고체역학 (Beer) — Torsion: Problem 3.32

3.32 (a) Determine the angle of twist caused by a 40-kip·in. torque T in the 3-in.-diameter solid aluminum shaft shown (\(G = 3.7 \times 10^6\) psi). (b) Solve part (a), assuming that the solid shaft has been replaced by a hollow shaft of the same outer diameter and a 1-in. inner diameter.