If we think about two rocks of equal mass on the Moon, one on the near side and one on the far side, then we can think of the tidal force as the difference between the gravitational force by Earth on the near-side rock and the gravitational force by Earth on the far-side rock. How quickly does this tidal force decrease with increasing distance from Earth?

Question

Quizplus · Accepted Answer

The tidal force is the difference between the gravitational force on the near side and the far side of the rock. The gravitational force is proportional to 1/r^2, so the tidal force is proportional to 1/r^3.

If We Think About Two Rocks of Equal Mass on the Moon