Unit momentum,collisions,impulse review quiz

Which object has the greatest momentum?

• 10 kg baby moving at 4 m/s

•  8 kg bowling ball moving at 5 m/s

• 6 kg dog running at 8 m/s

• 2 kg golf ball rolling at 20 m/s

An object with a mass of 3 kg has a momentum of 75 kg • m/s. What is its velocity?

•   0.4 m/s

• 7.1 m/s

• 25 m/s

• 72 m/s

 A stationary 1000 kg cannon fires a 10-kg projectile horizontally at a velocity of 300 m/s. What is the total momentum of the system before the explosion, and what is the total momentum of the system after the explosion?

• 0 kgm/s before, 300000 kgm/s after

• 300000 kgm/s before, 0 kgm/s after

• 0 kgm/s before, 0 kgm/s after

• 30 kgm/s before, 30 kgm/s after

A hockey player applies an average force of 80.0 N to a 0.25 kg hockey puck for a time of 0.10 seconds. Determine the impulse experienced by the hockey puck.

• 8 Ns

• 20 Ns

• 80 Ns

• 100 Ns

The brakes on your 8 kg bike change your speed from 30 m/s to 20 m/s.  Determine the impulse applied by the breaks. 

• + 80 kg m/s

• +.8 kg m/s

• – 80 kg m/s

• - .8 kg m/s

At an amusement park, bumper car X moves at a speed of 2.5 m/s toward car Y, which is at rest, as shown in the diagram below.

Car X collides with car Y. How does the momentum of each car change after the collision?

• Car X’s momentum increases, and car Y’s momentum decreases.

• Car X’s momentum decreases, and car Y’s momentum increases.

• Car X’s momentum is unchanged, and car Y’s momentum increases.

• Car X’s momentum is unchanged, and car Y’s momentum decreases.

A 60 kg student on ice skates stands at rest on a frictionless frozen pond holding a 60 kg brick. He throws the brick east with a speed of 18 m/s. What is the resulting velocity of the student

• 3.0 m/s west

• 18 m/s west

• 3.0 m/s east

• 18 m/s east

 Which statement accurately describes the use of an airbag in a car:

• An airbag increases the impulse of the collision.

• An airbag increases the time of the collision, thereby decreasing the force. 

• An airbag does little to help in a collision because it happens so fast.

• An airbag decreases the time of a collision, thereby decreasing the force.

Two cars are involved in a head-on collision, which of the following is correct?

• the cars loose all of their momentum as soon as they hit each other.

• The total momentum is conserved before and after the collision

• The total momentum is greater after the collision

• The total momentum is greater before the collision

If two objects have the same mass, then the faster moving object has ____________ momentum.

• more 
• less
• the same