Impulse and momentum.

A 2.5 kg ball moving at 5 m/s collides with a 2.5 kg stationary ball in a perfectly elastic collision.  What is the velocity of the second ball after the collision? 

• 5 m/s
• 2.5 m/s
• 10 m/s
• 7.5 m/s

A 50 kg ball rolls down the street at 5 m/s. Calculate the momentum of the ball. 

• 55 kg*m/s
• 100 kg*m/s
• 250 kg*m/s
• 500 kg*m/s

A person on a stationary skateboard throws a bowling ball with a velocity of 5.0 m/s. What is a possible speed of the person after the throw? 

• 0 m/s
• 1.5 m/s
• 5.0  m/s
• 7.5 m/s

The law of conservation of momentum states that, 

• p before is less than p after
• p before is the same as p after
• p before is more than p after

When the speed of an object is doubled, its momentum

• remains unchanged in accord with the conservation of momentum.
• doubles
• quadruples
• decreases

What is a system called when there is no external force on it?

• integral

• unified

• isolated

• closed

The impulse-momentum theorem states that

• the impulse on an object is equal to the change in momentum it causes 
• the force on a moving object is equal to the magnitude of the impulse.
• the impulse on an object is greater than the change in momentum it causes 
• the impulse on an object is less than the change in momentum it causes

The units for Impulse are

• N/s
• N.s
• N
• m/s

An impulse depends on

• weight and force

• force and time

• electric charge and time

• none of these

The air bag on a car reduces the force experienced by the driver, by extending the time of impact.

• True

• False