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

Blue charge is at origin with positive q charge

Red charge at point (d1,0) with unknown positive charge q_red

Yellow charge at point (d2cos(theta),-d2sin(theta)) with negative 2q charge

The net electric force on the blue sphere has a magnitude F and is directed in the - y direction.

Suppose that the magnitude of the charge on the yellow sphere is determined to be 2q. Calculate the charge q_red on the red sphere. Express your answer in terms of q, d1, d2, and theta.

2. Relevant equations

electric force F = kq_1q_2/r^2 where k = 9*10^9, q_1 and q_2 represent point charges, and r is distance between point charges

3. The attempt at a solution

F = [(k*q_yellow*q_blue)/d2^2 ] + [(k*q_red*q_blue)/d1^2]

F = [(k*(-2q)*q)/d2^2] + [(k*q_red*q)/d1^2]

d1^2[F - ((k*(-2q)*q)/d2^2)] / kq = q_red

i think i'm on the right track but i did not use theta which i need to, where did i go wrong

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# Homework Help: Finding charge based on net force and other charges

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