# Kepler’s Third Law Kepler’s Third Law of planetary motionstates that the square of the period T of a planet (the time ittakes for the planet to make a complete revolution about thesun) is directly proportional to the cube of its average distance d from the sun.(a) Express Kepler’s Third Law as an equation.(b) Find the constant of proportionality by using the fact thatfor our planet the period is about 365 days and the average distance is about 93 million miles.(c) The planet Neptune is about 2.79  109mi from the sun.Find the period of Neptune.

Question

Kepler’s Third Law Kepler’s Third Law of planetary motion
states that the square of the period T of a planet (the time it
takes for the planet to make a complete revolution about the
sun) is directly proportional to the cube of its average distance d from the sun.
(a) Express Kepler’s Third Law as an equation.
(b) Find the constant of proportionality by using the fact that
for our planet the period is about 365 days and the average distance is about 93 million miles.
(c) The planet Neptune is about 2.79  109
mi from the sun.
Find the period of Neptune.