The diffusion coefficients for iron in

nickel are given at two temperatures:

a$.$ Determine the values of $D_0$ and the

activation energy $Q_d.$

b$.$ What is the magnitude of $D$ at $1100C?$

c$.$ At what temperature will the diffusion

will have a $D$ value of $5\mathrm{.}5{10}^{-15}\frac{m^2}{s}?$