Gravitations! need help with formula

[Sirsh]

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[rl.bhat]

But when i substitute the values into the equation they dont both equal the same amount on each sides. help me please!
That has to be. What is your problem? Post a specific problem where you want to apply this relationship. Mainly this relation is used to compare the distances of two planets when their periods of revolution is known.

 

[Sirsh]

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 shouldnt both sides of the equations equal the same value when their values are substituted into the equation?

 

[Sirsh]

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