5.1.3 Conservation of Momentum

Question 1

Conservation of Momentum

Answer 1

• For a given system if , the system’s total momentum,, is conserved ().
• Conservation of momentum is a consequence of Newton’s second law applied to a system of particles,

Question 2

A 120 kg astronaut in space throws a 2 kg wrench at a velocity of 3 m / s. How fast and in which direction does the astronaut move?

Answer 2

0.05 m / s in the opposite direction of the wrench

Question 3

If two cars of equal mass and moving at the same speed collide and come to rest, how is momentum conserved?

Answer 3

The momentum of the cars was zero before the collision.

Question 4

Momentum is conserved when a bowling ball falls onto a trampoline and bounces back to its original height.

Answer 4

false

Question 5

If an object in outer space is moving at a constant velocity and continues moving at that velocity forever, which of the following best describes the principle(s) at work?

Answer 5

Conservation of energy and momentum

Question 6

A 60 kg bumper car coasting at a speed of 5.0 m / s crashes into another bumper car of mass 50 kg, moving at a speed of 2.0 m / s in the same direction. Immediately after the collision, the speed of the first car is 3.4 m / s (in the same direction as before). What is the speed of the second car?

Answer 6

3.9 m / s

Question 7

A cue ball collides with two other pool balls of the same mass. Which of the following describes the final speed of each of the balls?

Answer 7

The final speed can’t be determined

Question 8

Momentum is conserved when ________________.

Answer 8

the net external force is zero

Question 9

A woman is in a rowboat in the middle of a lake without a paddle. How can she reach the shore without leaving the boat?

Answer 9

By throwing something in the opposite direction she wants to go.