$($I need drawing and sloving please!!$)$

A torsion bar is used as a suspension element for a vehicle. The bar has a diameter of $20$ mm $.$ It is

subjected to a torsional moment of $450N.m$ and an axial tensile force of $36\mathrm{.}0$ kN $.$ Draw a stress

element on the surface of the bar, and then draw the Mohr's circle for the element.