Angular Momentum - Turntable and Dumbbells


While spinning on the turntable, a person can vary his/her moment of inertia by extending/retracting both arms. To pronounce this effect, the experimentee can hold onto the provided dumbbells. Extending one's arms while spinning increases their moment of inertia, decreasing angular velocity, and vise versa. Figure skaters use this effect to spin at high rates.