Magnetic Braking Pendulum

1. Magnetic Braking Pendulum Materials: Strong magnet pendulum; aluminum/copper plate What you do: Swing magnet through metal plate gap vs open air. What students see: Swing damps rapidly near conductor. Question: Where does the motion energy go? 2. Electromagnet Strength Test Materials: Iron bolt; insulated wire; low-voltage battery; paper clips What you do: Compare coil with fewer vs more turns briefly. What students see: One coil lifts more clips. Question: What can we change to make an electromagnet stronger? 3. Which Liquids Conduct? Materials: Low-voltage conductivity tester; distilled water; salt water; sugar water; vinegar What you do: Test liquids with same electrodes. What students see: Some complete circuit much better than others. Question: Why does dissolved salt conduct but sugar may not?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: Where does the motion energy go? Question: What can we change to make an electromagnet stronger? Question: Why does dissolved salt conduct but sugar may not?