Blow Between Two Cans
Cans move toward each other instead of apart.
Teaching & key ideas
What you do: Place cans close together and blow through the gap.
What students see: Cans move toward each other instead of apart.
Why it works: Faster air between them has lower pressure; outside air pushes inward.
Question to ask: Why didn't the air push them apart?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why didn't the air push them apart?