What happens to an electron in the electric field

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Discussion Overview

The discussion revolves around the behavior of an electron in a uniform electric field, particularly focusing on the changes in kinetic and potential energy as the electron moves towards a positive plate. Participants explore concepts related to electric fields, forces on charged particles, and energy transformations, with varying levels of understanding and clarity.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant suggests that the electron loses kinetic energy while moving towards the positive plate, implying it does work against the electric field.
  • Another participant counters that the electron gains kinetic energy as it moves towards the positive plate, as it is attracted to the positive charge, indicating that work is done on the electron.
  • There is a discussion about the direction of the electric field, with some participants asserting that the field direction is from positive to negative, while others clarify that the electron, being negatively charged, is attracted to the positive plate.
  • A participant mentions the formula for electric force (F=qE) and suggests that the negative charge of the electron results in a force acting in the direction of the electric field.
  • Another participant notes that as the electron approaches the positive plate, its kinetic energy increases, correlating with the decrease in electrostatic potential energy.
  • A participant reflects on their learning style, expressing a preference for visualizing concepts before moving to mathematical formulations, and shares a personal anecdote related to the topic.

Areas of Agreement / Disagreement

Participants express differing views on whether the electron does work against the electric field or gains kinetic energy as it moves towards the positive plate. There is no consensus on the interpretation of energy changes, and the discussion remains unresolved regarding the understanding of work done on the electron.

Contextual Notes

Some participants indicate a need for stronger foundational knowledge in physics concepts, which may affect their understanding of the discussion. The conversation includes varying levels of clarity and confidence in the explanations provided.

hikarigenzo
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Hi,im new here. Can you explain to me what happens to the kinetic energy of an electron when it is accelerated in a uniform electric field? My guess is it will go to the positive plate and loses kinetic energy because it isdoing work against the field. Can anyone clarify this?

Thanks
 
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Firstly, welcome.

Why do you think that it is doing work against the field? Negative charge moving up potential is a decrease in potential energy, i.e. work is done to the electron as it is gaining kinetic energy.
 
I think maybe my basic is not strong enough. Correct me if I am wrong. The electric field direction is from positive to negative right? So the electron need to do work to go to the positive plate. Am i right?
 
No, electrons are negatively charged and are attracted to the positive plate. The direction the arrows in the field point in many pictures is meaningless. It could easily be the other way around and it would change nothing. It's simply that like charges repel and opposite charges attract.
 
hikarigenzo said:
I think maybe my basic is not strong enough. Correct me if I am wrong. The electric field direction is from positive to negative right? So the electron need to do work to go to the positive plate. Am i right?

Well, not really. You may work more on the defining formulae. The formulae for field strenth is F=qE. The negativity of q would mean that F would be positive alone the negative direction of E
 
Thanks for all the replies, so what happens to the kinetic energy and potential energy of it?
 
hikarigenzo said:
Thanks for all the replies, so what happens to the kinetic energy and potential energy of it?

Electrostatic potential decreases of course. Since there is no other force acting on the electron, all these potentials lost to kinetic. Actually, you mentioned accelerated in OP, so what's confusing?
 
I have to oversimplify, get a physical picture in myhead and then build up to the mathematical explanation. I think in pictures and envy folks whose mind jumps immediately to the formula.

If i correctly recall a physics class problem from forty++ years ago,
However many volts are across the plates responsible for the field, as it approaches the positive plate the electron's kinetic energy approaches that many electron-volts ..

here's a practical example that even I could follow.

http://wps.aw.com/wps/media/objects/877/898586/topics/topic07.pdf

old jim
 

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