A section of the steel shaft of 1.12 in diameter is supporting a fully reversed bending moment M = 2800 lb-in as well as a steady torque T = 4000 lb-in. The shaft material has the following properties; Sm = 72 ksi, Se = 27 ksi, Sy = 68 ksi, and Sut = 80 ksi. (A) Find the factor of safety against a fatigue failure using the Goodman criterion. (B) Estimate the number of rotations of shaft expected before a fatigue failure