What Are the Effects of Five Charges in an Electrical Field?

  • Thread starter Thread starter xma123
  • Start date Start date
  • Tags Tags
    Charges Field
Click For Summary

Homework Help Overview

The discussion revolves around understanding the effects of multiple charges within an electrical field, specifically focusing on how to calculate the resultant electric field at a point due to five charges. The original poster expresses confusion regarding the complexity of the problem, which is the last question on their paper.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants explore the electric field produced by a single charge and discuss the vector sum of fields from multiple charges. They consider the effects of symmetry and the cancellation of fields from charges positioned in certain configurations. Questions arise regarding the direction of the electric field and the implications of charge polarity.

Discussion Status

Participants are actively engaging with the problem, offering insights into the calculation of electric fields and discussing the implications of charge arrangements. There is a recognition of the need to clarify the direction of the electric field and the significance of charge types, with some guidance provided on how to approach the problem conceptually.

Contextual Notes

There is a mention of a diagram that contains relevant information for the problem, but specific details about the configuration of the charges are not provided in the discussion. The original poster indicates that this question is more complex than previous ones, suggesting a potential gap in foundational understanding.

xma123
Messages
9
Reaction score
0
http://imgur.com/a3vxU


Really haven't a clue how to go about this, it's the last question on the paper and nothing before it is anything near as complex as this.

Any help much appreciated
 
Physics news on Phys.org
What's the field at the center from a single charge? Then find the vector sum of all the field contributions. Take advantage of symmetry.
 
Imagine the top charge is also absent. What would the field be due to the four charges?
 
So due to each charge the field is E=kq/r2

The 4 in the middle cancel, giving a field of either positive or negative of the single field charge above. So would the answer be option 3?
 
What is the direction of j? Of the field?
 
voko said:
What is the direction of j? Of the field?

The picture is all the info given on this
 
xma123 said:
So due to each charge the field is E=kq/r2
Good. That's the magnitude of the field, so be sure to count the direction.
The 4 in the middle cancel, giving a field of either positive or negative of the single field charge above.
Yes, the 4 in the middle cancel. But I don't know what you mean by "either positive or negative". Which is it? What's the direction of the field from the top charge?
 
You have enough information to deduce the direction of the field by the top charge. As for the direction of j, I am sure you have heard of the standard basis vectors i, j and k. What are they?
 
Apologies, it's late. The j vector acts in the y direction, so the top charge would act in the upwards of y, +j vector and therefore option 3.

By positive or negative I was referring to the difference betweent options 3 and 4.
 
  • #10
xma123 said:
the top charge would act in the upwards of y

Why is that?
 
  • #11
voko said:
Why is that?

Oh damn, they're positive charges, so the field acts downwards away from the top charge.

This would give a "negative" field in the y direction and so option 4 is correct?
 
  • #12
xma123 said:
they're positive charges, so the field acts downwards away from the top charge

Correct!
 
  • #13
voko said:
Correct!

Thanks very much for your patience, much appreciated
 

Similar threads

Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 4 ·
Replies
4
Views
972
Replies
1
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
23
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 26 ·
Replies
26
Views
3K
Replies
9
Views
1K
  • · Replies 12 ·
Replies
12
Views
3K