Air Pressure and Bernoulli: Rising Paper

This simple activity is a great introduction to Bernoulli. 

Cut strips of paper, about 1 cm wide.

Hold a single strip up to your lip. 

What do you think will happen if you blow across the paper?  How will the paper move? 

Many students will think that blowing across the paper will push it down.  In fact, just the opposite happens:

By blowing, you push the air molecules above the paper out of the way, so the air molecules located below the paper are unbalanced and push the paper up.