A wire suspended vertically from one of its ends is stretched by attaching a weight of $200\ N$ to the lower end. The weight stretches the wire by $1\ mm$. Then the elastic energy stored in the wire ……… $J$

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?

If the tension on a wire is removed at once, then

A wire is suspended by one end. At the other end a weight equivalent to $20\, N$ force is applied. If the increase in length is $1.0\, mm$, the increase in energy of the wire will be …….  $joule$

What is called elastic energy density ? Write its formula and dimensional formula.