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EO # 2 Review Sheet
1. An object of 2 kg mass, acted upon by a net force of 20 N, will experience what acceleration?
a. 5 m/s2
b. 10 m/s2
c. 7.5 m/s2
d. 12.4 m/s2
2. A box rests on a level table. Let W be the weight of the box, and N is the normal of the table on the
box. In magnitude, W is opposite and ___ N, and the two forces ___ action-reaction pair.
a. equals, are
b. equals, are not
c. is greater than, are
d. is greater than, are not
3. A 2.0 kg object is acted on by a force F. The object is moving with acceleration of 10 m/s2. Find F.
a. 0.2 N
b. 5 N
c. 12 N
d. 20 N
e. none of them
4. You jump off a truck and accelerate toward the surface of the Earth. Does the Earth accelerate
toward you?
a. Yes, but the acceleration of the Earth is very small
b. No, the acceleration of the Earth is zero
c. Yes, Newton's 3rd Law implies the accelerations are equal
d. cannot be determined
e. none of the above
5. All objects tend to maintain their state of motion because they have:
a. mass
b. weight
c. speed
d. acceleration
e. all of these
6. If a 60 ton Patton tank collides with a little Honda Civic, which vehicle will experience the greater
impact force?
a. The tank
b. The Civic
c. Both the same
d. Neither feels a force
7. If a net force is acting on an object, then ______
a. The object is at rest
b. The object is moving with constant velocity
c. The object is being accelerated
d. The object is losing mass
8. In Newtonian mechanics, ____ is the cause and _____ the effect.
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a. acceleration . . . velocity
b. force . . . acceleration
c. acceleration . . . force
d. force . . . velocity
e. none of the above
9. A 1000 kg sports car of mass accelerates from rest to 20 m/s in 6.6 s. What is the force exerted by
the road on the car?
a. 1500 N
b. 1750 N
c. 2750 N
d. 3000 N
10. Two forces act on an object. A 10 N force is directed North and a 5 N force South. The object moves
at constant acceleration of 2 m/s2. What is the mass of the object?
a. 7.5 kg
b. 2.5 kg
c. 7.5 kg
d. 5 kg
e. none of the above
11. Bill weighs 160 lb. He is standing on a scale inside an elevator. What is the reading on the scale if the
elevator is accelerating downward?
a. 160 lb
b. less than 160 lb
c. greater than 160 lb
d. zero
12. Two forces, 300 N and 500 N, act on an 80-kg particle. Their directions are 300 N north and 500 N
east. Find the magnitude of the resultant acceleration if the forces make a 90 0 angle with each other.
a. 5.45 m/s2
b. 6.24 m/s2
c. 6.85 m/s2
d. 7.29 m/s2
e. 8.09 m/s2
13. A crate is pulled across a horizontal floor by a rope tied to the crate. The rope makes an angle of 37
degrees with the horizontal. Find the frictional force if the tension in the rope is 10N and the crate
moves with constant velocity.
a. 3.0 N
b. 5.0 N
c. 7.0 N
d. 8.0 N
e. none of them
14. A crate slides down a 35o ramp with constant speed. What is the coefficient of kinetic friction
between the crate and the ramp?
a. 0.25
b. 0.45
c. 0.50
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d. 0.60
e. 0.70
15. The coefficient of static friction between the tires of a car and asphalt is
steepest angle of a slope on which the car can be parked?
a. 22.5 o
b. 30 o
c. 37 o
d. 45 o
. What is the
16. A 500 N weight is hung at the middle of a rope attached to two buildings at the same level. If the
breaks in the tension exceed 1800 N, what is the minimum angle the rope can make with the horizontal?
a. 4 o
b. 8 o
c. 11 o
d. 18 o
17. Sam is using a rope to pull a box weighing 300 N across a floor with constant velocity. The rope makes
an angle of 300 above the horizontal. If the tension in the rope is 100 N, what is the normal force exerted
by the floor on the box?
a. 300 N
b. 290 N
c. 270 N
d. 250 N
18. A 5.0 kg block is pulled horizontally across a floor by a string attached to it with an acceleration of 2
m/s2 k. What is the tension in the string if the coefficient of sliding kinetic friction between the block
and floor is 0.2?
a. 5.6 N
b. 9.8 N
c. 19.8 N
d. 28.9 N
19. A force of 250 N pushes a 50-kg box along a horizontal surface. The force is directed 30 0 below the
horizontal. What is the acceleration of the box if the coefficient of kinetic friction between the box and
the surface is 0.30?
a. 0.637 m/s2
b. 1.77 m/s2
c. 3.16 m/s2
d. 6.31 m/s2
20. The word "normal" in the phrase "normal force" indicates that:
a. the force is exerted by a surface
b. the force is exerted by an object
c. the force exerted by a surface is parallel to itself
d. the force exerted by a surface is perpendicular to itself
21. A 1.50 kg mass is acted upon by a force of 16.0 N applied at an angle of 60 0 above the horizontal.
What is the acceleration of the mass?
