Soap-Powered Paper Boat
Boat zips forward.
Teaching & key ideas
What you do: Float boat; touch soap at notch in rear.
What students see: Boat zips forward.
Why it works: Soap lowers surface tension behind the boat, creating an imbalance.
Question to ask: What pushes the boat forward?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: What pushes the boat forward?