Which of the following describes the r in Kepler’s Third Law?

Question

A. The orbital radius of the orbiting object when it is closest to the sun.

B. The period of the orbiting object in units of time.

C. The orbital radius of the orbiting object when it is farthest away from the sun.

D. The average orbital radius of the orbiting object.

Answer 1

The correct answer is:

D. The average orbital radius of the orbiting object.

Kepler's Third Law states that the square of the period of orbit (T^2) of a planet is directly proportional to the cube of the semi-major axis of its orbit (r^3). In this context, "r" refers to the average distance from the central body (such as the Sun) to the orbiting object, which is often represented by the semi-major axis of the elliptical orbit.