Question

let the period of revolution of a Planet at a distance R from a star be T.prove that if it was at a distance of 2R from the star, its period of revolution will be √8T.

Answer 1

According to the Kepler’s third law

T^2=R^3

Here T is the period of revolution and R is the distance of planet from star.

Let t be the period of revolution of a planet which was at a distance 2R from star.

I hope this will help you