Question

A -8.0nC charge and a +5nC charge are located on the x-axis at x=-1.0cm and x=+4.0cm respectively.

a) At what postion or positions, from - $\infty$ to + $\infty$ , on the x-axis is the electric field zero? (There may be more than one answer).

b)What is the electric potential at this (these) location? (There may be more than one answer).

Answer 1

First of all, determine the kind of questions the problem is doing to do, so you will know which equation to use. In this case:

$\vec{F}=K*\frac{q1*q2}{r^{2}}$

Where K is a constant $8.99\times 10^{9}$ , q1 and q2 are the charge and r is the distance. It is zera where the distance between the charge is reached one respect to the other. It is easy more than you think, use logic.