7- The design specification for the gear and shaft system shown require that steel shafts of the same diameter be used for both AB and CD. It is further specified that Tmax 60 MPa and that the angle through which end D of shaft CD rotates must not exceed 1.5. Using G = 80 GPa and considering only stresses caused by torsion, determine the minmum diameter shaft that may be used. A 400 mm 63 B 40 mm 100 mm 600 mm T = 1000 Nm