Radiation from the sun
1. The sun's radiation can be approximated by a black body. The surface temperature of the sun is about 5800 K and its radius is 0.7 × 109 m. The distance from the earth to the sun is 1.5 × 1011 m. The radius of the earth is 6.4 × 106 m. Estimate the average temperature of the earth from this information. Be careful to state your assumptions and approximations explicitly.
2. From the nature of your assumptions in the previous question (rather than your knowledge of the actual temperature), would you expect a more accurate calculation with this data to give a higher or lower answer? Explain your reasons clearly to obtain one bonus point per reason.