Determing the kinetic energy of an electron

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Homework Help Overview

The discussion revolves around determining the kinetic energy of an electron in the context of electric fields and potential energy. Participants are exploring the relationship between kinetic energy and potential energy as the electron moves through different points in an electric field.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Some participants attempt to apply the conservation of energy principle, questioning the correctness of their calculations regarding kinetic energy. Others raise concerns about the implications of electric fields on the electron's motion, particularly regarding its ability to move between plates with different voltages.

Discussion Status

The discussion is active with various interpretations being explored. Some participants provide guidance on considering potential energy changes and suggest using electronvolts for calculations. There is no explicit consensus on the correct approach or interpretation of the problem.

Contextual Notes

Participants note potential confusion regarding the setup of the problem, including the behavior of the electron in relation to the electric field and the implications of voltage differences between plates.

Turion
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Homework Statement



sxvTCH3.png


Homework Equations


The Attempt at a Solution



KEi + PEi = KEf
2.4 x 10-19 + e(1) = KEf
KEf = 4.002 x 10-19 J

So option c would be correct, right? Thank you in advance.
 
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This one is a trick question, right? It would need 0 kinetic energy because the electric field itself would move the electron to the left until it reaches point C.
 
This one doesn't even make sense to me. How can the electron go back to plate D if plate D has the higher voltage?

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Turion said:

Homework Statement



sxvTCH3.png


Homework Equations





The Attempt at a Solution



KEi + PEi = KEf
2.4 x 10-19 + e(1) = KEf
KEf = 4.002 x 10-19 J

So option c would be correct, right? Thank you in advance.

No. The electron is repelled by the negative plate so its KE decreases when it moves from B to A.
And it's easier if you work in eV directly.
The potential difference between B and A is 1 V so the change in potential energy is 1eV.

And I think you are supposed to post one problem per topic.
 

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