Torque needs to be applied in order to change the angular momentum of a body when the body is free to rotate around an axis. The amount of torque that must be applied to the body in order to produce a specific angular acceleration (the rate at which the body's angular velocity changes) is proportional to the body's moment of inertia.
Torque needs to be applied in order to change the angular momentum of a body when the body is free to rotate around an axis. The amount of torque that must be applied to the body in order to produce a specific angular acceleration (the rate at which the body's angular velocity changes) is proportional to the body's moment of inertia.