(B) The skateboard speeds up because the cat adds vertical momentum to the system.
(C) The skateboard continues moving at the same speed as the cat and skateboard exert equal and
opposite forces on each other that cancel out during the collision.
(D) The skateboard slows down due to the cat’s loss of kinetic energy when it lands on the
skateboard and stops moving vertically.
(E) The skateboard slows down due to the added mass of the cat to the horizontally moving
skateboard.3 . The initial velocity (v 1 ) of a cue ball is to the left. After striking the eight ball, the cue ball has a
final velocity (v 2 ), as shown in the figure. The direction of the impulse from the eight ball on the cue
ball is best described by which of the following vectors?
(A)
(B) (C)
(D)
(E)
4 . An air force jet has a Gatling gun mounted in its nose such that it can fire an ordnance round directly
forward at a velocity of v 0 . The total mass of the jet and ordinance is M . The ordnance mass is m .
While flying at a velocity of vj , the jet fires the ordnance directly forward as shown in the figure.
What will be the final velocity (vf ) of the jet after it fires the ordnance?