consider position b, and then solve the following problem. assume the angle to the vertical line for position b is 45 degrees. now also assume that the main muscle that holds the arm in position is the deltoid muscle, represented by a red arrow. the angle of the deltoid muscle is 15 degrees and its distance to the center of rotation is 17 cm. if the cog for the arm is 38 cm from the center of rotation, and its weight is 35 n, what is the force that the deltoid muscle must exert to keep the arm stationary in 45 degrees position?