The carpenter builds an outer house wall having a layer of wood 3.2 cm thick on the outside and a layer of Styrofoam insulation 2.3 cm thick as inside the wall surface. The wood consists of a thermal conductivity of k = .080 W/m-K and the Styrofoam consists of a thermal conductivity of k = .010 W/ m-K. The interior surface temperature is 19.0 o C. and the exterior surface temperature is -10 o C.
Determine the temperature at the plane where the wood meets up the Styrofoam?