#$2.$ A copper$-$nickel couple is formed as shown in below. After a $520-$h heat treatment at $1020C,$ the concentration of $Ni$ is $3\mathrm{.}0wt\%$ at the $1\mathrm{.}0-mm$ position within the copper. respectively. pts$)$At what temperature should the rkcouple be heated to produce this same concentration $($i$.$e$.,3\mathrm{.}0Wt\%Ni)$ at a $2\mathrm{.}0-mm$ position after $560-$h$?$ The pre$-$exponential and activation energy for the diffusion of $Ni$ in $Cu$ are $2\mathrm{.}7{10}^{-4}\frac{m^2}{s}$ and $236,000\frac{J}{m}ol,$