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## Homework Statement

Given two charged particles:

1) 5x10^-9 C, (-.03 m, 0 m)

2) -20x10^-9 C (.04 m, .02 m)

find the electric field at the origin.

## Homework Equations

F = (kQq)/r^2

E = (kQ)/r^2

## The Attempt at a Solution

So I know since 1)'s charge is plus, its field vector is

[itex] ( (8.99x10^{-9}) (Q) ) / (.03)^2 [/itex] i hat, meaning its going to the right

I use arctan to find the angle between the origin and 2), it is 26.57 deg, and pathagorean theorem to find the distance r to be .045m

since 2) is - charged, its electric field is going away from the origin at 26.57 degrees.

[itex] ( (8.99x10^{-9}) (Q) ) / (.045)^2 [/itex]

Now I can break it down in to components, but how am I suppose to find Q, the charge of the origin?

If they gave me a value for the electric force between the origin and one of the particles I can find Q, but with this information I dont see any way I can find it?

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