4(a). Knowing that a 0.30 in. -diameter hole has been drilled through each of the shafts AB, BC, and CD, determine (a) the shaft in which the maximum shearing stress occurs, (b) the magnitude of that stress. 600 .lb-in. 1,500 lb-in. 500-1b-in B dan=0.75 in. AD dac= dan Figure 4(a) 4(b). The solid rod AB has a diameter dAB = 60 mm and is made of a steel for which the allow- Able shearing stress is 85 MPa. The pipe CD, which has an outer diameter of 90 mm and a wall thickness of 6 mm, is made of aluminum for which the allowable shearing stress is 54 MPa. Determine the largest torque T that may be applied at A. 90 mm Figure 4(b) dcp=1.40 in. 1.0 in.

Fig: 1