고체역학 (Beer) — Torsion: Problem 3.44

3.44 For the gear train described in Prob. 3.43, determine the angle through which end A rotates when \( T = 5 \text{ lb}\cdot\text{in.} \), \( l = 2.4 \text{ in.} \), \( d = \frac{1}{16} \text{ in.} \), \( G = 11.2 \times 10^6 \text{ psi} \), and \( n = 2 \). (Context from Prob. 3.43: A coder F, used to record in digital form the rotation of shaft A, is connected to the shaft by means of the gear train shown, which consists of four gears and three solid steel shafts each of diameter d. Two of the gears have a radius r and the other two a radius nr. If the rotation of the coder F is prevented, determine in terms of T, l, G, J, and n the angle through which end A rotates.)