To develop muscle tone, a woman lifts a 2.00-kg weight held in her hand. She uses her biceps muscle to flex the lower arm through an angle of 60.0º . (a) What is the angular acceleration if the weight is 24.0 cm from the elbow joint, her forearm has a moment of inertia of 0.250 kg ? m2 , and the net force she exerts is 750 N at an effective perpendicular lever arm of 2.00 cm? (b) How much work does she do?

Step-by-step solution Step 1 o f 10 (a) The net torque acting on the elbow joint is given as, Here, is the torque due to the force exerted by the biceps and is the torque on the elbow joint due to weight in the forearm. Step 2 o f 10 Calculate the torque due to the force exerted by the biceps from relation, Here, is the force exerted and is the perpendicular distance. Step 3 o f 10 Substitute for and for in equation, Solve, Step 4 o f 10 Calculate the torque on the elbow joint due to weight in the forearm from relation, Here, m is the mass of the object, g is the gravitational acceleration and R the distance. Step 5 o f 10 Substitute for , for , and for in equation, Solve