im supposed to show why angular momentum is conserved in a rotating body with no external torques or forces acting on it. i know to use the I_1*w_1=I_2*w_2 where I is the moment of inertia of the object in motion and w is the angular speed. My qu estiosn are: which equation for Inertia should I use for a human body sitting on a rotating stool? And how do I calculate angular frequency? Can I just record the amount of rotations per unit of time?