(a) Calculate the magnitude of the force, FM, required of the 'deltoid' muscle to hold up the outstr

(a) Calculate the magnitude of the force, FM, required of
the "deltoid" muscle to hold up the outstretched arm shown in
Fig. 12-56. The total mass of the arm is 3.3 kg. (b) Calculate the
magnitude of the force FJ exerted by the shoulder joint on the
upper arm and the angle (to the horizontal) at which it acts.