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Physics: Momentum, Work, Energy, Power
Name:
1.
2.
The momentum of a 5-kilogram object moving at
6 meters per second is
A.
1 kg
C.
11 kg
4.
5.
6.
m/sec
B.
m/sec
5 kg
7.
m/sec
D. 30 kg
m/sec
A 60-kilogram student running at 3.0 meters per
second has a kinetic energy of
A.
3.
Date:
180 J
B.
270 J
C.
540 J
8.
D. 8100 J
A cart of mass m traveling at speed v has kinetic
energy KE. If the mass of the cart is doubled and
its speed is halved, the kinetic energy of the cart
will be
A.
half as great
B.
C.
one-fourth as great
D. four times as great
9.
twice as great
Which of the following objects has the greatest
momentum?
10.
As the unbalanced force applied to an object
increases, the time rate of change of the object's
momentum
A.
decreases
C.
remains the same
B.
increases
A cart weighing 10 newtons is pushed 10 meters
on a level surface by a force of 5 newtons. What
is the increase in its potential energy?
A.
1 joule
B.
50 joules
C.
100 joules
D. 0 joules
An unbalanced 6.0-newton force acts eastward on
an object for 3.0 seconds. The impulse produced
by the force is
A.
18 N
s east
B.
2.0 N
s east
C.
18 N
s west
D. 2.0 N
s west
What is the magnitude of the velocity of
a 25-kilogram mass that is moving with a
momentum of 100 kilogram-meters per second?
A.
a 1-kg object moving at 200 m/sec
B.
a 10-kg object moving at 30 m/sec
C.
a 20-kg object moving at 20 m/sec
A.
0.25 m/s
B.
D. a 100-kg object moving at 2 m/sec
C.
40 m/s
D. 4.0 m/s
One joule is equivalent to one
A.
newton
meter3
C.
watt2
newton
11.
B.
kilogram meter3
D.
kilogram meter2
second2
As a 1.0-kilogram mass falls freely to the Earth,
its momentum
A.
decreases
C.
remains the same
B.
increases
page 1
2500 m/s
A 25-kilogram mass travels east with a constant
velocity of 40 meters per second. The momentum
of this mass is
A.
1:0
103 kg m=s east
B.
9:8
103 kg m=s east
C.
1:0
103 kg m=s west
D. 9:8
103 kg m=s west
12.
13.
A 0.025-kilogram bullet is red from a ri e by an
unbalanced force of 200 newtons. If the force acts
on the bullet for 0.1 second, what is the maximum
speed attained by the bullet?
A.
5 m/s
B.
C.
400 m/s
D. 800 m/s
17.
A.
20 m/s
A pendulum swings as shown in the diagram.
At which position is the kinetic energy of the
pendulum bob least?
A.
A
B.
C.
C
D. D
Each of the blocks in the diagrams is lifted
vertically for the distance indicated. Which block
will gain the most gravitational potential energy?
B.
B
C.
14.
15.
16.
A constant braking force of 10 newtons applied
for 5 seconds is used to stop a 2.5-kilogram cart
traveling at 20 meters per second. The magnitude
of the impulse applied to stop the cart is
A.
10 N
s
B.
30 N
C.
50 N
s
D. 100 N
D.
s
s
Two rocks weighing 5 newtons and 10 newtons,
respectively, fall freely from rest near the Earth's
surface. After 3 seconds of free-fall, compared to
the 5-newton rock, the 10-newton rock has greater
A.
acceleration
B.
C.
momentum
D. speed
18.
height
In a baseball game, a batter hits a ball for a home
run. Compared to the magnitude of the impulse
imparted to the ball, the magnitude of the impulse
imparted to the bat is
A.
less
B.
greater
C.
A student drops two eggs of equal mass
simultaneously from the same height. Egg A lands
on the tile oor and breaks. Egg B lands intact
without bouncing, on a foam pad lying on the
oor. Compared to the magnitude of the impulse
on egg A as it lands, the magnitude of the impulse
on egg B as it lands is
A.
19.
the same
B.
greater
C.
the same
An object 10 meters above the ground has Z joules
of potential energy. If the object falls freely, how
many joules of kinetic energy will it have gained
when it is 5 meters above the ground?
A.
page 2
less
Z
B.
2Z
C.
Z
2
D. 0
Physics: Momentum, Work, Energy, Power
20.
