An unknoAn unknown additional charge q3 is now placed at point B, located at coordinates (0 m, 15.0 m ). Find the magnitude and sign of q3 needed to make the total electric field at point A equal to zero. wn additional charge q3 is now placed at point B, located at coordinates (0 m, 15.0 m ). Find the magnitude and sign of q3 needed to make the total electric field at point A equal to zero.\

hello your question has some missing information attached below is the missing information

answer : q3 = 0.300 nC

Explanation:

Given that Eay is in the Y axis ( upward ) , E3 will be downward and this will make the sign on the the charge ( q3 ) to be positive

E3 = Eay.   ( for an electric field to be neutral/zero the electric field in the opposite direction will have same magnitude )

To calculate the value of q3 we will apply the relation below

 K*q3/( 15 - 12 )^2  = 0.300

           = (9 * 10^9) * (q3 / 9 ) = 0.300

∴ q3 = 0.300 / 10^9

        = 0.300 nC

Note : The value of Eay is been calculated outside this solution as it is not part of the question asked  

that would be b i just took the test : )

fgravity=10x10=100n case 1

fgravity=30x20=600n case 2

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