A point particle that has a charge of 12.5 µC is located at x = 0, y = 0 and a point particle that has a charge q is located at x = 10.0 cm, y = 0. The electric force on a point particle that has a charge of 5.0 µC at x = 20.0 cm, y = 0 is -(19.7) N . Determine the charge q.