The shaft shown in Fig. 1 rotates and carries a steady load of 2000 lb and a steady torque...

The shaft shown in Fig. 1 rotates and carries a steady load of 2000 lb and a steady torque of 20,000 in. lb. What is the largest value of the distance “x” that can be used without failure if Syp = 60,000 psi, Se = 44,000 psi, Nfs = 2.50, and Kft = Kfb = 1.0.

Figure 1