A 0.60-kilogram softball initially at rest is hit with
a bat. The ball is in contact with the bat for
0.20 second and leaves the bat with a speed of
25 meters per second. What is the magnitude of
the average force exerted by the ball on the bat?
A.
21.
8.3 N
B.
15 N
C.
3.0 N
24.
D. 75 N
If the speed of a moving object is doubled, which
quantity associated with the object must also
double?
A.
its momentum
B.
its kinetic energy
C.
its acceleration
What is the magnitude of the impulse applied to
the 30.-kilogram rollerskater?
D. its gravitational potential energy
22.
23.
In the diagram below, a 60.-kilogram rollerskater
exerts a 10.-newton force on a 30.-kilogram
rollerskater for 0.20 second.
The magnitude of the momentum of an object is
64.0 kilogram meters per second. If the velocity
of the object is doubled, the magnitude of the
momentum of the object will be
25.
A.
50. N
s
B.
2.0 N
s
C.
6.0 N
s
D. 12 N
s
Which two quantities can be expressed using the
same units?
A.
32.0 kg m/s
B.
64.0 kg m/s
A.
energy and force
C.
128 kg m/s
D. 256 kg m/s
B.
impulse and force
C.
momentum and energy
Which is an acceptable unit for impulse?
A.
N m
B.
C.
J s
D. kg m/s
D. impulse and momentum
J/s
26.
Four machines do the amounts of work listed in
the table shown. The time they take to do the
work is also listed. Which machine develops the
most power?
Machine
A
B
C
D
A.
page 3
A
Work
Time
1,000 joules
10 sec
2,000 joules
10 sec
1,000 joules
2,000 joules
B.
B
5 sec
5 sec
C.
C
D. D
Physics: Momentum, Work, Energy, Power
27.
28.
29.
30.
31.
How much work is required to lift a 2-kilogram
mass to a height of 10 meters?
A.
5 joules
B.
C.
100 joules
D. 200 joules
32.
20 joules
A garden tractor drags a plow with a force of
500 newtons a distance of 10 meters in 20 seconds.
How much work is done?
A.
25 joules
B.
C.
2,500 joules
D. 5,000 joules
33.
1,000 joules
As the length of time it takes a student to swim
100 meters decreases, the power developed by the
student
A.
decreases
C.
remains the same
B.
34.
increases
How much work will a 500-watt motor do in
10 seconds?
A.
0.02 joule
B.
C.
500 joules
D. 5,000 joules
35.
50 joules
What force is required to do 60 joules of work in
sliding an object a distance of 10 meters across a
level oor?
A.
6 newtons
B.
10 newtons
C.
60 newtons
D. 600 newtons
Car A and car B are of equal mass and travel up
a hill. Car A moves up the hill at a constant
speed that is twice the constant speed of car B.
Compared to the power developed by car B, the
power developed by car A is
A.
the same
B.
twice as much
C.
half as much
D. four times as much
What is the maximum distance that a 60-watt
motor may vertically lift a 90-newton weight in
7.5 seconds?
A.
2.3 m
B.
5.0 m
C.
140 m
D. 1100 m
The graph shows the force exerted on a block
as a function of the block's displacement in the
direction of the force. How much work did the
force do in displacing the block 5.0 meters?
The diagram here shows a 1-kilogram aluminum
sphere and a 3-kilogram copper sphere of equal
radius located 20 meters above the ground.
A.
36.
Just before striking the ground, the speed of the
copper sphere is 20 meters per second. What is
the momentum of the copper sphere?
A.
10 kg-m/sec
B.
20 kg-m/sec
C.
60 kg-m/sec
D. 600 kg-m/sec
page 4
0J
B.
20 J
C.
0.80 J
D. 4.0 J
If a net force of 10 newtons acts on a 6.0-kilogram
mass for 8.0 seconds, the total change of
momentum of the mass is
A.
48 kg
m/s
B.
60 kg
C.
80 kg
m/s
D. 480 kg
m/s
m/s
Physics: Momentum, Work, Energy, Power
37.
38.
40.
The diagram shows a 1:0 103 -newton crate to
be lifted at constant speed from the ground to
a loading dock 1.5 meters high in 5.0 seconds.
What power is required to lift the crate?
A.
1:5
103 W
B.
2:0
102 W
C.
