4. The sun can be approximated as a spherical black body with a surface temperature of 5762 K. The irradiation from the sun as measured by a satellite in earth orbit is 1353W/m². The distance from the earth to the sun is approximately 1.5 x 10¹¹ m. Assuming that the sun radiates evenly in all directions perfectly (like a black surface), estimate the diameter of the sun. Compare your answer with one listed by a reputable source. (10 pts)