Question

Consider three charges q1, q2, q3 each equal to q at the vertices of an equilateral triangle of side l. What is the force on a charge Q (with the same sign as q) placed at the centroid of the triangle?

Answer 1

$F=\frac{K{q}_{1}q}{x^2}⟶sameforallthree,\because distancebetweenchargesissame.$

As we can see, equal forces radially acting outward direction, canceling each components, therefore net force at center is zero