answers

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NAME
MIDTERM REVIEW
1. A student on an amusement park ride moves in a circular
path with a radius of 3.5 meters once every 8.9 seconds.
The student moves at an average speed of
A) 0.39 m/s
C) 2.5 m/s
B) 1.2 m/s
D) 4.3 m/s
2. A car travels 20. meters east in 1.0 second. The
displacement of the car at the end of this 1.0-second
interval is
A) 20. m
C) 20. m east
B) 20. m/s
D) 20. m/s east
3. A moving body must undergo a change of
A) velocity
C) position
B) acceleration
D) direction
4. A car travels 90. meters due north in 15 seconds. Then
the car turns around and travels 40. meters due south in
5.0 seconds. What is the magnitude of the average
velocity of the car during this 20.-second interval?
A) 2.5 m/s
C) 6.5 m/s
B) 5.0 m/s
D) 7.0 m/s
5. A truck, initially traveling at a speed of 22 meters per
second, increases speed at a constant rate of 2.4 meters
per second 2 for 3.2 seconds. What is the total distance
traveled by the truck during this 3.2-second time
interval?
A) 12 m
B) 58 m
C) 70. m D) 83 m
6. A roller coaster, traveling with an initial speed of 15
meters per second, decelerates uniformly at –7.0 meters
per second2 to a full stop. Approximately how far does
the roller coaster travel during its deceleration?
9. A rock is dropped from a bridge. What happens to the
magnitude of the acceleration and the speed of the rock
as it falls? [Neglect friction.]
A)
B)
C)
D)
Both acceleration and speed increase.
Both acceleration and speed remain the same.
Acceleration increases and speed decreases.
Acceleration remains the same and speed
increases.
10. A rock dropped off a bridge takes 5 seconds to hit the
water. Approximately what was the rock's velocity just
before impact?
A) 5 m/s
C) 50 m/s
B) 2 m/s
D) 125 m/s
11. A ball is thrown straight downward with a speed of
0.50 meter per second from a height of 4.0 meters.
What is the speed of the ball 0.70 second after it is
released? [Neglect friction.]
A) 0.50 m/s
C) 9.8 m/s
B) 7.4 m/s
D) 15 m/s
12. A rock falls from rest a vertical distance of 0.72 meter
to the surface of a planet in 0.63 second. The magnitude
of the acceleration due to gravity on the planet is
A) 1.1 m/s 2
C) 3.6 m/s 2
B) 2.3 m/s 2
D) 9.8 m/s 2
13. The graph below represents the displacement of an
object moving in a straight line as a function of time.
A) 1.0 m B) 2.0 m C) 16 m D) 32 m
7. Starting from rest, an object rolls freely down an incline
that is 10 meters long in 2 seconds. The acceleration of
the object is approximately
A) 5 m/sec
C) 10 m/sec
B) 5 m/sec 2
D) 10 m/sec 2
8. A child riding a bicycle at 15 meters per second
accelerates at -3.0 meters per second 2 for 4.0 seconds.
What is the child’s speed at the end of this 4.0-second
interval?
A) 12 m/s
C) 3.0 m/s
B) 27 m/s
D) 7.0 m/s
What was the total distance traveled by the object
during the 10.0-second time interval?
A) 0 m
B) 8 m
C) 16 m D) 24 m
MIDTERM REVIEW
14. Which graph best represents the motion of an object
whose speed is increasing?
A)
B)
C)
D)
15. Base your answer to the following question on the graph below, which represents the relationship between
the displacement of an object and its time of travel along a straight line.
What is the magnitude of the object's total displacement after 8.0 seconds?
A) 0 m
B) 2 m
C) 8 m
D) 16 m
Base your answers to questions 16 through 20 on the graph below which represents the displacement of an
object as a function of time.
