Name:

Period:WEP-Work and Power

1. The work done in accelerating an object along africtionless horizontal surface is equal to the change
in the object’s
1. momentum
2. velocity
3. potential energy
4. kinetic energy

5. A motor used 120 watts of power to raise a 15-newton object in 5.0 seconds. Through what verticaldistance was the object raised?
1. 1.6 m
2. 8.0 m
3. 40 m
4. 360 m

2. The graph below represents the relationship between
the work done by a student running up a flight ofstairs and the time of ascent.

6. The diagram below shows points A, B, and C at ornear Earth’s surface. As a mass is moved from A toB, 100 joules of work are done against gravity.

What does the slope of this graph represent?
1. impulse
2. momentum
3. speed
4. power
3. A student does 60 joules of work pushing a 3.0-kilogram box up the full length of a ramp that is 5.0
meters long. What is the magnitude of the force
applied to the box to do this work?
1. 20 N
2. 15 N
3. 12 N4. 4.0 N
4. A boat weighing 900 newtons requires a horizontal
force of 600 newtons to move it across the water at
15 meters per second. The boat’s engine must provide energy at the rate of
1. 2.5 × 10-2 J
2. 4.0 × 101 W
3. 7.5 × 103 J
4. 9.0 × 103 W
APlusPhysics: WEP-Work and Power

What is the amount of work done against gravity as
an identical mass is moved from A to C?
1. 100 J
2. 173 J
3. 200 J
4. 273 J
7. One watt is equivalent to one
1. N∙m
2. N/m
3. J∙s
4. J/s
8. Two weightlifters, one 1.5 meters tall and one 2.0
meters tall, raise identical 50-kilogram masses above
their heads. Compared to the work done by theweightlifter who is 1.5 meters tall, the work done by
the weightlifter who is 2.0 meters tall is
1. less
2. greater
3. the same
9. A 40-kilogram student runs up a staircase to a floor
that is 5.0 meters higher than her starting point in
7.0 seconds. The student’s power output is
1. 29 W
2. 280 W
3. 1.4 × 103 W
4. 1.4 × 104 W
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10. A 3.0-kilogram block is initially at rest on a frictionless, horizontal surface. The block is moved 8.0 meters in 2.0
seconds by the application of a 12-newton horizontal force, as shown in the diagram below.

What is the average power developed while moving the block?
1. 24 W
2. 32 W
3. 48 W
4. 96 W

11. The graph below shows the relationship between thework done by a student and the time of ascent as thestudent runs up a flight of stairs.

The slope of the graph would have units of
1. joules
2. seconds
3. watts
4. newtons
12. The amount of work done against friction to slidea box in a straight line across a uniform, horizontal
floor depends most on the
1. time taken to move the box
2. distance the box is moved
3. speed of the box
4. direction of the box’s motion
13. What is the average power developed by a motor
as it lifts a 400-kilogram mass at a constant speed
through a vertical distance of 10 meters in 8 seconds?
1. 320 W
2. 500 W
3. 4,900 W
4. 32,000 W
Page 80

WEP.A1, WEP.A214. The work done in lifting an apple one meter near
Earth’s surface is approximately
1. 1 J
2. 0.01 J
3. 100 J
4. 1000 J
15. A 70-kilogram cyclist develops 210 watts of power
while pedaling at a constant velocity of 7.0 meters
per second east. What average force is exerted eastward on the bicycle to maintain this constant speed?
1. 490 N
2. 30 N3. 3.0 N
4. 0 N
16. A 95-kilogram student climbs 4.0 meters up a ropein 3.0 seconds. What is the power output of thestudent?
1. 130 W
2. 380 W
3. 1200 W
4. 3700 W
17. Which is an SI unit for work done on an object?
1.

kg • m2s2

2.

kg • m2s

3.

kg • ms

4.

kg • ms2

APlusPhysics: WEP-Work and PowerName:

Period:WEP-Work and Power

18. As shown in the diagram below, a child applies a
constant 20-newton force along the handle of awagon which makes a 25° angle with the horizontal.

How much work does the child do in moving thewagon a horizontal distance of 4.0 meters?
1. 5.0 J
2. 34 J
3. 73 J
4. 80 J
19. Which graph best represents the relationship between the power required to raise an elevator and thespeed at which the elevator rises?

22. Which quantity is a measure of the rate at which
work is done?
1. energy
2. power
3. momentum
4. velocity
23. What is the average power required to raise a 1.81 ×
104-newton elevator 12.0 meters in 22.5 seconds?
1. 8.04 × 102 W
2. 9.65 × 103 W
3. 2.17 × 105 W
4. 4.89 × 106 W
24. A 15.0-kilogram mass is moving at 7.50 meters per
second on a horizontal, frictionless surface. Whatis the total work that must be done on the mass toincrease its speed to 11.5 meters per second?
1. 120 J
2. 422 J
3. 570 J
4. 992 J
25. A truck weighing 3.0 × 104 newtons was driven up ahill that is 1.6 × 103 meters long to a level area thatis 8.0 × 102 meters above the starting point. If thetrip took 480 seconds, what was the minimum power
required?
1. 5.0 × 104 W
2. 1.0 × 105 W
3. 1.2 × 1010 W
4. 2.3 × 1010 W

20. A 110-kilogram bodybuilder and his 55-kilogram
friend run up identical flights of stairs. The bodybuilder reaches the top in 4.0 seconds while hisfriend takes 2.0 seconds. Compared to the power
developed by the bodybuilder while running up thestairs, the power developed by his friend is
1. the same
2. twice as much
3. half as much
4. four times as much
21. Which quantity is a vector?
1. impulse
2. power
3. speed
4. timeAPlusPhysics: WEP-Work and Power

26. A joule is equivalent to a
1. N∙m
2. N∙s
3. N/m
4. N/s
27. What is the power output of an electric motor thatlifts a 2.0-kilogram block 15 meters vertically in 6.0
seconds?
1. 5.0 J
2. 5.0 W
3. 49 J
4. 49 W

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Period:WEP-Work and Power

Base your answers to questions 28 and 29 on the information and diagram below.

