Multiple Choice
Identify the
letter of the choice that best completes the statement or answers the question.


1.

A force does
work on an object if a component of the force a.  is perpendicular to the displacement of the
object.  b.  is parallel to the displacement of the
object.  c.  perpendicular to the displacement of the object moves the object along
a path that returns the object to its starting position.  d.  parallel to the
displacement of the object moves the object along a path that returns the object to its starting
position.   


2.

Work is done
when a.  the displacement is not
zero.  b.  the displacement is zero.  c.  the force is
zero.  d.  the force and displacement are
perpendicular.   


3.

A 1.00
´ 10^{3} kg
sports car accelerates from rest to 25.0 m/s in 7.50 s. What is the average power output of the
automobile engine? a.  20.8 kW  c.  41.7 kW  b.  30.3 kW  d.  52.4 kW     


4.

The
magnitude of the component of the force that does the work is 43.0 N. How much work is done on a
bookshelf being pulled 5.00 m at an angle of 37.0° from the horizontal? a.  172
J  c.  129
J  b.  215
J  d.  792
J     


5.

A worker
pushes a wheelbarrow with a horizontal force of 50.0 N over a level distance of 5.0 m. If a
frictional force of 43 N acts on the wheelbarrow in a direction opposite to that of the worker, what
net work is done on the wheelbarrow? a.  250 J  c.  35 J  b.  0.0 J  d.  10.0 J     


6.

A hill is
100 m long and makes an angle of 12° with the horizontal. As a 50 kg jogger runs up the hill, how much work does gravity
do on the jogger? a.  50 000
J  c.  –10 000
J  b.  10 000
J  d.  0.0
J     


7.

A child
moving at constant velocity carries a 2 N icecream cone 1 m across a level surface. What is the net
work done on the icecream cone?


8.

A
construction worker pushes a wheelbarrow 5.0 m with a horizontal force of 50.0 N. How much work is
done by the worker on the wheelbarrow? a.  10 J  c.  250 J  b.  1250 J  d.  55 J     


9.

A horizontal
force of 200 N is applied to move a 55 kg television set across a 10 m level surface. What is the
work done by the 200 N force on the television set? a.  4000
J  c.  2000
J  b.  5000
J  d.  6000
J     


10.

A flight
attendant pulls a 50.0 N flight bag a distance of 250.0 m along a level airport floor at a constant
speed. A 30.0 N force is exerted on the bag at an angle of 50.0° above the horizontal.
How much work is done on the flight bag? a.  12 500 J  c.  4820 J  b.  7510 J  d.  8040 J     


11.

Which of the
following energy forms is involved in winding a pocket watch? a.  electrical
energy  c.  gravitational potential
energy  b.  nonmechanical energy  d.  elastic potential energy     


12.

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     


13.

A 3.00 kg
toy falls from a height of 10.0 m. Just before hitting the ground, what will be its kinetic energy?
(Disregard air resistance. g = 9.81 m/s^{2}.) a.  98.0
J  c.  29.4
J  b.  0.98
J  d.  294
J     


14.

If the only
force acting on an object is friction during a given physical process, which of the following
assumptions must 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.   


15.

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     


16.

If both the
mass and the velocity of a ball are tripled, the kinetic energy of the ball is increased by a factor
of


17.

Which of the
following energy forms is associated with an object in motion? a.  potential
energy  c.  nonmechanical
energy  b.  elastic potential energy  d.  kinetic energy     


18.

Which of the
following energy forms is associated with an object due to its position? a.  potential  c.  total  b.  positional  d.  kinetic     


19.

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 involves position.  d.  although both energies
involve position, only potential involves motion.   


20.

Which of the
following energy forms is associated with an object due to its position relative to
Earth? a.  potential
energy  c.  gravitational potential
energy  b.  elastic potential energy  d.  kinetic energy     


21.

Which of the
following energy forms is stored in any compressed or stretched object? a.  nonmechanical
energy  c.  gravitational potential
energy  b.  elastic potential energy  d.  kinetic energy     


22.

The equation
for determining gravitational potential energy is PE_{g} = mgh. Which
factor(s) in this equation is (are) NOT a property of an object?


23.

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     


24.

As an object
is lowered into a deep hole in the ground, which of the following assumptions must be made in regard
to the object’s potential energy? a.  The potential energy increases.  b.  The potential energy
decreases.  c.  The potential energy remains constant.  d.  The potential energy
increases and then decreases.   


