Pendulum Nose Challenge
It swings back but does not hit the release point.
Teaching & key ideas
What you do: Release pendulum from teacher's nose without pushing; stand still.
What students see: It swings back but does not hit the release point.
Why it works: Without extra energy, it cannot rise higher than where it started.
Question to ask: Why doesn't it come back higher?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why doesn't it come back higher?