If Young's modulus of iron is $2 \times 10^{11} \ N/m^2$ and the interatomic spacing between two molecules is $3 \times 10^{-10} \ m$,the interatomic force constant is ......... $N/m$.

Why are springs made of steel instead of copper?

Two wires of the same length and material are stretched by the same force. If their masses are in the ratio $3:4$,then the ratio of their elongations is

The following four wires are made of the same material. Which one will have the largest elongation when subjected to the same tension?

$A$ metal rod of length $L$ and cross-sectional area $A$ is heated through $T^{\circ} C$. What is the force required to prevent the expansion of the rod lengthwise? $[Y=$ Young's modulus of the material of rod,$\alpha=$ coefficient of linear expansion $]$

$A$ rubber cord $10\, m$ long is suspended vertically. How much does it stretch under its own weight? (Density of rubber is $1500\, kg/m^3$,$Y = 5 \times 10^8\, N/m^2$,$g = 10\, m/s^2$)