25.

A 40.0 N
crate is pulled up a 5.0 m inclined plane at a constant velocity. If the plane is inclined at an
angle of 37° to the horizontal and there is a constant force of friction of 10.0 N between the
crate and the surface, what is the net gain in potential energy by the crate? a.  120
J  c.  210
J  b.  –120
J  d.  –210
J     


26.

A 0.002 kg
coin, which has zero potential energy at rest, is dropped into a 10.0 m well. After the coin comes to
a stop in the mud, what is its potential energy? a.  0.000 J  c.  –0.196 J  b.  0.196
J  d.  0.020
J     


27.

A 5.00
´ 10^{2} N crate
is at the top of a 5.00 m ramp, which is inclined at 20.0° with the horizontal. What is its potential energy? (g
= 9.81 m/s^{2}.) a.  855 J  c.  815 J  b.  2350 J  d.  8390 J     


28.

Why
doesn’t the principle of mechanical energy conservation hold in situations when frictional
forces are present? a.  Kinetic energy is not simply converted to a form of potential
energy.  b.  Potential energy is simply converted to a form of gravitational
energy.  c.  Chemical energy is not simply converted to electrical
energy.  d.  Kinetic energy is simply converted to a form of gravitational
energy.   


29.

A 16.0 kg
child on roller skates, initially at rest, rolls 2.0 m down an incline at an angle of
20.0° with the horizontal. If there is no friction between incline and skates, what is the
kinetic energy of the child at the bottom of the incline? (g = 9.81
m/s^{2}.) a.  210
J  c.  11
J  b.  610
J  d.  110
J     


30.

A pole
vaulter clears 6.00 m. With what velocity does the vaulter strike the mat in the landing area?
(Disregard air resistance. g = 9.81 m/s^{2}.) a.  2.70
m/s  c.  10.8
m/s  b.  5.40
m/s  d.  21.6
m/s     


31.

A bobsled
zips down an ice track starting at 150 m vertical distance up the hill. Disregarding friction, what
is the velocity of the bobsled at the bottom of the hill?
(g = 9.81
m/s^{2}.) a.  27
m/s  c.  45
m/s  b.  36
m/s  d.  54
m/s     


32.

A
professional skier starts from rest and reaches a speed of 56 m/s on a ski slope 30.0° above the horizontal.
Using the work–kinetic energy theorem and disregarding friction, find the minimum distance along
the slope the skier would have to travel in order to reach this speed. a.  110
m  c.  320
m  b.  160
m  d.  640
m     


33.

A 40.0 N
crate starting at rest slides down a rough 6.0 m long ramp inclined at 30.0° with the horizontal.
The force of friction between the crate and ramp is 6.0 N. Using the work–kinetic energy
theorem, find the velocity of the crate at the bottom of the incline. a.  8.7
m/s  c.  4.5
m/s  b.  3.3
m/s  d.  6.4
m/s     


34.

A 15.0 kg
crate, initially at rest, slides down a ramp 2.0 m long and inclined at an angle of 20.0° with the horizontal.
Using the work–kinetic energy theorem and disregarding friction, find the velocity of the crate
at the bottom of the ramp. (g = 9.81 m/s^{2}.) a.  6.1
m/s  c.  9.7
m/s  b.  3.7
m/s  d.  8.3
m/s     


35.

A
parachutist with a mass of 50.0 kg jumps out of an airplane at an altitude of 1.00 ´ 10^{3} m. After the parachute deploys, the parachutist lands with a
velocity of 5.00 m/s. Using the work–kinetic energy theorem, find the energy that was lost to
air resistance during this jump. (g = 9.81 m/s^{2}.) a.  49 300
J  c.  198 000
J  b.  98 800
J  d.  489 000
J     


36.

A horizontal
force of 2.00 ´ 10^{2} N is applied to a 55.0 kg cart across a 10.0 m level surface,
accelerating it 2.00 m/s^{2}. Using the work–kinetic energy theorem, find the force of
friction that slows the motion of the cart? (Disregard air resistance. g = 9.81
m/s^{2}.) a.  110
N  c.  80.0
N  b.  90.0
N  d.  70.0
N     


37.

Which of the
following is the rate at which energy is transferred? a.  potential
energy  c.  mechanical
energy  b.  kinetic energy  d.  power     


38.

Which of the
following equations is NOT an equation for power?


39.

