Having trouble finding the potential between two positive point charges.

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Homework Help Overview

The discussion revolves around calculating the electric potential between two positive point charges, specifically focusing on the potential at a point where the electric field is zero. The original poster is attempting to find the potential using the formula for electric potential due to point charges.

Discussion Character

  • Exploratory, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • The original poster attempts to calculate the total potential by summing the potentials from each charge, but expresses uncertainty about their calculations leading to an incorrect result. Some participants question the completeness of the original poster's working, suggesting that more details are needed to identify the error.

Discussion Status

The discussion is ongoing, with participants seeking clarification on the calculations. There is an acknowledgment of a potential discrepancy in the results, but no consensus has been reached regarding the source of the error. Some guidance has been offered regarding the formula for electric potential.

Contextual Notes

The original poster has provided specific values for the charges and distances involved, but there is a lack of detailed working shown, which is noted as a barrier to identifying the issue in their calculations.

nontradstuden
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Homework Statement





How to find the potential between two positive point charges?

I don't know where I'm going wrong.

==I am adding V_1 and V_2. converted mC to C, cm to m, correct value of k.

V1= kq1 / r1
v2= kq2/ r2.


==I am adding both of these, but I'm not getting the correct answer.

===Problem:

A point charge of q1 = 2.37 µC is 44 cm from a charge of q2 =26.4 µC. Where is the electric field zero? What is the value of the potential there?
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electric field is zero at 0.101m (correct answer).

I have r1= .101m and r2= .44m - .101= .34m.

I'm using the correct value of k.

== The answer is given as 2.34 * 10^6 V.


Can you help me find out where I'm doing wrong?
 
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We cannot tell where you are going wrong if you do not post all your working.
 
haruspex said:
We cannot tell where you are going wrong if you do not post all your working.


Edit: The potential at the point is equal to the sum of the two potentials of the two point charges.

V= kq_1 / r_1 + kq_2 /r_2

V= (9*10^9 Nm^2/C^2)* (2.37 * 10^-6 C)/ .101m + (9*10^9 Nm^2/C^2)*(26.4*10^-6 C) / .34m = 9.10*10^5 V.

The correct answer is 2.34 *10^6 V.

I don't know what I'm doing wrong.
 
I agree with your answer (almost: 9.11e5).
 

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