Momentum

75kg ice hockey forward movingat 5.0m/s collides with a stationary 85kg.

5m/s

in an automobile collison, a 44- kilogram passengermoving at 15 m/s is brought to rest by an air bag during a 0.10-second time interval. what is the magniture of the average force exerted on the passenger during this time?

6,600N.

A 2-kg ball is thrown at 3 m/s. What is the ball's momentum? p=mv (2-kg)(3 m/s)= 6-kg*m/s

6-kg*m/s

A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball that is initially at rest. After the putty sticks to the ball, both are set in motion with a combined momentum that is... A. less than 1 unit. B. more than 1 unit. C. 1 unit. D. Not enough information to say.

1

Suppose a girl is standing on a pond where there is no friction between her feet and the ice. In order to get off the ice she can

throw something in the direction opposite to the way she wants to go.

Charlotte, a 65.0kg skin diver, shoots a 2.0kg spear with a speed of 15m/s at a fish who darts quickly away without getting hit. How fast does Charlotte move backwards when the spear is shot?

.46m/s direction opp to spear

A ball is moving at 4 m/s and has a momentum of 48 kg m/s. What is the ball's mass? p=mv 48=(m)(4 m/s) 48/4=12

12 kg

In order to increase the final momentum of a golf ball, we could... A. increase the force acting on it. B. increase the time of contact with the ball. C. follow through when hitting the ball. D. swing as hard as possible. E. all of the above.

All of above

In order to increase the final momentum of golf ball we could

All of above

15. A car traveling along the highway needs a certain amount of force exerted on it to stop. More stopping force may be required when the car has

All of these

The momentum change of an object is equal to the

Impulse acting on it

A 2,400kg car is traveling at a speed of 20 m/s. Compared to the magnitude of the force required to stop the car in 18 seconds, the magnitude of the force required to stop the car in 9 seconds is:

Twice as great

Two objects, A and B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, they reach the ground at the same time, but A has higher? a) momentum b) acceleration c) speed

a) momentum

Two gliders having the same mass and speeds move towards each other on an air track and together. After the collisions the velocity of the gliders is? a) zero b) one half the original velocity c) the same as the original velocity

a) zero

A cannon recoils from launching a cannonball. The speed of the cannon's recoil is small be the _________. a) force against the cannon is relatively small b) cannon has far more mass than the cannonball c) momentum of the cannon is unchanged

b) cannon has far more mass than the cannonball

The reason padded dashboards are used in cars is that they _____. a) decrease the impulse in a collision b) increase the time of impact in a collision c) increase the force of impact in a collision

b) increase the time of impact in a collision

The momentum of an object is defined as the object's __________.

b) mass times its velocity

Superman is at rest in space when he throws an asteroid that has more mass than he does. Which moves faster, superman or the asteroid? a) they both move at the same speed b) superman c) the asteroid

b) superman

Which has more momentum, a large truck moving at 30 miles per hour or a small tuck moving at 30 miles per hour? a) the small truck b) the large truck c) both have the same momentum

b) the large truck

A ping-pona ball launcher is fired. Compared to the impulse on a ball, the impulse on the launcher is ________. a) larger b) the same c) smaller

b) the same

Compared to a sports car moving at 30 miles per hour, the same sports car moving at 60 miles per hour has ________. a) four times as much momentum b) the same momentum c) twice as much momentum

c) twice as much momentum

Recoil is noticeable if we throw a heavy ball while standing on roller skates. If instead we through the motions of throwing the ball but hold onto it, our net recoil velocity will be? a) the same as before b) small but noticeable c) zero

c) zero

A karate expert executes a swift blow and serves a cement block with her bare hand. a) the impulse on both the block and the experts hand have the same magnitude b) the time of impact on both the block and the experts hand is the same c) the force on both the block and experts hand have the same magnitude d) all of the above

d) all of the above

If the momentum of an object changes and its mass remains constant, _____________. a) its velocity is changing b) there is a force acting on it c) it is accelerating (it is decelerating) d) all of the above

d) all of the above

A freight train rolls along track...

doubled

A collision is considered elastic if _____________. a)there is no lasting deformation b) after the collision, the objects have the same shape as before the collision c) the objects that collide don't get hot d) there is no sound generated during the collision e) all of the above

e) all of the above

The force of an apple hitting the ground depends upon? a) the speed of the apple just before it hits b) whether or not the apple bounces c) the time of impact with the ground d) air resistance on the apple as it falls e) all of the above

e) all of the above

In order to catch a ball, a baseball player moves his or her hand backward in the direction of the ball's motion. Doing this reduces the force of impact on the player's hand principally because

the time of impact is increased