What is the
average power supplied by a 60.0 kg secretary running up a flight of stairs rising vertically 4.0 m
in 4.2 s? a.  380
W  c.  610
W  b.  560
W  d.  670
W     


40.

What is the
average power output of a weight lifter who can lift 250 kg 2.0 m in 2.0 s? a.  5.0 ´ 10^{2}
W  c.  4.9
kW  b.  2.5
kW  d.  9.8
kW     


41.

Water flows
over a section of Niagara Falls at a rate of 1.20 ´ 10^{6} kg/s and falls 50.0 m. What is the power of the
waterfall? a.  589
MW  c.  147
MW  b.  294
MW  d.  60.0
MW     


42.

Which of the
following has the greatest momentum? a.  truck with a mass of 2250 kg moving at a velocity of 25
m/s  b.  car with a mass of 1210
kg moving at a velocity of 51 m/s  c.  truck with a mass of 6120 kg moving at a velocity of 10
m/s  d.  car with a mass of 1540
kg moving at a velocity of 38 m/s   


43.

Which of the
following has the greatest momentum? a.  tortoise with a mass of 270 kg moving at a velocity of 0.5
m/s  b.  hare with a mass of 2.7
kg moving at a velocity of 7 m/s  c.  turtle with a mass of 91 kg moving at a velocity of 1.4
m/s  d.  roadrunner with a mass
of 1.8 kg moving at a velocity of 6.7 m/s   


44.

What
velocity must a 1340 kg car have in order to have the same momentum as a 2680 kg truck traveling at a
velocity of 15 m/s to the west? a.  6.0 ´ 10^{1 }m/s to the west  c.  3.0 ´ 10^{1 }m/s to the west  b.  6.0 ´ 10^{1 }m/s to
the east  d.  3.0 ´ 10^{1 }m/s to
the east     


45.

A child with
a mass of 23 kg rides a bike with a mass of 5.5 kg at a velocity of 4.5 m/s to the south. Compare the
momentum of the child with the momentum of the bike. a.  Both the child and the
bike have the same momentum.  b.  The bike has a greater momentum than the
child.  c.  The child has a greater momentum than the
bike.  d.  Neither the child nor the bike has momentum.   


46.

When
comparing the momentum of two moving objects, which of the following is correct? a.  The object with the
higher velocity will have less momentum if the masses are equal.  b.  The more massive object
will have less momentum if its velocity is greater.  c.  The less massive object
will have less momentum if the velocities are the same.  d.  The more massive object
will have less momentum if the velocities are the same.   


47.

A baseball
is pitched very fast. Another baseball of equal mass is pitched very slowly. Which of the following
statements is correct? a.  The fastmoving baseball is harder to stop because it has more
momentum.  b.  The slowmoving baseball is harder to stop because it has more
momentum.  c.  The fastmoving baseball is easier to stop because it has more
momentum.  d.  The slowmoving baseball is easier to stop because it has more
momentum.   


48.

A roller
coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller
coaster a.  is greater up the hill
than down the hill.  c.  remains the same
throughout the ride.  b.  is greater down the hill than up the
hill.  d.  is zero throughout the
ride.     


49.

A person
sitting in a chair with wheels stands, causing the chair to roll backward across the floor. The
momentum of the chair a.  was zero while stationary and increased when the person
stood.  b.  was greatest while the person sat in the
chair.  c.  remained the same.  d.  was zero when the
person got out of the chair and increased while the person sat.   


50.

A student
walks to class at a velocity of 3 m/s. To avoid walking into a door as it opens, the student slows to
a velocity of 0.5 m/s. Now late for class, the student runs down the corridor at a velocity of 7 m/s.
The student had the least momentum a.  while walking at a velocity of 3 m/s.  b.  while dodging the
opening door.  c.  immediately after the door opened.  d.  while running to class
at a velocity of 7 m/s.   


51.

An ice
skater initially skating at a velocity of 3 m/s speeds up to a velocity of 5 m/s. The momentum of the
skater a.  decreases.  c.  remains the
same.  b.  increases.  d.  becomes zero.     


52.

If a force
is exerted on an object, which statement is true? a.  A large force always produces a large change in the object’s
momentum.  b.  A large force produces a large change in the object’s momentum
only if the force is applied over a very short time interval.  c.  A small force applied
over a long time interval can produce a large change in the object’s
momentum.  d.  A small force produces a large change in the object’s
momentum.   


