Singing Aluminum Rod
Rod produces a loud eerie tone.
Teaching & key ideas
What you do: Hold at center and rub/slide fingers along rod.
What students see: Rod produces a loud eerie tone.
Why it works: Friction excites a resonant longitudinal vibration mode.
Question to ask: Where is the rod moving if we can barely see it?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Where is the rod moving if we can barely see it?