Consider a rectangular sheet of solid material of length l=9 cm and width d =4 cm. The coefficient of linear expansion is α=3.1 × 10^-5 K^-1 at room…

Consider a rectangular sheet of solid material of length $\displaystyle l=9 \mathrm{~cm}$ and width $\displaystyle \mathrm{d}=4 \mathrm{~cm}$. The coefficient of linear expansion is $\displaystyle \alpha=3.1 \times 10^{-5} \mathrm{~K}^{-1}$ at room temperature and one atmospheric pressure. The mass of sheet $\displaystyle \mathrm{m}=0.1 \mathrm{~kg}$ and the specific heat capacity $\displaystyle C_v=900 \mathrm{~J} \mathrm{~kg}^{-1} \mathrm{~K}^{-1}$. If the amount of heat supplied to the material is $\displaystyle 8.1 \times 10^2 \mathrm{~J}$ then change in area of the rectangular sheet is :