2. Using your knowledge of circular motion and gravitation, derive an equation that shows the relationship between the orbital period (T) of a planet in a circular orbit and the radius of the planetary orbit (R).
4pi^2/GM = T^2/r^3
39.478/ 3.247E+14 = 1.08E+11/ 7.474E+21
1.215E-13 = 1.445E-11
I'm thought that the formula i had rearranged would have answered this question, except shouldn't both sides of the equations equal the same value when their values are substituted into the equation?