Question

Particles A and B carryon charge 3.0nC are at the base corners of an equilateral triangle 2.8 m on a side

What is the potential[relative to zero at infinity] at the apex of the triangle?

Answer 1

$$U=k\frac{q}{a}\\U=(9\cdot10^{9})\frac{(3\cdot10^{-9})}{2.8}=9.6\ V$$