$A$ $5 \, m$ long wire is fixed to the ceiling. $A$ weight of $10 \, kg$ is hung at the lower end and is $1 \, m$ above the floor. The wire is elongated by $1 \, mm$. The energy stored in the wire due to stretching is ......... $J$.

Determine the elastic potential energy stored in a stretched wire.

Two wires $A$ and $B$ having same length and material are stretched by the same force. Their diameters are in the ratio $1: 3$. The ratio of energy density of wire $A$ to that of wire $B$ when stretched,is (in $: 1$)

When a $8 \,m$ long wire is stretched by a load of $10 \,kg-wt$, it is elongated by $1.5 \,mm$. The energy stored in the wire in this process is $\left(g=10 \,ms^{-2}\right)$ (in $\,J$)

What is called elastic potential energy? Write its different formulas.

An $8\,m$ long copper wire and $4\,m$ long steel wire,each of cross-section $0.5\,cm^2$,are fastened end to end and stretched by a $500\,N$ force. The elastic potential energy of the system is (Young's modulus: $Y_{cu} = 1 \times 10^{11}\,N/m^2$,$Y_{steel} = 2 \times 10^{11}\,N/m^2$):