고체역학 (Beer) — Torsion: Problem 3.70

3.70 A hollow steel drive shaft (\(G = 11.2 \times 10^6\) psi) is 8 ft long and its outer and inner diameters are respectively equal to 2.50 in. and 1.25 in. Knowing that the shaft transmits 200 hp while rotating at 1500 rpm, determine (a) the maximum shearing stress, (b) the angle of twist of the shaft.