Concepts

Bernoulli's principle

Overview

A ball or other object is suspended in the air stream provided by a reversed vacuum cleaner according to the Bernoulli's principle.

Details

Equipment

• [1] Reversed vacuum cleaner
• [1] 2 L plastic bottle with a small amount of water inside
• Styrofoam and plastic balls of various sizes

Classroom Assembly

1. Plug in the reversed vacuum.

Important Notes

• Ensure demo will not be placed beneath low-hanging lights or low ceiling.

Script

1. Place a ball on top of the vacuum cleaner.
2. Turn on the vacuum. Notice that the ball is floating in the air.
3. Replace the ball with a different-sized ball or a plastic bottle.
4. Try floating two styrofoam balls at once. This should be possible with two large ones.
5. Catch the floating object(s) mid-air before turning off the vacuum.

Additional Resources