16. How far is the object from the starting point at the end of 3 seconds?
A) 0 m
B) 2.0 m
C) 3.0 m
D) 9.0 m
17. What is the velocity of the object at t = 1 second?
A) 1.0 m/s
B) 2.0 m/s
C) 3.0 m/s
D) 1.5 m/s
18. During which time interval is the object at rest?
A) 0-2 s
B) 2-3 s
C) 3-4 s
D) 4-6 s
MIDTERM REVIEW
19. What is the average velocity of the object from t = 0 to t = 3 seconds?
A) 1.0 m/s
B) 2.0 m/s
C) 3.0 m/s
D) 0 m/s
20. During which time interval is the object accelerating?
A) 0-2 s
B) 2-3 s
C) 3-4 s
D) 4-6 s
Base your answers to questions 21 through 26 on the graph below which represents the relationship
between speed and time for an object in motion along a straight line.
21. What is the acceleration of the object during the time interval t = 3 seconds to t = 5 seconds?
A) 5.0 m/sec 2
B) 7.5 m/sec 2
C) 12.5 m/sec 2
D) 17.5 m/sec 2
22. What is the average speed of the object during the time interval t = 6 seconds to t = 8 seconds'?
A) 7.5 m/sec
B) 10 m/sec
C) 15 m/sec
D) 17.5 m/sec
23. What is the total distance traveled by the object during the first 3 seconds?
A) 15 m
B) 20 m
C) 25 m
D) 30 m
24. During which interval is the object's acceleration the greatest?
A) AB
B) CD
C) DE
D) EF
25. During the interval t = 8 seconds to t = 10 seconds, the speed of the object is
A) zero
C) decreasing
B) increasing
D) constant, but not zero
26. What is the maximum speed reached by the object during the 10 seconds of travel?
A) 10 m/sec
B) 25 m/sec
C) 150 m/sec
27. What is the momentum of a 1.5 × 10 3-kilogram car as it
travels at 30. meters per second due east for 60.
seconds?
A)
B)
C)
D)
4.5 × 10 4 kg•m/s, east
4.5 × 10 4 kg•m/s, west
4.5 × 10 6 kg•m, east
4.5 × 10 6 kg•m, west
D) 250 m/sec
28. An object traveling at 4.0 meters per second has a
momentum of 16 kilogram-meters per second. What is
the mass of the object?
A) 64 kg
C) 12 kg
B) 20 kg
D) 4.0 kg
MIDTERM REVIEW
29. An air bag is used to safely decrease the momentum of
a driver in a car accident. The air bag reduces the
magnitude of the force acting on the driver by
34. In the diagram below, a 60.-kilogram rollerskater exerts
a 10.-newton force on a 30.-kilogram rollerskater for
0.20 second.
A) increasing the length of time the force acts on
the driver
B) decreasing the distance over which the force acts
on the driver
C) increasing the rate of acceleration of the driver
D) decreasing the mass of the driver
30. A 3.0-kilogram object is acted upon by an impulse
having a magnitude of 15 newton•seconds. What is the
magnitude of the object’s change in momentum due to
this impulse?
A) 5.0 kg•m/s
C) 3.0 kg•m/s
B) 15 kg•m/s
D) 45 kg•m/s
31. Which quantity has both a magnitude and a direction?
What is the magnitude of the impulse applied to the
30.-kilogram rollerskater?
A) 50. N•s
C) 6.0 N•s
B) 2.0 N•s
D) 12 N•s
35. When a 1.0-kilogram cart moving with a speed of 0.50
meter per second on a horizontal surface collides with a
second 1.0-kilogram cart initially at rest, the carts lock
32. A 75-kilogram hockey player is skating across the ice at
together. What is the speed of the combined carts after
a speed of 6.0 meters per second. What is the
the collision? [Neglect friction.]
magnitude of the average force required to stop the
A) 1.0 m/s
B) 0.50 m/s
player in 0.65 second?
