The work done by an electric field in accelerating a charged particle?

AI Thread Summary
The discussion revolves around calculating the work done by an electric field on a charged particle and its implications for kinetic and potential energy. The particle has a charge of 3.2x10^-19 C and is subjected to a uniform electric field of 39000 N/C across a distance of 4.5x10^-3 m. The force on the particle is calculated to be 12 fN, and the work done by the electric field is determined to be 56.2 aJ. The increase in kinetic energy is confirmed to be equal to the work done, while the change in potential energy is noted to be the negative of the kinetic energy gain due to conservation of energy principles. Overall, the calculations for parts B and C yield the same result of 56.2 aJ.
Dongorgon
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Homework Statement


A particle with a charge of 3.2x10^-19 C accelerates from rest between two charged plates. The electric field is uniform and is 39000 N/C. The distance between the plates is 4.5x10^-3 m.

A) Calculate the force on the particle
B) How much work is done by the electric field in accelerating the particle between the two plates?
C) What is the increase in kinetic energy of the particle?
D) What is the change in potential energy of the particle?

Homework Equations



My answers so far:

A) Using F=QE to get an answer of 12fN

B) I'm not sure on the validity of this answer, or infact the right equation to use for this question and parts B and C.

I've used WD = FxD
Therefore, an answer of 56.2 aJ

C) Would the increase in kinetic energy be simply the change in energy experienced for part B)?

Any help would be greatly appreciated!
 
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A) correct!
B) correct!
C) You are right!
D) The change in P.E. will be equall to minus the gain in K.E. (conservation of energy)
 
cosmic dust said:
A) correct!
B) correct!
C) You are right!
D) The change in P.E. will be equall to minus the gain in K.E. (conservation of energy)

So both part B and C have the same answers of 56.2 aJ?

For D would the answer be along these lines?

25iss5w.png
 
Dongorgon said:
So both part B and C have the same answers of 56.2 aJ?

For D would the answer be along these lines?

25iss5w.png

Since the particle acquires a P.E. because of the work done on it and this is converted to K.E., so the answer to (D) is << solution deleted by Mentor -- but use his hint to fix your answer... >>
 
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