Potential difference, electric potential energy and work

AI Thread Summary
To determine the work required to move charge q2 to infinity, it is necessary to calculate the change in electric potential energy (PEe). This involves finding the total potential energy of all four charges and subtracting the potential energy of the three charges without q2. The difference in these energies represents the work needed to move q2. An alternative and simpler approach is to calculate the electric potential at q2's position due to the three stationary charges. This method streamlines the process of finding the work required.
r_swayze
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Four charges are arranged at the corners of a rectangle as shown in the diagram. How much work needs to be done to move the charge q2 to infinity?

Since change in PEe = W, am I suppose to find total potential electric energy of the four charges and then subtract the total potential electric energy of the three charges without q2? Would the difference in the two potential electric energies be the work it takes to move q2 to infinity?
 

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r_swayze said:
Four charges are arranged at the corners of a rectangle as shown in the diagram. How much work needs to be done to move the charge q2 to infinity?

Since change in PEe = W, am I suppose to find total potential electric energy of the four charges and then subtract the total potential electric energy of the three charges without q2? Would the difference in the two potential electric energies be the work it takes to move q2 to infinity?

That would work, but it's easier to calculate the potential from the 3 non-moving charges at the position where q2 is.
 
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