# A steel rod of cross-sectional area

Question:

A steel rod of cross-sectional area $4 \mathrm{~cm}^{2}$ and length $2 \mathrm{~m}$ shrinks by $0.1 \mathrm{~cm}$ as the temperature decreases in night. If the rod is clamped at both ends during the day hours, find the tension developed in it during night hours. Young's modulus of steel = $1.9 \times 10^{11} \mathrm{~N} / \mathrm{m} 2$.

Solution: