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1 The diagram below shows a 50.-kilogram crate on a frictionless plane at
angle face="Symbol">q to the horizontal. The crate is pushed at constant speed up
the incline from point A to point B by force F.
If angle face="Symbol">q were increased, what would be the effect on the magnitude
of force F and the total work W done on the crate as it is moved from A to B?
(1) W would remain the same and the magnitude of F would decrease.
(2) W would remain the same and the magnitude of F would increase.
(3) W would increase and the magnitude of F would decrease.
(4) W would increase and the magnitude of F would increase.
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2 A vector makes an angle, face="Symbol">q, with the horizontal. The horizontal
and vertical components of the vector will be equal in magnitude if angle face="Symbol">q
is
(1) 30°
(2) 45°
(3) 60°
(4) 90°
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3 A car initially traveling at a speed of 16 meters per second accelerates uniformly
to a speed of 20. meters per second over a distance of 36 meters. What is
the magnitude of the car’s acceleration?
(1) 0.11 m/s2
(2) 2.0 m/s2
(3) 0.22 m/s2
(4) 9.0 m/s2
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4 A ball is thrown at an angle of 38° to the horizontal. What happens to the magnitude
of the ball’s vertical acceleration during the total time interval that the
ball is in the air?
(1) It decreases, then increases.
(2) It decreases, then remains the same.
(3) It increases, then decreases.
(4) It remains the same.
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5 A man standing on a scale in an elevator notices that the scale reads 30 newtons
greater than his normal weight. Which type of movement of the elevator could cause
this greater-than-normal reading?
(1) accelerating upward
(2) accelerating downward
(3) moving upward at constant speed
(4) moving downward at constant speed
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Base your answers to questions 6 and 7 on the information below.
Projectile A is launched horizontally at a speed of 20. meters per second
from the top of a cliff and strikes a level surface below, 3.0 seconds later.
Projectile B is launched horizontally from the same location at a speed of 30.
meters per second.
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6 The time it takes projectile B to reach the level surface is
(1) 4.5 s
(2) 2.0 s
(3) 3.0 s
(4) 10. s
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7 Approximately how high is the cliff?
(1) 29 m
(2) 44 m
(3) 60. m
(4) 104 m
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8 A 60-kilogram skydiver is falling at a constant speed near the surface of Earth.
The magnitude of the force of air friction acting on the skydiver is approximately
(1) 0 N
(2) 6 N
(3) 60 N
(4) 600 N
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9 An astronaut weighs 8.00 × 102 newtons on the surface of Earth.
What is the weight of the astronaut 6.37 × 106 meters above the
surface of Earth?
(1) 0.00 N
(2) 2.00 × 102N
(3) 1.60 × 103 N
(4) 3.20 × 103 N
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10 A 10.-newton force is required to hold a stretched spring 0.20
meter from its rest position. What is the potential energy stored in the stretched
spring?
(1) 1.0 J
(2) 2.0 J
(3) 5.0 J
(4) 50. J
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11 When a 12-newton horizontal force is applied to a box on a horizontal tabletop,
the box remains at rest. The force of static friction acting on the box is
(1) 0 N
(2) between 0 N and 12 N
(3) 12 N
(4) greater than 12 N
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12 Ball A of mass 5.0 kilograms moving at 20. meters per second collides
with ball B of unknown mass moving at 10. meters per second in the same direction.
After the collision, ball A moves at 10. meters per second and ball B at
15 meters per second, both still in the same direction. What is the mass of ball
B?
(1) 6.0 kg
(2) 2.0 kg
(3) 10. kg
(4) 12 kg
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13 A 1.5-kilogram lab cart is accelerated uniformly from rest to a speed
of 2.0 meters per second in 0.50 second. What is the magnitude of
the force producing this acceleration?
(1) 0.70 N
(2) 1.5 N
(3) 3.0 N
(4) 6. 0 N
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14 The diagram below represents the magnetic field near point P.
If a compass is placed at point P in the same plane as the magnetic field,
which arrow represents the direction the north end of the compass needle will point?
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15 Which person has the greatest inertia?
(1) a 110-kg wrestler resting on a mat
(2) a 90-kg man walking at 2 m/s
(3) a 70-kg long-distance runner traveling at 5 m/s
(4) a 50-kg girl sprinting at 10 m/s
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16 A child is riding on a merry-go-round. As the speed of the merry-go-round is
doubled, the magnitude of the centripetal force acting on the child
(1) remains the same
(2) is doubled
(3) is halved
(4) is quadrupled
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17 The magnitude of the electrostatic force between two point charges is F. If the
distance between the charges is doubled, the electrostatic force between the charges
will become
(1) F/2
(2) 2F
(3) F/4
(4) 4F
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18 As a ball falls freely (without friction) toward the ground, its total mechanical
energy
(1) decreases
(2) increases
(3) remains the same
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19 A 0.50-kilogram ball is thrown vertically upward with an initial kinetic
energy of 25 joules. Approximately how high will the ball rise? [Neglect air resistance.]
(1) 2.6 m
(2) 5.1 m
(3) 13 m
(4) 25 m
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20 What is the average power developed by a motor as it lifts a 400.-kilogram
mass at constant speed through a vertical distance of 10.0 meters in 8.0
seconds?
(1) 320 W
(2) 500 W
(3) 4,900 W
(4) 32,000 W
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