Chapter 6 Study Questions w/ MC

Problems
Chapter 6 practice problems are assigned from the text as follows:
#3 page 201, #2 page 203, #3 page 214;
From the end of the chapter (pages 224 to 227): #s 22, 30(H), 32 (H), 39 (H), 42, & 43 (H).
Short Answer
Give a brief but comprehensive answer limited in scope to the specific question.  Complete sentences are not required in the short answer section of tests, nor is it necessary to restate the question in your answer.

	1.	A baseball pitcher’s first pitch is a fastball, moving at high speed. The pitcher’s second pitch—with the same ball—is a changeup, moving more slowly. Which pitch is harder for the catcher to stop? Explain your answer in terms of momentum.

	2.	Is it possible for a spaceship traveling with constant velocity to experience a change in momentum? Explain your answer.

	3.	How can a small force produce a large change in momentum?

	4.	A force is applied to stop a moving shopping cart. How would increasing the time interval change the force required?

	5.	Explain how to subtract two velocity vectors going in different (but not opposite) directions.  Use the terminology:  and .  Use a diagram to illustrate.

	6.	A large moving ball collides with a small stationary ball. Describe how the momentum of each ball changes.

	7.	State, in words, the law of conservation of momentum for an isolated system.

	8.	Write, in expanded algebraic form, the equation for the conservation of momentum in a two-body system.

	9.	Write, in expanded algebraic form, the equation for the conservation of momentum in a three-body system.

	10.	Two objects move separately after colliding, and both the total momentum and total kinetic energy remain constant. Identify the type of collision.

	11.	Two objects stick together and move with the same velocity after colliding. Identify the type of collision.

	12.	After colliding, objects are deformed and lose some kinetic energy. Identify the type of collision.

	13.	Why is the sound produced by a collision evidence that the collision is not perfectly elastic?

Two snowballs are traveling straight toward each other. One snowball has twice the mass of the other, but is moving at half the speed. The snowballs meet head-on in a perfectly inelastic collision.

	14.	(6-1) What is the total momentum of the system containing the two snowballs before the collision?

	15.	Describe how the collision affects the total momentum and total kinetic energy of the system.

Two billiard balls of equal mass are traveling straight toward each other with the same speed. They meet head-on in an elastic collision.

	16.	(6-1) What is the total momentum of the system containing the two balls before the collision?

	17.	Describe how the collision affects the total momentum and total kinetic energy of the system.

	18.	Describe how the velocities of the balls change as a result of the collision.

Explanations
Include diagrams as necessary.  Complete and reasoned arguments expected.

	19.	A moderate force will break an egg. Using the concepts of momentum, force, and time interval, explain why an egg is more likely to break when it is dropped on concrete than if it is dropped on grass.

	20.	Describe and explain the effect of a collision between a large meteor and the Earth.  Use appropriate terminology from the text (esp. section 6.3), and lecture.  The Chicxulub (CHICK-SHOO-LOOP’) crater on the Yucatan coast is an example of just such a collision.

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

____	21.	Which of the following equations can be used to directly calculate an object’s momentum, p?
a.	p = mv	b.		c.	p = FDt	d.	Dp = FDt	

____	22.	What are the SI units for momentum?
a.	N·m	b.	J	c.	kg·m/s	d.	kg·m/s	

____	23.	Which of the following equations can be used to directly calculate the change in an object’s momentum?
a.	p = mv	b.		c.	p = FDt	d.	Dp = FDt	

____	24.	A ball with a momentum of 4.0 kg·m/s hits a wall and bounces straight back without losing any kinetic energy. What is the change in the ball’s momentum?
a.	–8.0 kg·m/s	b.	–4.0 kg·m/s	c.	0.0 kg·m/s	d.	8.0 kg·m/s	

____	25.	The impulse experienced by a body is equivalent to the body’s change in
a.	velocity.	b.	kinetic energy.	c.	momentum.	d.	force.	

____	26.	Two objects with different masses collide and bounce back after an elastic collision. Before the collision, the two objects were moving at velocities equal in magnitude but opposite in direction. After the collision,
a.	the less massive object had gained momentum.	
b.	the more massive object had gained momentum.	
c.	both objects had the same momentum.	
d.	both objects lost momentum.