A solid shaft has a radius r and is acted upon by the forces and torque shown in Figure $2.$ Determine in terms of r$,$ the normal and shear stresses acting on the shaft at Element H$,$ the maximum shear stress, average stresses, principal stresses and principal plane acting on element H$.[10$ marks$]$ Note: Marks will be awarded when using Mohr circle only. No marks will be awarded when using transformation equation.

A$,$ B$,$ C in the question denotes the last three digits of your student number respectively. If your student number is $400266351,$ than A$=3,$B$=5$ and C$=1.$ Therefore for this question, the variables have the following magnitudes:$-$