C) 0.25 m/s
D) 0 m/s
A) 120 N B) 290 N C) 690 N D) 920 N
36. A 3.1 kilogram gun initially at rest is free to move.
33. Which situation will produce the greatest change of
When a 0.015-kilogram bullet leaves the gun with a
momentum for a 1.0-kilogram cart?
speed of 500. meters per second, what is the speed of
the gun?
A) accelerating it from rest to 3.0 m/s
A) energy
C) power
B) impulse
D) work
B) accelerating it from 2.0 m/s to 4.0 m/s
C) applying a net force of 5.0 N for 2.0 s
D) applying a net force of 10.0 N for 0.5 s
A) 0.0 m/s
C) 7.5 m/s
B) 2.4 m/s
D) 500. m/s
37. A 2.0-kilogram ball traveling north at 4.0 meters per
second collides head on with a 1.0-kilogram ball
traveling south at 8.0 meters per second. What is the
magnitude of the total momentum of the two balls after
collision?
A) 0 kg-m/s
C) 16 kg-m/s
B) 8.0 kg-m/s
D) 32 kg-m/s
38. An 80.-kilogram skater and a 60.-kilogram skater stand
at rest in the center of a skating rink. The two skaters
push each other apart. The 60.-kilogram skater moves
with a velocity of 10. meters per second east. What is
the velocity of the 80.-kilogram skater? [Neglect any
frictional effects.]
A) 0.13 m/s west
C) 10. m/s east
B) 7.5 m/s west
D) 13. m/s east
MIDTERM REVIEW
39. Which object has the greatest inertia?
A)
B)
C)
D)
a 0.010-kg bullet traveling at 90. m/s
a 30.-kg child traveling at 10. m/s on her bike
a 490-kg elephant walking with a speed of 1.0 m/s
a 1500-kg car at rest in a parking lot
44. The graph below represents the relationship between
the forces applied to an object and the corresponding
accelerations produced.
40. A person is standing on a bathroom scale in an elevator
car. If the scale reads a value greater than the weight of
the person at rest, the elevator car could be moving
A)
B)
C)
D)
downward at constant speed
upward at constant speed
downward at increasing speed
upward at increasing speed
41. The diagram below shows a horizontal 12-newton force
being applied to two blocks, A and B, initially at rest on
a horizontal, frictionless surface. Block A has a mass of
1.0 kilogram and block B has a mass of 2.0 kilograms.
What is the inertial mass of the object?
A) 1.0 kg
C) 0.50 kg
B) 2.0 kg
D) 1.5 kg
45. What is the magnitude of the net force acting on a
2.0 × 103- kilogram car as it accelerates from rest to a
speed of 15 meters per second in 5.0 seconds?
A) 6.0 × 10 3 N
C) 3.0 × 10 4 N
B) 2.0 × 10 4 N
D) 6.0 × 10 4 N
46. A 400-newton girl standing on a dock exerts a force of
100 newtons on a 10 000-newton sailboat as she pushes
it away from the dock. How much force does the
sailboat exert on the girl?
The magnitude of the acceleration of block B is
A) 6.0 m/s 2
C) 3.0 m/s 2
B) 2.0 m/s 2
D) 4.0 m/s 2
42. Two forces, F 1 and F 2, are applied to a block on a
frictionless, horizontal surface as shown below.
A) 25 N
C) 400 N
B) 100 N
D) 10 000 N
47. An object weighing 4 Newtons rests on a horizontal
tabletop. The force of the tabletop on the object is
A) 0 N
C) 4 N downward
B) 4 N horizontally
D) 4 N upward
48. On the planet Gamma, a 4.0-kilogram mass experiences
a gravitational force of 24 Newtons. What is the
acceleration due to gravity on planet Gamma?
If the magnitude of the block's acceleration is 2.0
meters per second 2, what is the mass of the block?
A) 1 kg
B) 5 kg
C) 6 kg
D) 7 kg
43. A 25-newton horizontal force northward and a
35-newton horizontal force southward act concurrently
on a 15-kilogram object on a frictionless surface. What
is the magnitude of the object's acceleration?
