고체역학 (Beer) — Torsion: Problem 3.80

3.80 A 2.5-m-long steel shaft of 30-mm diameter rotates at a frequency of 30 Hz. Determine the maximum power that the shaft can transmit, knowing that \(G = 77.2 \text{ GPa}\), that the allowable shearing stress is \(50 \text{ MPa}\), and that the angle of twist must not exceed \(7.5^\circ\).