Fresh snow absorbs 80 percent of the incident solar radiation with wavelengths shorter than (lambda)1 =0.4 µm, 10 percent of the radiation between (lambda)1 and (lambda)2 = 1 µm, and 100 percent of the radiation with wavelengths longer than (lambda)2. The sun's surface is approximated adequately by a black surface with the temperature Tsun = 5800K. Determine a) the fraction of the total incident solar radiation that is absorbed by the fresh snow, and b) if convection and re-radiation are neglected and if the snow is at 0C, the rate of melting per unit m^2.