You are given a sheet of steel with a modulus of rigidity is G = 80.8 Gpa, a length L = 1 m, width w = 100 mm, and thickness t = 1 mm. You are asked to design a shaft cross-section by shaping the given steel sheet. The machine that is available to you can shape the sheet metal into three different sections i) an open-circle, ii) a closed-square, iii) a closed-circle. (a) Calculate the stress and deflection in each design if the only load the shaft will undergo is a 10 N-m torque. (b) As the designer which cross-section would you pick for fabrication and why?