Angular Momentum of a Back Tuck
- Because the gymnast is traveling in a circular path, she experiences angular momentum. Angular momentum is the product of angular velocity and the body's moment of inertia (L=Iω). A moment of inertia (I) is how far the mass is from the center of the axis of rotation. Like linear momentum, angular momentum is conserved.
- By tucking in her knees, the gymnast brings her mass closer to the center of the axis of rotation, thereby decreasing the moment of inertia. When the gymnast decreases her moment of inertia, her angular velocity increases proportionally. Her increased angular velocity allows the gymnast to complete the rotation.