Physics test 4

The change in the linear momentum of a body is equal in the _____________ applied to it

impulse

A valid unit for momentum is which of the following ?

kg x m/s

A 2500-kg truck moving at 10 m/s strikes a car waiting at a traffic light, hooking bumpers. The two continue to move together at 7.00 m/s. What is the mass of the stuck car ?

1070 kg

A skier of mass of 40 kg initially at rest pushes off the top of the hill. How fast will she be moving at the bottom of the hill if the vertical height of the hill is 10 m ?

14 m/s

A 1000 kg object moving at 20 m/s collides with a brick wall and comes to a complete stop. If the collision time is 0.01 s what was the average stopping force ?

2 x 10^6 N

A 1000 kg car whose speed is 20 m/s has a kinetic energy of

2.0 x 10^5

A 0.12 kg ball is moving at 6 m/s when it is hit by a bat, causing it to reverse direction and have a speed of 14 m/s. What is the magnitude of the change in the momentum of the ball ?

2.4 kg x m/s

A 1200 kg automobile moving at 25 m/s. What is the momentum ?

30000 kg m/s

A ball of mass 12 kg is moving at 4 m/s. What is the ball's momentum ?

48 kg x m/s

A block is observed to have a kinetic energy of 600 J at the bottom of a smooth hill. The total mechanical of the block upon stopping is

600 J

A 1500 kg truck moving at 10 m/s collides head on with a 500 kg car at rest. If the collision is completely inelastic, what is the velocity of the two cars after the collision ?

7.5 m/s

A shopper in a supermarket pushes a cart with a force of 25 N directed at an angle of 25° downward from the horizontal. The work done by the shopper as she moves down a 42 m length of aisle is

952 J

A pecan falls from the tree. Compare its kinetic energy K, to its potential energy U

K increases and U deceases

Which of the following is that form of energy associated with an object's location in a conservative force field ?

Potential

The impulse experienced by a body is equivalent to its change in:

momentum

In an elastic collision of two objects,

momentum is conserved and kinetic energy is conserved

A fly splats on your windshield: The collision is

perfectly inelastic

The rate at which work is done ?

power

If you push an object twice as far while applying the same force, you do

twice as much work

What is not a unit of energy ?

watt