Electric potential energy formula deltaPE=-qE(deltaX)

[Mohd Taqi]

About the formula deltaPE=-qE(deltaX) .. Whats the negative sign means ?

 

[jbriggs444]

If the E field points to the right and the charge moves to the right, the field is providing energy to the charge. To conserve energy, this means that less potential energy remains. So the delta PE is negative.

 

[Mohd Taqi]

So do you mean as the charge moves from left to the right its PE is decreasing ? Btw, the charge is positive or negative ?

 

[jbriggs444]

I was assuming a positive charge. That keeps the number of negations we have to worry about to a minimum.

Yes, if the E field points rightward and a positive charge moves rightward, the potential energy of that charge is reduced.

 

[Mohd Taqi]

Oh okay .. I finally understand it. Thank you ..