. Before the collision, the two objects were moving at velocities equal in magnitude but opposite in direction. After the collision, a. the less massive object had gained momentum. b. the more massive object had gained momentum. c. both objects had the same momentum. d. both objects lost momentum.
A
12. Two billiard balls collide. Identify the type of collision a. elastic b. perfectly elastic c. inelastic d. perfectly inelastic
A
12. Two billiard balls collide. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
A
13. In a two-body collision, a. momentum is always conserved. b. kinetic energy is always conserved. c. neither momentum nor kinetic energy is conserved. d. both momentum and kinetic energy are always conserved.
A
15. Two objects move separately after colliding, and both the total momentum and total kinetic energy remain constant. Identify the type of collision. a. elastic c. inelastic b. nearly elastic d. perfectly inelastic
A
16. Two carts with masses of 1.5 kg and 0.7 kg, respectively, are held together by a compressed spring. When released, the 1.5 kg cart moves to the left with a velocity of 7 m/s. What is the velocity of the 0.7 kg cart? (Disregard the mass of the spring.) a. 15 m/s to the right c. 7 m/s to the right b. 15 m/s to the left d. 7 m/s to the left
A
2. A baseball is pitched very fast. Another baseball of equal mass is pitched very slowly. Which of the following statements is correct? a. The fast-moving baseball is harder to stop because it has more momentum. b. The slow-moving baseball is harder to stop because it has more momentum. c. The fast-moving baseball is easier to stop because it has more momentum. d. The slow-moving baseball is easier to stop because it has more momentum.
A
2. A person sitting in a chair with wheels stands up, causing the chair to roll backward across the floor. The momentum of the chair a. was zero while stationary and increased when the person stood. b. was greatest while the person sat in the chair. c. remained the same. d. was zero when the person got out of the chair and increased while the person sat.
A
3. A person sitting in a chair with wheels stands, causing the chair to roll backward across the floor. The momentum of the chair a. was zero while stationary and increased when the person stood. b. was greatest while the person sat in the chair. c. remained the same. d. was zero when the person got out of the chair and increased while the person sat.
A
4. Which of the following situations is an example of change in momentum? a. A tennis ball is hit into a net. b. A helium-filled balloon rises upward into the sky. c. An airplane flies into some scattered white clouds. d. A bicyclist rides over a leaf on the pavement.
A
5. A ball with a momentum of 4.0 kg•m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum? a. 8.0 kg•m/s c. 0.0 kg•m/s b. 4.0 kg•m/s d. 8.0 kg•m/s
A
5. Two objects with different masses collide and bounce back after an elas- tic collision. Before the collision, the two objects were moving at veloci- ties equal in magnitude but opposite in direction. After the collision, a. the less massive object had gained momentum. b. the more massive object had gained momentum. c. both objects had the same momentum. d. both objects lost momentum.
A
7. A large moving ball collides with a small stationary ball. The momentum a. of the large ball decreases, and the momentum of the small ball increases. b. of the small ball decreases, and the momentum of the large ball increases. c. of the large ball increases, and the momentum of the small ball decreases. d. does not change for either ball.
A
7. Two objects with different masses collide and bounce back after the collision. Before the collision, the two objects were moving at velocities equal in magnitude but opposite in direction. After the collision, a. the less massive object gained momentum. b. the more massive object gained momentum. c. both objects had the same momentum. d. both objects lost momentum.
A
7. Which of the following situations is an example of a significant change in momentum? a . A tennis ball is hit into a net. b. A helium-filled balloon rises upward into the sky. c. An airplane flies into some scattered white clouds. d. A bicyclist rides over a leaf on the pavement.
A
8. A ball with a momentum of 4.0 kg•m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum? a. -8.0 kg•m/s c. 0.0 kg•m/s b. -4.0 kg•m/s d. 8.0 kg•m/s
A
9. In a two-body collision, a. momentum is always conserved. b. kinetic energy is always conserved. c. neither momentum nor kinetic energy is conserved. d. both momentum and kinetic energy are always conserved.
