A very thick slab of clay has an initial moisture content of $c_0=14wt\%.$ Air is passed over the top surface

to dry the clay. Assume a relative resistance of the gas at the surface of zero. The equilibrium moisture

content at the surface is constant at $c_1=3\mathrm{.}0wt\%.$ The diffusion of the moisture in the clay can be

approximated by a diffusivity of $D_{AB}=1\mathrm{.}29{10}^{-8}\frac{m^2}{s}.$ After $1\mathrm{.}0h$ of drying, calculate the concentration

of water at points $0\mathrm{.}005,0\mathrm{.}01,$ and $0\mathrm{.}02m$ below the surface. Assume that the clay is a semi$-$infinite solid

and that the Y value can be represented using concentrations of wt $\%$ rather than kmo$\frac{l}{m^3}.$ Plot the values

versus $x.$

Please do not use the error function.