Question

6
the diagram shows a dwarf planet with three moons, each with the same mass. which moon experiences the greatest gravitational force?
a moon 1 because gravity always acts in a downward direction
b moon 2 because it is closest to the dwarf planet
c moon 3 because it is furthest from the dwarf planet
d they all experience the same gravitational force

Explanation:

Newton's law of universal gravitation states gravitational force $F=G\frac{m_1m_2}{r^2}$, where $G$ is a constant, $m_1,m_2$ are masses, and $r$ is the distance between objects. Since all moons have equal mass and the dwarf planet's mass is constant, force is inversely proportional to $r^2$. The closer the moon (smaller $r$), the greater the gravitational force. Moon 2 is the closest, so it experiences the strongest gravitational pull.

Answer:

B. Moon 2 because it is closest to the dwarf planet