Calculating Period of Mars Using Kepler's Law: Appendix C

[Collegestudent5]

The mean distance of Mars from the Sun is 1.52 time that of Earth from the Sun. From Kepler's law of periods, calculate the number of years required for Mars to make one revolution around the Sun; compare your answer with the value given in Appendix C.


Kepler's Law of periods is: T^2=[4 x (pi)^2 x r^3]/[GM]

Appendix C says the Period=1.88 y

I have no idea how to begin this problem. Please help set me in the right direction.

 

[sagebum]

http://hyperphysics.phy-astr.gsu.edu/hbase/kepler.html This site says you can reduce the equation down to T^2 = a^3, but I don't know how it works. Try reducing the equation to the simpler form