Select a diameter of a steel driveshaft that transmits 250 hp at 5000 rpm. Bending and axial load are negligible. Note: Select the diameter as 3 inches. What is the nominal shear stress at the surface? If a hollow shaft of inside diameter 0.9 times outside diameter is used, what outside diameter would be required to give the same outer-surface stress? How do the weights of the solid and hollow shaft compare? Rotation unknown diameter 250 hp, n=5000 rpm