Balloon Whistle

A loud whirring/whistling sound develops. Ask students to predict what will happen. Place nut in balloon, inflate, then swirl balloon safely. Key idea: The nut rolls around and vibrates the stretched balloon surface. Ask: Why does spinning make sound? Safety and cleanup: Teacher demo; no deliberate popping. https://www.google.com/search?q=%22Balloon+Whistle%22+science+demonstration+experiment