To develop muscle tone, a woman lifts a 4.00 kg mass held in her hand. She uses her biceps muscle to flex the lower arm through an angle of 60.0°. Ignore gravity.
(a) What is the angular acceleration if the mass is 24.0 cm from the elbow joint, her forearm having a moment of inertia of 0.250 kg·m2, and the muscle force being 650 N at an effective perpendicular lever arm of 1.80 cm?
rad/s2
(b) How much work does she do?
J