Question

A hot water radiator at 310k temperature radiates thermal radiates like a black body. Its total surface area is 1.6 m^2. Find the thermal power radiated by it.

Answer 1

Stefan’s Law of Radiation (black body):

$E = σAT^4$

A is the surface area, m²

T is the surface temperature of the black body, K

Stefan’s constant $\sigma = 5.670 \times 10^{−8} \frac {W}{( m^2 ⋅ K^4 )}$

$A = 1.6 m^2$

$T = 310 K$

$E = 5.670 \times 10^{−8}\times1.6\times 310^4 = 5.670 \times 10^{−8}\times 1.6\times 9.235 \times 10^{9} = 837.8 W$

Answer: 837.8 W