Two rectangular surfaces are perpendicular to each other with a common edge that measures 1.6 m. Surface one is 0.8 m wide, has an emissivity of 0.75, and is maintained at 450 K. Surface two is a blackbody that measures 1.2 m high and is maintained at 700 K. If the surrounding surfaces are taken to be at 290 K with an emissivity of 0.85, what is the net rate of radiative heat transfer between the two surfaces and between surface one and the surroundings