Chapter 8

Question 1

What is another term for momentum?

Answer 1

inertia in motion

Question 2

What is the formula for momentum?

Answer 2

mass x velocity (mv)

Question 3

When direction is not important then, what is the formula for momentum?

Answer 3

mass x speed

Question 4

A moving object can have a large__________, if it has a large _________, a high _________, or both?

Answer 4

momentum; mass; speed

Question 5

Who has more momentum: a car and a truck moving at the same speed?

Answer 5

the truck b/c it has more mass

Question 6

Who has more momentum: a fast car or a slow truck?

Answer 6

fast car

Question 7

Does a truck at rest have momentum?

Answer 7

NO

Question 8

If the momentum changes, what also may have changed?

Answer 8

mass or the velocity

Question 9

If the mass remains unchanged what changed?

Answer 9

The velocity and the acceleration

Question 10

What produces acceleration?

Answer 10

Force

Question 11

The greater the ________ on an object, the __________ its change in __________, and hence the __________ its change in __________.

Answer 11

force; greater; velocity; greater; momentum

Question 12

The change in momentum depends on the ________that acts and the _________of time it acts.

Answer 12

force; length

Question 13

If youn apply a brief force to a stalled automobile, you produce a ________ in its __________.

Answer 13

change; momentum

Question 14

If you apply a force over an extended period of time and you produce a _________________ in the automobile’s momentum.

Answer 14

greater change

Question 15

A force sustained for a long time produces more _________ in momentum than does the same force applied briefly.

Answer 15

change

Question 16

The quantity force x time interval is called

Answer 16

impulse

Question 17

The formula for impulse

Answer 17

force x time interval (Ft)

Question 18

The greater the _______ exerted on something, the greater will be the change in ________.

Answer 18

impulse; momentum

Question 19

impulse=change in momentum

Answer 19

Ft=mchangev

Question 20

What does the impulse-momentum relationship help us analyze?

Answer 20

A variety of situations where the momentum changes.

Question 21

21). To increase the momentum of an object, it makes sense to apply the ___________ possible for as long as possible

Answer 21

greatest force

Question 22

Examples of 21).

Answer 22

A golfer teeing off and a baseball player trying for a homerun do both of these things when they swing as hard as possible and follow through with their swing.

Question 23

The forces involved in impulses usually vary from

Answer 23

instant to instant.

Question 24

A golf club exerts ______force on a ball until it hits it.

Answer 24

zero

Question 25

When you hit either the wall of a haystack and come to a stop, your momentum is decreased by the ________impulse.

Answer 25

same

Question 26

The same impulse means the same amount of force or the same amount of time. T or F

Answer 26

False

Question 27

What does impulse mean?

Answer 27

The product of force and time

Question 28

By hitting the haystack instead of the wall, you extend

Answer 28

the time during which your momentum is brought to zero.

Question 29

A longer contact force reduces the ________ and decreases the resulting _________

Answer 29

force; deceleration

Question 30

If time is extended 100 times, the force of impact is reduced how many times?

Answer 30

100 times

Question 31

Whenever we wish the force to be small, we extend the

Answer 31

time

Question 32

32). When jumping from an elevated position down to the ground, you should

Answer 32

Bend your knees when your feet make contact with the ground

Question 33

When you bend your knees in 32). you extend the _______during which your _________ decreases by 10 to 20 times that of a stiff-legged, abrupt landing.

Answer 33

time; momentum

Question 34

In 32). the resulting force on your bones is __________ by 10 or 20 times

Answer 34

reduced

Question 35

A wrestler thrown to the floor tries to extend his _______ of hitting the mat by relaxing his muscles and spreading the __________ into a series of smaller ones as his foot, knee, hip, ribs, and shoulder successively hit the mat.

Answer 35

time; impulse

Question 36

When a boxer gets punched, the __________provided by the boxer's jaw must counteract the ___________of the punch.

Answer 36

impulse; momentum

Question 37

When the boxer moves away from the punch, he increases the _____________________ and reduces the __________.

Answer 37

time of contact; force

Question 38

A dish falling on the carpet: since time is longer hitting the carpet than the sidewalk, a _____________force results.

Answer 38

smaller force

Question 39

What are greater when an object bounces?

Answer 39

impulses

Question 40

The impulse required to bring an object to a stop and then to "throw it back again" is ________than the impulse required merely to bring the object to a stop.

Answer 40

greater

Question 41

If you catch a falling flowerpot what did you provide to reduce its momentum to zero.

Answer 41

impulse

Question 42

It takes greater __________to catch a falling pot and throw it upward again.

Answer 42

impulse

Question 43

What supplies the impulse if a flower pot if it bounces off your head?

Answer 43

Your head

Question 44

Were the waterwheels used in gold mining operations effective?

Answer 44

No

Question 45

What was the problem with the waterwheels?

Answer 45

The flat paddles on the water wheels.

Question 46

What did Lester A. Pelton design?

Answer 46

The curve-shaped paddle

Question 47

What did Pelton's design do?

Answer 47

It made a U-turn upon impact with the paddle.

Question 48

What did the U-turn paddle do?

Answer 48

The water "bounced" the impulse exerted on the waterwheel increased.

Question 49

If you wish to change the momentum, you have to exert an __________ on it.

Answer 49

impulse

Question 50

To change the momentum of a basketball or a car an outside ______ or _______ is required.

Answer 50

push; pull

Question 51

If an outside force is present, no change in momentum is possible. T or F

Answer 51

False

Question 52

In a cannonball and cannon action and reaction system. Did the momentum change?

Answer 52

No, because the internal forces canceled and there were no external forces.

Question 53

Is momentum a vector quantity?

Answer 53

Yes

Question 54

When the cannonball is fired it gains ________ but it also gains _________ in the opposite direction.

Answer 54

momentum; momentum

Question 55

A system will have the same _________ before some _______ interaction as it has after the interaction occurs.

Answer 55

momentum; internal

Question 56

What does the law of conservation describe?

Answer 56

the momentum of a system

Question 57

The law of conservation of momentum states that, in the _________of an __________force, the ___________of a system remains ______________.

Answer 57

absence; external; momentum; unchanged

Question 58

If a system undergoes changes wherein all forces are internal, the net momentum of the system before and after is the...

Answer 58

same

Question 59

Whenever objects collide in the absence of external forces, the net momentum of both objects before the collison equals the...

Answer 59

net momentum of both objects after the collison.

Question 60

When a moving billard ball collides head on with a ball at rest, the first ball comes to ______ and the second ball moves away with a velocity ________ to the _________ velocity of the first ball.

Answer 60

rest; equal; initial

Question 61

When objects collide w/o being permanently deformed and w/o generating heat, this collision is _________

Answer 61

elastic

Question 62

In elastic collisons the sum of momentum vectors is the _______ before and after each collision

Answer 62

same

Question 63

A collision in which the colliding objects become distorted and generate heat during the collision is...

Answer 63

inelastic

Question 64

Does momentum conservation hold true for inelastic collisons?

Answer 64

yes

Question 65

Whenever colliding objects become tangled or coupled up, what type of collision occurs?

Answer 65

a totally inelastic collision

Question 66

Do most collisions usually involve some external force?

Answer 66

yes

Question 67

Are perfect elastic collisions common in the everyday world?

Answer 67

No

Question 68

Is momentum conserved even when the interacting objects don't move in a straight line?

Answer 68

Yes

Question 69

The ______sum of the momenta is the ______before and after a collision.

Answer 69

vector; same