The area of cross-section of a railway track is $0.01 \mathrm{~m}^2$. the temperature variation is $10^{\circ} \mathrm{C}$. Coefficient of linear expansion of material of track is $10^{-5} /{ }^{\circ} \mathrm{C}$. The energy stored per meter in the track is $\_\_\_\_$ $\mathrm{J} / \mathrm{m}$.
(Young's modulus of material of track is $10^{11} \mathrm{Nm}^{-2}$ )