Grouping: Teacher demo + student prediction
Take-home: No take-home; optional observation card
Key ideas: Electromagnetic induction, eddy currents, opposing magnetic fields, energy conservation.
Start with: Drop a magnet through copper tubing and compare it with a nonmagnetic object.
Success check: Students predict and compare fall times/materials and explain why the magnet slows.
Try changing: Tube material; magnet strength; tube thickness.
Preparation: Test apparatus before class.
Lesson flow: Day 1: Prediction → dramatic drop comparison → explain Lenz's Law qualitatively → repeat with material/geometry variation
Video:
Lenz's Law
Safety and cleanup: Teacher handles strong magnets; keep away from electronics/medical devices; no small magnets for student handling.
https://www.youtube.com/watch?v=QwUq8xM_8bY&t=43s