Chapter 11 – Torque and Angular Momentum
only torques that can change the angular momentum of a system are the external torques acting on a system. The net external torque acting on a system of particles is equal to the time rate of change of the system's total angular momentum L. Rigid body (rotating about a fixed axis with constant angular speed ω): li = (ri )( pi )(sin 90 ) = (ri )( mivi) Magnitude Direction: li .