Download Q3 Lab Physics Study Guide

Lab Physics Q3 Study Guide
Momentum and Collisions
Review Sheet
Write the letter of the correct answer in the space provided.
_____ 1. What is the product of an object’s mass and its velocity?
a. kinetic energy
b. momentum
c. impulse
d. inertia
_____ 2. Which of the following has the greatest momentum?
a. a 4.0 kg bowling ball moving at 2.0 m/s
b. a 0.15 kg baseball moving at 10.0 m/s
c. a 1.6  103 kg car moving at 0.5 m/s
d. a 0.02 kg bullet moving at 950 m/s
_____ 3. How does the momentum of an object change if the object’s velocity
doubles?
a. The momentum doubles.
b. The momentum increases by a factor of four.
c. The momentum decreases by a factor of 1/2.
d. The momentum decreases by a factor of 1/4.
_____ 4. What are the units of momentum?
a. N
b. J
c. kgm/s
d. kgm/s2
_____ 5. Which of the following can determine the magnitude of the change in
an object’s momentum?
a. mass and acceleration
b. force and time interval
c. force and distance
d. acceleration and time interval
_____ 6. Which of the following is true of changes in momentum?
a. A small force may produce a large change in momentum by acting
over a short time interval.
b. A small force may produce a large change in momentum by acting
over a long distance.
c. A large force may produce a small change in momentum by acting
over a short time interval.
d. A small force may produce a large change in momentum by acting
on a very massive object.
_____ 7. If a net force acts on an object, then the object’s momentum
a. will increase.
b. will decrease.
c. will either increase or decrease.
d. may or may not change.
_____ 8. Which of the following involves a change in momentum?
a. A bowling ball rolls down the lane at constant speed.
b. A car coasts down a hill at constant speed.
c. A sky diver descends with terminal velocity.
d. A spacecraft travels at constant speed while slowly losing mass.
9.A 1.0  104 kg spacecraft is traveling through space with a speed of 1200 m/s
relative to Earth. A thruster fires for 2.0 min, exerting a continuous force of
25 kN on the spacecraft in a direction opposite the spacecraft’s motion.
Calculate the initial momentum and the final momentum of the spacecraft.
_____ 10. Two cars collide, lock bumpers, and move together after the collision.
What kind of collision is this?
a. elastic collision
b. inelastic collision
c. perfectly elastic collision
d. perfectly inelastic collision
_____ 11. A tennis ball is dropped from 1.0 m, bounces off the ground, and rises to
0.85 m. What kind of collision occurred between the ball and the
ground?
a. elastic collision
b. inelastic collision
c. perfectly elastic collision
d. perfectly inelastic collision
_____ 12. In what kind of collision is kinetic energy always conserved?
a. elastic collision
b. inelastic collision
c. perfectly elastic collision
d. perfectly inelastic collision
_____ 13. A helium atom collides with another helium atom in an elastic
collision. Which of the following is true?
a. Both momentum and kinetic energy are conserved.
b. Momentum is conserved but kinetic energy is not conserved.
c. Kinetic energy is conserved but momentum is not conserved.
d. Neither momentum nor kinetic energy is conserved.
_____ 14. Two playground balls collide in an inelastic collision. Which of the
following is true?
a. Both momentum and kinetic energy are conserved.
b. Momentum is conserved, but kinetic energy is not conserved.
c. Kinetic energy is conserved, but momentum is not conserved.
d. Neither momentum nor kinetic energy is conserved.
_____ 15. Which of the following is not evidence that kinetic energy has been lost
in a collision?
a. The collision produces a sound.
b. At least one of the objects is deformed after the collision.
c. At least one of the objects increases in temperature as a result of the
collision.
d. One of the objects is at rest after the collision.
16. Explain the difference between inelastic and perfectly inelastic collisions.
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17. A 0.16 kg billiard ball moving to the right at 1.2 m/s has a head-on elastic
collision with another ball of equal mass moving to the left at 0.85 m/s. The
first ball moves to the left at 0.85 m/s after the collision. Find the velocity of
the second ball after the collision, and verify your answer by calculating the
total kinetic energy before and after the collision.
_____ 18 A batter hits a baseball back to the pitcher at the same speed as the
pitch. Which of the following is true?
a. The momentum of the ball is the same before and after the batter hits
the ball.
b. The magnitude of the ball’s momentum is greater after the batter hits
the ball.
c. The magnitude of the ball’s momentum is less after the batter hits
the ball.
d. The magnitude of the ball’s momentum is the same before and after
the batter hits the ball.
_____ 19. 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.
_____ 20. 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.
_____ 21. 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.
_____ 22. 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.
Momentum and Collisions continued
_____ 23. 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.
_____ 24. A billiard ball hits the edge of another billiard ball that is initially at
rest. The second ball moves off at an angle. Which of the following is
true?
a. The momentum of the first ball doesn’t change.
b. The momentum of the second ball doesn’t change.
c. The total momentum of the system increases.
d. The momentum lost by the first ball is gained by the second ball.
_____ 25. A croquet ball moving at 2.0 m/s strikes another ball of equal mass.
The first ball stops moving after the collision. What is the velocity of
the second ball after the collision?
a. 2.0 m/s
b. 0 m/s
c. 2.0 m/s
d. 4.0 m/s
26. Describe the changes in momentum that take place when two billiard balls of
equal mass but moving at different speeds collide head-on.
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27. 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.