Three particles, two with mass m and one mass M, might be arranged in any of the four configurations known below. Rank the configurations according to the magnitude of the gravitational force on M, least to greatest.

Question

Quizplus · Accepted Answer

1) M and m are far apart, so the force between them is the weakest.
2) M and m are closer, so the force between them is stronger than in configuration 1.
3) In this case, all three particles are equidistant from each other, so the forces cancel out and there is no net force on M.
4) M is closest to the two particles with mass m, so the force on M is the greatest in this configuration.

Three Particles, Two with Mass M and One Mass M