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## Homework Statement

I have a question that I can't figure out.

Question is

"Two charges are fixed in location: charge q1 = +8e is located at the origin and charge q2 = -2e is located on the x-axis at x = L. At what point (other than infinitely away) can a proton (a unit positive charge e) be placed so that it has net zero force acting on it"

## Homework Equations

F = (kq1q2)/r^2

## The Attempt at a Solution

I have got that q1 is (8e x 1.602 x 10^-19C) = 1.282 x 10^-18C

and q 2 is (-2e x 1.602 x 10^-19C) = 3.204 x 10^-19C

k = 8.988 x 10^9Nm^2C^-2

Am assuming that a unit positive charge is 1C (although did originally think it could possibly be 1.602 x 10^-19C, the size of one proton, would that be correct?)

When pumping in these values into the formula, and rearranging the formula so F = 0N, this will obviously give a distance of 0 which would be incorrect, also not sure how the added proton fits in anywhere. Have spent a few hours trying to find another way but am a bit stuck. Thanks in advance for any help =)