Stainless steel ball bearings (density=8085 kg/m^3 and Cp=0.480 kj/kg* C) having a diameter of 1. cm are to be quenched in water at a rate of 800 per min. The balls leave the oven at a uniform temp of 900C and are exposed to air at 25C for a while before they are dropped in the water. If the temp of the balls drop to 850C prior to quenching, determine the rate of hear transfer from the balls to the air.