(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A charge of q1 = -8.5 μC is at y = 6.0 m, and a charge of q2 = -6 μC is at y = -4.0 m. Locate the point (other than infinity) at which the total electric field is zero.

2. Relevant equations

E=k(q/r^2)

E1=E2

Quadratic Equation

3. The attempt at a solution

9x10^9 (8.5x 10^-6)/(10-r)^2 = 9x10^9(6x10^-6)/r^2

8.5r^2 = 6(100-20r + r^2)

8.5r^2= 600-120r+6r^2

2.5r^2+120r-600=0

so using the quadratic equation

-120+-SqRt [120^2-(4)(2.5)(-600)] / 2(2.5)

-120+-SqRt [(14400-(-6000)] / 5

-120+-SqRt 20400 / 5

-120 +-142.8/ 5

R= 4.56, -148.56

with realistic value being 4.56

Im using webassign and I submitted 8 previous different answers before submitting 4.5. I know the answer was not 4.5 but 4.56, but is it that sensitive. Since it is my last allowed attempt, I want to be sure it is 4.56 before submitting.

Thank you

sorry if its hard to understand, i dont know how to do the symbols and stuff

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# Homework Help: Two point charges along the y-axis.

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