Multiple Choice
Identify the choice that best completes the
statement or answers the question.
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1.
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In mechanics, physicists use three basic quantities to derive additional
quantities. Mass is one of the three quantities. What are the other two?
a. | length and force | b. | power and force | c. | length and
time | d. | force and time | e. | power and time |
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2.
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Which formula is dimensionally consistent with an expression yielding a value
for velocity? (a is acceleration, x is distance, and t is time)
a. | v/t2 | b. | vx2 | c. | v2/t | d. | at | e. | v/x2 |
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3.
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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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4.
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Wiley Coyote has missed the elusive road runner once again. This time, he leaves
the edge of the cliff at 50.0 m/s horizontal velocity. If the canyon is 100 m deep, how far from his
starting point at the edge of the cliff does the coyote land?
a. | 226 m | b. | 247 m | c. | 339
m | d. | 400 m | e. | 452 m |
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5.
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The accelerating force of the wind on a small 200-kg sailboat is 707 N
northeast. If the drag of the keel is 500 N acting west, what is the acceleration of the boat?
a. | 1.5 m/s2 due east | b. | 2.5 m/s2 due
north | c. | 3.0 m/s2 northeast | d. | 2.0 m/s2 north by
northwest | e. | 1.5 m/s2 due west |
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6.
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Old Faithful geyser in Yellowstone Park shoots water hourly to a height of 40 m.
With what velocity does the water leave the ground?
a. | 7.0 m/s | b. | 14 m/s | c. | 20
m/s | d. | 28 m/s | e. | 34 m/s |
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7.
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A billiard ball collides in an elastic head-on collision with a second identical
ball. What is the kinetic energy of the system after the collision compared to that before
collision?
a. | the same as | b. | one fourth | c. | twice | d. | four times | e. | None of the above
choices are valid. |
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8.
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A grindstone spinning at the rate of 8.3 rev/s has what approximate angular
speed?
a. | 3.2 rad/s | b. | 26 rad/s | c. | 52
rad/s | d. | 81 rad/s | e. | 97 rad/s |
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9.
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An 800-N billboard worker stands on a 4.0-m scaffold supported by vertical ropes
at each end. If the scaffold weighs 500 N and the worker stands 1.0 m from one end, what is the
tension in the rope nearest the worker?
a. | 450 N | b. | 500 N | c. | 800
N | d. | 850 N | e. | 900 N |
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10.
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A projectile is hurled at an angle θ with
respect to the horizontal at a speed v. Which expression represents the time it takes
the projectile to reach its highest point?
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11.
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Which of the following free-body diagrams is correctly drawn? Note, the choice
is at the lower left corner of each picture.
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12.
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Under what circumstances is the static friction force acting on a stationary
block on a ramp LESS THAN AND NOT EQUAL TO than μ times the normal
force?
a. | When the friction force is greater than the object’s weight | b. | When the downhill
force due to the object’s weight is less than μFn | c. | When the downhill force due tothe
object’s weight is greater than μFn | d. | When the object
first starts to slide as you tilt the ramp up | e. | The friction force is never less than μFn |
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13.
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When an object is on a tilted ramp that is slowly rising, sooner or later it
will slip and slide downhill. When this happens, what is the value of kinetic
friction?
a. | The kinetic friction is the tangent of the angle of ramp tilt. | b. | The kinetic friction
is the cosine of the angle of ramp tilt. | c. | The kinetic friction is the sine of the angle
of ramp tilt. | d. | There is insufficient information to tell what the coefficient of kinetic friction
is. |
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14.
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 Consider the Atwood’s machine
shown. What is the magnitude of the acceleration of the system?
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15.
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A spring is used to shake a mass. First the spring is compressed, then the
mass is released from rest. The mass oscillates back and forth at a steady rate. Where in the
oscillating mass’s motion is the spring potential energy the least?
a. | when it is in the release position | b. | when it is as far as it can get from the
release position | c. | when it is in the position where the spring was not compressed | d. | when it is between b
and c listed above. | e. | when it is between a and c above.
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16.
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25 Joules of work is done on an arrow by a bow. The mass of the arrow is
0.20 kg. Calculate the kinetic energy of the arrow just after it leave the bow.
a. | 25 Joules | b. | 2.0 Joules | c. | 15.8 Joules | d. | 250
Joules | e. | 5 Joules |
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17.
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Work is performed by an electric engine that supplies 100 Watts of power.
If the work done is lifting a toy elevator at 2 m/s, calculate the force applied.
a. | 200 N | b. | 20 N | c. | 50 N | d. | 0.50 N | e. | 100
N |
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18.
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An air track cart with a mass of 300 grams collides elastically with another
air-track cart with a mass of 50 grams. If the larger cart was moving at 0.5 m/s to the right
and the smaller cart was moving at 0.5 m/s to the left prior to the collision, find the velocity of
the larger cart after the collision.
a. | 0.166 m/s | b. | 0.834 m/s | c. | 150 m/s | d. | 6.0
m/s | e. | 1.2 m/s |
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19.
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A penny is placed on a rotating turntable. Write an expression that
determines the coefficient of friction between the penny and the turntable using the mass of the
penny mp, the tangential velocity of the penny v, the radius of the turntable r, and
the acceleration of gravity g.
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20.
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A spark plug specifies that no more than 100 N m of torque be applied to
the spark plug or it will strip. Using a 0.75 meter long torque wrench, what is the maximum
force you can apply perpendicular to the end of the handle before the spark plug is stripped?
a. | 133 N | b. | 75 N | c. | 7.5 N | d. | 25 N | e. | 67
N |
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21.
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 Consider the skateboarder shown in the
picture. Considering the position of the boy’s feet and the position of the skateboard on
the rail, which foot is exerting more force on the skateboard? a. | his left foot (on the right side of the picture) | b. | his right foot (on
the left side of the picture) | c. | both feet exert equal force | d. | the feet do not
exert a force on the board |
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22.
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In the derivation of Kepler’s Third Law from the centripetal force
equation and the law of gravity, what simplifying assumption is made?
a. | The orbit is a circle. | b. | The sun is at one focus of the
ellipse. | c. | The closer the planet is to the sun the faster it will go. | d. | Planets closer to
the sun have smaller orbital periods. | e. | No simplifying assumption is made; the
derivation is valid for all orbits. |
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