Find the electric potential energy

[Fatima Hasan]

Homework Statement

Homework Equations

$V= \frac {kq}{r}$
$V= \frac {U}{q}$

The Attempt at a Solution

$V= \frac {kq}{r}$ = 9*10⁹*-5*10^-9 /0.1= -450 V
$U= \frac {V}{q}$ = -450 * -2*10^-9 = 900nJ
Is my answer correct ?

 

[gneill]

Homework Statement

View attachment 223345

Homework Equations

$V= \frac {kq}{r}$
$V= \frac {U}{q}$

The Attempt at a Solution

$V= \frac {kq}{r}$ = 9*10⁹*-5*10^-9 /0.1= -450 V
$U= \frac {V}{q}$ = -450 * -2*10^-9 = 900nJ
Is my answer correct ?

Yes, but the form of your second relevant equation in your last line of calculations is not. Fortunately you did the actual calculation correctly anyways