with an arm held against the body vertically, the forearm, mass 0.365 m long, is then rotated at the elbow into horizontal position. the center of mass of the 1.65 kg forearm is 0.165 m away from the elbow. a 4.00 kg mass is held at the end of the forearm opposite the elbow. if the arm is held at rest horizontally what is the force supplied by the bicep muscles attached to the forearm 0.0350 m away from the elbow?