A solid constant-diameter circular shaft is subjected to torques TA = 420 lb ft, TB = 1,040 lb ft, Tc = 850 lb. ft, and Tp = 230 lb-ft, acting in the directions shown in Figure 6.5. The bearings shown allow the shaft to turn freely. D TD Te B FIGURE P6.5 (a) Plot a torque diagram showing the internal torque in segments (1), (2), and (3) of the shaft. Use the sign convention presented in Section 6.6. (b) If the allowable shear stress in the shaft is 6,000 psi, what is the minimum acceptable diameter for the shaft?