Two objects are confined by their mutual gravitational force but isolated from any other forces. Which of these moves at constant velocity?
A) their barycenter
B) the more massive object
C) the less massive object
D) None of these are correct.

Question

Quizplus · Accepted Answer

The barycenter, or center of mass, of a two-object system moves at a constant velocity if the system is isolated from external forces. This is because the internal forces (i.e., the gravitational forces between the two objects) do not affect the motion of the system's center of mass according to the conservation of momentum.

Two Objects Are Confined by Their Mutual Gravitational Force but Isolated