1. A large opaque plate has a top surface temperature Ts = 150.1 ◦C and is insulated on the bottom side. The top of the plate emits E" = 1090 W m2 and is exposed to air T[infinity] = 195.45◦C with a convective heat transfer coefficient h = 15 W m2·K . Incident to the plate is irradiation G" = 2000 W m2 , of which 1200 W m2 is reflected. (a) Determine the emissivity, absorptivity, reflectivity, and radiosity (in W m2 ) of the plate. (b) Does the plate behave as a gray surface? (c) Determine the net heat flux q 00 (in W m2 ). Specify if this is into or out of the plate. Answer : q 00 net = 390 W m2