Determing the kinetic energy of an electron

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SUMMARY

The discussion centers on calculating the kinetic energy (KE) of an electron in an electric field, specifically using the equation KEi + PEi = KEf. The initial kinetic energy (KEi) is given as 2.4 x 10-19 J, and the final kinetic energy (KEf) is calculated to be 4.002 x 10-19 J. Participants clarify that the electron is repelled by the negative plate, resulting in a decrease in kinetic energy as it moves from point B to point A, with a potential difference of 1 V affecting the potential energy (PE).

PREREQUISITES
  • Understanding of kinetic energy and potential energy concepts
  • Familiarity with electric fields and voltage
  • Basic knowledge of energy conservation principles
  • Ability to perform calculations involving joules and electron volts (eV)
NEXT STEPS
  • Study the relationship between electric fields and particle motion
  • Learn how to convert between joules and electron volts (eV)
  • Explore the concept of potential difference in electric circuits
  • Investigate the effects of electric fields on charged particles
USEFUL FOR

Students studying physics, particularly those focusing on electromagnetism and energy conservation, as well as educators seeking to clarify concepts related to kinetic and potential energy in electric fields.

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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