Physics Chapter 6

19. A bullet with a mass of 5.00 x 10^

3 is loaded into a gun. The loaded gun has a mass of 0.52 kg. The bullet is fired, causing the empty gun to recoil at a speed of 2.1 m/s. What is the speed or velocity of the bullet? - 220 m/s

2. What velocity must a 1340 kg car have in order to have the same momentum as a 2680 kg truck traveling at a velocity of 15 m/s to the west?

3.0 X 10^1 m/s to the west

10. A 2.0 kg softball is pitched to you at 20 m/s You hit the ball back along the same path and at the same speed. If the bat was in contact with the ball for 0.10 s, what is the magnitude of the average force the bat exerted?

800N

Which of the following statements properly relates the variables in the equation F(delta)t = (delta)p?

A large constant force acting over a long time interval causes a large change in momentum.

A ball with a mass of 0.15 kg and a velocity of 5.0 m/s strikes a wall and bounces straight back with a velocity of 3.0 m/s. What is the change in momentum of the ball?

-1.20 kg•m/s

A rubber ball with a mass of 0.30 kg is dropped onto a steel plate. The ball's velocity just before impact is 4.5 m/s and just after impact is 4.2 m/s. What is the change in the ball's momentum?

-2.6 kg•m/s

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?

-8.0 kg•m/s

25. An object with a mass of 0.10 kg makes an elastic head on collision with a stationary object with a mass of 0.15 kg. The final velocity of the 0.10 kg object after the collision is

0.045 m/s and the final velocity of the 0.15 kg object after the collision is 0.16 m/s. What was the initial velocity of the 0.10 kg object? - 0.20 m/s

8. A 50 kg pitching machine (excluding the baseball) is placed on a frozen pond. The machine fires a 0.40 kg baseball with a speed of 35 m/s in the horizontal direction. What is the recoil speed of the pitching machine

0.28 m/s

18. A swimmer with a mass of 75 kg dives off a raft with a mass of 500 kg. If the swimmer's speed is 4 m/s immediately after leaving the raft, what is the speed of the raft?

0.6 m/s

26. a 90 kg halfback runs north and is tackled by a 120 kg opponent running south at 4 m/s. The collision if perfectly inelastic. Just after the tackle, both players move at a velocity of 2 m/s north. Calculate the velocity of the 90 kg player just before the tackle.

10 m/s north

14. If a force is exerted on an object, which statement is true?

A small force applied over a long time interval can produce a large change in the object's momentum.

An infant throws 5 g of applesauce at a velocity of 0.2 m/s. All of the applesauce collides with a nearby wall and sticks. What is the decrese in kinetic energy of the applesauce?

1 x 10^-4 J

7. If you pitch a baseball with twice the kinetic energy you gave it in the previous pitch, the magnitude of its momentum is

1.41 times as much

5. A 0.06 kg tennis ball moves at a velocity of 12 m/s. The ball is struck by a racket, causing it to rebound in the opposite direction at a speed of 18 m/s. What is the change in the ball's momentum?

1.8 kgm/s

20. Two carts with masses of 1.5 kg and 0.7 kg, respectively, are held together by a compressed spring. When released, the 1.5 kg cart moves to the left with a velocity of 7 m/s. What is the velocity of the 0.7 kg cart? (disregard the mass of the spring)

15 m/s to the right

12.A 1500 kg car traveling at 25 m/s east collides with a 1000 kg car traveling at 16.67 m/s south. The two cars stick together after the collision. What is the speed of the cars after the collision? (Hint: Like velocity, momentum is a vector)

16.4 m/s

6.0 X 10

2 kg tennis ball moves at a velocity of 12 m/s. The ball is struck by a racket, causing it to rebound in the opposite direction at a speed of 18 m/s. What is the change in the ball's momentum? - -1.8 kg•m/s

9. A constant 6.0 N force acts for 4.0 s on a 12 kg object. What is the object's change in velocity?

2.0 m/s

6. The SI unit of momentum is which of the following?

N x s

When comparing the momentum of two moving objects, which of the following is correct?

