Coin Vortex in a Funnel

Coin circles faster as it spirals inward. Ask students to predict what will happen. Launch coin around the rim. Key idea: Gravitational potential energy becomes kinetic energy as radius decreases. Ask: Why does the coin move faster near the middle? Safety and cleanup: Coin stays in funnel; teacher handles. https://www.isu.edu/physics/outreach/physics-class-demos/mechanics/coin-vortex-funnel/