When a block of mass $M$ is suspended by a long wire of length $L$, the length of the wire become $(L+l) .$ The elastic potential energy stoped in the extended wire is :

If a spring extends by $x$ on loading, then the energy stored by the spring is (if $T$ is tension in the spring and $k$ is spring constant)

Weight is suspended to the end of elastic spring its increased length depends upon what ?

Two wires of the same material (Young's modulus  $Y$ ) and same length $L$  but radii  $R$  and  $2R$  respectively are joined end to end and a weight  $W$  is suspended from the combination as shown in the figure. The elastic potential energy in the system is

One end of a slack wire (Young's modulus $Y$, length $L$ and cross-sectional area $A$ ) is clamped to a rigid wall and the other end to a block (mass $m$ ), which rests on a smooth horizontal plane. The block is set in motion with a speed $v$. What is the maximum distance, then the block will travel after the wire becomes taut?

The work done in increasing the length of a $1$ $metre$ long wire of cross-section area $1\, mm^2$ through $1\, mm$ will be ....... $J$ $(Y = 2\times10^{11}\, Nm^{-2})$