While exercising in a fitness center, a man lies face down on a bench and lifts a weight with one lower leg by contracting the muscles in the back of the upper leg. (a) find the angular acceleration (in rad/s2) produced given the mass lifted is 12.5 kg at a distance of 28.0 cm from the knee joint. the moment of inertia of the lower leg is 0.900 kg · m2, the muscle force is 1475 n, and its effective perpendicular lever arm is 3.00 cm.