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Assume we have apositive source charge And near it a positive test charge And we moved this test charge away from the source charge to a certain point, will the external work be positive or negative

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  • $\begingroup$ Hint: work done along path $C$ is given by $W = \int_{C} \vec{F} \cdot d\vec{s}$. In your case $\vec{F}$ is given by Coulomb's law, and $d\vec{s}$ is the infinitesimal displacement. $\endgroup$ – K_inverse Sep 10 '18 at 1:01
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Think about it this way: that positive charge should naturally repel. When it gets to its location after being allowed to repel, it will have kinetic energy. You therefore have to do negative work to get it to that position and have it be stationary by taking away its kinetic energy.

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  • $\begingroup$ Will it stop at the point i want $\endgroup$ – Ahmad Eldesokey Sep 10 '18 at 23:27

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