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## Homework Statement

"Let there be two point charges ##q_1=3.5μC## and ##q_2=-3.5μC## located at ##(0,0.3 m)## and ##(0,-0.3 m)## respectively. What force do these two charges exert on a test charge ##Q=4.5μC## at ##(0.4 m,0)##?"

*title should read "due to two point charges"* <Moderator's note: title edited>

## Homework Equations

## The Attempt at a Solution

First off, ##∑F_x=0## because the two point charges cancel each other out in the x-direction. Now I calculate ##∑F_y=2F_y##.

##F_y=k\frac{q_1⋅Q}{y^2}=(9.0N_{10^9}⋅m^2⋅C^{-2})(\frac{3.5μC⋅4.5μC}{(0.3m)^2})##

##F_y=(9.0N_{10^{3}}⋅m^2⋅C^{-2})(\frac{15.75C^2}{0.09m^2})=1575000N##

##∑F_y=3200000N##

I am not sure what I'm doing wrong, here.

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