A flat silicon wafer 15 cm in diameter (surface area 176.7 cm²) is removed from an annealing furnace and laid flat-side down onto a flat insulating surface. It is then allowed to cool down to room temperature, which is maintained at a constant 20°C (293 K). Initially, the silicon wafer is at 1020°C. The heat-transfer coefficient for the air over the exposed flat surface of the silicon wafer is 20 W/m²·K. What is the heat-transfer rate, in Watts, from the wafer surface to the surrounding air after 330 seconds? Thermophysical properties of silicon at the temperature range of interest are: