A square with each side of length 0.15m has four charges fixed in place at each corner. At two of the corners we have a negative charge of -2.0mC, while a third corner has a positive charge of +6.0mC. In the final corner there is a different charge q.
i.) If the total force acting on the q charge has a magnitude of 7.5N, then what is q?
ii.) The charge q is replaced by a new charge, and now the +6.0mC charge feels a 9.2N force attracting it to the center of the square. What is the new unknown charge?