A hollow shaft 30 mm inner diameter and 50 mm outer diameter is subjected to a twisting moment of 800 N-m and an axial compressive force of 40 kN. Determine the factor of safety according to theories of failure based on Normal stress theory. Maximum shear stress theory and Distortion energy theory. The tensile and compressive yield strength of material is 280 N/mm2 and Poisson’s ratio = 0.3.