Calculating Force and Kinetic Energy in an Electric Field

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Homework Help Overview

The discussion revolves around calculating the force on an electron and its kinetic energy increase while it moves through an electric field between two charged plates. The electric field strength is given, but the problem presents challenges in finding straightforward solutions and relevant information in textbooks or online resources.

Discussion Character

  • Exploratory, Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the force on the electron and its kinetic energy increase, referencing equations related to force and kinetic energy. Some participants suggest considering the work done by the electric force as it relates to kinetic energy. Questions arise regarding the meaning of "V" in the context of the problem and its relevance.

Discussion Status

Participants are exploring different aspects of the problem, with some guidance offered regarding the relationship between work and kinetic energy. There is a lack of consensus on the significance of certain variables, and the discussion is ongoing with various interpretations being considered.

Contextual Notes

There is mention of missing information regarding the electric potential difference, which is noted as unknown and potentially unhelpful for solving the problem. The original poster expresses confusion about the application of certain equations and variables.

adrianx
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electric field

I can't find any straight forward solutions to this problem.. it's not addressed in the textbook (even though there is a chapter problem about it) and the internet doesn't have what I need either. I'm hoping someone could give me some insight on this.

An electron (q = -1.602 x 10^-19 C) is projected horizontally into the space between two oppositely charged metal plates. The electric field between the plates is 503.0 N/C, directed up.
(a) While in the field, what is the force on the electron?

(b) If the vertical deflection of the electron as it leaves the plates is 3.20 mm, how much has its kinetic energy increased due to the electric field?

For (a), I found the force to be 8.058E-17N down.

(b), I think I need to know what the velocity is. I know a few equations but I don't know how to use them for this.
The equations I know are:
K = (1/2)mv^2 which I found (on the 'net) to be equal to eV = (1/2)mv^2.
kinematic equations
F = ma = qE
 
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Fot the second point,how about considering that the work done by the electric force is equal to the variation of the KE?

Daniel.

P.S.What "V" are u talking about?
 
Genius! The chapter and my professor didn't mention anything about work (or kinetic energy as it applies to the electric field for that matter).

Thank you so much :)

I don't know what that V is.. some webpages I found just used it. When I tried to apply it, I just used the elementary charge e (don't ask me why..)
 
That probably is the ACCELERATING (ELECTRIC) POTENTIAL DIFFERENCE.In this problem,it's unknown and moreover useless...

Daniel.
 

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