고체역학 (Beer) — Stress and Strain—Axial Loading: Problem 2.9

2.9 A 9-kN tensile load will be applied to a 50-m length of steel wire with \( E = 200 \text{ GPa} \). Determine the smallest diameter wire that can be used, knowing that the normal stress must not exceed \( 150 \text{ MPa} \) and that the increase in length of the wire must not exceed \( 25 \text{ mm} \).