A carpenter builds an outer house wall with a layer of wood 2.0 cm thick on the outside and a layer of an insulation 3.5 cm thick as the inside wall surface. The wood has K=0.08 W/m⋅K and the insulation has K=0.01 W/m⋅K . The interior surface temperature is 19∘C and the exterior surface temperature is −10∘C .
(a) What is the temperature at the plane where the wood meets the insulation?
(b) What is the rate of heat flow per square metre through this wall?