Two thin aluminum plates, the first polished and the second painted black, are placed horizontally outdoors, where they are cooled by air at 10?C. The heat transfer coefficient is 5 W/m2K on both the top and the bottom.
The top is irradiated with 750 W/m2 and it radiates to the sky at 250 K. The earth below the plates is black at 10?C. Find the equilibrium temperature of each plate.