The surface temperature of the sun is `T_(0)` and it is at average distance `d` from a planet. The radius of the sun is `R`. The temperature at which planet radiates the energy is

The surface temperature of the sun is 'T'K and the solar constant for a plte is 's' . The sun subtends an angle theta at the planet. Then,

A planet of radius r_(0) is at a distance r from the sun (r gtgt r_(0)) . The sun has radius R. Temperature of the planet is T_(0) , and that of the surface of the sun is T_(s) . Calculate the temperature of another planet whose radius is 2r_(0) and which is at a distance 2r from the sun. Assume that the sun and the planets are black bodies.

In the previous problem, if theta is the angle sbtended by the Sun at the planet, then temperature at which planet radiates energy is proportional to

The period T and mean distance R of a planet from the sun are related by

If r denotes the mean distance of a planet from the sun and T is the time period of planet, then