(Electric Charge and Electric Field)

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Homework Help Overview

The discussion revolves around calculating electric potential difference and electric field strength related to a point charge. The original poster presents a scenario involving a -3.6 µC point charge and two points in relation to it, seeking assistance with the calculations of electric potential and electric field.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the appropriate equations for electric potential and electric field, with some confusion regarding the concepts of electric potential versus velocity. Questions arise about the correct application of formulas and the meaning of variables involved.

Discussion Status

Participants are actively engaging with the problem, questioning assumptions about the equations and definitions. Some guidance has been offered regarding the correct formula for electric potential, but there is still uncertainty about its application and the significance of certain variables.

Contextual Notes

There appears to be confusion regarding the distinction between electric potential and electric field, as well as the relevance of certain constants in the equations. Participants express a desire for clarity on these concepts as they relate to the problem at hand.

Axeman2k
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Please Help! (Electric Charge and Electric Field)

Consider point a which is 70 cm north of a -3.6 µC point charge, and point b which is 84 cm west of the charge (Fig. 17-23).


(a) Determine Vba = Vb - Va.
V = ____
(b) Determine Eb - Ea.
Magnitude
N/C = ____
Direction = _____
° (counterclockwise from east is positive)

Thanks for your help!
 

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At first I was thinking the first part had to do with the E = (KQ1)/r2 equation. You take that for both point a and b then subtract b-a to get the final velocity. That didnt seem to work, and I have been looking frantically for the past 30 min through my notes and have not been able to find an equation to start off this problem. I think I may be confusing test charges with normal charges.
 
That is not velocity,that is ELECTRIC POTENTIAL.And you shouldn't be using the formula for the electric field,but the formula for the electric potential...

Daniel.
 
Hmmm... tried the equation V=Ed for potential but that didnt work. Am I using the right equation?
 
No,u should be using the electric potential created by an electric charge...

[tex]V(r)=\frac{1}{4\pi\epsilon_{0}\epsilon_{r}} \frac{q}{r}[/tex]

Daniel.
 
Haven't had a chance to use that equation... can you explain where the e sub 0 and r come from please?
 
Those are electric permitivities.The one with the subscript "0" is the electric permitivity of vacuum.The one with the "r" subscript is the relative electric permitivity of the medium wrt the vacuum and is dimensionless...

Irrelevant into discussion,really.U got a problem to solve...

Daniel.
 
I don't think it's irrelevant, I like to know all the values and what they are if I am going to use an equation. I just find it hard to believe, Axeman, you don't know what [tex]\epsilon_{0}[/tex] is since it seems you are in an electricity class.
 
What do you mean...??He SHOULD KNOW what [itex]\epsilon_{0}[/itex] is.Even if he's in High School...

Daniel.
 

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