A
A 2 kg mass moving to the right makes an elastic head-on collision with a 4 kg mass moving to the left at 4 m/s. The 2 kg mass reverses direction after the collision and moves at 3 m/s. The 4 kg mass moves 1 m/s to the left. What was the initial velocity of the 4 kg mass? a. 3m/stotheright c. 4m/stotheleft b. 1 m/s to the left d. 4 m/s to the right
A
A 65.0 kg ice skater standing on frictionless ice throws a 0.15 kg snowball horizontally at a speed of 32.0 m/s. At what velocity does the skater move backward? a. 0.07 m/s c. 0.15 m/s b. 0.30 m/s d. 1.20 m/s
A
A large moving ball collides with a small stationary ball. The momentum a. of the large ball decreases, and the momentum of the small ball increases. b. of the small ball decreases, and the momentum of the large ball increases. c. of the large ball increases, and the momentum of the small ball decreases. d. does not change for either ball.
A
Two objects move separately after colliding, and both the total momentum and total kinetic energy remain constant. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
A
1. Which of the following has the greatest momentum? a. truck with a mass of 2250 kg moving at a velocity of 25 m/s b. car with a mass of 1210 kg moving at a velocity of 51 m/s c. truck with a mass of 6120 kg moving at a velocity of 10 m/s d. car with a mass of 1540 kg moving at a velocity of 38 m/s
B
10. A 75 kg person walking around a corner bumped into an 80 kg person who was running around the same corner. The momentum of the 80 kg person a. increased. c. remained the same. b. decreased. d. was conserved.
B
12. Two swimmers relax close together on air mattresses in a pool. One swimmer's mass is 48 kg, and the other's mass is 55 kg. If the swimmers push away from each other, a. their total momentum triples. c. their total momentum doubles. b. their momenta are equal but opposite. d. their total momentum decreases.
B
12. Which of the following best describes the momentum of two bodies after a two-body collision if the kinetic energy of the system is conserved? a. must be less c. might also be conserved b. must also be conserved d. is doubled in value
B
14. Which of the following statements about the conservation of momentum is not correct? a. Momentum is conserved for a system of objects pushing away from each other. b. Momentum is not conserved for a system of objects in a head-on collision. c. Momentum is conserved when two or more interacting objects push away from each other. d. The total momentum of a system of interacting objects remains constant regardless of forces between the objects.
B
3. A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster a. is greater up the hill than down the hill. b. is greater down the hill than up the hill. c. remains the same throughout the ride. d. is zero throughout the ride.
B
3. An ice skater skates at a velocity of 3 m/s. The skater then speeds up so that the velocity is increased to 5 m/s. The momentum of the skater a. decreased. c. remained the same. b. increased. d. became zero.
B
4. Which of the following statements properly relates the variables in the equation Ft p? a. A large constant force changes an object's momentum over a long time interval. b. A large constant force acting over a long time interval causes a large change in momentum. c. A large constant force changes an object's momentum at various time intervals. d. A large constant force does not necessarily cause a change in an object's momentum.
B
6. A 75 kg person walking around a corner bumped into an 80 kg person who was running around the same corner. The momentum of the 80 kg person a. increased. c. remained the same. b. decreased. d. was conserved.
B
6. The change in an object's momentum is equal to a. the product of the mass of the object and the time interval. b. the product of the force applied to the object and the time interval. c. the time interval divided by the net external force. d. the net external force divided by the time interval.
B
6. Two swimmers relax close together on air mattresses in a pool. One swimmer's mass is 48 kg, and the other's mass is 55 kg. If the swim- mers push away from each other, a. their total momentum triples. b. their momenta are equal but opposite. c. their total momentum doubles. d. their total momentum decreases.
B
7. A 75 kg person walking around a corner bumped into an 80 kg person who was running around the same corner. The momentum of the 80 kg person a. increased. c. remained the same. b. decreased. d. was conserved.
B
7. Which of the following statements about the conservation of momen- tum is not correct? a. Momentum is conserved for a system of objects pushing away from each other. b. Momentum is not conserved for a system of objects in a head-on collision. c. Momentum is conserved when two or more interacting objects push away from each other. d. The total momentum of a system of interacting objects remains constant regardless of forces between the objects.
