Hot air and a floating ball

Friday, October 17th, 2008
Today we tried an interesting investigation using hot air (from a hair dryer). We tried holding a table tennis ball over a hair dryer. The rising hot air keeps the ball floating in the air, with the help of gravity so the ball doesn't fly out of the air stream. This experiment doesn't work with a heavy bouncy ball because this is too heavy for the air to lift, or with a light foam ball since this ball is too light to stay in the warm air flow so it gets knocked over very quickly.