A 1200-W iron is left on the ironing board with its base exposed to the air....

  

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A 1200-W iron is left on the ironing board with its base exposed to the air. About 90 percent of the heat generated in the iron is dissipated through its base whose surface area is 150 cm, and the remaining 10 percent through other surfaces. Assuming the heat transfer from the surface to be uniform, determine (a) the amount of heat the iron dissipates during a 2-hour period, in kWh, (b) the heat flux on the surface of the iron base, in W/m2, and (c) the total cost of the electrical energy consumed during this 2-hour period. Take the unit cost of electricity to be $0.07/kWh. D 8cm Filament d = 0.5 mm L=5 cm A 1200-W iron is left on the ironing board with its base exposed to the air. About 90 percent of the heat generated in the iron is dissipated through its base whose surface area is 150 cm, and the remaining 10 percent through other surfaces. Assuming the heat transfer from the surface to be uniform, determine (a) the amount of heat the iron dissipates during a 2-hour period, in kWh, (b) the heat flux on the surface of the iron base, in W/m2, and (c) the total cost of the electrical energy consumed during this 2-hour period. Take the unit cost of electricity to be $0.07/kWh. D 8cm Filament d = 0.5 mm L=5 cm