Physics

Problem

The earth receives at its surface radiation from the sun at the rate of

1400 \text{ W/m}^2

. The distance of the centre of the sun from the surface of the earth is

1.5 \times 10^{11} \text{ m}

and the radius of the sun is

7 \times 10^8 \text{ m}

. Treating the sun as a black body, it follows from the above data that its surface temperature is.....K.