Electric Potential Energy Problem. Intuition needed

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Discussion Overview

The discussion revolves around a physics problem involving three identical, negatively charged particles positioned in a straight line. Participants explore the dynamics of the particles when released from rest, specifically focusing on the expected motion and final velocities of the particles, particularly particle B, which is positioned between the other two particles.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant questions why particle B, positioned equidistant between two other negatively charged particles, would not remain stationary and instead would move, despite the symmetrical forces acting on it.
  • Another participant suggests that particle B would have a speed equal to that of the particles accelerating to the left and right, indicating a potential misunderstanding of the forces at play.
  • A participant expresses confusion about the expected final speed of particle B and seeks clarification on the calculations involved, particularly given the specified distances between the particles.
  • Some participants express similar expectations regarding particle B's motion, questioning the validity of the claim that it would move.

Areas of Agreement / Disagreement

There is no consensus among participants regarding the motion of particle B. Some believe it should remain stationary, while others argue that it will move, leading to an unresolved debate about the dynamics involved.

Contextual Notes

The discussion lacks specific calculations or detailed explanations of the forces acting on the particles, which may contribute to the confusion regarding particle B's motion. Assumptions about the system's behavior and the influence of electric forces are not fully articulated.

FerPhys
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There's this problem that was given in my physics class..
"Three identical, negatively charged particles are situated at rest in a straight line, as shown below. All three are released simultaneously, and are free to move. Find the maximum velocities attained by particles A, B, and C. They have have a mass of 1.70 grams and a charge of -700x10-6C."
The picture just has particles A, B , and C horizontal to one another with a distance of 2cm from A to B and 2 cm from B to C. Making the distance from A to C 4cm.
I hope you guys can imagine the picture well enough its not too bad.
Anyways, you solve for the total potential energy of the system and solve for the final velocity. I expected particle B, however, to have a final speed of zero, since it wouldn't move at all since it has an negatively charged particle to its right and left at the same distance that are identical. Apparently, that is wrong. Why does particle B move when it is EXACTLY in the middle of the other two? Also, in what direction would it move?
Thanks a bunch! This question is driving me nuts.
 
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FerPhys said:
There's this problem that was given in my physics class..
"Three identical, negatively charged particles are situated at rest in a straight line, as shown below. All three are released simultaneously, and are free to move. Find the maximum velocities attained by particles A, B, and C. They have have a mass of 1.70 grams and a charge of -700x10-6C."
The picture just has particles A, B , and C horizontal to one another with a distance of 2cm from A to B and 2 cm from B to C. Making the distance from A to C 4cm.
I hope you guys can imagine the picture well enough its not too bad.
Anyways, you solve for the total potential energy of the system and solve for the final velocity. I expected particle B, however, to have a final speed of zero, since it wouldn't move at all since it has an negatively charged particle to its right and left at the same distance that are identical. Apparently, that is wrong. Why does particle B move when it is EXACTLY in the middle of the other two? Also, in what direction would it move?
Thanks a bunch! This question is driving me nuts.
Are you sure, there's nothing more to the question?
 
FerPhys said:
I expected particle B, however, to have a final speed of zero, since it wouldn't move at all since it has an negatively charged particle to its right and left at the same distance that are identical. Apparently, that is wrong.
I expect idem. So who claims it's wrong ?
 
Apparently B would have a speed the same as the particle that accelerates to the right which is also the speed of the particle that accelerates to the left.
And there's nothing more to the question that's it.
 
Well, given the 2 cm distances I wonder what the value of that speed is according to the "apparent" answer ?
 

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