53.

The change
in an object’s momentum is equal to a.  the product of the mass of the object and the time
interval.  b.  the product of the force applied to the object and the time
interval.  c.  the time interval divided by the net external
force.  d.  the net external force divided by the time
interval.   


54.

A force is
applied to stop a moving shopping cart. Increasing the time interval over which the force is
applied a.  requires a greater
force.  c.  requires a smaller
force.  b.  has no effect on the force needed.  d.  requires the same force.     


55.

Which of the
following situations is an example of a visible change in momentum? a.  A hiker walks through a
spider’s web.  c.  A volleyball hits a
mosquito in the air.  b.  A car drives over a pebble.  d.  A baseball is hit by a bat.     


56.

Which of the
following situations is an example of change in momentum? a.  A tennis ball is hit
into a net.  b.  A heliumfilled balloon rises upward into the
sky.  c.  An airplane flies into
some scattered white clouds.  d.  A bicyclist rides over a leaf on the
pavement.   


57.

A 6.0
´ 10^{–2}
kg tennis ball moves at a velocity of 12 m/s. The ball is struck by a racket, causing it to rebound
in the opposite direction at a speed of 18 m/s. What is the change in the ball’s
momentum? a.  –0.38
kg·m/s  c.  –1.1
kg·m/s  b.  –0.72 kg·m/s  d.  –1.8 kg·m/s     


58.

A rubber
ball with a mass of 0.30 kg is dropped onto a steel plate. The ball’s velocity just before
impact is 4.5 m/s and just after impact is 4.2 m/s. What is the change in the ball’s
momentum? a.  –0.09
kg·m/s  c.  –4.0
kg·m/s  b.  –2.6 kg·m/s  d.  –12 kg·m/s     


59.

A ball with
a momentum of 4.0 kg·m/s hits a wall and bounces straight back without losing any kinetic energy. What is
the change in the ball’s momentum? a.  0.0 kg·m/s  c.  8.0 kg·m/s  b.  –4.0 kg·m/s  d.  –8.0 kg·m/s     


60.

A ball with
a mass of 0.15 kg and a velocity of 5.0 m/s strikes a wall and bounces straight back with a velocity
of 3.0 m/s. What is the change in momentum of the ball? a.  –0.30
kg·m/s  c.  –0.15
kg·m/s  b.  –1.20 kg·m/s  d.  –7.50 kg·m/s     


61.

The impulse
experienced by a body is equivalent to the body’s change in a.  velocity.  c.  momentum.  b.  kinetic energy.  d.  force.     


62.

A moderate
force will break an egg. However, an egg dropped on the road usually breaks, while one dropped on the
grass usually does not break because for the egg dropped on the grass, a.  the change in momentum
is greater.  c.  the time interval for
stopping is greater.  b.  the change in momentum is less.  d.  the time interval for stopping is less.     


63.

Which of the
following statements properly relates the variables in the equation FDt = Dp? a.  A large constant force changes an object’s momentum over a long
time interval.  b.  A large constant force acting over a long time interval causes a large
change in momentum.  c.  A large constant force changes an object’s momentum at various
time intervals.  d.  A large constant force does not necessarily cause a change in an
object’s momentum.   


64.

A large
moving ball collides with a small stationary ball. The momentum a.  of the large ball
decreases, and the momentum of the small ball increases.  b.  of the small ball
decreases, and the momentum of the large ball increases.  c.  of the large ball
increases, and the momentum of the small ball decreases.  d.  does not change for
either ball.   


65.

A rubber
ball moving at a speed of 5 m/s hit a flat wall and returned to the thrower at 5 m/s. The magnitude
of the momentum of the rubber ball a.  increased.  c.  remained the same.  b.  decreased.  d.  was not
conserved.     


66.

Two objects
with different masses collide and bounce back after an elastic collision. Before the collision, the
two objects were moving at velocities equal in magnitude but opposite in direction. After the
collision, a.  the less massive object
had gained momentum.  b.  the more massive object had gained momentum.  c.  both objects had the
same momentum.  d.  both objects lost momentum.   


67.

Two skaters
stand facing each other. One skater’s mass is 60 kg, and the other’s mass is 72 kg. If the
skaters push away from each other without spinning, a.  the 60 kg skater
travels at a lower momentum.  b.  their momenta are equal but opposite.  c.  their total momentum
doubles.  d.  their total momentum decreases.   


68.

