Heat received by the Earth due to solar radiations is `1.35 KWm^(-2)`. It is also known that the temperature of the Earth’s crust increases `1^(@)C` for every 30 m of depth. The average thermal conductivity of the Earth’s crust is `K = 0.75 J (msK)^(-1)` and radius of the Earth is `R = 6400 km`.
(i) Calculate rate of heat loss by the Earth’s core due to conduction.
(ii) Assuming that the Earth is a perfect block body estimate the temperature of its surface.

Answer

(i) `1.29xx10^(13)W` (ii) 276 K