Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6*10-11 m^2/s and the diffusion flux is found to be 1.2*10-7 kg/(m^2*s). also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m^3. how far into the sheet from this high-pressure side will the concentration be 2kg/m^3? assume a linear concentration profile.