A) 0.67 m/s 2
C) 2.3 m/s 2
B) 1.7 m/s 2
D) 4.0 m/s 2
A) 0.17 m/s 2
C) 9.8 m/s 2
B) 6.0 m/s 2
D) 96 m/s 2
49. What is the weight of a 5.0-kilogram object at the
surface of the Earth?
A) 5.0 kg
C) 49 N
B) 25 N
D) 49 kg
MIDTERM REVIEW
50. The graph below shows the weight of three objects on
planet X as a function of their mass.
54. If a 30-Newton force is required to accelerate a
2-kilogram object at 10 meters per second 2, over a level
floor, then the magnitude of the frictional force acting
on the object is
A) 0 N
B) 10 N C) 20 N D) 30 N
55. According to your reference table, Approximate
Coefficents of Friction, what is the minimum horizontal
force needed to start a 300. N steel block on a steel
table in motion?
The acceleration due to gravity on planet X is
m/s 2
A) 0.17
C) 9.8 m/s 2
m/s 2
B) 6.0
D) 50. m/s 2
51. An 8.0-newton wooden block slides across a horizontal
wooden floor at constant velocity. What is the
magnitude of the force of kinetic friction between the
block and the floor?
A) 2.4 N B) 3.4 N C) 8.0 N D) 27 N
52. The diagram below shows a 4.0-kilogram object
accelerating at 10. meters per second 2 on a rough
horizontal surface.
A) 0.57 N
C) 171 N
B) 074 N
D) 222 N
56. Jill is pulling a 200. Newton sled through the snow at
constant velocity using a horizontal force of 10.
Newtons. What is the kinetic coefficient of friction of
the sled on the snow?
A) 0.02
B) 0.05
C) 0.20
D) 20
57. Two forces act concurrently on an object. Their
resultant force has the largest magnitude when the
angle between the forces is
A) 0°
B) 30°
C) 90°
D) 180°
58. In the diagram below, a 20.-newton force due north and
a 20.-newton force due east act concurrently on an
object, as shown in the diagram below.
What is the magnitude of the frictional force Ff acting
on the object?
A) 5.0 N B) 10. N C) 20. N D) 40. N
53. The diagram below shows a student applying a
10.-newton force to slide a piece of wood at constant
speed across a horizontal surface. After the wood is cut
in half, one piece is placed on top of the other, as
shown.
What is the magnitude of the force, F, required to slide
the stacked wood at constant speed across the surface?
A) 40 N B) 20 N C) 10 N D) 5.0 N
The additional force necessary to bring the object into a
state of equilibrium is
A) 20. N, northeast
C) 28 N, northeast
B) 20. N, southwest
D) 28 N, southwest
59. A 5.0-newton force and a 7.0-newton force act
concurrently on a point. As the angle between the
forces is increased from 0° to 180°, the magnitude of
the resultant of the two forces changes from
A) 0.0 N to 12.0 N
C) 12.0 N to 2.0 N
B) 2.0 N to 12.0 N
D) 12.0 N to 0.0 N
MIDTERM REVIEW
60. A girl leaves a history classroom and walks 10. meters
north to a drinking fountain. Then she turns and walks
30. meters south to an art classroom. What is the girl’s
total displacement from the history classroom to the art
classroom?
A) 20. m south
C) 40. m south
B) 20. m north
D) 40. m north
61. The components of a 15-meters-per-second velocity at
an angle of 60.° above the horizontal are
A)
B)
C)
D)
7.5 m/s vertical and 13 m/s horizontal
13 m/s vertical and 7.5 m/s horizontal
6.0 m/s vertical and 9.0 m/s horizontal
9.0 m/s vertical and 6.0 m/s horizontal
67. Which quantity includes both magnitude and direction?
A) mass
C) distance
B) time
D) velocity
68. A 75-kilogram bicyclist coasts down a hill at a constant
speed of 12 meters per second. What is the kinetic
energy of the bicyclist?
