Bernoulli’s Principle

I make a bet that I can levitate a ping-pong ball with just my breath.  I throw some balls to some of the students to see if they can do it.  A few moments later, I produce a straw (the bendable kind; shape it like a pipe) and “levitate” the ball by blowing through the straw.

It’s an old demo but it works.  I then pass out some straws and let them do it.  One of those enjoyable moments as a teacher when you see the kids all red-faced and out of breath.