A square tube section has side dimension of 500 mm and thickness of 13 mm. If the section is used for a 2.75 m-long beam subjected to 140 kN.m torque at both ends, calculate the maximum shear stress...

A square tube section has side dimension of 500 mm and thickness of 13 mm. If the section is used for a 2.75 m-long beam subjected to 140 kN.m torque at both ends, calculate the maximum shear stress and the angle of twist between the ends. Use G = 80 GPa.