The factor of safety of a machine bar is 2.25. This bar is made of AISI 1006 cold-drawn steel and is loaded by the forces F=0.55 kN and T=25.N.m. Use both the maximum-shear theory and the distortion-energy theory to design the bar diameter D. During the design process, the shear stress caused by the lateral shear force, that is, F=0.55 kN, can be negligible.