# Working with Point Charges - Potential Energy

Two point charges each of magnitude 2.00 Ã¬C are located on the x axis. One is at x = 1.00 m, and the other is at x = -1.00 m.

(a) Determine the electric potential on the y axis at y = 0.500 m.

(b) Calculate the change in electric

potential energy of the system as a third charge of

-3.00 Ã¬C is brought from infinitely far away

to a position on the y axis at y = 0.500 m.

https://brainmass.com/physics/work/point-charges-potential-energy-electric-14125

#### Solution Preview

Potential at y = 0.5m is the sum of the potentials of both the charges.

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<br>V(y=0.5) = Q/(4 pi * E_0)R + Q/(4 pi * E_0)R

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<br>where E_o = permitivity of free space and R is the distance from the charge to the point.

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<br>from the attached figure, we get, using Pythagorous theorem,

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<br>R = Sqrt[1^2 + 0.5^2] = sqrt[1.25] = 1.12m

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<br>Also we know, 1/(4 pi E_o) = k = 9 * 10^9

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<br>Thus, V at the ...

#### Solution Summary

Answer with proper explanations.