Two swimmers
relax close together on air mattresses in a pool. One swimmer’s mass is 48 kg, and the
other’s mass is 55 kg. If the swimmers push away from each other, a.  their total momentum
triples.  c.  their total momentum
doubles.  b.  their momenta are equal but opposite.  d.  their total momentum decreases.     


69.

A soccer
ball collides with another soccer ball at rest. The total momentum of the balls a.  is
zero.  c.  remains
constant.  b.  increases.  d.  decreases.     


70.

In a
twobody collision, a.  momentum is conserved.  b.  kinetic energy is
conserved.  c.  neither momentum nor kinetic energy is
conserved.  d.  both momentum and kinetic energy are
conserved.   


71.

The law of
conservation of momentum states that a.  the total initial momentum of all objects interacting with one another
usually equals the total final momentum.  b.  the total initial momentum of all objects interacting with one another
does not equal the total final momentum.  c.  the total momentum of all objects interacting with one another is
zero.  d.  the total momentum of all objects interacting with one another remains
constant regardless of the nature of the forces between the objects.   


72.

Which of the
following statements about the conservation of momentum is NOT correct? a.  Momentum is conserved
for a system of objects pushing away from each other.  b.  Momentum is not
conserved for a system of objects in a headon collision.  c.  Momentum is conserved
when two or more interacting objects push away from each other.  d.  The total momentum of a
system of interacting objects remains constant regardless of forces between the
objects.   


73.

A swimmer
with a mass of 75 kg dives off a raft with a mass of 500 kg. If the swimmer’s speed is 4 m/s
immediately after leaving the raft, what is the speed of the raft? a.  0.2
m/s  c.  0.6
m/s  b.  0.5
m/s  d.  4.0
m/s     


74.

A bullet
with a mass of 5.00 ´ 10^{–3} kg is loaded into a gun. The loaded gun has a mass of 0.52 kg.
The bullet is fired, causing the empty gun to recoil at a speed of 2.1 m/s. What is the speed of the
bullet? a.  48
m/s  c.  120
m/s  b.  220
m/s  d.  360
m/s     


75.

A 65.0 kg
ice skater standing on frictionless ice throws a 0.15 kg snowball horizontally at a speed of 32.0
m/s. At what velocity does the skater move backward? a.  0.07
m/s  c.  0.15
m/s  b.  0.30
m/s  d.  1.20
m/s     


76.

Two skaters,
each with a mass of 50 kg, are stationary on a frictionless ice pond. One skater throws a 0.2 kg ball
at 5 m/s to the other skater, who catches it. What are the velocities of the skaters when the ball is
caught? a.  0.02 m/s moving
apart  c.  0.02 m/s moving toward
each other  b.  0.04 m/s moving apart  d.  0.04 m/s moving toward each other     


77.

Two carts
with masses of 1.5 kg and 0.7 kg, respectively, are held together by a compressed spring. When
released, the 1.5 kg cart moves to the left with a velocity of 7 m/s. What is the velocity of the 0.7
kg cart? (Disregard the mass of the spring.) a.  15 m/s to the right  c.  7 m/s to the right  b.  15 m/s to the
left  d.  7 m/s to the
left     


78.

Each croquet
ball in a set has a mass of 0.50 kg. The green ball travels at 10.5 m/s and strikes a stationary red
ball. If the green ball stops moving, what is the final speed of the red ball after the
collision? a.  10.5
m/s  c.  12.0
m/s  b.  6.0
m/s  d.  9.6
m/s     


79.

A diver with
a mass of 80.0 kg jumps from a dock into a 130.0 kg boat at rest on the west side of the dock. If the
velocity of the diver in the air is 4.10 m/s to the west, what is the final velocity of the diver
after landing in the boat? a.  2.52 m/s to the west  c.  1.56 m/s to the west  b.  2.52 m/s to the
east  d.  1.56 m/s to the
east     


80.

Two objects
move separately after colliding, and both the total momentum and total kinetic energy remain
constant. Identify the type of collision. a.  elastic  c.  inelastic  b.  perfectly elastic  d.  perfectly inelastic     


81.

Two objects
stick together and move with the same velocity after colliding. Identify the type of
collision. a.  elastic  c.  inelastic  b.  perfectly elastic  d.  perfectly inelastic     


82.

After
colliding, objects are deformed and lose some kinetic energy. Identify the type of
collision. a.  elastic  c.  inelastic  b.  perfectly elastic  d.  perfectly inelastic     


83.

