Apoint of charge 4.9 μc is placed at the origin (x1 = 0) of a coordinate system, and another charge of -1.1 μc is placed on the x-axis at x2 = 0.28 m. a) where on the x-axis can a third charge be placed in meters so that the net force on it is zero?
b) what if both charges are positive; that is, what if the second charge is 1.9 μc?

a)The third charge is placed at a distance of r=0.253 m from the charge of on right side of it

b) The third charge is placed at a distance of r=0.1762 m from the charge of magnitude on its right side on x axis.

Explanation:

Given:

a)Let the The third charge is placed at a distance of r m from the charge of on right side of it.  When one charge is positive and other charge is negative and net force on third charge is zero

b) If both charges are positive

Let The third charge is placed at a distance of r from the charge of magnitude on its right side on x axis. then

double the distance = divide strength by 4