3:0
102 W
D. 7:5
103 W
A force is applied to a block, causing it to
accelerate along a horizontal, frictionless surface.
The energy gained by the block is equal to the
A.
work done on the block
B.
power applied to the block
C.
impulse applied to the block
D. momentum given to the block
41.
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 the box moves.
A 75-kilogram boy initially at rest skis down the
slope as shown. Assuming no frictional loss, what
will be his kinetic energy at the bottom of the
slope?
Force vs.Distance
42.
What is the total work done in moving the box
6.0 meters?
A.
39.
9.0 J
B.
18 J
C.
27 J
D. 36 J
43.
A 100-kilogram person acquires a velocity of
15 meters per second down a ski slope. What is
the skier's kinetic energy?
A.
22,500 joules
B.
11,250 joules
C.
1,500 joules
D. 115 joules
A.
1,500 joules
B.
7,500 joules
C.
15,000 joules
D. 75,000 joules
As a falling apple approaches the ground, its
potential energy
A.
decreases
C.
remains the same
B.
increases
The work done in raising an object must result in
an increase in the object's
A.
internal energy
B.
kinetic energy
C.
gravitational potential energy
D. heat energy
page 5
Physics: Momentum, Work, Energy, Power
44. As the pendulum swings from position A to
position B as shown in the diagram, what is the
relationship of kinetic energy to potential energy?
[Neglect friction.]
48.
Work is being done when a force
A.
acts vertically on a cart that can only move
horizontally
B.
is exerted by one team in a tug of war when
there is no movement
C.
is exerted while pulling a wagon up a hill
D. of gravitational attraction acts on a person
standing on the surface of the Earth
A.
The kinetic energy decrease is more than the
potential energy increase.
B.
The kinetic energy increase is more than the
potential energy decrease.
C.
The kinetic energy decrease is equal to the
potential energy increase.
49.
D. The kinetic energy increase is equal to the
potential energy decrease.
45.
46.
A.
5,000 sec
B.
C.
10 sec
D. 0.2 sec
50 sec
A.
January
B.
March
C.
July
D. September
Three people of equal mass climb a mountain
using paths A, B, and C shown in the diagram.
Along which path(s) does a person gain the
greatest amount of gravitational potential energy
from start to nish?
A basketball player who weighs 600 newtons
jumps 0.5 meter vertically o the oor. What is
her kinetic energy just before hitting the oor?
A.
47.
50.
How long would it take a machine to do 5,000
joules of work if the power rating of the machine
is 100 watts?
The Earth is closest to the Sun during January and
farthest from the Sun during July. During which
month is the gravitational potential energy of the
Earth with respect to the Sun the greatest?
30 J
B.
60 J
C.
300 J
D. 600 J
A.
A, only
If the speed of an object is doubled, its kinetic
energy will be
B.
B, only
C.
C, only
A.
halved
B.
D. The gain is the same along all paths.
C.
quartered
D. quadrupled
doubled
page 6
Physics: Momentum, Work, Energy, Power
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Physics: Momentum, Work, Energy, Power
01/27/2016
1.
Answer:
D
21.
Answer:
A
2.
Answer:
B
22.
Answer:
C
3.
Answer:
A
23.
Answer:
D
4.
Answer:
C
24.
Answer:
B
5.
Answer:
D
25.
Answer:
D
6.
Answer:
B
26.
Answer:
C
7.
Answer:
B
27.
Answer:
D
8.
Answer:
D
28.
Answer:
D
9.
Answer:
A
29.
Answer:
B
10.
Answer:
D
30.
Answer:
D
11.
Answer:
A
31.
Answer:
C
12.
Answer:
D
32.
Answer:
A
13.
Answer:
D
33.
Answer:
B
14.
Answer:
C
34.
Answer:
B
15.
Answer:
C
35.
Answer:
B
16.
Answer:
C
36.
Answer:
C
17.
Answer:
B
37.
Answer:
C
18.
Answer:
C
38.
Answer:
C
19.
Answer:
C
39.
Answer:
B
20.
Answer:
D
40.
Answer:
A
Teacher's Key
41.
Answer:
C
42.
Answer:
A
43.
Answer:
C
44.
Answer:
D
45.
Answer:
B
46.
Answer:
C
47.
Answer:
D
48.
Answer:
C
49.
Answer:
C
50.
Answer:
D
Page 2