A large positively charged object with charge $q_{+}=4\mathrm{.}25C$ is brought near a negatively charged plastic ball suspended from a

string of negligible mass. The suspended ball has a charge of $q_{-}=-55\mathrm{.}3nC$ and a mass of $13\mathrm{.}5g.$

What is the angle $$ that the string makes with the vertical

when the positively charged object is $21\mathrm{.}5cm$ from the

$=$

suspended ball?

The positively charged object is at the same height as the

suspended ball.