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NAME ______________________________________ DATE _______________ CLASS ____________________
Chapter
HOLT PHYSICS
5 Test A
Work and Energy
Copyright © by Holt, Rinehart and Winston. All rights reserved.
MULTIPLE CHOICE On the line at the left of each statement, write the letter of
the choice that best completes the statement or answers the question.
1.
A force does work on an object if a component of the force
a. is perpendicular to the displacement of the object.
b. is parallel to the displacement of the object.
c. perpendicular to the displacement of the object moves the object along a path that
returns to its starting position.
d. parallel to the displacement of the object moves the object along a path that
returns to its starting position.
2.
Which of the following energy forms is NOT involved in hitting a tennis ball?
a. kinetic energy
b. chemical potential energy
c. gravitational potential energy
d. elastic potential energy
3.
If the only force acting on an object during a given physical process is friction, which
of the following assumptions must be made in regard to the object’s kinetic energy?
a. The kinetic energy decreases.
b. The kinetic energy increases.
c. The kinetic energy remains constant.
d. The kinetic energy decreases and then increases.
4.
Which of the following energy forms is associated with an object in motion?
a. potential energy
c. nonmechanical energy
b. elastic potential energy
d. kinetic energy
5.
Which of the following energy forms is associated with an object due to its position
relative to Earth?
a. potential energy
c. gravitational potential energy
b. elastic potential energy
d. kinetic energy
6.
Which form of energy is involved in weighing fruit on a spring scale?
a. kinetic energy
c. gravitational potential energy
b. nonmechanical energy
d. elastic potential energy
7.
Which of the following energy forms is associated with an object’s interaction with
the environment?
a. potential energy
c. mechanical energy
b. kinetic energy
d. nonmechanical energy
Chapter 5
33
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NAME ______________________________________ DATE _______________ CLASS ____________________
5
HOLT PHYSICS
continued
Test A
8.
Which of the following is the rate at which energy is transferred?
a. potential energy
c. mechanical energy
b. kinetic energy
d. power
9.
The magnitude of the component of the force that does the work is 43.0 N. How
much work is done on a bookshelf being pulled 5.00 m at an angle of 37.0° from the
horizontal?
a. 172 J
c. 129 J
b. 215 J
d. 792 J
10.
A horizontal force of 200 N is applied to move a 55 kg television set across a 10 m
level surface. What is the work done by the 200 N force on the television set?
a. 4000 J
c. 2000 J
b. 5000 J
d. 6000 J
11.
A 3.00 kg toy falls from a height of 10.0 m. Just before hitting the ground,
what will its kinetic energy be? (Disregard air resistance; g = 9.81 m/s2.)
a. 98.0 J
c. 29.4 J
b. 0.98 J
d. 294 J
12.
Old Faithful geyser in Yellowstone National Park shoots water every hour to a height
of 40.0 m. With what velocity does the water leave the ground? (Disregard air
resistance; g = 9.81 m/s2.)
a. 7.00 m/s
c. 19.8 m/s
b. 14.0 m/s
d. 28.0 m/s
13.
A bobsled zips down an ice track starting at 150 m vertical distance up the hill.
Disregarding friction, what is the velocity of the bobsled at the bottom of the hill?
(g = 9.81 m/s2)
a. 27 m/s
c. 45 m/s
b. 36 m/s
d. 54 m/s
14.
What is the average power supplied by a 60.0 kg person running up a flight of stairs
rising vertically 4.0 m in 4.2 s?
a. 380 W
c. 610 W
b. 560 W
d. 670 W
15.
A 1.00 × 103 kg sports car accelerates from rest to 25.0 m/s in 7.50 s. What is the
average power output of the automobile engine?
a. 20.8 kW
c. 41.7 kW
b. 30.3 kW
d. 52.4 kW
34
Holt Physics Chapter Tests
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Chapter
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NAME ______________________________________ DATE _______________ CLASS ____________________
Chapter
5
HOLT PHYSICS
continued
Test A
SHORT ANSWER
provided.
Write the answers to the following questions in the space
16. In the following sentence, is the everyday or the scientific meaning of work intended?
A student works on a term paper.
17. A child pulls a toy across the floor. Is the work done on the toy positive or negative? Explain
Copyright © by Holt, Rinehart and Winston. All rights reserved.
your reasoning.
18. Is conservation of mechanical energy likely to hold in this situation? A soccer ball is thrown
into the air. (Disregard air resistance.) Explain your reasoning.
Chapter 5
35
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NAME ______________________________________ DATE _______________ CLASS ____________________
Chapter
5
HOLT PHYSICS
continued
Test A
19. Explain how energy, time, and power are related.
20. Which motor performs more work in the same amount of time—a 10 kW motor or a 20 kW
Copyright © by Holt, Rinehart and Winston. All rights reserved.
motor? Explain your reasoning.
36
Holt Physics Chapter Tests
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NAME ______________________________________ DATE _______________ CLASS ____________________
Chapter
HOLT PHYSICS
5 Test B
Work and Energy
Copyright © by Holt, Rinehart and Winston. All rights reserved.
MULTIPLE CHOICE On the line at the left of each statement, write the letter of
the choice that best completes the statement or answers the question.
1.
If the work done on an object results in a change in only the object’s speed if the net
work is negative,
a. the object speeds up and work is done by the object on another object.
b. the object speeds up and the net force does work on the object.
c. the object slows down and work is done by the object on another object.
d. the object slows down and the net force does work on the object.
2.
Which of the following energy forms is involved in winding a pocket watch?
a. electrical energy
c. gravitational potential energy
b. nonmechanical energy
d. elastic potential energy
3.
