Blow Over a Paper Strip
Paper rises into the air stream.
Teaching & key ideas
What you do: Hold strip under lower lip and blow across its top.
What students see: Paper rises into the air stream.
Why it works: Fast air above has lower pressure; higher pressure below pushes the strip upward.
Question to ask: Why did blowing over it make it go up?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why did blowing over it make it go up?