Equilibrium of Charges on a Square: Find q

Click For Summary

Homework Help Overview

The discussion revolves around a problem involving electrostatics, specifically the equilibrium of charges arranged at the corners of a square with an additional charge at the center. The original poster seeks to determine the value of the central charge, q, given that the system is in equilibrium.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants question the clarity of the problem setup, particularly the role of the central charge q and its known value. Some express skepticism about the necessity of calculating q, while others suggest that the equilibrium condition should be examined in relation to the forces acting on the corner charges.

Discussion Status

The conversation is ongoing, with various interpretations of the problem being explored. Some participants have provided insights into the forces involved, while others are awaiting further clarification or visual aids to enhance understanding. There is no explicit consensus on the interpretation of the problem or the value of q.

Contextual Notes

There are indications that the discussion has been moved to a homework section, which some participants express concern about. This may influence the nature of the responses and the expectations for problem-solving within the thread.

mirzaicpc
Messages
5
Reaction score
0
four charges each equal -Q placed at the four edges of a square and a charge q is placed at the centre. if system is in equilibrium the value of q is,

the answer is q = Q/4 * ( 1 + 2(√2)

can anyone please solve this, would be great
 
Physics news on Phys.org
That sounds like a homework question, you should probably take it there. Also, I don't understand the setup; you say a charge "q" is placed in the middle. So, isn't the value of q ... q?
 
Are you sure about the answer ? It should be zero I guess net force will be zero any case so we can't tell anything about q and Q
 
ya i am sure abt it,
 
But the problem as you describe it make no sense. You already know the value of q, why do you need to calculate it again?

Also, please spend more time writing your responses.
 
Q's are stable or unstable ?
 
this was one of the replies i got, but couldn't understand it, hope it will help
 

Attachments

  • IMG-20150603-WA0001.jpg
    IMG-20150603-WA0001.jpg
    40.5 KB · Views: 448
I solved it.I will send a picture I hope it will be not a problem cause its not in homework section
 
thank you so much,,, waiting for the pic
 
  • #10
Who moved this in homework section I will be banned now. This post first opened general physics forum.For that I send picture.I don't take any responsibility to share this picture.I don't break the rules.
 
  • #11
thank u so much people
 
  • #12
ArmanCham said:
Who moved this in homework section I will be banned now. This post first opened general physics forum.For that I send picture.I don't take any responsibility to share this picture.I don't break the rules.
Post number 2 stated it was homework, and in the post you edited, you knew it was homework, you won't be banned, don't worry, just make sure to follow the homework rules for helpers.
 
  • #13
ArmanCham said:
Who moved this in homework section I will be banned now
Don't panic. You're not getting banned. The moderators are just working to help you out by moving your post into the forum where it should have been placed to start with. We're not evil overlords around here. [Though I hear that the ban stick is a fun thing to wield]

It is clear by inspection that the center charge will be in equilibrium regardless of the value of q.

So the original problem is surely intended to find the value of q for which the four equal charges at the corners are each in an equilibrium. Whether that equilibrium would be stable is a separate question that we need not delve into here.

One should be able to calculate the repulsion on each corner charge from its peers. And one should be able to calculate the attraction of the corner charge from the center charge in terms of the known value Q and the unknown value q. Find q such that the net force on a corner charge is zero and the problem is solved. I believe that is the approach that was taken in the posted answer.
 
Last edited:

Similar threads

Replies
5
Views
1K
Replies
9
Views
2K
  • · Replies 12 ·
Replies
12
Views
4K
  • · Replies 7 ·
Replies
7
Views
1K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 13 ·
Replies
13
Views
3K
Replies
23
Views
5K
  • · Replies 9 ·
Replies
9
Views
985
Replies
1
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K