A sheet of blackened iron of area 0.50m2 is heated in a furnace to 927∘C and then exposed to a surroundings that are effectively at 0K so that loss of heat by other modes is negligible.
(i) Convert the given temperature of the sheet to kelvin.
(ii) Calculate the radiant power emitted by the sheet at this temperature.
(iii) If the temperature of the sheet is subsequently reduced to 627∘C, determine the new radiant power and find the percentage decrease in power compared to part (ii).