Two ice skaters, Paula and Ricardo, push off from each other. Ricardo weighs more than Paula. Which skater, if either, has the greater momentum after the push-off?

Arailroad car collides with and sticks to an identical railroad car that is initially at rest. after the collision, the total kinetic energy of the two cars is a) the same as before. b) half as much as before. c) one third as much as before. d) one fourth as much as before. e) twice as much as before.