What you Need All you need is a party balloon, and some
enthusiasm What to do This is very simple, first try hitting the
balloon gently and see how it travels Now try bashing it really
hard, does it do what you would expect? What may happen You
should find that if you hit the balloon gently it flies across
the room and slows down gently. If you hit it really hard though
it moves very fast for a bit then suddenly slows down or changes
direction. Why does it happen? If you hit the balloon gently the
air will flow around it, there will be quite a lot of friction
compared to the mass of the balloon so it will slow down gently.
If you bash the balloon really hard you are not just making the
balloon move fast you are also making the air around it move
fast, and there is actually more energy in the rapidly moving
air than in the balloon itself. While it is going fast the
balloon seems to drag (or be pushed along by) a chunk of air
behind it (which the smoke allows you to see), this seems to be
circulating slightly,