Two balls of
dough collide and stick together. Identify the type of collision. a.  elastic  c.  inelastic  b.  perfectly elastic  d.  perfectly inelastic     


84.

Two
snowballs with masses of 0.40 kg and 0.60 kg, respectively, collide headon and combine to form a
single snowball. The initial speed for each is 15 m/s. If the velocity of the snowball with a mass of
1.0 kg is 3.0 m/s after the collision, what is the decrease in kinetic energy? a.  zero  c.  60
J  b.  110
J  d.  90
J     


85.

A 1.5
´ 10^{3} kg
truck moving at 15 m/s strikes a 7.5 ´ 10^{2} kg automobile stopped at a traffic light. The vehicles hook bumpers
and skid together at 10.0 m/s. What is the decrease in kinetic energy? a.  1.1 ´ 10^{5
}J  c.  1.7 ´ 10^{5
}J  b.  1.2 ´ 10^{4 }J  d.  6.0 ´ 10^{4 }J     


86.

A clay ball
with a mass of 0.35 kg has an initial speed of 4.2 m/s. It strikes a 3.5 kg clay ball at rest, and
the two balls stick together and remain stationary. What is the decrease in kinetic energy of the
0.35 kg ball? a.  1.6
J  c.  3.1
J  b.  4.8
J  d.  6.4
J     


87.

An infant
throws 5 g of applesauce at a velocity of 0.2 m/s. All of the applesauce collides with a nearby wall
and sticks. What is the decrease in kinetic energy of the applesauce? a.  2 ´ 10^{–4}
J  c.  1 ´ 10^{–3}
J  b.  0.5 ´ 10^{–4}
J  d.  1 ´ 10^{–4}
J     


88.

In an
elastic collision between two objects with unequal masses, a.  the total momentum of
the system will increase.  b.  the total momentum of the system will
decrease.  c.  the kinetic energy of one object will increase by the amount that the
kinetic energy of the other object decreases.  d.  the momentum of one
object will increase by the amount that the momentum of the other object
decreases.   


89.

A billiard
ball collides with a stationary identical billiard ball in an elastic headon collision. After the
collision, which is true of the first ball? a.  It maintains its initial velocity.  c.  It comes to rest.  b.  It has onehalf its
initial velocity.  d.  It moves in the
opposite direction.     


90.

A billiard
ball collides with a second identical ball in an elastic headon collision. What is the kinetic
energy of the system after the collision compared with the kinetic energy before the
collision? a.  unchanged  c.  two times as
great  b.  onefourth as great  d.  four times as great     


91.

Which of the
following best describes the kinetic energy of each object after a twobody collision if the momentum
of the system is conserved? a.  must be less  c.  might also be conserved  b.  must also be
conserved  d.  is doubled in
value     


92.

Which of the
following best describes the momenta of two bodies after a twobody collision if the kinetic energy
of the system is conserved? a.  must be less  c.  might also be conserved  b.  must also be
conserved  d.  is doubled in
value     


93.

An object
with a mass of 0.10 kg makes an elastic headon collision with a stationary object with a mass of
0.15 kg. The final velocity of the 0.10 kg object after the collision is –0.045 m/s and the
final velocity of the 0.15 kg object after the collision is 0.16 m/s. What was the initial velocity
of the 0.10 kg object? a.  0.16 m/s  c.  0.20 m/s  b.  –1.06 m/s  d.  –0.20 m/s     


94.

A 90 kg
halfback runs north and is tackled by a 120 kg opponent running south at 4 m/s. The collision is
perfectly inelastic. Just after the tackle, both players move at a velocity of 2 m/s north. Calculate
the velocity of the 90 kg player just before the tackle. a.  3 m/s
south  c.  10 m/s
north  b.  4 m/s south  d.  12 m/s north     


95.

A clay ball
with a mass of 0.35 kg strikes another 0.35 kg clay ball at rest, and the two balls stick together.
The final velocity of the balls is 2.1 m/s north. What was the first ball’s initial
velocity? a.  4.2 m/s to the
north  c.  2.1 m/s to the
north  b.  2.1 m/s to the south  d.  4.2 m/s to the south     


96.

