CHAPTER 6: Impulse and Momentum
Quiz Answers
QUIZ 6.1
Approximately how many kilograms would you need to have a weight of 2000 Newtons?
( )
( )
( )
( )
(x)
( )
( )
10 kilograms
20 kilograms
50 kilograms
100 kilograms
200 kilograms
400 kilograms
1000 kilograms
QUIZ 6.3
Would greater hand or fist speed be more effective in breaking concrete?
(x )
( )
( )
More effective
No difference
Less effective
QUIZ 6.4
A curling stone with a mass of 20 kilograms is sliding on the ice with a speed of 3
meters/second. What is the momentum of the stone?
_______________ kg× m/ s
(Answer: 60 kg× m/ s )
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QUIZ 6.5
A very soft ball hits a wall with a force of 8 Newtons. The time of the impulse is 1/4
second (0.25 s). What is the impulse generated by the ball on the wall?
_______________ N×s
(Answer: 2 N×s )
VIDEO QUIZ 6.1
What form of energy is stored in the stretched tennis racket strings and compressed golf
and tennis balls in the previous videos?
( )
( )
(x )
Kinetic Energy
Gravitational Potential Energy
Elastic Potential Energy
QUIZ 6.6
What form of energy is stored in the egg at a height of 2 meters before I release it?
( )
(x)
( )
Kinetic Energy
Gravitational Potential Energy
Elastic Potential Energy
VIDEO QUIZ 6.2
What will happen to the egg landing on a pillow?
( )
(x)
Egg breaks
Egg doesn't break
VIDEO QUIZ 6.3
What is the physics behind the egg-on-pillow surviving intact?
2
( )
concrete.
( )
( )
(x)
The momentum change of the egg-on-pillow was smaller than for the egg-onThe velocity of the egg-on-pillow was smaller than for the egg-on-concrete.
The time of the collision of the egg-on-pillow was less so the force was less.
The time of the collision of the egg-on-pillow was greater so the force was less.
QUIZ 6.7
If F = p = 0 , what does that tell you about the momentum before a process as compared
to the momentum after the process?
( )
( )
process.
(x )
The momentum before the process is less than the momentum after the process.
The momentum before the process is greater than the momentum after the
The momentum before the process is the same as the momentum after the process.
VIDEO QUIZ 6.4
Weber is not skating particularly fast before the collision. Palmieri skates into Weber and
almost stops after banging into him. To conserve momentum, what must happen to
Weber after the collision?
( )
( )
(x )
Weber must stop also.
Weber must skate into Palmieri.
Weber must travel in the direction that Palmieri was skating before the collision.
QUIZ 6.8
I drop a baseball onto a concrete floor from a height of 1 meter. What happens?
( )
(x)
( )
The baseball will bounce back up to a height of 1 meter.
The baseball will bounce back up to a height less than 1 meter.
The baseball will bounce back up to a height greater than 1 meter.
QUIZ 6.9
I drop a baseball onto a concrete floor from a height of 1 meter. How high will it bounce?
( )
( )
( )
( )
0-0.25 meter
0.25-0.5 meter
0.5-0.75 meter
0.75-1.0 meter
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QUIZ 6.10
Rank the Coefficients of Restitution for the following balls:
A
B
C
D
E
Baseball
Superball
Tennis Ball
Basketball
Soccer Ball
Answer: B > D > C > A
QUIZ 6.11
If we let some air out of a basketball, how would the Coefficient of Restitution be
affected?
(x)
( )
( )
The COR of the basketball would decrease.
The COR of the basketball would remain the same.
The COR of the basketball would increase.
VIDEO 6.17: Properly inflated and under-inflated Basketballs dropped from a height of 1
meter
Makes sense I hope. How do you think other factors such as temperature will
affect the bounciness of a ball? Does this matter in any case? Maybe you could check it
out.
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QUIZ 6.12
Two balls of mass one kilogram apiece are connected by a thin rod (sort of like a barbell).
We'll assume the mass of the rod is so small we can ignore it. As shown above, the balls
are one meter apart at positions of 0 and 1 meter. What is the position of the center of
mass of this system? (Remember, think "average position" of the total mass.)
( )
( )
(x)
( )
( )
0
0.25 meter
0.50 meter
0.75 meter
1.00 meter
QUIZ 6.13
Now we've replaced the ball on the right by a more massive, 3 kilogram ball. Everything
else is the same. Now, what is the position of the center of mass of this system?
( )
( )
( )
(x)
( )
0
0.25 meter
0.50 meter
0.75 meter
1.00 meter
QUIZ 6.14
Above is depicted a (flat) disk with a mass of 2 kilograms and a radius of 0.5 meter.
Along the x-direction as shown by the scale, what is the position of the center of mass of
the disk?
( )
( )
(x )
( )
( )
0
0.25 meter
0.50 meter
0.75 meter
1.00 meter
QUIZ 6.15
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Above is depicted a (flat) hoop with a mass of 2 kilograms and a radius of 0.5 meter.
Along the x-direction as shown by the scale, what is the position of the center of mass of
the disk?
( )
( )
(x )
( )
( )
0
0.25 meter
0.50 meter
0.75 meter
1.00 meter
QUIZ 6.16
Above is depicted a semicircular hoop with a mass of 2 kilograms and a radius of 0.5
meter. Along the x-direction as shown by the scale, what is the approximate position of
the center of mass of the half-hoop?
( )
( )
( )
(x)
( )
0
0.25 meter
0.50 meter
0.75 meter
1.00 meter
VIDEO QUIZ 6.8
When Michael Jordan raises his legs while he is in the air, what happens to the height of
his center of mass?
( )
(x)
( )
The height of his center of mass stays in the same place.
The height of his center of mass increases.
The height of his center of mass decreases.
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