3- a. Determine the ditribution of shear stress in the following circular shafts that are subject to a maximum torque of 7.5 Nm by calculating the polar second moment of area. 110 a) R R = 5mm r = 3mm b) O R b. Using the previous answers; determine the angular deflection in both shafts. Both shafts are 20 cm long and the modulus of rigidity for the material is 60GN/m^2. a) R = 5mm r = 3mm b)