Two objects are in circular orbits of different radii around the Sun. Which object has the lowest orbital speed?
A) The one closest to the Sun.
B) The one farthest from the Sun.
C) Once in orbit around the Sun, all objects have the same orbital speed regardless of distance from the Sun. It is the greater radius and greater resulting circumference that causes the object farther from the Sun to take longer to complete an orbit.
D) This cannot be found without knowing the relative masses of the objects.

Question

Quizplus · Accepted Answer

The object farthest from the Sun has the lowest orbital speed due to Kepler's laws of planetary motion, specifically the law of areas, which implies that objects farther from the Sun move slower in their orbits.

Two Objects Are in Circular Orbits of Different Radii Around