Hammer-and-Ruler Balance

Heavy hammer can balance in a surprising arrangement. Ask students to predict what will happen. Loop string so hammer hangs under ruler supported at table edge. Key idea: Combined center of mass sits under the support point. Ask: How can the heavy hammer stay up? Safety and cleanup: Teacher handles hammer; use low setup. https://www.google.com/search?q=%22Hammer-and-Ruler+Balance%22+science+demonstration+experiment