B
8. Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 72 kg. If the skaters push away from each other without spinning, a. the 60 kg skater travels at a lower momentum. b. their momenta are equal but opposite. c. their total momentum doubles. d. their total momentum decreases.
B
8. Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 72 kg. If the skaters push away from each other without spinning, a. the lighter skater has less momentum. b. their momenta are equal but opposite. c. their total momentum doubles. d. their total momentum decreases.
B
9. Which of the following best describes the momentum of two bodies after a two-body collision if the kinetic energy of the system is conserved? a. must be less c. might also be conserved b. must also be conserved d. is doubled in value
B
A 20 kg shopping cart moving at a velocity of 0.5 m/s collides into a store wall and stops. The momentum of the shopping cart a. increased. c. remained the same. b. decreased. d. was conserved.
B
A bowling ball with a mass of 7.0 kg strikes a pin that has a mass of 2.0 kg. The pin flies forward with a velocity of 6.0 m/s, and the ball continues forward at 4.0 m/s. What was the original velocity of the ball? a. 4.0 m/s c. 6.6 m/s b. 5.7 m/s d. 3.3 m/s
B
A bullet with a mass of 5.00 × 10−3 kg is loaded into a gun. The loaded gun has a mass of 0.52 kg. The bullet is fired, causing the empty gun to recoil at a speed of 2.1 m/s. What is the speed of the bullet? a. 48 m/s c. 120 m/s b. 220 m/s d. 360 m/s
B
A rubber ball with a mass of 0.30 kg is dropped onto a steel plate. The ball's velocity just before impact is 4.5 m/s and just after impact is 4.2 m/s. What is the change in the ball's momentum? a. -0.09 kg • m/s c. -4.0 kg • m/s b. -2.6 kg • m/s d. -12 kg • m/s
B
A student walks to class at a velocity of 3 m/s. To avoid walking into a door as it opens, the student slows to a velocity of 0.5 m/s. Now late for class, the student runs down the corridor at a velocity of 7 m/s. The student has the least momentum a. while walking at a velocity of 3 m/s. b. while dodging the opening door. c. while stopping to open the door. d. while running to class at a velocity of 7 m/s.
B
The change in an object's momentum is equal to a. the product of the mass of the object and the time interval. b. the product of the force applied to the object and the time interval. c. the time interval divided by the net external force. d. the net external force divided by the time interval.
B
Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 72 kg. If the skaters push away from each other, a. the 60 kg skater travels at a lower momentum. b. their momenta are equal but opposite. c. their total momentum doubles. d. their total momentum decreases.
B
Two snowballs with masses of 0.40 kg and 0.60 kg, respectively, collide head-on and combine to form a single snowball. The initial speed for each is 15 m/s. If the velocity of the snowball with a mass of 1.0 kg is 3.0 m/s after the collision, what is the decrease in kinetic energy? a. zero c. 60 J b. 110 J d. 90 J
B
1. When comparing the momentum of two moving objects, which of the following is correct? a. The object with the higher velocity will have less momentum if the masses are equal. b. The more massive object will have less momentum if its velocity is greater. c. The less massive object will have less momentum if the velocities are the same. d. The more massive object will have less momentum if the velocities are the same.
C
14. A billiard ball collides with a stationary identical billiard ball in an elastic head-on collision. After the collision, which of the following is true of the first ball? a. It maintains its initial velocity. b. It has one-half its initial velocity. c. It comes to rest. d. It moves in the opposite direction.
C
15. A swimmer with a mass of 75 kg dives off a raft with a mass of 500 kg. If the diver's speed is 4 m/s immediately after leaving the raft, what is the speed of the raft? a. 0.2 m/s c. 0.6 m/s b. 0.5 m/s d. 4.0 m/s
C
17. A clay ball with a mass of 0.35 kg has an initial speed of 4.2 m/s. It strikes a 3.5 kg clay ball at rest, and the two balls stick together and remain stationary. What is the decrease in kinetic energy of the 0.35 kg ball? a. 1.6J c. 3.1J b. 4.8 J d. 6.4 J
C
18. A 90 kg halfback runs north and is tackled by a 120 kg opponent running south at 4 m/s. The collision is perfectly inelastic. Just after the tackle, both players move at a velocity of 2 m/s north. Compute the velocity of the 90 kg player just before the tackle. a. 3 m/s south c. 10 m/s north b. 4 m/s south d. 12 m/s north
C
18. A billiard ball collides with a stationary identical billiard ball in an elastic head-on collision. After the collision, which of the following is true of the first ball? a. It maintains its initial velocity. c. It comes to rest. b. It has one-half its initial velocity. d. It moves in the opposite direction.