The less massive object will have less momentum if the velocities are the same

Which of the following situations is an example of a visible change in momentum?

a baseball is hit by a bat

30. In a two

body collision - momentum is conserved

24. which of the following best describes the momenta of two bodies after a two body collision if the kinetic energy of the system is conserved?

must also be conserved

Two balls of dough collide and stick together. Identify the type of collision

perfectly inelastic

15. A force is applied to stop a moving shopping cart. Increasing the time interval over which the force is applied

requires a smaller force to stop the cart

In an elastic collision between two objects with unequal masses

the momentum of one object will increase by the amount that the momentum of the other object decreases

The change in an object's momentum is equal to

the product of the force applied to the object and the time interval

Which of the following statements about the conservation of momentum is NOT correct?

Momentum is not conserved for a system of objects in a head-on collision.

11.A ping pong ball moving east at a speed of 4 m/s colllides with a stationary bowling ball. The ping pong ball bounces back to the west, and the bowling ball moves very slowly to the east. Which object experiences the greater magnitude of impulse during the collision?

Neither, both experience the same magnitude impulse

4. A child with a mass of 23 kg rides a bike with a mass of 5.5 kg at a velocity of 4.5 m/s to the south. Compare the momentum of the child with the momentum of the bike

The child has a greater momentum than the bike.

A baseball is pitched very fast. Another baseball of equal mass is pitched very slowly. Which of the following statements is correct?

The fast-moving baseball is harder to stop because it has more momentum.

Which of the following situations is an example of change in momentum?

a tennis ball is hit into the net

1. Which of the following has the greatest momentum?

car with a mass of 1210 kg moving at a velocity of 51 m/s

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

elastic

An ice skater initially skating at a velocity of 3 m/s speeds up to a velocity of 5 m/s. The momentum of the skater

increases

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

inelastic

3. A roller coaster climbs up a hill at 4 m/s and then zips down the hill at 30 m/s. The momentum of the roller coaster

it is greater down the hill than up the hill

23. Which of the following best describes the kinetic energy of each object after a two body collision if the momentum of the system is conserved?

might also be conserved

The impulse experienced by a body is equivalent to the body's change in

momentum

27. A large moving ball collides with a small stationary ball. The momentum

of the large ball decreases, and the momentum of the small ball increases.

17. Two snowballs with masses of 0.40 kg and 0.60 kg, respectively, collide head

on and combine to form a single snowball. The initial speed for each is 15 m/s. If the velocity of the snowball with a mass of 1.0 kg is 3.0 m/s after the collision, what is the decrease in kinetic energy - 110 J

21. A billiard ball collides with a stationary identical billiard ball in an elastic head

on-collision. After the collion, which is true of the first ball? - It comes to rest

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

perfectly inelastic

A rubber ball moving at a speed of 5 m/s hit a flat wall and returned to the thrower at 5 m/s. The magnitude of the momentum of the rubber ball

remained the same

A soccer ball collides with another soccer ball at rest. The total momentum of the balls

remains constant.

28.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

the less massive object had gained momentum.

A moderate force will break an egg. However, an egg dropped on the road usually breaks, while one dropped on the grass usually does not break because for the egg dropped on the grass

the time interval for stopping is greater.

The law of conservation of momentum states that

the total momentum of all objects interacting with one another remains constant regardless of the nature of the forces between the objects

29. Two swimmers relax close together on air mattresses in a pool. One swimmer's mass is 48kg and the other's mass is 55kg. If the swimmers push away from each other

their momenta are equal but opposite

Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 72kg. If the skaters push away from each other without spinning

their momenta are equal but opposite

Which of the following has the greatest momentum?

tortoise with a mass of 270 kg moving at a velocity of 0.5 m/s

22. A billiard ball collides with a second identical ball in an elastic head on collision. What is the kinetic energy of the system after the collision compared with the kinetic energy before the collision?

unchanged

13.. A person sitting in a chair with wheels stands, causing the chair to roll backward across the floor. The momentum of the chair

was zero while stationary and increased when the person stood

A student walks to class at a velocity of 3 m/s. To avoid walking into a door as it opens, the student slows to a velocity of 0.5 m/s. Now late for class, the student runs down the corridor at a velocity of 7 m/s. The student had the least momentum

while dodging the opening door