State the universal law of gravitation. How is the force between two bodies affected if the distance between them is tripled?

(N/A) The universal law of gravitation states that every object in the universe attracts every other object with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
Mathematically,$F = G \frac{m_1 m_2}{r^2}$,where $G$ is the universal gravitational constant.
If the distance $r$ is tripled,the new distance becomes $r' = 3r$.
The new force $F'$ will be $F' = G \frac{m_1 m_2}{(3r)^2} = G \frac{m_1 m_2}{9r^2} = \frac{1}{9} F$.
Therefore,the force becomes $\frac{1}{9}$ times the original force.