When Bill Nye explains scientific concepts, youngsters are likey to remember the illustrations and comparisons he utilizes. They may even remember his bad jokes, but Nye has made it clear that he will do almost anything if it means that kids will become more interested in science. The former standup comic talks about elephants on bikes compared to mice on bikes in Bill Nye the Science Guy: Momentum, and then discusses the momentum of pool balls.
Disney Educational - Bill Nye The Science Guy: Momentum