Astronomy
posted by Rebecca .
Show that Kepler's third law is consistent (approximately) for the orbits of the Mars
and Saturn. Show all your calculations and appropriate units.
P Mars = 690 days; a Mars = 2.3 x 108 km
P Saturn = 10,700 days; a Saturn = 1.4 x 109 km

Please place a ^ before your exponents.
You can prove Kepler's third law is obeyed in this case by showing that the ratio P^2/a^3 is the same for both planets.
You can use any units you want, as long as they are the same for both planets.
If you need a review of this subject, see
http://en.wikipedia.org/wiki/Kepler's_laws_of_planetary_motion
or many other easily Googled sites.