(6) Consider a 20-cm-thick large concrete plane wall (k = 0.77 W/m K) subjected to convection on both sides with T1= 27C and h =5 W/m K on the inside, and T2 = 8C and h = 12 W/m K on the outside. Assuming constant thermal conductivity with no heat generation and negligible radiation, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the wall, (b) obtain a relation for the variation of temperature in the wall by solving the differential equation, and (c) evaluate the temperatures at the inner and outer surfaces of the wall