The force of gravity varies inversely with the square of the distance between given planet and the sun because
$$F_g=\frac{GMm}{r^2}$$

Question

The force of gravity varies inversely with the square of the distance between given planet and the sun because 
$$F_g=\frac{GMm}{r^2}$$

anonymous · Answer

@Jemurray3

anonymous · Answer

what is the "varies" symbol again?

$$F\;\;\; \frac 1{r^2}$$

anonymous · Answer

$$ \propto $$
\propto    which is short for "proportional to"

anonymous · Answer

"varies inversely" means proportional to  $\frac 1 r$ correct?
$\frac 1 {r^2}$

anonymous · Answer

if A varies inversely with B, you say 
$$ A \propto \frac{1}{B} $$
here, you're saying "The force (A) is varies inversely with the square of the distance (B)".  So A is the force, and B is r^2.
$$ F \propto \frac{1}{r^2} $$