Two parallel black rectangular surfaces, whose back sides are insulated, are oriented parallel to each other with a spacing of 5 m. They measure 5 m by 10 m. The surroundings are black at 0 K. The two surfaces are maintained at 200 and 100 K, respectively. Determine the following:
a. The net radiant heat transfer between the two surfaces
b. The net heat supplied to each surface
c. The net heat transfer between each surface and the surroundings