Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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In one-dimensional motion, the average speed of an object that moves from one
place to another and then back to its original place has which of the following properties?
a. | It is positive. | b. | It is negative. | c. | It is
zero. | d. | It can be positive, negative, or zero. | e. | It isn't
zero. |
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2.
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An object moves 20 m east in 30 s and then returns to its starting point taking
an additional 50 s. If west is chosen as the positive direction, what is the sign associated with the
average velocity of the object?
a. | + | b. | - | c. | 0 (no sign) | d. | any of the
above | e. | It isn't zero. |
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3.
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A cheetah can maintain its maximum speed of 100 km/hr for 30.0 seconds. What
minimum distance must a gazelle running 80.0 km/hr be ahead of the cheetah to escape?
a. | 100 m | b. | 167 m | c. | 70.0
m | d. | 83.0 m | e. | 184 m |
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4.
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A 50-g ball traveling at 25.0 m/s is bounced off a brick wall and rebounds at
22.0 m/s. A high-speed camera records this event. If the ball is in contact with the wall for 3.50
ms, what is the average acceleration of the ball during this time interval?
a. | 13 400 m/s2 | b. | 6 720 m/s2 | c. | 857
m/s2 | d. | 20 m/s2 | e. | 15 m/
s2 |
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5.
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A strobe photograph of a car moving along a straight road shows the interval
between each successive image to be diminishing. If the direction of motion of the car is taken as
positive, which of the following are negative?
a. | the speed of the car | b. | the average velocity of the
car | c. | the average acceleration of the car | d. | the instantaneous velocity of the
car | e. | all of the above |
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6.
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When a drag strip vehicle reaches a velocity of 60 m/s, it begins a negative
acceleration by releasing a drag chute and applying its brakes. While reducing its velocity back to
zero, its acceleration along a straight line path is a constant -7.5
m/s2. What displacement does it undergo during this deceleration period?
a. | 40 m | b. | 80 m | c. | 160
m | d. | 240 m | e. | 310 m |
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7.
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If the displacement of an object is given in SI units by Dx = -3 t + 4 t 2, at t = 2 s its
velocity and acceleration are, respectively:
a. | positive, positive. | b. | positive, negative. | c. | negative,
negative. | d. | negative, positive. | e. | negative, zero. |
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8.
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A rock is thrown straight up with an initial velocity of 19.6 m/s. What time
interval elapses between the rock's being thrown and its return to the original launch point?
(Acceleration due to gravity is 9.80 m/s2.)
a. | 4.00 s | b. | 5.00 s | c. | 8.00
s | d. | 10.0 s | e. | 15.0 s |
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9.
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A rock, released at rest from the top of a tower, hits the ground after 1.5 s.
What is the speed of the rock as it hits the ground? (g = 9.8 m/s2 and air
resistance is negligible)
a. | 15 m/s | b. | 20 m/s | c. | 31
m/s | d. | 39 m/s | e. | 40 m/s |
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10.
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Omar throws a rock down with speed 12 m/s from the top of a tower. The rock hits
the ground after 2.0 s. What is the height of the tower? (air resistance is negligible)
a. | 20 m | b. | 24 m | c. | 44
m | d. | 63 m | e. | 71 m |
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11.
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Human reaction time is usually about 0.20 s. If your lab partner holds a ruler
between your finger and thumb and releases it without warning, how far can you expect the ruler to
fall before you catch it? The nearest value is:
a. | 4.0 cm. | b. | 9.8 cm. | c. | 16
cm. | d. | 20 cm. | e. | 24 cm. |
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12.
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A basketball player can jump 1.6 m off the hardwood floor. With what upward
velocity did he leave the floor?
a. | 1.4 m/s | b. | 2.8 m/s | c. | 4.2
m/s | d. | 5.6 m/s | e. | 6.5 m/s |
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13.
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A water rocket, launched from the ground, rises vertically with acceleration of
30 m/s2 for
1.0 s when it runs out of "fuel." Disregarding air resistance,
how high will the rocket rise?
a. | 15 m | b. | 31 m | c. | 61
m | d. | 120 m | e. | 132 m |
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14.
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A parachutist jumps out of an airplane and accelerates with gravity to a maximum
velocity of 58.8 m/s in 6.00 seconds. She then pulls the parachute cord and after a 4.00-second
constant deceleration, descends at 10.0 m/s for 60.0 seconds, reaching the ground. From what height
did the parachutist jump?
a. | 914 m | b. | 1 130 m | c. | 1 520
m | d. | 1 750 m | e. | 1 820 m |
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15.
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A ball is thrown vertically upwards at 19.6 m/s. For its complete trip (up and
back down to the starting position), its average speed is:
a. | 19.6 m/s. | b. | 9.80 m/s. | c. | 4.90
m/s. | d. | 3.15 m/s. | e. | not given. |
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