Kepler's Third Law of planetary motion states that the square ofthe period T of a planet (the time it takes for the planetto make a complete revolution about the sun) is directlyproportional to the cube of its average distance d fromthe sun.
(a) Express Kepler's Third Law as anequation.
T =
(b) Find the constant of proportionality by using the fact that forour planet the period is about 365 days and the averagedistance is about 93 million miles. (Use 93 instead of93,000,000.)
k = 
(c) The planet Neptune is about 2.79×109 mifrom the sun. Find the period of Neptune.