Dry Paper Towel Underwater
The towel stays dry.
Teaching & key ideas
What you do: Stuff towel in cup, invert cup straight down into water, then remove.
What students see: The towel stays dry.
Why it works: Trapped air fills the cup and keeps water out.
Question to ask: What is inside the 'empty' cup?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: What is inside the 'empty' cup?