Q $(3).$ A double window called thermopane is one in which two layers of glass are used separated by a layer of dry stagnant air. In a given window, each of the glass layers is $6\mathrm{.}35mm$ thick separated by a $6mm$ space of stagnant air. The thermal conductivity of the glass is $0\mathrm{.}869\frac{W}{m}*K$ and that of air is $0\mathrm{.}026$ over the temperature range used. For a temperature drop of $27\mathrm{.}8$ K over the system, calculate the heat loss for a window $0\mathrm{.}9m1\mathrm{.}8m.$