A small sphere (emissivity = .9, radius = r1) is located at the center of a spherical asbestos shell (thickness = 1cm, outer radius = r2). The thickness of the shell is small compared to the inner and outer radii of the shell. The temperature of the small sphere is 800 C, while the temperature of the inner surface of the shell is 600 C, both temperatures remaining constant. Assuming that r2/r1 = 10 and ignoring any air inside the shell, Discover the temperature of the outer surface of the shell.