1. The problem statement, all variables and given/known data A +15μC point charge Q1 is at a distance of 20mm from a +10μC charge Q2. Explain why there is a point along the line between the two charges at which the electric field strength is zero. After this, calculate the distance from this point to Q1 and Q2. 3. The attempt at a solution First of all, I know that both charges are the same, so their electric fields act in repelling each other. I'm going to guess that the reason why theres a point in which electric field strength is zero, is because at this point, both charge's respectively fields cancel each other out in equal measures, leaving a net field strength of zero. Is more explanation okay? On the second part of the question where I'm asked to calculate the distance of this point from Q1 and Q2, I'm really stuck. I know the equation for finding the electric field strength of a charge is: E = Q/(4*pi*e*r^2) where, E = electric field strength, e = epsilon nought, r = distance between the charge and P, Q = charge.