<Dl> <Dd> (r i − S) y = (r i − S) × y, (\ displaystyle (r_ (i) - S) \ mathbf (y) = (\ mathbf (r) _ (i) - \ mathbf (S)) \ times \ mathbf (y),) </Dd> </Dl> <Dd> (r i − S) y = (r i − S) × y, (\ displaystyle (r_ (i) - S) \ mathbf (y) = (\ mathbf (r) _ (i) - \ mathbf (S)) \ times \ mathbf (y),) </Dd> <P> for an arbitrary vector y . </P> <P> Let R be the center of mass of the rigid system, then </P>

Calculate moment of inertia from center of gravity