G A 1000-W iron is left on the ironing board with its base exposed to the air at 23°C. The convection heat transfer coefficient between the base surface and the surrounding air is 20 W/m2·°C. If the base has an emissivity of 0.4 and a surface area of 0.02 m2, determine the temperature of the base of the iron.

The temperature of the base of the iron is 6,273 °C

Explanation:

P = heA(T2 - T1)

P is power rating of the iron = 1000 W

h is convective heat transfer coefficient between the base surface and the surrounding air = 20 W/m^2.°C

e is emissivity of the base of the iron = 0.4

A is surface area of the base of the iron = 0.02 m^2

T2 is temperature of the base of the iron

T1 is temperature of the surrounding air = 23 °C

T2 = (1000/20×0.4×0.02) + 23 = (1000/0.16) + 23 = 6,250 + 23 = 6,273 °C

oil flow is a highly convective flow compared to water flow at normal temperature and pressure.