Question

A Fisherman (100 kg) sitting on the ice notices that during the day the ice has become perfectly frictionless. Luckily the fisherman has caught 5 large fish (2 kg each) and knows he can throw some of them away in order to make it to the shore. Unluckily, a polar bear (200 kg) is approaching at 4m/s (I don’t know how he got started sliding, maybe he sneezed or flapped his ears). The fisherman can throw fish at 20m/s.

a)      If the fisherman throws the fish (all 5 at once) toward the polar bear, what will be his recoil velocity? (This is not a rocket equation problem.)

b)         If the polar bear catches the fish, what will be its new velocity?

c)         It turns out that the polar bear is a lousy catch and the fish bounce off the polar bear elastically at a 30° angle from their original direction of travel. Set up equations sufficient to solve for the final velocity (size and direction) of the fish and the polar bear. (Treat all the fish as one, 10kg mass.)

Answer 1