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a. 4.33 m/s2
b. 5.33 m/s2
c. 6.33 m/s2
d. 7.35 m/s2
22. A weight of 5000 N is suspended by two cables. The object is at rest. The first cable is horizontal
and the second makes an angle of 143o with the first cable. Find the tension of the first cable.
a. 4000 N
b. 6640 N
c. 8310 N
d. 3340 N
23. Two blocks with masses 2.00 kg and 4.00 kg are placed side-by-side on a frictionless horizontal
surface. A horizontal force with a magnitude of 5.20 N is applied to the 2.00 kg block perpendicular to its
surface. What is the magnitude of the force on the 4.00 kg block?
a. 2.60
b. 3.11
c. 3.47
d. 3.89
24. A 43 kg child sits in a massless swing. With what horizontal force must the seat be pulled so that the
ropes form an angle of 35o with respect to the vertical?
a. 300 N
b. 320 N
c. 340 N
d. 360 N
25. A physics student holds a 2.40 kg block against a wall by pressing on it perpendicularly to the wall.
Find the minimum force she must exert if the coefficient of static friction is
a. 7.53
b. 73.5
c. 23.5
d. 235
e. not enough information
.
26. A bumper protects a car during a collision because it:
a. increases the time of impact
b. decreases the time of impact
c. increases the force of impact
d. increases kinetic energy transfer
27. If two objects have the same momentum, then:
a. the object with the greater mass will have the smaller velocity
b. the object with the greater mass will have the larger velocity
c. both objects have the same velocity
d. both objects have only the same speed
28. A 3-kg ball is rolling at a speed of 6 m/s. What is the magnitude of the momentum of the ball?
a. 6 m/s
b. 18 kg*m/s
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c. 18 m/s
d. 6 kg*m/s
29. A brick falls to the ground. If the time for the collision of the brick and the ground is increased by a
factor of 4, the force of the collision with the ground will change by a factor of:
a. 4
b. 16
c. 1/4
d. 1/16
30. A 0.30 kg ball is dropped onto a concrete driveway. The ball's velocity before impact is 4.5 m/s and
after impact is 4.2 m/s. What is the change in the ball's momentum?
a. 0.09 kg-m/s
b. 2.6 kg-m/s
c. 4.0 kg-m/s
d. 116 kg-m/s
31. What is the speed of a 0.145 kg object moving with a momentum of 5.80 Ns?
a. 0.841 m/s
b. 1.19 m/s
c. 40.0 m/s
d. 36.0 m/s
32. Which is a vector?
a. linear momentum
b. impulse
c. neither a nor b
d. both a and b
33. Mike jumps 1 m down onto a walkway. His downward motion stops in 0.02 seconds. If he forgets to
bend his knees, what force is transmitted to his leg bones? Mike's mass is 70-kg.
a. 15,490 N
b. 7,010 N
c. 4,900 N
d. 3,500 N
34. A 1.5 kg ball falls onto a floor. Just before it strikes the floor, its velocity is 12 m/s. The ball bounces
up with a velocity of 10 m/s. Find the impulse on the ball.
a. 3 N*s
b. 15 N*s
c. 18 N*s
d. 33 N*s
35. A soccer player kicks a soccer ball initially at rest setting it in motion at a velocity of 30 m/s. If the
ball has a mass of 0.5 kg and the time of contact is 0.025 s, what is the force exerted on the player's
foot?
a. 188 N
b. 375 N
c. 600 N
d. 900 N
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36. The driver of a 2000 kg car moving at 30 m/s presses on the break pedal. If the braking force is
10,000 N, how far does the car travel before stopping?
a. 45 m
b. 90 m
c. 135 m
d. 180 m
37. A 2 kg ball moving at 3 m/s hits a wall and bounces off. Immediately after the collision, it moves at 3
m/s in the opposite direction. What is the change in the object's momentum?
