Question

.Calculate the rate of heat energy emitted by 65 m² of a polished iron surface with an emissivity of 0.06 and a surface temperature of 40*C

Answer 1

According to Stephan-Boltzman law:

$$\frac Qt=\sigma eA(T_2^4-T_1^4),$$

where

$\sigma$ - Stephan-Boltzmann constant,

e - emissivity,

A - area, m²

T₂ - surface temperature, K,

T₁ - temperature of the environment, 300 K.

$$\frac Qt=5.67·10^{-8}·0.06·65(313^4-300^4)=331\text{ W}.$$