A 10-kilogram block is pushed across a floor by a horizontal force of 50 newtons. The block moves from point A topoint B in 3.0 seconds.

28. Using a scale of 1.0 centimeter = 1.0 meter, determine the magnitude of the displacement of the block as itmoves from point A to point B.

29. Calculate the power required to move the block from point A to point B in 3.0 seconds. [Show all work, including the equation and substitution with units.]

30. How much work is required to lift a 10-newton
weight from 4.0 meters to 40 meters above the surface of Earth?
1. 2.5 J
2. 3.6 J
3. 3.6 × 102 J
4. 4.0 × 102 J
31. Student A lifts a 50-newton box from the floor toa height of 0.40 meter in 2.0 seconds. Student B
lifts a 40-newton box from the floor to a height of0.50 meter in 1.0 second. Compared to student A,student B does
1. the same work but develops more power
2. the same work but develops less power
3. more work but develops less power
4. less work but develops more power

33. A 60-kilogram student climbs a ladder a verticaldistance of 4.0 meters in 8.0 seconds. Approximately
how much total work is done against gravity by thestudent during the climb?
1. 2.4 × 103 J
2. 2.9 × 102 J
3. 2.4 × 102 J
4. 3.0 × 101 J
34. A box is pushed to the right with a varying horizontal force. The graph below represents the relationship between the applied force and the distance thebox moves.

32. The graph below represents the relationship between
the work done by a person and time.

Identify the physical quantity represented by theslope of the graph.
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WEP.A1, WEP.A2

What is the total work done in moving the box 6.0
meters?
1. 9.0 J
2. 18 J
3. 27 J
4. 36 J
APlusPhysics: WEP-Work and PowerName:

Period:WEP-Work and Power

35. The total work done in lifting a typical high school
physics textbook a vertical distance of 0.10 meter isapproximately
1. 0.15 J
2. 1.5 J
3. 15 J
4. 150 J

36. Through what vertical distance is a 50-newton object moved if 250 joules of work is done against thegravitational field of Earth?
1. 2.5 m
2. 5.0 m
3. 9.8 m
4. 25 m37. A small electric motor is used to lift a 0.50-kilogram
mass at constant speed. If the mass is lifted a vertical distance of 1.5 meters in 5.0 seconds, the average
power developed by the motor is
1. 0.15 W
2. 1.5 W
3. 3.8 W
4. 7.5 W
38. What is the maximum amount of work that a 6000watt motor can do in 10 seconds?
1. 6.0 × 101 J
2. 6.0 × 102 J
3. 6.0 × 103 J
4. 6.0 × 104 J
39. How much work is done by the force lifting a0.1-kilogram hamburger vertically upward at constant velocity 0.3 meter from a table?
1. 0.03 J
2. 0.1 J
3. 0.3 J
4. 0.4 J
40. The watt∙second is a unit of
1. power
2. energy
3. potential difference
4. electric field strengthAPlusPhysics: WEP-Work and Power

41. Which quantity has both a magnitude and direction?
1. energy
2. impulse
3. power
4. work
42. Two elevators, A and B, move at constant speed.
Elevator B moves with twice the speed of elevator
A. Elevator B weighs twice as much as elevator A.
Compared to the power needed to lift elevator A,
the power needed to lift elevator B is
1. the same
2. twice as great
3. half as great
4. four times as great
43. What is the maximum height to which a motor
having a power rating of 20.4 watts can lift a
5.00-kilogram stone vertically in 10 seconds?
1. 0.0416 m
2. 0.408 m
3. 4.16 m
4. 40.8 m
44. If a motor lifts a 400-kilogram mass a verticaldistance of 10 meters in 8.0 seconds, the minimum
power generated by the motor is
1. 3.2 × 102 W
2. 5.0 × 102 W
3. 4.9 × 103 W
4. 3.2 × 104 W
45. The graph below represents the work done against
gravity by a student as she walks up a flight of stairs
at constant speed.

Compared to the power generated by the student
after 2.0 seconds, the power generated by the student
after 4.0 seconds is
1. the same
2. twice as great
3. half as great
4. four times as great

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46. Which graph best represents the greatest amount ofwork?

47. Calculate the average power required to lift a490-newton object a vertical distance of 2.0 metersin 10 seconds. [Show all work, including the equation and substitution with units.]

50. An electric motor has a rating of 4.0 × 102 watts.
How much time will it take for this motor to lift a50-kilogram mass a vertical distance of 8.0 meters?
[Assume 100% efficiency.]
1. 0.98 s
2. 9.8 s
3. 98 s4. 980 s
51. Calculate the minimum power output of an electricmotor that lifts a 1.30 × 104-newton elevator car
vertically upward at a constant speed of 1.50 meters
per second. [Show all work, including the equationand substitution with units.]

48. Which combination of fundamental units can beused to express the amount of work done on anobject?
1. kg∙m/s
2. kg∙m/s2
3. kg∙m2/s2
4. kg∙m2/s3
49. The graph below represents the relationship between
the force exerted on an elevator and the distance theelevator is lifted.

How much total work is done by the force in lifting
the elvator from 0.0 m to 9.0 m?
1. 9.0 × 104 J
2. 1.2 × 105 J
3. 1.5 × 105 J
4. 1.8 × 105 J
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APlusPhysics: WEP-Work and Power