Question

Given the equation P2 = A3, what is the orbital period, in years, for the planet Saturn? (Saturn is located 9.5 AU from the sun.) 5 years 29 years 229 years 500 years

Answer 1

The correct answer is 29 years.

In fact, the equation (Kepler's third law) says
$P^2 = A^2$
where P is the period in years, and A is the distance of Saturn from the Sun, expressed in A.U. We know this distance, $A=9.5 A.U$, so we can find the period of Saturn P:
$P= \sqrt{A^3}= \sqrt{(9.5 A.U.)^3}=29 years$