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## Homework Statement

## Homework Equations

## The Attempt at a Solution

**the electric field that Q is subjected to :**E = q/(4piεor^2) ... i think

**force that Q is subjected to :**

i substitute k here for 1/(4piεo) to get F = (kQq)/(r^2)... i know the capital Q is supposed to be there, but don't know how it is fitted in algebraically.

then its just dotted into some angles for the vector math

r = √ (x^2 + a^2)

Force exerted on Q, F = (kQ|q|)/(x^2 + a^2) ( cosϑ i - sinϑ j ) + (kQ|-q|)/(x^2 + a^2) ( - cosϑ i - sinϑ j )

= -2(kQ|q|)/(x^2 + a^2) sin j = -2(kQ|q|)/(x^2 + a^2) * (a/√ (x^2 + a^2) )

**work done in moving Q from (0,0) to (x,0)**

not sure how to tackle this one.. I have an idea though W = ∫ F . dr or F . Δ r

can i just multiply my above result for the force into the change in x from the origin to where the point sits at (x,0)

something like (F . 0) + (F . x) ?

could someone give me a hand with what my start, i know the math looks a little shaky, but i think what i have up is very close to correct for the first two parts of the question.

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