# Question #f3655

Jan 10, 2018

earth is in thermal equilibrium from a lot of years. It receives thermal energy from the sun by means of the radiation $\frac{Q}{t} = A \epsilon \sigma \left({T}_{1}^{4} - {T}_{2}^{4}\right)$
Q/t is the heat transmitted in the unit of time, A the surface of earth $\epsilon$ an absorbtion coefficient, $\sigma$ is Stefan's constant, T1 the sun temperature (in K degree) and T2 is the earth temperature.