Multiple ChoiceIdentify the choice that best completes the
statement or answers the question.
net momentum _{before} = net momentum _{after
}


1

A 4.0kg ball has a momentum of 20.0 kg·m/s. What is the ball's
speed?
a.  80.0 m/s  b.  20.0 m/s  c.  0.2
m/s  d.  5.0 m/s  e.  none of the
above 


2

The reason padded dashboards are used in cars is that they
a.  increase the time of impact in a collision.  b.  look nice and feel
good.  c.  decrease the momentum of a collision.  d.  decrease the impulse in a
collision.  e.  increase the force of impact in a collision. 


3

The momentum of an object is defined as the object's
a.  velocity times the time interval.  b.  force times the time
interval.  c.  mass times its velocity.  d.  mass times it acceleration.  e.  force times its
acceleration. 


4

A collision is considered elastic if
a.  after the collision, the objects have the same shape as before the
collision.  b.  the objects that collide don't get warmer.  c.  the objects
don’t stick together.  d.  there is no lasting
deformation.  e.  all of the above 


5

A 3kg ball is thrown at 7 m/s. What is the ball's momentum?
a.  7 kg·m/s  b.  49 kg·m/s  c.  21
kg·m/s  d.  3 kg·m/s  e.  none of the
above 


6

A cannon recoils from launching a cannonball. The speed of the cannon's
recoil is small because the
a.  impulse on the cannon is less than the impulse on the cannonball.  b.  force against the
cannon is relatively small.  c.  cannon has far more mass than the
cannonball.  d.  momentum of the cannon is unchanged.  e.  none of the
above 


7

The white ball below strikes the black 8ball below traveling at 3 m/s. Assuming
that each of the balls has the same mass, what is the velocity of the 8ball after the
collision?
a.  3 m/s  c.  1 m/s  b.  6m/s  d.  0 m/s 


8

A ball is moving at 6.0 m/s and has a momentum of 24.0 kg·m/s. What is the
ball's mass?
a.  0.3 kg  b.  24.0 kg  c.  144.0
kg  d.  4.0 kg  e.  none of the
above 


9

A 50kg child on a skateboard is traveling at 7.0
m/s. What is the resultant momentum?
a.  350 kg·m/s  b.  0.14 kg·m/s  c.  50
kg·m/s  d.  350 kg·m/s 


10

The momentum change of an object is equal to the
a.  force acting on it times its velocity.  b.  object's mass times the force acting on
it.  c.  force acting on it.  d.  velocity change of the
object.  e.  impulse acting on it. 


11

A 8kg ball is thrown at 5 m/s. What is the ball's momentum?
a.  25 kg·m/s  b.  8 kg·m/s  c.  5
kg·m/s  d.  40 kg·m/s  e.  none of the
above 


12

When these two freight cars of different mass
collide and couple, what will be their resultant velocity?
a.  10 m/s  b.  1.0 m/s  c.  2
m/s  d.  50 m/s 


13

A cannonball shot from a longbarrel cannon travels faster than one shot from a
shortbarrel cannon because the cannonball receives a greater
a.  impulse.  b.  force.  c.  both A and
B  d.  neither A nor B 


14

If the momentum of an object changes and its mass remains constant,
a.  its velocity is changing.  b.  there is a force acting on
it.  c.  it is accelerating (or decelerating).  d.  all of the above  e.  none of the
above 


15

Momentum of a system is conserved only when
a.  there is no net external force acting on the system.  b.  the system has zero
momentum.  c.  the system is not moving.  d.  there are no forces acting on the
system.  e.  there are no internal forces acting on the system. 


16

A cannon fires a cannonball. The speed of the cannonball will be the same as the
speed of the recoiling cannon
a.  because velocity is conserved.  b.  because both velocity and momentum are
conserved.  c.  because momentum is conserved.  d.  if the mass of the cannonball equals the mass
of the cannon.  e.  none of the above 


17

A table tennis ball launcher is fired. Compared to the force on the ball, the
force on the launcher is
a.  the same.  b.  smaller.  c.  larger. 


18

A ball is moving at 7.0 m/s and has a momentum of 49.0 kg·m/s. What is the
ball's mass?
a.  7.0 kg  b.  0.1 kg  c.  49.0
kg  d.  343.0 kg  e.  none of the
above 


19

Compared to a sports car moving at 30 miles per hour, the same sports car moving
at miles per hour has
a.  twice as much momentum.  b.  four times as much
momentum.  c.  the same momentum. 


20

A 2.0kg ball has a momentum of 6.0 kg·m/s. What is the ball's
speed?
a.  0.3 m/s  b.  3.0 m/s  c.  12.0
m/s  d.  6.0 m/s  e.  none of the
above 


21

Which has more momentum, a large truck moving at 30 miles per hour or a small
truck moving at 30 miles per hour?
a.  The large truck  b.  Both have the same
momentum.  c.  The small truck 
