Three equal positive point charges of magnitude Q = 4.00ì C are located at three corners of a square of edge length d = 6.9 cm. A negative charge -14.00ì C is placed on the fourth corner. At the position of the negative charge, what is the magnitude of the electric field due to the three positive charges?

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What is the magnitude of the attractive force on the negative charge?

1 answer

Do this the same way as your triangle problem