The Bernoulli Ball

What to Do You will need the following items for this experiment: Straw Ping Pong ball or small styrofoam ball from craft store Someone who can blow really hard Here's what you do: Take the straw, hold it in your mouth, and point it straight up. Blow pretty hard through the straw to make a good air stream. Set the ball gently in the air stream. The ball should float in the stream! It will bob around, but do not chase it! Keep the straw pointed straight up. Don't move! If the effect is working right, the ball will stay in the stream because of the Bernoulli effect. If you are not having any luck, try this.: Blow very steady. A steady stream is more important than blowing very hard. Make sure the straw is pointed straight up. Make sure you are not chasing the ball.   Explanation Bernoulli's principle tells us that air that is moving at high speed has lower pressure than still air. The air moves around the ball to create a pocket around the ball of low pressure air. When the ball moves to the side of the pocket, it will be pushed back in. And the upward force from the air stream keeps the ball aloft. It's quite a cool effect! Other Things to Try With a stronger air stream, you can levitate a bunch of different things. There are two guys from Ohio who call themselves "The Flying Bernoulli Brothers" who have made a career of doing this! They hold up beach balls, pop bottles (empty, of course) and even light bulbs! This is a very cool effect, and you are encouraged to experiment. Try using blow dryers, vacuums (if they have a "blow" setting), leaf blowers, fans, and anything else you can think of! (Note: fans often do not work all that well, since they will have a pocket of slower moving air in the center, where the motor and the center of the fan blades are. Ask Mr. Miller to demonstrate his Bernoulli Blower next time you are in class. The contents of the page was modified from that created for the Little Shop of Physics, Colorado State University

Follow-up 1. What does Bernoulli's principle tell us? 2. What happens as the air stream reaches the ball? What is created around the ball? 3. Describe the movement of the ball as it reaches the side of the air pocket. 4. Why does the ball stay up? 5. Fans often do not work well with this experiment for what reason? 6. Who are "The Flying Bernoulli Brothers?" List several items they have succefully levitated.   Obtaining credit for your efforts Print a copy of the blank laboratory write-up paper. Read and complete each section, incomplete write-ups receive no credit. Have your parent check your work and sign the paper.