A simple way to demonstrate the Bernoulli Principle.

Watch The Video:

Other Demos of Interest:

Bernoulli Floating Ball

Lifting Plates with Air Flow

How to Make a Vortex Cannon

Teachable Topics:

  • conservation of energy
  • pressure
  • principles of flight


This follows the same principle as the Bernoulli Floating Ball demo, for which features a more mathematical approach to Bernoulli’s Principle.

Bernoulli’s Principle states that the higher the velocity of a fluid, the lower the pressure. The running water thus has lower pressure than the air surrounding it. When the ball is hung in the stream of water, it remains in the water even as you tilt the string that is suspending it.

The force of gravity tries to pull the ball downward and out of the water, but the ball is pushed back into the water by the higher pressure outside of the water stream.


Only when the string is angled far enough such that the force of gravity is stronger than the force created by the pressure difference, will the ball fall out of the water stream.


  • ping pong ball
  • string
  • running tap


  • attach string to ping pong ball
  • turn on tap
  • suspend ping pong ball in water and see how far you can angle the string before ball falls out of water