Materials required:- a glass funnel or plastic funnel and a Ping-Pong ball (or small ball made from a torn balloon)
With your right hand hold the broad side of the funnel downward. Hold the ball in your left hand. Blow hard into the funnel and remove your hand from the ball. See how the ball hangs freely in the air within the funnel. Is it magic or juggling? Stop blowing. Does the ball float in the air still? Sure, you will like to repeat it many times.
What is the secret of it? Blow the air above the ball. It moves away due to the less air pressure; the air below the ball has more pressure than the air above. So it lifts u p the ball. W hen you stop blowing air pressure above and below the ball is the same. Hence the ball falls down due to its own weight.