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


1.

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


2.

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


3.

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. 


4.

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


5.

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


6.

In order to increase the final momentum of a golf ball, we could
a.  increase the force acting on it.  b.  follow through when hitting the
ball.  c.  increase the time of contact with the ball.  d.  swing as hard as
possible.  e.  all of the above 


7.

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


8.

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


9.

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


10.

Which of the following has the largest momentum?
a.  A large truck parked in a parking lot  b.  A tightrope walker crossing Niagara
Falls  c.  The science building at your school  d.  A pickup truck traveling down the
highway  e.  A dog running down the street 


11.

A freight train rolls along a track with considerable momentum. If it were to
roll at the same speed but had twice as much mass, its momentum would be
a.  zero.  b.  unchanged.  c.  quadrupled.  d.  doubled. 


12.

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.  cannon has far more
mass than the cannonball.  c.  momentum of the cannon is
unchanged.  d.  force against the cannon is relatively small.  e.  none of the
above 


13.

In order to catch a ball, a baseball player moves his or her hand backward in
the direction of the ball's motion. Doing this reduces the force of impact on the player's
hand principally because
a.  the time of impact is decreased.  b.  the time of impact is
increased.  c.  the velocity of the hand is reduced.  d.  the momentum of impact is
reduced.  e.  none of the above 


14.

A car traveling along the highway needs a certain amount of force exerted on it
to stop. More stopping force may be required when the car has
a.  less stopping distance.  b.  more momentum.  c.  more
mass.  d.  all of the above  e.  none of the
above 


15.

When you jump off a step, you usually bend your knees as you reach the ground.
By doing this, the time of the impact is about 10 times more what it would be in a stifflegged
landing, and the average force on your body is reduced by
a.  less than 10 times.  b.  about 10 times.  c.  more than 10
times. 


16.

A karate expert executes a swift blow and splits a cement block with her bare
hand.
a.  The forces on both the block and the expert's hand have the same
magnitude.  b.  The times of impact on both the block and the expert's hand are the
same.  c.  The impulses on both the block and the expert's hand have the same
magnitude.  d.  all of the above  e.  none of the
above 


17.

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

True/False Indicate whether the
statement is true or false.


18.

Impulse is defined as the force exerted on an object times the time it
lasts.


19.

When a baseball player follows through in hitting the ball, the contact time
with the ball is longer.


20.

Automobile dashboards that are padded lengthen the time of impact in case of a
collision.


21.

If a net force acts on a system, the system's momentum will change.

Essay  Do not need to do these
online. You have a "practice questions" wkst in your hw packet that
has the same questions.


22.

In terms of momentum change, explain why it is best to "give" when
catching a baseball. Provide other examples of situations in which you want to lengthen the impact
time in a collision.


23.

Why would a .22 rifle bullet travel farther than a .22 pistol bullet shot at the
same angle? (This question refers directly to one of your study guide questions. Use the
concept of Impulse in your explanation!)


24.

What does it mean to say that momentum is conserved? Give an example where
momentum is conserved in a collision.


25.

A railroad diesel engine coasting at 12 km/h runs into a stationary flatcar. The
diesel weighs 5 times as much as the flatcar. Assuming the cars couple together, how fast are they
moving after the collision?

Problem


26.

A 10kg cement block moving horizontally at 6 m/s plows into a bank of sand and
comes to a stop in 2 s. What is the average impact force on the bank?


27.

An 8kg blob of clay moving horizontally at 2 m/s hits a 3kg blob of clay at
rest. What is the speed of the two blobs stuck together immediately after the collision?


28.

A 40kg football player leaps through the air to collide with and tackle a 50kg
player heading toward him, also in the air. If the 40kg player is heading to the right at 9 m/s and
the 50kg player is heading toward the left at 2 m/s, if the larger player stops his momentum as they
hit and all the momentum is transferred to the smaller player, how fast will the smaller player be
sent backwards?


29.

A 50kg cart moving at 100 km/h collides headon with an approaching 50kg cart
moving at 10 km/h (in the opposite direction). If the two carts stick together, what will be their
speed?


30.

A 30kg girl and a 50kg boy face each other on frictionfree roller skates. The
girl pushes the boy, who moves away at a speed of 3 m/s. What is the girl's speed?


31.

A 70kg freefloating astronaut fires 0.10kg of gas at a speed of 30 m/s from
her propulsion pistol. What is the astronaut's recoil speed?