a. + 12 kg m/s
b. -12 kg m/s
c. 0 kg m/s
d. +6 kg m/s
e. -6 kg m/s
f. More than one of the above is possible
38. Momentum of a system is conserved only when:
a. there are no forces acting on the system
b. there are no external forces acting on the system
c. there are no internal forces acting on the system
d. the system is not moving
e. the system has been moving long enough to gain momentum
39. An elephant is hit by a ping pong ball. The magnitude of the change in momentum is
a. greatest for the elephant
b. greatest for the ping pong ball
c. the same for both
d. depends on the ratio of the masses of the ball and elephant
e. none of these
40. A 1000 kg car traveling east at 20 m/s collides head-on with a 1500 kg car traveling west at 10 m/s.
The cars stick together after the collision. What is their common velocity after the collision?
a. 3 m/s east
b. 4 m/s east
c. 6 m/s west
d. 14 m/s east
e. none of these
41. Which of the following is a correct statement of the law of conservation of momentum?
a. The rate of change of momentum of a body is equal to the net force applied to it.
b. The total momentum of an isolated system of bodies remains constant.
c. The total momentum is always conserved.
d. The sum of the momenta impulses of the objects in an isolated system is always conserved.
e. none of these
42. A large platform is initially at rest on a smooth surface. A dog on the platform starts running toward
the east. The mass of the dog is one-half the mass of the platform. When the dog moves toward the east
with a speed vo, the platform moves toward the ________ with a speed ________.
a. east ... vo/2
b. east ... 2 vo
c. west ... vo/2
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d. west ... 2 vo
e. none of these
43. A 0.240 kg glider moving with a velocity of 0.600 m/s collides head-on with a 0.260 kg glider moving
along the same line in the opposite direction with a velocity of 0.200 m/s. The collision is perfectly
inelastic. The final velocity of the combined gliders is _____ m/s.
a. 0.563
b. 0.184
c. 0.0484
d. -0.392
e. none of these
44. A 20,000 kg car moving with a speed of 4.00 m/s collides with a 50,000 kg car moving with a speed of
1.80 m/s in the same direction. Find the speed of the combined cars after the collision which is perfectly
inelastic.
a. 1.60 m/s
b. 2.43 m/s
c. 2.00 m/s
d. 1.57 m/s
e. none of these
45. A 40 kg boy dives horizontally off a 600 kg raft. If the boy's speed at the moment he is leaving the
raft is 4 m/s, what is the raft's speed?
a. 0.2 m/s
b. 0.56 m/s
c. 0.6 m/s
d. 4 m/s
e. none of these
46. A cannonball explodes into several fragments in mid-air. The total momentum of the fragments after
this explosion:
a. is the same as the momentum of the cannonball immediately before the explosion
b. has been changed into the kinetic energy of the fragments
c. is less than the momentum of the cannonball immediately before the explosion
d. is more than the momentum of the cannonball immediately before the explosion
e. has been changed into radiant energy
47. What is the work required to stretch a spring with a constant force of 2500 N/m by 4.00 cm.
a. 4 J
b. 0
c. 3 J
d. 2 J
48. An 80-N crate is pushed at constant speed for a distance of 5.0 m upward along a smooth inclined
plane that makes an angle of 300 with the horizontal. If the force on the crate is parallel to the slope,
what is the work done by the pushing force?
a. -200 J
b. 61 J
c. 140 J
d. 200 J
e. 260 J
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49. A force of 30.0 N is required to stretch a spring by 0.20 m. What work is done in stretching a spring
from 0 to 0.40 m?
a. 12.0 J
b. 6.00 J
c. 3.00 J
d. 1.50 J
50. A 6.00 kg block slides down a 3.40 m long inclined plane. The speed of the block at the bottom is 5.40
m/s. If the height of the plane is 2.00 m, what is the work done by friction?
a. -118 J
b. -30.1 J
c. -85.5 J
d. -8.85 J
51. Jim climbs up a rope from an initial height of 1.30 m to a final height of 3.20 m. If Jim's mass is 45
kg, what is the change in his gravitational potential energy?
a. 85.5 J
b. 838 J
c. 1980 J
d. 187 J
52. An object thrown vertically upward will ________ kinetic energy and ________ gravitational
potential energy.
