Question

What is the potential energy if a +4 nC charge moves from infinity to point A, 5 cm away from a +3 μC charge?

Answer 1

Potential energy:

$U=\frac{kQq}{r}$

$U=\frac{(9×10^9\frac{Nm^2}{C^2})(+3×10^{-6}C)(+4×10^{-9}C}{(0.05m)}$