Hammer-and-Ruler Balance

1. Hammer-and-Ruler Balance Materials: Ruler; string; hammer What you do: Loop string so hammer hangs under ruler supported at table edge. What students see: Heavy hammer can balance in a surprising arrangement. Question: How can the heavy hammer stay up? 2. Folded Paper Holds Weight Materials: 2 sheets paper; books/counters What you do: Compare flat paper bridge with folded/accordion paper. What students see: Folded paper supports much more weight. Question: Did we add more paper or just change its shape? 3. Tornado in a Bottle Materials: Clear bottle(s); water; connector or single bottle What you do: Swirl water strongly before letting it drain. What students see: A visible funnel forms. Question: What shape does the spinning water make?

Predict → observe three demonstrations → compare what changed → choose independent activity station → cleanup/share. Guiding questions: Question: How can the heavy hammer stay up? Question: Did we add more paper or just change its shape? Question: What shape does the spinning water make?