A) 4.5
C) 5.4
10 2 J
10 3 J
B) 9.0
D) 1.1
10 2 J
l0 4 J
69. An object falls freely near Earth’s surface. Which graph
best represents the relationship between the object’s
kinetic energy and its time of fall
A)
B)
C)
D)
62. An airplane flies with a velocity of 750. kilometers per
hour, 30.0º south of east. What is the magnitude of the
eastward component of the plane’s velocity?
A) 866 km/h
C) 433 km/h
B) 650 km/h
D) 375km/h
63. Equilibrium exists in a system where three forces are
acting concurrently on an object. If the system includes
a 5.0-newton force due north and a 2.0-newton force
due south, the third force must be
A) 7.0 N south
C) 3.0 N south
B) 7.0 N north
D) 3.0 N north
64. In the diagram below, the weight of a box on a plane
inclined at 30. is represented by the vector W.
70. An object moving at a constant speed of 25 meters per
second possesses 450 joules of kinetic energy. What is
the object’s mass?
A) 0.72 kg
C) 18 kg
B) 1.4 kg
D) 36 kg
71. A car travels at constant speed v up a hill from point A
to point B, as shown in the diagram below.
What is the magnitude of the component of the weight
(W) that acts parallel to the incline?
A) W
C) 0.87 W
B) 0.50 W
D) 1.5 W
65. Which quantity is scalar?
A) mass
C) momentum
B) force
D) acceleration
66. Which terms represent a vector quantity and its
respective unit?
A)
B)
C)
D)
weight – kilogram
mass – kilogram
force – newton
momentum – newton
As the car travels from A to B, its gravitational potential
energy
A) increases and its kinetic energy decreases
B) increases and its kinetic energy remains the
same
C) remains the same and its kinetic energy decreases
D) remains the same and its kinetic energy remains
the same
MIDTERM REVIEW
72. A 1.00-kilogram ball is dropped from the top of a
building. Just before striking the ground, the ball’s
speed is 12.0 meters per second. What was the ball’s
gravitational potential energy, relative to the ground, at
the instant it was dropped? [Neglect friction.]
A) 6.00 J
C) 72.0 J
B) 24.0 J
D) 144 J
73. A girl rides an escalator that moves her upward at
constant speed. As the girl rises, how do her
gravitational potential energy and kinetic energy
change?
A) Gravitational potential energy decreases and
kinetic energy decreases.
B) Gravitational potential energy decreases and
kinetic energy remains the same.
C) Gravitational potential energy increases and
kinetic energy decreases.
D) Gravitational potential energy increases and
kinetic energy remains the same.
74. A spring gains 2.34 joules of elastic potential energy as
it is compressed 0.250 meter from its equilibrium
position. What is the spring constant of this spring?
A) 9.36 N/m
C) 37.4 N/m
B) 18.7 N/m
D) 74.9 N/m
75. A spring with a spring constant of 4.0 newtons per
meter is compressed by a force of 1.2 newtons. What is
the total elastic potential energy stored in this
compressed spring?
A) 0.18 J
C) 0.60 J
B) 0.36 J
D) 4.8 J
76. The graph below represents the relationship between
the force applied to a spring and spring elongation for
four different springs.
77. How much work is done by the force lifting a
0.1-kilogram hamburger vertically upward at constant
velocity 0.3 meter from a table?
A) 0.03 J B) 0.1 J
C) 0.3 J D) 0.4 J
78. As a box is pushed 30. meters across a horizontal floor
by a constant horizontal force of 25 newtons, the
kinetic energy of the box increases by 300. joules. How
much total internal energy is produced during this
process?
A) 150 J B) 250 J C) 450 J D) 750 J
79. As shown in the diagram below, a child applies a
constant 20.-newton force along the handle of a wagon
which makes a 25° angle with the horizontal.
