Welcome back to more science! What will happen if you put a ping pong ball on a hair dryer and turn it on? This experiment will have you experimenting with air pressure and how things fly.
Materials:
Ping pong ball
Hair dryer
Procedure:
- Point the hair dryer straight up; don’t turn it on yet
- Put the ping pong ball on the vent end of the hair dryer
- Turn on the hair dryer and watch the ping pong ball float in place about a foot in the air!
- Try to tilt the hair dryer a little and see how far you can do it before the ball drops
Explanation:
The round shape and the really light weight help this object “float” in the air. If you tried this with a tennis ball, it probably didn’t work. If you tried this with a crumpled-up piece of paper, it also probably didn’t work. Even if the ping pong ball had a little dent in it, it wouldn’t easily stay locked in the air flow as nicely as an undented one. Why?
The explanation involves a lot of science, but I’ll try to make it easy to understand. Think of a big jet flying. When it moves up into the air, it is called “lift.” Lift is a force that is caused by a difference in air speed. Basically, slow-moving air wants to move into faster-moving air (like a vacuum cleaner!) and pushes things in between. A jet’s wing is rounded which causes this difference in speed. Now, a ping pong ball is round all over so when the air flows over it, it has an even amount of air across it, keeping the pressure balanced. Air around the flow is slower, and so that “pushes” the ball in the air flow and keeps it locked in there.
Going further:
You should be thinking about how to experiment with this already! Like what other objects will do this? How many ping pong balls can you put in the hair dryer and keep them afloat?
If you happen to have a leaf blower, can you get this to work with a beach ball? Make sure to ask your parents before you go experimenting!
Keep track of what you learned here today in a journal: you never know when you might ask a good science question, or need to apply what you’ve learned in an experiment or at school.
LOOKING FOR MORE science experiments? Find them here!
About the author:
Steve Davala has been teaching math and science to middle and high schoolers since 2000. He writes books, plays music, carves wood and he loves learning new things. Ask him a question at steve.davala@gmail.com.
© This experiment was created by Steve Davala using concepts and ideas from “Invitations to Science Inquiry” by Tik Liem.