A 2 kg mass
moving to the right makes an elastic headon collision with a 4 kg mass moving to the left at 4 m/s.
The 2 kg mass reverses direction after the collision and moves at 3 m/s. The 4 kg mass moves to the
left at 1 m/s. What was the initial velocity of the 2 kg mass? a.  3 m/s to the
right  c.  4 m/s to the
left  b.  1 m/s to the
left  d.  4 m/s to the
right     


97.

Which of the
following angles equals 2p rad?


98.

One radian
is equal to a.  60°.  c.  57.3°.  b.  58°.  d.  56°.     


99.

How would an
angle in radians be converted to an angle in degrees? a.  The angle in radians
would be multiplied by 180°/p.  b.  The angle in radians would be multiplied by 360°/p.  c.  The angle in radians would be multiplied by 180°/2p.  d.  The angle in radians would be multiplied by 2p/360°.   


100.

How would
you convert an angle in degrees to an angle in radians? a.  multiply the angle
measured in degrees by 2p/180°  b.  multiply the angle measured in degrees by 2p/360°  c.  multiply the angle
measured in degrees by p/360°  d.  multiply the angle measured in degrees by
2pr°   


101.

A cave
dweller rotates a pebble in a sling with a radius of 0.30 m counterclockwise through an arc length of
0.96 m. What is the angular displacement of the pebble? a.  1.6
rad  c.  3.2
rad  b.  –1.6
rad  d.  –3.2
rad     


102.

Earth has an
equatorial radius of approximately 6380 km, and it rotates 360° every 24 h. What is
the angular displacement of a person standing at the equator for 3.0 h? a.  0.26
rad  c.  0.78
rad  b.  0.52
rad  d.  0.39
rad     


103.

A child sits
on a carousel at a distance of 3.5 m from the center and rotates through an arc length of 6.5 m. What
is the angular displacement of the child? a.  1.9 rad  c.  3.0 rad  b.  0.93 rad  d.  5.0 rad     


104.

A bucket on
the circumference of a water wheel travels an arc length of 18 m. If the radius of the wheel is 4.1
m, what is the angular displacement of the bucket? a.  1.0
rad  c.  3.7
rad  b.  4.4
rad  d.  2.3
rad     


105.

What is the
approximate angular speed of a wheel rotating at the rate of 5.0 rev/s? a.  3.2
rad/s  c.  16
rad/s  b.  1.6 rad/s  d.  31 rad/s     


106.

A grinding
wheel initially at rest with a radius of 0.15 m rotates until it reaches an angular speed of 12.0
rad/s in 4.0 s. What is the wheel's average angular acceleration? a.  96
rad/s^{2}  c.  3.0
rad/s^{2}  b.  48 rad/s^{2}  d.  0.33 rad/s^{2}     


107.

A potter's
wheel moves from rest to an angular speed of 0.54 rad/s in 30.0 s. What is the angular acceleration
of the wheel? a.  16
rad/s^{2}  c.  0.018
rad/s^{2}  b.  1.3 rad/s^{2}  d.  0.042 rad/s^{2}     


108.

A Ferris
wheel initially at rest accelerates to a final angular speed of 0.70 rad/s and rotates through an
angular displacement of 4.90 rad. What is the Ferris wheel's average angular
acceleration? a.  0.10
rad/s^{2}  c.  1.80
rad/s^{2}  b.  0.05 rad/s^{2}  d.  0.60 rad/s^{2}     


109.

A Ferris
wheel rotates with an initial angular speed of 0.50 rad/s and accelerates over a 7.00 s interval at a
rate of 4.0 ´ 10^{–2} rad/s^{2}. What is its angular speed? a.  0.20
rad/s  c.  0.46
rad/s  b.  0.30 rad/s  d.  0.78 rad/s     


110.

An
automobile tire with a radius of 0.30 m starts at rest and accelerates at a constant angular
acceleration of 2.0 rad/s^{2} for 5.0 s. What is the angular displacement of the
tire? a.  12
rad  c.  2.0
rad  b.  25
rad  d.  0.50
rad     


111.

A bicycle
wheel rotates with a constant angular acceleration of 3.0 rad/s^{2}. If the initial angular
speed of the wheel is 1.5 rad/s, what is the angular displacement of the wheel after 4.0
s? a.  6.0
rad  c.  3.0 ´ 10^{1}
rad  b.  24
rad  d.  36
rad     


112.

A gear in a
machine accelerates at 11.2 rad/s^{2}. If the wheel's initial angular speed is 5.40 rad/s,
what is the wheel's angular speed after exactly 3.0 seconds? a.  39.0
rad/s  c.  209
rad/s  b.  13.6 rad/s  d.  28.2 rad/s     


113.

