I currently learning about electrical potential energy and work. I am having a h

Question

I currently learning about electrical potential energy and work. I am having a hard time understanding some of the concepts. Are the statements I have composted below correct?

For a positive charge

-If an external force and the displacement are in opposite directions, the work done is negative. (because it gains PE)

I think my professor gave the example here of using your hand to push an object up in the air?

-If an external force and the displacement are in the same direction, the work done is positive. (because it looses PE)

For a negative charge:

-If the external force and the displacement are in the same direction, work done is positive. (Because the electron would normally want to travel opposite of the electric field, thus it takes work to move it in the same direction)

-If the external force and the displacement are in opposite directions, the work done is negative.

Is this correct? If not please explain!!

**UPDATE: I think I might have stated these incorrectly. It should read "If the electric field and..." not "If an external force..."

Explanation / Answer

Other than the correction that you have made yourself (electric field vs external force), your understanding seems to be clear.

To be further convinced, we would recommend you to try out 2-3 numerical questions (number problems) using a combination of a different/same direction of electric field, displacement, velocity etc and see if you are getting correct answers.

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