"Prob. 4.5-16. The aluminum-alloy shaft AD in Fig. P4.5-16 (G= 3.8 x 10³ ksi) has a 40-in. long tubular section AC anda 30-in.-long solid section CD. The diameters are (d), (do)2= dy = 2.0 in. and (d), = (d)₂ = 1.75 in. A 2 kip-in. torque acts at section B. What is the allowable torque T₁2 0 that may be added at end A if the angle of rotation at A is not to exceed (1) allow = 0.10 rad, and the magnitude of the shear stress is not to exceed Tallow = 4 ksi anywhere in the shaft? =