Bernoulli Ping Pong

Materials

· Straw

· Ping Pong Ball

· Top of a Bottle

Bottle Cap with a Hole

Procedure

1. Insert the small end of the bent straw into the hole of the bottle cap.

2. Screw the cap onto the top of the bottle.

3. Take a deep breath and blow through the straw.

4. Place ping pong ball on top of straw in the stream of air.

5. What do you notice happening?

6. Why does the ping pong ball not float away? 

Science Behind it!

The Floating Ping Pong Ball is a wonderful example of Bernoulli’s Principle, the same principle that allows heavier-than-air objects, like airplanes, to fly. We have a Bernoulli table here at OH WOW! as part of our A-mazing Airwaves exhibit.  Have you ever gotten a plastic ball to float above the white pipes at our Bernoulli table?

The air from the straw, as you blow through it, produces the levitating ball phenomenon using Bernoulli’s Principle. The fast air moving that you are blowing around the sides of the ball is at a lower pressure than the surrounding, stationary air. If you look closely, you’ll see that the ball wobbles while it is levitating in midair. The ball is attempting to leave the area of low pressure, but the higher air pressure surrounding it forces it back into the low pressure area.

Extended Science!!

Are there any other objects that you can make float using the apparatus that you’ve created?