Consider a diffusion couple composed of two cobalt-iron alloys; one has a composition of 75 wt% Co-25 wt% Fe; the other alloy composition is 50 wt% Co-50 wt% Fe. If this couple is heated to a temperature of 800°C (1073 K) for 20,000 s, determine how far from the original interface into the 50 wt% Co-50 wt% Fe alloy the composition has increased to 52 wt%Co-48 wt% Fe. For the diffusion coefficient, assume values of 6.6 ( 10-6 m2/s and 247,000 J/mol, respectively, for the pre-exponential and activation energy?