Magnetic Braking on Aluminum

1. Magnetic Braking on Aluminum Materials: Strong magnet; aluminum baking sheet or plate What you do: Slide magnet over/near sheet compared with nonmagnetic object. What students see: Magnet motion is noticeably resisted. Question: How can aluminum slow a magnet if it isn't magnetic? 2. Magnetized Needle Compass Materials: Needle; bar magnet; cork/foam; water dish What you do: Magnetize needle, float it, and let it settle. What students see: Needle turns to roughly north-south. Question: What invisible field is turning the needle? 3. Mystery Black Box Magnet Materials: Small closed box with hidden magnet/object; steel paper clip outside What you do: Move clip around box and ask students to map attraction. What students see: Students infer something hidden from its effects. Question: How can we learn about something we can't see?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: How can aluminum slow a magnet if it isn't magnetic? Question: What invisible field is turning the needle? Question: How can we learn about something we can't see?