Levitating Ball

How

1. Turn the crank and watch how the ball “hangs” in the stream of air.
2. Try turning more slowly and more quickly – see how the height changes.

Why

By turning the crank you drive a turbine (fan) that produces an upward force on the ball. When this force balances the ball’s weight (acting downward), the ball stays at a steady height.

Why doesn’t the ball fall out to the side?

If the ball drifts away from the center of the air jet, the airflow becomes faster on one side than on the other. On the faster-flowing side the pressure is slightly lower, so a “restoring force” pushes the ball back toward the center of the jet. This is a flow effect often explained using Bernoulli’s principle and the tendency of a jet to “stick” to a nearby surface.

Fun facts

You can recreate this experiment at home with a ping – pong ball and a hair dryer.