In our Zoom shows, students explore Bernoulli’s Principle together. In the gallery of parent-provided photos below, you can see students making ping pong balls float in two different ways.
If you are interested in trying this on your own, all you need is a lightweight, hollow ball like a ping pong ball or a ‘ball pit’ ball and a hair dryer. Aim the hair dryer straight up and place the ball in the air flow. It’s that simple! You can also slowly turn the hair dryer to an angle once you have it going and make the ball float with nothing underneath.
It also is fun to try the same thing with a bendable straw and a ping pong ball, as you can see in the photos below. Making the ball float with your own air can take a little practice, but it’s pretty satisfying!
The science of Bernoulli’s principle can sound pretty complicated, but put simply, where there is a faster stream of air from the hair dryer or straw, there is less dense air, or less air pressure. The higher pressure air that surrounds that air stream helps contain the ball in its lower pressure stream.
The faster moving air has a lower pressure than the surrounding air, simply because the current is moving those air molecules out of the way, the same way a stick floating in a river doesn’t stay in one place. Using water as an example makes sense, because Bernoulli’s principle applies to other fluids like water as well!
To see a fun video showing Bernouill’s principle, see this post from last year!