Answer
(a) $-2.2\times 10^4V$
(b) $-2.2\times 10^4V$
(c) $-1.5\times 10^4V$
Work Step by Step
(a) We know that
$V=\frac{kq}{r}$
We plug in the known values to obtain:
$V=\frac{8.99\times 10^9(-7.2\times 10^{-6})}{3.0}$
$V=-2.2\times 10^4V$
(b) We know that
$V=\frac{kq}{r}$
We plug in the known values to obtain:
$V=\frac{8.99\times 10^9(-7.2\times 10^{-6})}{3.0}$
$V=-2.2\times 10^4V$
(c) We know that
$V=\frac{kq}{r}$
We plug in the known values to obtain:
$V=\frac{8.99\times 10^9(-7.2\times 10^{-6})}{\sqrt{(3.0)^2+(-3.0)^2}}$
$V=-1.5\times 10^4V$