1. The problem statement, all variables and given/known data I've been failing to find examples dealing with "longitudinal" thermal conductivity and how two objects in contact with each other would affect the heat flow compared to not being in contact at all. Problem: Given the following information, determine the thermal energy at 1 meter from the heat source for material X for the two cases 1) Where material X is not contact with material Y 2) Where material X and Y are in contact as shown. For both cases, first assume materials are in vacuum, then assume there are in ambient air at STP (273 K). 2. Relevant equations Thermal Conductivity X: 2,000 W/(m K) Y: 50 W/(m K) d1 = 0.00001 m d2 = 1 m Heat Source q = 100 W Heat Transfer Coefficient Air: 10 W/(m^2 K) 3. The attempt at a solution What I am struggling with is whether the conduction between X and Y would essentially "shorten" the conduction of material X itself. I am also unsure if thermal radiation would come into play. Any help is appreciated!