(Solved): Find the heat transfer per unit area through the composite wall. Assume one-dimensional heat flow. ...

Find the heat transfer per unit area through the composite wall. Assume one-dimensional heat flow. \\[ \\begin{array}{l} k_{A}=150 \\mathrm{~W} / \\mathrm{m}^{\\circ} \\mathrm{C} \\\\ k_{B}=30 \\mathrm{~W} / \\mathrm{m}^{\\circ} \\mathrm{C} \\\\ k_{C}=50 \\mathrm{~W} / \\mathrm{m}^{\\circ} \\mathrm{C} \\\\ k_{D}=70 \\mathrm{~W} / \\mathrm{m}^{\\circ} \\mathrm{C} \\\\ A_{B}=A_{D} \\end{array} \\]