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The exact SAME QUESTIONS Along with DETAILED EXPLANATIONS can be found here Online Exam Index Link
by choosing the corresponding  "STUDY GUIDE VERSION"

  Solutions to the WRITTEN QUESTIONS are to be found in the unit answers link

  Momentum HW Study Guide1

Momentum Homework 1

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 mc003-1.jpgmiles 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 stiff-legged 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 long-barrel cannon travels faster than one shot from a short-barrel 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 10-kg 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 8-kg blob of clay moving horizontally at 2 m/s hits a 3-kg blob of clay at rest. What is the speed of the two blobs stuck together immediately after the collision?
 

 28. 

A 40-kg football player leaps through the air to collide with and tackle a 50-kg player heading toward him, also in the air. If the 40-kg player is heading to the right at 9 m/s and the 50-kg 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 50-kg cart moving at 100 km/h collides head-on with an approaching 50-kg cart moving at 10 km/h (in the opposite direction). If the two carts stick together, what will be their speed?
 

 30. 

A 30-kg girl and a 50-kg boy face each other on friction-free 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 70-kg free-floating astronaut fires 0.10-kg of gas at a speed of 30 m/s from her propulsion pistol. What is the astronaut's recoil speed?
 



 
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