Two asteroids, of the same mass, have a gravitational potential energy U. If a third asteroid, of the same mass, moves toward them, to a position such that the distances between the three asteroids are the same, the gravitational potential energy of the system will have changed by
A) 4U.
B) U.
C) 2U.
D) 3U.
E) 5U.

Question

Quizplus · Accepted Answer

The initial gravitational potential energy (U) is between two asteroids. When a third asteroid of the same mass is added at an equal distance from the other two, it creates two additional unique pairs, each with a gravitational potential energy of U (since the masses and distances are the same). Therefore, the total gravitational potential energy becomes 3U, indicating an increase of 2U from the original state.

Two Asteroids, of the Same Mass, Have a Gravitational Potential