고체역학 (Gere) — Torsion: Problem 3.7-4

3.7-4 A solid steel shaft ABC with diameter \( d = 40 \text{ mm} \) is driven at A by a motor that transmits \( 75 \text{ kW} \) to the shaft at \( 15 \text{ Hz} \). The gears at B and C drive machinery requiring power equal to \( 50 \text{ kW} \) and \( 25 \text{ kW} \), respectively. Compute the maximum shear stress and angle of twist in the shaft between the motor at A and the gear at C. Assume that \( G = 75 \text{ GPa} \).