A 0.32-kg ball is moving horizontally at 30 m/s just before ...

[kodithompson]

A 0.32-kg ball is moving horizontally at 30 m/s just before suddenly bouncing off a wall Just after the bounce, it is moving horizontally at 25 m/s but in the opposite direction.
 
  (a) What is the magnitude of the change in momentum of the ball during the bounce? (b) What percentage of the ball's original kinetic energy was lost in the collision?

Question 2

Mort and Velma are twins, born at the same time on Earth. Velma is taken on a long trip into outer space, at a speed close to lightspeed, and returns to Earth. When she returns,
 
  A) Mort observes that he is younger than Velma, but Velma will observe that she is younger than Mort.
  B) Mort and Velma observe that they have aged equally.
  C) Mort observes that he is older than Velma, and Velma observes that she is older than Mort.
  D) Mort and Velma both observe that Velma is older than Mort.
  E) Mort and Velma both observe that Mort is older than Velma.

[peilian]

Answer to Question 1

(a) 18 N  s (b) 31

Answer to Question 2

E

[kodithompson]

Excellent

[peter]

TYSM