Question

If a wire is stretched by 2% then the find the energy stored in the wire per unit volume

Answer 1

Answer:

Strain energy stored per unit volume is=Y$2\times10^{-4}$$j/m^{3}$

Explanation:

Since wire is streched by 2% so it contained strain energy as length is changing.

let a wire of original length is L and 2% of L is 0.02 L

We know that the strain energy stored per unit volume is=$\frac{Stress\times strain}{2}$

we know that young modulous Y=$\frac{stress}{strain}$

so,after cross multiply we get,

Stress=Y strain

So, strain energy stored per unit volume is=$\frac{strain^{2} }{2} \times Y$

we know that strain=$\frac{change\ in\ length }{original \ length}$

strain=$\frac{0.02L}{L}$

Strain=0.02

so,strain energy stored per unit olume is=$\frac{0.02^{2} }{2}$Y

                                                                    =Y$2\times10^{-4}$ $j/m^{3}$