Spool/String Direction Trick

Spool can roll toward or away from the pull. Ask students to predict what will happen. Pull string at different angles along table/floor. Key idea: Torque direction depends on the line of force relative to the contact point. Ask: How can pulling one way make it roll another? Safety and cleanup: Large spool only. https://www.google.com/search?q=%22Spool%2FString+Direction+Trick%22+science+demonstration+experiment