A ball rolls
downhill with an angular speed of 2.5 rad/s and has a constant angular acceleration of 2.0
rad/s^{2}. If the ball takes 11.5 s to reach the bottom of the hill, what is the final
angular speed of the ball? a.  13 rad  c.  33 rad/s  b.  31 rad/s  d.  25.5 rad/s     


114.

A helicopter
has 3.0 m long rotor blades that are rotating at an angular speed of 63 rad/s. What is the tangential
speed of each blade tip? a.  99 m/s  c.  21 m/s  b.  190 m/s  d.  66 m/s     


115.

A point on
the rim of a 0.30 m radius rotating wheel has a tangential speed of 4.0 m/s. What is the tangential
speed of a point 0.20 m from the center of the same wheel? a.  0.8
m/s  c.  2.6
m/s  b.  1.3
m/s  d.  8.0
m/s     


116.

A cylinder
with a diameter of 0.150 m rotates in a lathe at a constant angular speed of 35.6 rad/s. What is the
tangential speed of the surface of the cylinder? a.  2.67 m/s  c.  2.37 ´ 10^{2 }m/s  b.  5.34 m/s  d.  4.75 ´ 10^{2 }m/s     


117.

An
automobile tire with a radius of 0.3 m accelerates from rest at a constant 2 rad/s^{2} over a
5 s interval. What is the tangential component of acceleration for a point on the outer edge of the
tire? a.  30
m/s^{2}  c.  0.6
m/s^{2}  b.  7 m/s^{2}  d.  0.3 m/s^{2}     


118.

A hamster
gets on a stationary wheel with a radius of 0.15 m and runs until the wheel rotates at an angular
speed of 12.0 rad/s in 4.0 s. What is the tangential acceleration of the wheel's
edge? a.  0.45
rad/s^{2}  c.  0.65
rad/s^{2}  b.  0.6 rad/s^{2}  d.  1.30 rad/s^{2}     


119.

A contestant
in a game show spins a stationary wheel with a radius of 0.50 m so that it has a constant angular
acceleration of 0.40 rad/s^{2}. What is the tangential acceleration of a point on the edge of
the wheel? a.  0.20
m/s^{2}  c.  1.3
m/s^{2}  b.  0.60 m/s^{2}  d.  0.73 m/s^{2}     


120.

A stone on
the edge of the tire of a unicycle wheel with a radius of 0.25 m has a centripetal acceleration of
4.0 m/s^{2}. What is the tire's angular speed? a.  1.0
rad/s  c.  3.2
rad/s  b.  2.0 rad/s  d.  4.0 rad/s     


121.

A point on
the rim of a rotating wheel with a 0.37 m radius has a centripetal acceleration of 19.0
m/s^{2}. What is the angular speed of the wheel? a.  0.89
m/s  c.  3.2
rad/s  b.  1.6 rad/s  d.  7.2 rad/s     


122.

If the
distance from the center of a merrygoround to the edge is 1.2 m, what centripetal acceleration does
a passenger experience when the merrygoround rotates at an angular speed of 0.5
rad/s? a.  1.7
m/s^{2}  c.  0.3
m/s^{2}  b.  0.9 m/s^{2}  d.  0.6 m/s^{2}     


123.

A 0.40 kg
ball on a 0.50 m string rotates in a circular path in a vertical plane. If the angular speed of the
ball at the bottom of the circle is 8.0 rad/s, what is the force that maintains circular
motion? a.  5.6
N  c.  13
N  b.  11
N  d.  20.0
N     


124.

A 0.40 kg
ball on a 0.50 m string rotates in a circular path in a vertical plane. If a constant angular speed
of 8.0 rad/s is maintained, what is the tension in the string when the ball is at the top of the
circle? a.  9.0
N  c.  13
N  b.  11
N  d.  10.0
N     


125.

A roller
coaster loaded with passengers has a mass of 2.0 ´ 10^{3} kg; the radius of curvature of the track at the lowest
point of the track is 24 m. If the vehicle has a tangential speed of 18 m/s at this point, what force
is exerted on the vehicle by the track? a.  2.3 ´ 10^{4 }N  c.  3.0 ´ 10^{4 }N  b.  4.7 ´ 10^{4 }N  d.  2.7 ´ 10^{4 }N     
