5–21. If the 40-mm-diameter rod is subjected to a uniform
distributed torque of t0 = 1.5 kN #mNm, determine the shear
stress developed at point C.
5–22. If the rod is subjected to a uniform distributed
torque of t0 = 1.5 kN #mNm, determine the rod’s minimum
required diameter d if the material has an allowable shear
stress of tallow = 75 MPa.