If the only force acting on an object during a given physical process is friction, which
of the following assumptions must be made in regard to the object’s kinetic energy?
a. The kinetic energy decreases.
b. The kinetic energy increases.
c. The kinetic energy remains constant.
d. The kinetic energy decreases and then increases.
4.
Which of the following energy forms is associated with an object due to its position?
a. potential
c. total
b. positional
d. kinetic
5.
Which of the following energy forms is stored in any compressed or stretched object?
a. nonmechanical energy
c. gravitational potential energy
b. elastic potential energy
d. kinetic energy
6.
The equation for determining gravitational potential energy is PEg = mgh. Which
factor(s) in this equation is (are) NOT a property of an object?
a. g
c. m
b. h
d. both g and h
7.
As an object is lowered into a deep hole in the ground, which of the following
assumptions must be made in regard to the object’s potential energy?
a. The potential energy increases.
b. The potential energy decreases.
c. The potential energy remains constant.
d. The potential energy increases and then decreases.
Chapter 5
37
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NAME ______________________________________ DATE _______________ CLASS ____________________
5
HOLT PHYSICS
continued
Test B
8.
Which of the following is the rate at which energy is transferred?
a. potential energy
c. mechanical energy
b. kinetic energy
d. power
9.
A worker pushes a wheelbarrow with a horizontal force of 50.0 N over a level distance
of 5.0 m. If a frictional force of 43 N acts on the wheelbarrow in a direction opposite
to that of the worker, what net work is done on the wheelbarrow?
a. 250 J
c. 35 J
b. 0.0 J
d. 10.0 J
10.
A cashier pushes a grocery cart 5.0 m with a horizontal force of 50.0 N. How much
work is done by the cashier on the grocery cart?
a. 10 J
c. 250 J
b. 1250 J
d. 55 J
11.
A pole vaulter clears a bar that is 6.00 m above the ground. With what velocity does
the vaulter strike the mat in the landing area? (Disregard air resistance; g = 9.81 m/s2.)
a. 2.70 m/s
c. 10.8 m/s
b. 5.40 m/s
d. 21.6 m/s
12.
A bobsled zips down an ice track starting at a vertical distance of 150 m up the hill.
Disregarding friction, what is the velocity of the bobsled at the bottom of the hill? (g =
9.81 m/s2)
a. 27 m/s
c. 45 m/s
b. 36 m/s
d. 54 m/s
13.
What is the average power output of a weight lifter who can lift 250 kg
2.0 m in 2.0 s?
a. 5.0 × 102 W
c. 4.9 kW
b. 2.5 kW
d. 9.8 kW
14.
Water flows over a section of Niagara Falls at a rate of 1.20 × 106 kg/s and falls down a
height of 50.0 m. What is the power of the waterfall?
a. 589 MW
c. 147 MW
b. 294 MW
d. 60.0 MW
SHORT ANSWER
provided.
Write the answers to the following questions in the space
15. In the following sentence, is the everyday or the scientific meaning of work intended?
A road cleaner does work shoveling snow.
38
Holt Physics Chapter Tests
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Chapter
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NAME ______________________________________ DATE _______________ CLASS ____________________
Chapter
5
HOLT PHYSICS
continued
Test B
16. How is work related to force and displacement?
17. Is conservation of mechanical energy likely to hold in this situation?
An ice skater glides across freshly made ice. Explain your reasoning.
Copyright © by Holt, Rinehart and Winston. All rights reserved.
18. What does the wattage of a light bulb indicate?
Chapter 5
39
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NAME ______________________________________ DATE _______________ CLASS ____________________
Chapter
5
HOLT PHYSICS
continued
Test B
19. How is a machine’s power rating related to its rate of doing work on an object?
PROBLEM Write your answer to the following question on the line to the left
and show your work in the space provided.
A skier with a mass of 88 kg hits a ramp of snow at 16 m/s and becomes airborne. At
the highest point of flight, the skier is 3.7 m above the ground. What is the skier’s
gravitational potential energy at this point?
Copyright © by Holt, Rinehart and Winston. All rights reserved.
20.
40
Holt Physics Chapter Tests
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Chapter 5 Test Form A
Chapter 5 Test Form B
1. B
2. B
3. A
4. D
5. C
6. D
7. A
8. D
9. B
10. C
11. D
12. D
13. D
14. B
15. C
16. everyday meaning
17. The work done on the toy is positive, because
1. C
2. D
3. A
4. A
5. B
6. D
7. B
8. D
9. C
10. C
11. C
12. D
13. B
14. A
15. scientific meaning
16. Work is equal to the magnitude of the compo-
Copyright © by Holt, Rinehart and Winston. All rights reserved.
the force is in the same direction as the displacement of the toy.
18. Yes, mechanical energy is conserved, because
there is no force of friction acting on the ball.
19. Power is the rate at which energy is transferred.
In other words, power is the energy transferred
in a given time interval.
20. The more powerful 20 kW motor would do
work in a shorter amount of time (or the 20 kW
motor does twice as much work in the same
amount of time).
nent of a force parallel to the displacement of
the object multiplied by the displacement of an
object.
17. No, mechanical energy is not conserved, because
there is kinetic friction between the surface of
the ice and the blade of the skate.
18. The wattage tells the rate at which energy is converted by the bulb.
19. The power rating of a machine indicates the rate
at which it does work on an object. A machine
with a high power rating can perform the same
amount of work as a lower-rated machine in less
time; that is, its rate is higher.
20. 3.2 × 103 J
Answer Key
205