Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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A baseball thrown from the outfield is released from shoulder height at an
initial velocity of 29.4 m/s at an initial angle of 30.0° with
respect to the horizontal. If it is in its trajectory for a total of 3.00 s before being caught by
the third baseman at an equal shoulder-height level, what is the ball's net vertical
displacement during its 3-s trajectory?
a. | 11.0 m | b. | 9.80 m | c. | 22.1
m | d. | zero | e. | 44.1 m |
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2.
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A stone is thrown with an initial speed of 15 m/s at an angle of 53° above the horizontal from the top of a 35 m building. If g = 9.8
m/s2 and air resistance is negligible, then what is the magnitude of the vertical velocity
component of the rock as it hits the ground?
a. | 9.0 m/s | b. | 18 m/s | c. | 26
m/s | d. | 29 m/s | e. | 32 m/s |
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3.
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A rifle is aimed horizontally toward the center of a target 100 m away. If the
bullet strikes 10 cm below the center, what was the velocity of the bullet? (Ignore air
friction.)
a. | 300 m/s | b. | 333 m/s | c. | 500
m/s | d. | 700 m/s | e. | 751 m/s |
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4.
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A ball is launched from ground level at 30 m/s at an angle of 35° above the horizontal. How far does it go before it is at ground level
again?
a. | 14 m | b. | 21 m | c. | 43
m | d. | 86 m | e. | 97 m |
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5.
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An astronaut applies a force of 500 N to an asteroid, and it accelerates at 7.00
m/s2. What is the asteroid's mass?
a. | 71 kg | b. | 135 kg | c. | 441
kg | d. | 3 500 kg | e. | 3.600 kg |
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6.
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Rita accelerates a 0.40-kg ball from rest to 9.0 m/s during the 0.15 s in which
her foot is in contact with the ball. What average force does she apply to the ball during the
kick?
a. | 48 N | b. | 72 N | c. | 24
N | d. | 60 N | e. | 76 N |
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7.
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An automobile of mass 2 000 kg moving at 30 m/s is braked suddenly with a
constant braking force of 10 000 N. How far does the car travel before stopping?
a. | 45 m | b. | 90 m | c. | 135
m | d. | 180 m | e. | 210 m |
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8.
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Two blocks, joined by a string, have masses of 6.0 and 9.0 kg. They rest on a
frictionless horizontal surface. A 2nd string, attached only to the 9-kg block, has horizontal force
= 30 N applied to it. Both blocks accelerate. Find the tension in the string between the
blocks.
a. | 18 N | b. | 28 N | c. | 12
N | d. | 15 N | e. | 16 N |
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9.
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As a basketball player starts to jump for a rebound, he begins to move upward
faster and faster until he leaves the floor. During this time that he is in contact with the floor,
the force of the floor on his shoes is:
a. | bigger than his weight. | b. | equal in magnitude and opposite in direction to
his weight. | c. | less than his weight. | d. | zero. | e. | the answer depends
on his weight. |
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10.
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A boxcar of mass 200 tons at rest becomes uncoupled on a 2.5° grade. If the track is considered to be frictionless, what speed does the
boxcar have after 10 seconds?
a. | 0.37 m/s | b. | 0.59 m/s | c. | 1.3
m/s | d. | 4.3 m/s | e. | 5.2 m/s |
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11.
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A 5 000-N weight is held suspended in equilibrium by two cables. Cable 1 applies
a horizontal force to the right of the object and has a tension, T1. Cable 2
applies a force upward and to the left at an angle of 37.0° to the
negative x axis and has a tension, T2. What is the tension,
T1?
a. | 4 000 N | b. | 6 640 N | c. | 8 310
N | d. | 3 340 N | e. | 9 120 N |
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12.
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A 500-N tightrope walker stands at the center of the rope such that each half of
the rope makes an angle of 10.0° with the horizontal. What is the
tension in the rope?
a. | 1 440 N | b. | 1 000 N | c. | 500
N | d. | 2 900 N | e. | 2 100 N |
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13.
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A block of mass 5.00 kg rests on a horizontal surface where the coefficient of
kinetic friction between the two is 0.200. A string attached to the block is pulled horizontally,
resulting in a 2.00-m/s2 acceleration by the block. Find the tension in the string.
(g = 9.80 m/s2)
a. | 0.200 N | b. | 9.80 N | c. | 19.8
N | d. | 10.0 N | e. | 15.6 N |
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