Rolling Can Mass Race
One reaches bottom first even though total mass is similar.
Teaching & key ideas
What you do: Release both down the same ramp.
What students see: One reaches bottom first even though total mass is similar.
Why it works: How mass is distributed changes rotational inertia and acceleration.
Question to ask: Why does where the mass sits matter?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why does where the mass sits matter?