Two planets travel in circular orbits about a star.The period of planet A is T,while that of planet B is 3T.What is the ratio of the orbital radii,R_A/R_B? A) 0.33 B) 0.19 C) 0.48 D) 0.69

Question

Quizplus · Accepted Answer

The ratio of the orbital radius is given by the square root of the ratio of the periods, i.e., R_A/R_B = √(TB/TA) = √(3T/T) = √3 = 1.732 Therefore, R_A/R_B ≈ 0.48, so the best choice is C.

Two Planets Travel in Circular Orbits About a Star