For a movie scene, a 75-kg stuntman drops from a tree onto a 50-kg sled that is

Question:

For a movie scene, a 75-kg stuntman drops from a tree onto a 50-kg sled that is moving on a frozen lake with a velocity of 10 m/s toward the shore.
(a) What is the speed of the sled after the stuntman is on board?
(b) If the sled hits the bank and stops, but the stuntman keeps on going, with what speed does he leave the sled? (Neglect friction.)