Two-Ball Super Bounce

1. Two-Ball Super Bounce Materials: Basketball; tennis ball What you do: Stack tennis ball on basketball and drop together. What students see: Tennis ball rockets much higher than its starting height. Question: Where did the tennis ball get extra speed? 2. Rolling Can Mass Race Materials: Two identical cans/cylinders with mass arranged differently What you do: Release both down the same ramp. What students see: One reaches bottom first even though total mass is similar. Question: Why does where the mass sits matter? 3. Spool/String Direction Trick Materials: Large spool/yo-yo; string What you do: Pull string at different angles along table/floor. What students see: Spool can roll toward or away from the pull. Question: How can pulling one way make it roll another?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: Where did the tennis ball get extra speed? Question: Why does where the mass sits matter? Question: How can pulling one way make it roll another?