I need help determining what kind of charge is pushed into the direction of an electric field (positive / negative) -

I believe the answer is negative because the field always points from the positive charge to the negative charge and so the net force upon the negative charge is from the positive charge.

Is this correct?

edit: The correct answer is positive because the two positive charges repel each other into the field.

  • $\begingroup$ Do two positive charges attract each other or repel each other? $\endgroup$ – The Photon Feb 12 '17 at 20:56
  • $\begingroup$ They repel each other $\endgroup$ – hama Feb 12 '17 at 21:07
  • $\begingroup$ Therefore is the 2nd positive charge experiencing a force in the direction of or opposite to the field produced by the first positive charge? $\endgroup$ – The Photon Feb 12 '17 at 21:08
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    $\begingroup$ Now you've answered your question for yourself, so you can post your own answer. $\endgroup$ – The Photon Feb 12 '17 at 21:14
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    $\begingroup$ thank you . is it correct to say an electric field tells us the direction a positive charge would travel in that field? $\endgroup$ – hama Feb 12 '17 at 21:15

It is an established convention that the electric field points from positive to negative charges. The force on a charged particle with charge $q$ and velocity $\vec{v}$ is given by the Lorentz Force Law $$\vec{F}=q(\vec{E}+\vec{v}\times\vec{B})$$ with electric field $\vec{E}$ and magnetic field $\vec{B}$ (the names for these fields vary in literature, notation surprisingly does not). This accounts for positive and negative charge. The static electric field around a point charge $q$ in it's rest frame is given as $$\vec{E}(\vec{x})=\frac{q}{4\pi\epsilon_0}\frac{\vec{x}}{\|\vec{x}\|^3},$$ which also accounts for the sign of the charge. For more details refer to standard sources on electrostatics. This means that it is positive charges that are accelerated in the direction of the $\vec{E}$ field.


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