Electric Potential: Find at Infinity w/ Two Point Charges

Click For Summary

Homework Help Overview

The discussion revolves around calculating the electric potential at infinity for a system of two point charges positioned along the x and y axes. The original poster expresses uncertainty about how to approach the concept of electric potential at infinity, particularly in relation to the contributions from both charges.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to understand the implications of calculating electric potential at infinity, questioning how to treat multiple point charges in this context. Some participants clarify that the potential at infinity is defined as zero and discuss the relationship between potential energy and work done by electric forces.

Discussion Status

Participants are exploring the definitions and implications of electric potential and potential energy. Some guidance has been offered regarding the potential at infinity being zero and the work-energy theorem, but there remains a lack of explicit consensus on the original poster's specific concerns about the two charges.

Contextual Notes

There is an ongoing discussion about the assumptions related to potential energy at infinity and how it relates to the work done when moving a charge from the origin to infinity. The original poster's understanding of potential energy and its change is still being clarified.

wave41
Messages
16
Reaction score
0
Hello everyone, I need alittle help with an assignment...I am given two charges one along the y-axis and one along the x, and I am asked to find the electric potential at infinite distance...I found the electric potential at the origin, but I am unsure about the eletric potential at infinity.Since when r final= infinity then it is o V at f...So the electric potential is equal to 1/4piE (Q/r)...what I am not sure about is as how to treat this with two point like charges...To find the electric potential at infinity...
Thank you
 
Physics news on Phys.org
The potential at infinity is just zero. Remember the definition of potential, as the integral of the electric field from infinity to the point in space you wish to calculate the potential. If that point happens to be infinity, you're moving from infinity to infinity, in other words, your not moving anywhere, and the potential is just zero, relative to infinity.
 
Thank you :smile:
 
I have another question about this problem...there is another part asking for the work done by electrical forces if the proton at the origin is moved from the origin to infinity?? Is it just the negative potential energy of the proton at the origin?
Thank you
 
Yes, because the work-energy theorem for conservative forces (such as the electric field force) is

[tex]W_C = -\Delta ({\rm PE}).[/tex]

So to find the work of all conservative forces acting on a particle as it moves from one point to another, find the change in potential energy between those two points.

Don't forget the negative sign (which appears because conservative forces try to minimize potential energy). Note also that one of the potential energy values (at infinity) is 0.
 
sorry I have another dumb question...Since the particle's PE is zero at infinity, so there is really no change and it is just the negative of the result I found at the origin where the particles is no?
 
Yes, this is correct.
 
thanks :smile:
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
Replies
5
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 22 ·
Replies
22
Views
5K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
64
Views
7K
Replies
1
Views
2K
Replies
1
Views
2K