How much work does the child do in moving the
wagon a horizontal distance of 4.0 meters?
A) 5.0 J
B) 34 J
C) 73 J
D) 80. J
80. A cart weighing 20 Newtons is pushed 10 meters on a
level surface by a force of 5 Newtons. How much work
was done on the cart?
A) 15 J
B) 50 J
C) 100 J D) 200 J
81. A horizontal force of 40 Newtons pushes a block along
a level table at a constant speed of 2 meters per second.
How much work is done on the block in 6 seconds?
A) 80 J
B) 120 J C) 240 J D) 480 J
82. A 2.0-kilogram block sliding down a ramp from a
height of 3.0 meters above the ground reaches the
ground with a kinetic energy of 50. joules. The total
work done by friction on the block as it slides down the
ramp is approximately
A) 6 J
B) 9 J
C) 18 J
D) 44 J
83. When a force moves an object over a rough, horizontal
surface at a constant velocity, the work done against
friction produces an increase in the object’s
Which spring has the greatest spring constant?
A) A
B) B
C) C
D) D
A) weight
C) potential energy
B) momentum
D) internal energy
MIDTERM REVIEW
84. A block weighing 15 Newtons is pulled to the top of an
incline that is 0.20 meter above the ground, as shown
below.
88. 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
A) 29 W
C) 1.4 × 10 3 W
If 4.0 joules of work are needed to pull the block the
full length of the incline, how much work is done
against friction?
A) 1.0 J B) 0.0 J
C) 3.0 J
D) 7.0 J
85. In the diagram below, 400. joules of work is done
raising a 72-newton weight a vertical distance of 5.0
meters.
B) 280 W
D) 1.4 × 10 4 W
89. In raising an object vertically at a constant speed of 2.0
meters per second, 10. watts of power is developed.
The weight of the object is
A) 5.0 N B) 20. N C) 40. N D) 50. N
90. A motor used 120. watts of power to raise a 15-newton
object in 5.0 seconds. Through what vertical distance
was the object raised?
A) 1.6 m
C) 40. m
B) 8.0 m
D) 360 m
91. A 15.0-kilogram mass is moving at 7.50 meters per
second on a horizontal, frictionless surface. What is the
total work that must be done on the mass to increase its
speed to 11.5 meters per second?
A) 120. J
C) 570. J
B) 422 J
D) 992 J
92. A horizontal force of 5.0 newtons acts on a
3.0-kilogram mass over a distance of 6.0 meters along a
horizontal, frictionless surface. What is the change in
kinetic energy of the mass during its movement over
the 6.0-meter distance?
A) 6.0 J
B) 15 J
C) 30. J D) 90. J
93. In the diagram below, an average force of 20. Newtons
is used to pull back the string of a bow 0.60 meter.
How much work is done to overcome friction as the
weight is raised?
A) 40. J B) 360 J C) 400. J D) 760 J
86. Which quantity is a measure of the rate at which work
is done?
A) energy
C) momentum
B) power
D) velocity
87. The rate at which work is done is measured in
A) Newtons
C) calories
B) joules
D) watts
As the arrow, leaves the bow, its kinetic energy is
A) 3.4 J
B) 6.0 J
C) 12 J
D) 33 J
MIDTERM REVIEW
96. A block weighing 40. newtons is released from rest on
an incline 8.0 meters above the horizontal, as shown in
the diagram below.
94.
As the pendulum swings from
position A to position B as shown in the diagram above,
what is the relationship of kinetic energy to potential
energy? [Neglect friction.]
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.
D) The kinetic energy increase is equal to the
potential energy decrease.
95. A pendulum is made from a 7.50-kilogram mass
attached to a rope connected to the ceiling of a
gymnasium. The mass is pushed to the side until it is at
position A, 1.5 meters higher than its equilibrium
position. After it is released from rest at position A, the
pendulum moves freely back and forth between
positions A and B, as shown in the diagram below.
