A surface has α_{s} = 0.72 and ε = 0.6 and is at 350 K. G_{D} = 350 and G_{d} = 400 W/m^{2}; the direct beam makes 30° with the normal; sky at 280 K. Determine (a) the total solar energy incident, (b) the solar radiation absorbed, (c) the net radiation heat transfer to the surface (all answers in W/m^{2}).