Academic Year 2015 – 2016
Science Enrichment Sheet - 2
PHYSICS
Chapter 6
Lesson 2. Conservation of momentum
Name : ____________________________________________ Date : _________
Grade : 9
Section : ________
1. A small marble collides with a billiard ball that is initially at rest. Which of the following is
true?
a. The momentum of each object increases.
b. The momentum of each object decreases.
c. The momentum of the billiard ball increases, and the momentum of the marble
decreases.
d. The total momentum before and after the collision is zero.
2. When two ice skaters initially at rest push off one another, their final momenta are
a. equal in magnitude and direction.
b. equal in magnitude and opposite in direction.
c. in the same direction but of different magnitudes
d. in opposite directions and possibly of different magnitudes.
3.
When two objects interact in an isolated system,
a. the momentum of each object is conserved.
b. the total momentum of the system is zero.
c. the total momentum is conserved only if the objects move in opposite directions.
d.the total momentum is always conserved.
4. Which of the following expresses the law of conservation of momentum?
a. The total momentum of an isolated system is zero.
b. The total momentum of any system always remains constant.
c. Every object in an isolated system maintains a constant momentum.
d. The total momentum of an isolated system remains constant regardless of the forces
between the objects in the system.
5. Conservation of momentum follows from
a. Newton’s first law.
b. Newton’s second law.
c. Newton’s third law.
d. the law of conservation of energy.
6. 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.
7. 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.
b. their momenta are equal but opposite.
c. their total momentum doubles.
d. their total momentum decreases.
8. A boy stands at one end of the floating raft that is stationary relative to the shore . He then
walks in a straight line to the opposite end of the raft, away from the shore.
(a) Does the raft move . Explain
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(b) What is the total momentum of the boy and the raft before the boy walks across the
raft ?
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(c) What is the total momentum of the boy and the raft after the boy walks across the raft ?
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9. Two isolated objects have a head – on collision . Explain your answer.
(a) If you know the change in momentum of one object , can you find the change in momentum
of the other object ?
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10. Two skaters initially at rest push against each other so that they move in opposite directions .
What is the total momentum of the two skaters when they begin moving . Explain
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11.
A 55 kg boy running at 2.0 m/s jumps onto a 2.0 kg skateboard. Calculate the final velocity of
the boy and the skateboard.
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