Carbon steel balls (density 7833 kg/m^(3) and specific heat of 0.465 kJ/kg-C) 8 mm in diameter are annealed by heating them first to 900oC in a furnace, and then allowing them to cool slowly to 100oC in ambient air at 35oC. If 2500 balls are to be annealed per hour, determine the total rate of heat transfer from the balls to the ambient air (kJ/hour).