S review. two identical particles, each having charge +q , are fixed in space and separated by a distance.d. a third particle with charge -q is free to move and lies initially at rest. on the perpendicular bisector of the two fixed charges a distance x from the midpoint between those charges (fig. p23.14). (c) how fast will the charge -q be moving when it is at the midpoint between the two fixed charges if initially it is released at a distance a<