$.$ At relatively low level of engineering stress $($ $)$ and engineering strain $($$=$L$/$Lo$),$ the stress$-$strain relationship is given by Hooke$$s law $($ $=$ E $,.$ E$=$ the modulus of elasticity or Young$$s modulus$).$ The Young$$s Modulus of copper$=1\mathrm{.}10$ x $1011$ Pascal. Calculate the elongation of $305$mm copper under $2\mathrm{.}76$ x $108$ Pascal