a. gain ... gain
b. gain ... lose
c. lose ... gain
d. lose ... lose
53. A car is moving up a hill at constant speed. Which statement below is correct?
a. its potential energy is constant
b. its total mechanical energy is constant
c. work is being done by a non-conservative force
d. none of the above
54. A 60 g golf ball is dropped from a level of 2 m high. It rebounds to 1.5 m. How much energy is lost?
a. 0.29 J
b. 0.5 J
c. 0.88 J
d. 1 J
55. An 80,000 kg plane is flying at 900 km/h at a height of 10 kilometers. What is its total mechanical
energy?
a. 250 MJ
b. 478 MJ
c. 773 MJ
d. 10,340 MJ
56. Bill pushes a 250 N weight wheelbarrow up a 6.0 m long ramp making 20 o angle with the horizontal.
Find the change in the gravitational potential energy of the wheelbarrow.
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a. 513 J
b. 1500 J
c. 3550 J
d. 4500 J
57. A 2000-kg ore car rolls 50 meters down a smooth 10o incline. There is a horizontal spring at the end
of the incline designed to stop the car in case of break failure. What is the force constant of the spring
if it would compress by 1 m to stop the ore car?
a. 340.3 kN/m
b. 680.7 kN/m
c. 980.0 kN/m
d. 1960.0 kN/m
58. Ruth is moving a heavy box a distance of 14.0 m across the floor of her bedroom. If she does 9000 J
of work in 3.00s, her power is _____.
a. 3000 W
b. 12000 W
c. 149 W
d. 1500 W
59. The rate at which work is done is equivalent to:
a. increase in potential energy
b. thermal energy
c. potential energy
d. power
60. A pulley-cable system on a construction site lifts a 20,000 N concrete block to a height of 40 m. If
this takes 2 min., what is the power of the pulley-cable system?
a. 6.7 kW
b. 3.3 kW
c. 13.3 kW
d. 400 kW
61. A jet engine is moving an airplane forward at a speed of 900 km/hr. If the thrust of the engine is 10 5
N, what is the power developed by the engine?
a. 5 MW
b. 10 MW
c. 25 MW
d. 50 MW
62. For safety reasons, the speed of a child at the bottom of a playground slide cannot exceed 6.0 m/s.
What is the maximum height of the slide?
a. 1.8 m
b. 2.9 m
c. 3.2 m
d. 4.5 m
63. Sarah and her bicycle have a total mass of 40 kg. Her speed at the top of a 10 m high and 100m long
hill is 5 m/s. If the force of friction on her way down is 20 N, at what speed will she be going when she
reaches the bottom?
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a. 5 m/s
b. 10 m/s
c. 11 m/s
d. She stops before she reaches the bottom
64. A boy on a roof throws one ball downward and an identical ball upward. The ball thrown downward hits
the ground with 100 J of kinetic energy. If both balls are thrown at the same speed and there is no air
friction, what is the kinetic energy of the second just before it hits the ground?
a. 100 J
b. 200 J
c. Less than 100 J
d. More than 200 J
e. none of the above
65. A 0.145 kg rock is thrown with a speed of 32.0 m/s at an angle of 40 0. What is its kinetic energy at
the top of its trajectory?
a. 43.6 J
b. 74.2 J
c. 30.6 J
d. 13.0 J
66. A rubber ball is dropped on the floor. The rebound speed is one-half the speed it had just before
hitting the floor. It will rise to ________ of the original height from which it was dropped.
a. 1/8
b. 1/6
c. 1/5
d. 1/4
e. 1/3
67. A 500 kg roller coaster car crests a 20m high hill at a speed of 10 m/s. It then rolls down the other
side, all the way to ground level, and climbs a second hill. What is the speed of the car when it is 10 m up
the second hill?
a. 15.3 m/s
b. 17.2 m/s
c. 8.9 m/s
d. 19.7 m/s
68. A pendulum, 2.0 m in length, is released with a push when the string is at an angle of 25 o from the
vertical. If the initial speed of the pendulum is 1.2 m/s, what is its speed at the bottom of the swing?
a. 2.3 m/s
b. 2.6 m/s
c. 2.0 m/s
d. 0.5 m/s
More problems can be found at the website below. Unit 1 Chapters 2-4 at the end of each lesson is a
Chapter Test and Answer Key.
http://montereyinstitute.org/courses/College%20Preparatory%20Physics%20I/nroc%20prototype%20fil
es/coursestartc.html
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