Do not round intermediate answers. Give your final answer(s) to three decimal places. Check your units. Two solid steel shafts are connected by the gears shown. A torque of magnitude 7 = 500 N-m is applied to shaft AB. Knowing that the allowable shearing stress is 65 MPa and considering only stresses due to twisting, determine the required diameter of: (a) shaft AB, (b) shaft CD. T A d(AB) = mm 140 mm D d(CD) = mm B 60 mm