Physics-electric charge(coulomb's law)

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Homework Help Overview

The discussion revolves around a problem involving electric charges and Coulomb's law, specifically calculating the position along the line joining two charges where a third charge experiences no net force. The charges in question are 1.67 µC and -0.6 µC, separated by a distance of 0.4 m.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the setup of the problem, including the need to find a point where the forces from the two charges cancel out. There is mention of the quadratic nature of the resulting equation and the implications of imaginary solutions based on initial setups. Some participants question the correctness of the initial equations used.

Discussion Status

The discussion is ongoing, with participants providing insights into the setup of the equations and suggesting corrections. There is a recognition of the need to clarify the conditions under which the third charge experiences no force, and some guidance has been offered regarding the correct formulation of the forces involved.

Contextual Notes

There is a note regarding the importance of clear communication in the thread, as some participants have expressed difficulty in understanding the initial setup due to reliance on images rather than text. Additionally, there are indications that the calculations may not have been thoroughly checked, leading to confusion about the existence of solutions.

josejayant13
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The question is this:
Calculate the position on the line joining 2 charges 1.67 uC and -0.6uC situated 0.4m apart where a third charge q does not experience any force?

uC=microcoulomb
 

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The reason it comes out as a quadratic equation because there are two places that satisfy the problem
(You can place it at a certain distance to the left of the charges, or a certain distance to the right of the charges.)

The reason your quadratic was imaginary is because you set up the initial equation wrong.

You want [itex]F_1+F_2=0[/itex] and therefore [itex]F_1=-F_2[/itex] (Whereas you wrote "[itex]F_1=F_2[/itex]" without the negative sign)



P.S.
In the future, it would be very helpful if you typed out your thoughts in the thread. The reason is that it can sometimes be difficult to read off of a picture. (And I almost didn't even notice that there were words in your picture!) Thank you :)
 
It did not give any solution
 
Let the point at which q[itex]_{3}[/itex] does not experience any force be x.(Let this x be measured from q[itex]_{1}[/itex])
Not distance of that specific point from q[itex]_{2}[/itex]=(0.4-x)
Since net force on q[itex]_{3 }[/itex] is zero so

kq[itex]_{1}[/itex]q[itex]_{3}[/itex]/x[itex]^{2}[/itex]=-kq[itex]_{2}[/itex]q[itex]_{3}[/itex]/(0.4-x)[itex]^{2}[/itex]
Put the values and get the answer.
 
josejayant13 said:
It did not give any solution

It does give a solution. Please re-check your calculations, what equation do you get after applying the correction Nathanael suggested?
 

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