Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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When a car makes a sharp left turn, what causes the passengers to move toward
the right side of the car?
a. | centripetal acceleration | c. | centrifugal
force | b. | centripetal force | d. | inertia |
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2.
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The centripetal force on an object in circular motion is
a. | perpendicular to the plane of the object’s motion. | b. | in the plane of the
object’s motion and perpendicular to the tangential speed. | c. | in the plane of the
object’s motion and in the same direction as the tangential speed. | d. | in the plane of the
object’s motion and in the direction opposite the tangential
speed. |
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3.
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Tides are caused by
a. | differences in the gravitational force of the sun at different points on
Earth. | b. | differences in the gravitational force of the moon at different points on
Earth. | c. | differences in Earth’s gravitational field strength at different points on
Earth’s surface. | d. | fluctuations in the gravitational attraction
between Earth and the moon. |
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4.
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Which of the following can be a centripetal force?
a. | friction | c. | tension | b. | gravity | d. | all of the
above |
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A child rides a bicycle in a circular path with a radius of 2.0 m. The
tangential speed of the bicycle is 2.0 m/s. The combined mass of the bicycle and the child is 43
kg.
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5.
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What is the magnitude of the centripetal force on the bicycle?
a. | 4.0 N | c. | 86 N | b. | 43 N | d. | 3.7 kN |
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6.
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What is the magnitude of the bicycle’s centripetal acceleration?
a. | 1.0 m/s2 | c. | 4.0 m/s2 | b. | 2.0 m/s2 | d. | 8.0
m/s2 |
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7.
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What kind of force provides the centripetal force on the bicycle?
a. | gravitational force | c. | air resistance | b. | friction | d. | normal force |
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8.
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The centripetal force on an object in circular motion is
a. | in the same direction as the tangential speed. | b. | in the direction
opposite the tangential speed. | c. | in the same direction as the centripetal
acceleration. | d. | in the direction opposite the centripetal
acceleration. |
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9.
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What is the efficiency of a machine that requires 1.00 ´ 10  J of input energy to do 35 J of work?
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10.
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Why does an astronaut weigh less on the moon than on Earth?
a. | The astronaut has less mass on the moon. | b. | The astronaut is
farther from Earth’s center when he or she is on the moon. | c. | The gravitational
field strength is less on the moon’s surface than on Earth’s surface. | d. | The astronaut is
continually in free fall because the moon orbits Earth. |
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11.
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An object’s tendency to resist acceleration is measured by the
object’s
a. | gravitational mass. | c. | gravitational field strength. | b. | inertial
mass. | d. | weight. |
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12.
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What term describes a change in the speed of an object in circular
motion?
a. | tangential speed | c. | centripetal acceleration | b. | tangential
acceleration | d. | centripetal
force |
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13.
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If you want to open a swinging door with the least amount of force, where should
you push on the door?
a. | close to the hinges | c. | as far from the hinges as possible | b. | in the
middle | d. | It does not matter
where you push. |
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14.
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Until the middle of the 16th century, most people believed ____ was at the
center of the universe.
a. | Earth | c. | the sun | b. | the moon | d. | a black hole |
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15.
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When an astronaut in orbit experiences apparent weightlessness,
a. | no forces act on the astronaut. | b. | no gravitational forces act on the
astronaut. | c. | the net gravitational force on the astronaut is zero. | d. | the net
gravitational force on the astronaut is not balanced by a normal
force. |
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16.
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Which of the following quantities measures the ability of a force to rotate or
accelerate an object around an axis?
a. | axis of rotation | c. | tangential force | b. | lever arm | d. | torque |
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17.
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When calculating the gravitational force between two extended bodies, you should
measure the distance
a. | from the closest points on each body. | b. | from the most distant points on each
body. | c. | from the center of each body. | d. | from the center of one body to the closest
point on the other body. |
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18.
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The gravitational force between two masses is 36 N. What is the gravitational
force if the distance between them is tripled? ( G = 6.673 ´
10 
N ·m  /kg  ) a. | 4.0 N | c. | 18 N | b. | 9.0 N | d. | 27 N |
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19.
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In this text, which of the following symbols represents the constant of
universal gravitation?
a. | F | c. | g | b. | G | d. | F |
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20.
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How would the speed of Earth’s orbit around the sun change if
Earth’s distance from the sun increased by 4 times?
a. | It would increase by a factor of 2. | c. | It would decrease by a factor of
2. | b. | It would increase by a factor of 4. | d. | The speed would not
change. |
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