In a production facility, 1.6-in-thick 2ft2ft square brass plates (=532.5lbm/ft3 and cp=0.091Btu/bmF) that are initially at a uniform temperature of 75F are heated by passing them through an oven at 1500F at a rate of 400 per minute. If the plates remain in the oven until their average temperature rises to 900F, determine the rate of heat transfer to the plates in the furnace. The rate of heat transfer to the plates in the furnace is Btu/s