고체역학 (Beer) — Torsion: Problem 3.34

3.34 (a) For the aluminum pipe shown (\(G = 27 \text{ GPa}\)), determine the torque \(T_0\) causing an angle of twist of \(2^\circ\). (b) Determine the angle of twist if the same torque \(T_0\) is applied to a solid cylindrical shaft of the same length and cross-sectional area.