고체역학 (Beer) — Stress and Strain—Axial Loading: Problem 2.6

2.6 A 60-m-long steel wire is subjected to a 6-kN tensile load. Knowing that \( E = 200 \text{ GPa} \) and that the length of the rod increases by \( 48 \text{ mm} \), determine (a) the smallest diameter that can be selected for the wire, (b) the corresponding normal stress.