고체역학 (Gere) — Torsion: Problem R-3.2

R-3.2 The angle of rotation between the ends of a nylon bar is \(3.5^\circ\). The bar diameter is \(70 \text{ mm}\) and the allowable shear strain is \(0.014 \text{ rad}\). The minimum permissible length of the bar is approximately: (A) \(0.15 \text{ m}\) (B) \(0.27 \text{ m}\) (C) \(0.40 \text{ m}\) (D) \(0.55 \text{ m}\)