What is the total amount of kinetic energy that the mass
has as it swings freely through its equilibrium position?
[Neglect friction.]
A) 11 J
B) 94 J
C) 110 J D) 920 J
If 50. joules of heat is generated as the block slides
down the incline, the maximum kinetic energy of the
block at the bottom of the incline is
A) 50. J
C) 320 J
B) 270 J
D) 3100 J
97. A ball is thrown vertically upward. As the ball rises, its
total energy (neglecting friction)
A) decreases
C) remains the same
B) increases
MIDTERM REVIEW
Base your answers to questions 98 through 100 on the information below.
A roller coaster car has a mass of 290. kilograms. Starting from rest, the car acquires 3.13 × 105
joules of kinetic energy as it descends to the bottom of a hill in 5.3 seconds.
98. Calculate the height of the hill. [Neglect friction.] [Show all work, including the equation and substitution
with units.]
99. Calculate the speed of the roller coaster car at the bottom of the hill. [Show all work, including the
equation and substitution with units.]
100. Calculate the magnitude of the average acceleration of the roller coaster car as it descends to the bottom
of the hill. [Show all work, including the equation and substitution with units.]
Base your answers to questions 101 and 102 on the
information below.
A 65-kilogram pole vaulter wishes to vault to a
height of 5.5 meters.
101. Calculate the minimum amount of kinetic energy the
vaulter needs to reach this height if air friction is
neglected and all the vaulting energy is derived from
kinetic energy. [Show all work, including the equation
and substitution with units.]
102. Calculate the speed the vaulter must attain to have the
necessary kinetic energy. [Show all work, including
the equation and substitution with units.]
Base your answers to questions 103 through 106 on the information below and on your knowledge of
physics.
The diagram below represents a 4.0-newton force applied to a 0.200-kilogram copper block
sliding to the right on a horizontal steel table.
103. Determine the weight of the block.
104. Calculate the magnitude of the force of friction acting on the moving block. [Show all work, including the
equation and substitution with units.]
MIDTERM REVIEW
105. Determine the magnitude of the net force acting on the moving block.
106. Describe what happens to the magnitude of the velocity of the block as the block slides across
the table.
107. The coefficient of kinetic friction between a
780.-newton crate and a level warehouse floor is
0.200. Calculate the magnitude of the horizontal force
required to move the crate across the floor at constant
speed.
Answer Key
midterm review
1.
C
37.
A
73.
D
2.
C
38.
B
74.
D
3.
C
39.
D
75.
A
4.
A
40.
D
76.
A
5.
D
41.
D
77.
C
6.
C
42.
B
78.
C
101. 3.5 × 10 3 J
7.
B
43.
A
79.
C
102. 10 m/s
8.
C
44.
C
80.
B
9.
D
45.
A
81.
D
103. 1.96 N or 2.0 N or
1.9 N
10.
C
46.
B
82.
B
11.
B
47.
D
83.
D
12.
C
48.
B
84.
A
13.
D
49.
C
85.
A
14.
C
50.
B
86.
B
15.
A
51.
A
87.
D
16.
C
52.
B
88.
B
17.
D
53.
C
89.
A
18.
B
54.
B
90.
C
19.
A
55.
D
91.
C
20.
C
56.
B
92.
C
21.
B
57.
A
93.
C
22.
D
58.
D
94.
D
23.
C
59.
C
95.
C
24.
A
60.
A
96.
B
25.
C
61.
B
97.
C
26.
B
62.
B
98.
27.
A
63.
C
28.
D
64.
B
29.
A
65.
A
30.
B
66.
C
31.
B
67.
D
32.
C
68.
C
33.
C
69.
D
34.
B
70.
B
35.
C
71.
B
36.
B
72.
C
99.
100.
104.
105. 3.3 N
106. — The magnitude of
the velocity increases.
— The block speeds
up
107. Ff = ƒFn= (.200) (780.
N) = 156 N
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