Physics
Vandebilt Catholic High School
W. Dupre
MOMENTUM -
GUIDE
For
the test know all the material covered in this chapter and know how to solve
problems using the impulse - momentum change relationship and the Law of
Conservation of Momentum.
Some
extra questions to be aware of!!
1.
What
is meant by an isolated system?
2.
The
white cue ball travels across the table and collides into the stationary eight
ball of equal mass. After the collision the cue ball is at rest. What must be
true of the speed of the eight ball?
3.
Consider
a falling ball. Define a system in which the total momentum is
conserved.
4.
During
a space walk, the tether connecting the astronaut to the space capsule breaks.
Explain how the astronaut can use his gas pistol to safely return to the
capsule.
5.
Two
trucks that look the same collide. One was originally at rest. The trucks stick
together and move off at more than half the original speed of the moving truck.
What can you say about the contents of the two trucks?
6.
Two
bullets of equal mass are shot at equal speeds at blocks of wood on a
frictionless surface. One bullet, made of rubber, bounces off the wood. The
other bullet, made of aluminum, penetrates into the wood. Which bullet makes the
wood move faster? Why?
7.
Which
collision represents the greatest possible danger to the passengers involved:
(1) two cars colliding and remaining entangled, or (2) the same two cars
colliding and rebounding off each other? Explain.
8.
If
the kinetic energy of a particle is zero, what is its momentum? If the total
energy of a particle is zero, is its momentum necessarily zero?
Explain.
9.
If
the velocity of a particle is doubled, by what factor is its momentum changed?
What happens to its kinetic energy?
10.
If
two particles have equal kinetic energies, are their momenta necessarily equal? Explain or give an
example.
11. Does
a large force always produce a larger impulse on a body than a smaller force?
Explain.
12.
If
two objects collide and one is initially at rest, is it possible for both to be
at rest after the collision? Is it possible for one to be at rest after the
collision? Explain.
13.
Will
a Mac truck always have more momentum than a roller skate? Explain.
14.
When
a ball rolls down an incline, its momentum in creases. Does this imply that
momentum is not con served? Explain.
15.
A
boy stands at one end of a floating raft that is stationary relative to the
shore. He then walks to the opposite end of the raft, away from the shore. What
happens to the center of mass of the system (boy + raft)? Describe the movement
of the raft.
16.
A
sharpshooter fires a rifle while standing with the butt of the gun against his
shoulder. If the forward momentum of a bullet is the same as the backward
momentum of the gun, why isn’t it as dangerous to be hit by the gun as by the
bullet?
17.
A
pole vaulter falls from a height of 15 ft onto a foam
rubber pad. Could you calculate his velocity just be fore he reaches the pad?
Would you be able to calculate the force exerted on him due to the collision?
Explain.
18.
A man is at rest sitting at one end of a
boat in the middle of a lake. If he walks to the opposite end of the boat toward
the east, why does the boat move west?
19.
Explain
how you would use a balloon to demonstrate the mechanism responsible for rocket
propulsion.
20.
A ball is dropped from a tall building in
21.
A
bomb, initially at rest, explodes into several pieces. In this process is the momentum
conserved? Explain.
22.
A
skaters standing still on a frictionless ice rink. Her friend throws a Frisbee
straight at her. In which of the following cases is the largest momentum
transferred to the skater? (a) The skater catches the Frisbee and holds it, (b)
catches it momentarily but drops it vertically down, (c) catches the Frisbee
momentarily and then throws it back to her friend.
23.
A
large sheet is held at its edges by two students in such a way that it forms a
nearly vertical net to catch an object. A third student, who happens to be the
star pitcher on the baseball team, is asked to throw a raw egg into the sheet.
Explain why the egg does not break in the process, regardless of the initial
speed of the egg.
24.How
does "follow through" increase our proficiency in certain activities such as
baseball, golf, boxing, tennis, etc.
25.
Explain
how the impulse-momentum relationship may allow for an individual to fall from a
three story building without serious injury.
26.
Theoretically, would it be less harmful
to be running in the same direction as a golf ball that is about to strike you
in the head or to be running in the opposite direction of the golf ball?
Explain.
27.
Distinguish between elastic and inelastic
collisions.
28.What
is the relationship between impulse and momentum.
29.
a)
When you ride a bike at full speed, which has the greater momentum - you are the
bike? b) Does this help
explain why you go over the handlebars if the bike is brought to a sudden
halt?
30.
Why
will you be hurt less if you fall on a floor with "give" instead of a rigid
one.