A man does a back flip on a trampoline and bounces off of it and falls on to the ground.
A boy throws a magic 8 ball against a pile of rocks. The ball bounces back and hits the boy in the head.
A dog watches a tennis ball bounce up and down and opens his mouth each time the ball hits the floor.
Two men hold either end of a long log and try to break it by running it into a tree. The log bounces back and hits both of them in the stomach.