#### Answer

$W= \frac{360}{r^{2}}$

#### Work Step by Step

Since $W$ is inversely proportional to the square of $r$, we have:
$W= \frac{k}{r^{2}}$
We are given: $W=10$ and $r=6$, so we have:
$10= \frac{k}{6^{2}}$
$k=36*10=360$
So the equation is:
$W= \frac{360}{r^{2}}$