A hollow and a solid cylindrical shaft are constructed of the same material. The shaf...

A hollow and a solid cylindrical shaft are constructed of the same material. The shafts are of identical length and crosssectional area and both are subjected to pure torsion. Determine the ratio of the largest torques that may be applied to the shafts for c=1.4b (a) if the allowable stress is and (b) if the allowable angle of twist is