Step-by-step tutorial
Step 1
Cut a circle out of a piece of paper. Then cut a slit to the center of the circle.
Step 2
Roll the circle into a cone and tape it in place.
Step 3
Cut off the tip of the cone, just wide enough for the straw to fit through. Tape the straw in place.
Step 4
Cut off the tip of the cone, just wide enough for the straw to fit through. Tape the straw in place.
Step 5
If you'd like, decorate your cone to look like a monster!
Step 6
Take a piece of tinfoil and roll it into a small ball.
Step 7
Blow into the straw and carefully place the ball in the airstream. If you get the placement right, your ball should levitate and spin!
Fact
This experiment is a great example of Bernoulli's principle in action. Bernoulli was an 18th century mathematician who proved that the faster a fluid (like water or air) moves, the lower the pressure it creates. When you blow into the straw, you are creating a column of fast moving, low-pressure air. Your tinfoil ball gets blown upwards, and then stays within the stream because the stationary air around it is at a higher pressure!