The amount of radiant power produced by the sun is approximately 3.9 x 1026 W. Assuming the sun to be a perfect blackbody sphere with a radius of 6.96 x 108 m, find its surface temperature (in kelvins).

2 answers

5797
The Radient power u of a black body is given by
u = sAT^4 known as Stefan-Boltzmann Law.

Here s is called Stefan Constant and its value is [math]5.67*10^{-8}W/m^2/K^4[/math]( sigma is used in place of s ), A is the sutface area of the black body and T is the absolute temprature of the black body.

[math]
T^4 = u/(sA) = 3.9*10^{26}/[5.67*10^{-8}*3.14*(6.96*10^8)^2]
[/math]

Find fourth root of this and you get T = 5800 K