The deltoid muscle connects the shoulder blade to the upper arm (humerus), and so contraction of the deltoid raises the arm. The deltoid tendon connects the humerus 15.0 cm from the shoulder joint at an angle of 20.0° with the horizontal. Suppose the arm weighs 39.5 N and its center of gravity is 36.4 cm from the shoulder joint. A weight W is held in the outstretched hand 90.0 cm from the shoulder joint.
a) Find the force the shoulder joint exerts on the humerus if W = 36.5 N. (Assume the +x direction is to the right.) _________N
b) What is the angle of the force on the shoulder joint above the horizontal? _________degrees