Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.
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1.
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What
is the common formula for work? Assume that W is the work, F is a constant force,  v is the change in velocity, and d is the displacement. a. | W =
FDv | c. | W =
Fd | b. | W =
Fd | d. | W =
F d | | | | |
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2.
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If
the sign of work is negative, a. | the displacement is perpendicular to the
force. | b. | the displacement is in the direction opposite the
force. | c. | the displacement is in the same direction as the
force. | d. | no work is done. | | |
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3.
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In
which of the following scenarios is work done? a. | A weightlifter holds a barbell overhead for 2.5
s. | b. | A construction
worker carries a heavy beam while walking at constant speed along a flat
surface. | c. | A car decelerates while traveling on a flat stretch of
road. | d. | A student holds a spring in a compressed
position. | | |
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4.
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A
worker does 25 J of work lifting a bucket, then sets the bucket back down in the same place. What is
the total net work done on the bucket?
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5.
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A
child pulls a balloon for 12 m with a force of 1.0 N at an angle 60° below
horizontal. How much work does the child do on the balloon? a. | –10
J | c. | 6.0
J | b. | –6.0
J | d. | 12
J | | | | |
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6.
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Which
of the following energy forms is associated with an object due to its position? a. | potential
energy | c. | total
energy | b. | positional energy | d. | kinetic energy | | | | |
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7.
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Which
of the following energy forms is not involved in hitting a tennis ball? a. | kinetic
energy | c. | gravitational
potential energy | b. | chemical potential energy | d. | elastic potential energy | | | | |
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8.
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Which
of the following formulas would be used to directly calculate the kinetic energy of an object with
mass m bouncing up and down on a spring with spring constant k?
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9.
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What
is the kinetic energy of a 0.135 kg baseball thrown at 40.0 m/s? a. | 54.0
J | c. | 108
J | b. | 87.0
J | d. | 216
J | | | | |
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10.
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If
friction is the only force acting on an object during a given physical process, which of the
following assumptions can be made in regard to the object’s kinetic energy? a. | The kinetic
energy decreases. | b. | The kinetic energy increases. | c. | The kinetic
energy remains constant. | d. | The kinetic energy decreases and then
increases. | | |
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11.
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The
main difference between kinetic energy and potential energy is that a. | kinetic energy
involves position, and potential energy involves motion. | b. | kinetic energy
involves motion, and potential energy involves position. | c. | although both
energies involve motion, only kinetic energy involves position. | d. | although both
energies involve position, only potential energy involves motion. | | |
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12.
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Which
form of energy is involved in weighing fruit on a spring scale? a. | kinetic
energy | c. | gravitational
potential energy | b. | nonmechanical energy | d. | elastic potential energy | | | | |
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13.
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Gravitational potential energy is always measured in relation to a. | kinetic
energy. | c. | total potential
energy. | b. | mechanical energy. | d. | a zero level. | | | | |
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14.
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If
the displacement of a horizontal mass-spring system was doubled, the elastic potential energy in the
system would change by a factor of
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15.
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In
the presence of frictional force, a. | nonmechanical energy is negligible and mechanical energy is no
longer conserved. | b. | nonmechanical energy is negligible and mechanical energy is
conserved. | c. | nonmechanical energy is no longer negligible and mechanical
energy is conserved. | d. | nonmechanical energy is no longer negligible and mechanical
energy is no longer conserved. | | |
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16.
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For
which of the following situations is the conservation of mechanical energy most likely to be a valid
assumption? a. | A skateboard
rolls across a sewer grate. | b. | A parachutist falls from a plane. | c. | You rub your
hands together to keep warm. | d. | A soccer ball flies through the air. | | |
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17.
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Which
of the following are examples of conservable quantities? a. | potential energy
and length | c. | mechanical
energy and mass | b. | mechanical energy and length | d. | kinetic energy and mass | | | | |
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18.
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Friction converts kinetic energy to a. | mechanical
energy. | c. | nonmechanical
energy. | b. | potential energy. | d. | total energy. | | | | |
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19.
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What
is the average power supplied by a 60.0 kg person running up a flight of stairs a vertical distance
of 4.0 m in 4.2 s? a. | 57 W | c. | 560 W | b. | 240
W | d. | 670
W | | | | |
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20.
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Which
of the following has the greatest power output? a. | a weightlifter who lifts a 250 N weight 2.1 m in 3.0
s | b. | a
mechanic’s lift that raises a 1.2 ´ 10 N car 2.1 m in 12
s | c. | a car engine
that does 1.2 ´ 10 J of work in 5.0
s | d. | a crane that
lifts a 2.5 ´ 10 N beam at a speed of 1.2
m/s | | |
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