C
19. A 15 g marble moves to the right at 3.5 m/s and makes an elastic head-on collision with a 22 g marble. The final velocity of the 15 g marble is 5.4 m/s to the left, and the final velocity of the 22 g marble is 2.0 m/s to the right. What is the initial velocity of the 22 g marble? a. 5.3 m/s to the left c. 4.0 m/s to the left b. 5.3 m/s to the right d. 4.0 m/s to the right
C
2. When comparing the momentum of two moving objects, which of the following is correct? a. The object with the higher velocity will have less momentum if the masses are equal. b. The more massive object will have less momentum if its velocity is greater. c. The less massive object will have less momentum if the velocities are the same. d. The more massive object will have less momentum if the velocities are the same.
C
2. When comparing the momentum of two moving objects, which of the following is correct? a. The object with the higher velocity will have less momentum if the masses are equal. b. The more massive object will have less momentum if its velocity is greater. c. The less massive object will have less momentum if the velocities are the same. d. The more massive object will have less momentum if the velocities are the same.
C
2.Achildwithamassof23kgridesabikewithamassof5.5kgata velocity of 4.5 m/s to the south. Compare the momentum of the child with the momentum of the bike. a. Both the child and the bike have the same momentum. b. The bike has a greater momentum than the child. c. The child has a greater momentum than the bike. d. Neither the child nor the bike has momentum.
C
4. A force is applied to stop a moving shopping cart. Increasing the time interval over which the force is applied a. requires a greater force. b. has no effect on the force needed. c. requires a smaller force. d. requires the same force.
C
4. A rubber ball moving at a speed of 5 m/s hit a flat wall and returned to the thrower at 5 m/s. The magnitude of the momentum of the rubber ball a. increased. b. decreased c. remained the same d. was not conserved
C
5. A moderate force will break an egg. However, an egg dropped on the road usually breaks, while one dropped on the grass usually does not break because for the egg dropped on the grass, a. the change in momentum is greater. b. the change in momentum is less. c. the time interval for stopping is greater. d. the time interval for stopping is less.
C
5. If a force is exerted on an object, which statement is true? a. A large force always produces a large change in the object's momentum. b. A large force produces a large change in the object's momentum only if the force is applied over a very short time interval. c. A small force applied over a long time interval can produce a large change in the object's momentum. d. A small force always produces a large change in the object's momentum.
C
5. The impulse experienced by a body is equivalent to the body's change in a. velocity. c. momentum. b. kinetic energy. d. force.
C
6. A moderate force will break an egg. However, an egg dropped on the road usually breaks, while one dropped on the grass usually does not break because for the egg dropped on the grass, a. the change in momentum is greater. c. the time interval for stopping is greater. b. the change in momentum is less. d. the time interval for stopping is less.
C
6. The impulse experienced by a body is equivalent to the body's change in a. velocity. c. momentum. b. kinetic energy. d. force.
C
8. A soccer ball collides with another soccer ball at rest. The total momentum of the balls a. is zero. c. remains constant. b. increases. d. decreases.
C
9. The impulse experienced by a body is equivalent to the body's change in a. velocity. c. momentum. b. kinetic energy. d. force.
C
A billiard ball collides with a stationary identical billiard ball in an elastic head-on collision. After the collision, which is true of the first ball? a. It maintains its initial velocity. b. It has one-half its initial velocity. c. It comes to rest. d. It moves in the opposite direction.
C
A soccer ball collides with another soccer ball at rest. The total momentum of the balls a. is zero. c. remains constant. b. increases. d. decreases.
C
Achildwithamassof23kgridesabikewithamassof5.5kgatavelocityof4.5m/s to the south. Compare the momentum of the child and the momentum of the bike. a. Both the child and the bike have the same momentum. b. The bike has a greater momentum than the child. c. The child has a greater momentum than the bike. d. Neither the child nor the bike has momentum.
C
After colliding, objects are deformed and lose some kinetic energy. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
C
The impulse experienced by a body is equivalent to the body's change in a. velocity. c. momentum. b. kinetic energy. d. force.
C
Which of the following best describes the kinetic energy of each object after a two- body collision if the momentum of the system is conserved? a. must be less c. might also be conserved b. must also be conserved d. is doubled in value
C
10. The law of conservation of momentum states that a. the total initial momentum of all objects interacting with one another usually equals the total final momentum. b. the total initial momentum of all objects interacting with one another does not equal the total final momentum. c. the total momentum of all objects interacting with one another is zero. d. the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects.
D
10. The law of conservation of momentum states that a. the total initial momentum of all objects interacting with one another usually equals the total final momentum. b. the total initial momentum of all objects interacting with one another does not equal the total final momentum. c. the total momentum of all objects interacting with one another is zero. d. the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects.
D
10. Two balls of dough collide and stick together. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
D
11. Two objects stick together and move with a common velocity after colliding. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
D
13. A 0.2 baseball is pitched with a velocity of 40 m/s and is then batted to the pitcher with a velocity of 60 m/s. What is the magnitude of the change in the ball's momentum? a. 4 kg • m/s c. 2 kg • m/s b. 8 kg • m/s d. 20 kg • m/s
D
13. A 1.5 103 kg truck moving at 15 m/s strikes a 7.5 102 kg automobile stopped at a traffic light. The vehicles hook bumpers and skid together at 10.0 m/s. What is the decrease in kinetic energy? a. 1.1 105J b. 1.2 104J c. 1.7 105J d. 6.0 104J
D
13. n an inelastic collision between two objects with unequal masses, a. the total momentum of the system will increase. b. the total momentum of the system will decrease. c. the kinetic energy of one object will increase by the amount that the kinetic energy of the other object decreases. d. the momentum of one object will increase by the amount that the momentum of the other object decreases.
D
14. A ball with a momentum of 4.0 kg • m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball's momentum? a. 0.0 kg • m/s c. 8.0 kg • m/s b. -4.0 kg • m/s d. -8.0 kg • m/s
D
16. Two objects stick together and move with a common velocity after colliding. Identify the type of collision. a. elastic c. inelastic b. nearly elastic d. perfectly inelastic
D
17. In an inelastic collision between two objects with unequal masses, a. the total momentum of the system will increase. b. the total momentum of the system will decrease. c. the kinetic energy of one object will increase by the amount that the kinetic energy of the other object decreases. d. the momentum of one object will increase by the amount that the momentum of the other object decreases.
D
3. A 0.2 kg baseball is pitched with a velocity of 40 m/s and is then batted to the pitcher with a velocity of 60 m/s. What is the magnitude of change in the ball's momentum? a. 2 kg•m/s c. 8 kg•m/s b. 4 kg•m/s d. 20 kg•m/s
D
8. Two balls of dough collide and stick together. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
D
9. Two objects stick together and move with the same velocity after colliding. Identify the type of collision. a. elastic c. inelastic b. perfectly elastic d. perfectly inelastic
D
A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. Throughout the ride, the momentum of the roller coaster a. remained the same. b. was zero. c. was greater up the hill than down the hill. d. was greater down the hill than up the hill.
D
A softball with a mass of 0.11 kg moves at a speed of 12 m/s. Then the ball is hit by a bat and rebounds in the opposite direction at a speed of 15 m/s. What is the change in momentum of the ball? a. -1.3 kg • m/s c. -0.33 kg • m/s b. -1.6 kg • m/s d. -3.0 kg • m/s
D
-Elastic collision:
a collision between ideally elastic bodies in which the final and initial kinetic energies are the same
-Perfectly inelastic collision:
a collision in which two objects stick together after colliding
-Momentum:
a quantity defined as the produce of the mass and velocity of an object
-Impulse:
the product of the force and the time over which the free acts on an object
