1) Calculate the magnitude of the force between the charge +q at y = +L and the charge Q. The distance is L + 3L = 2L. 2) Calculate the magnitude of the force between the charge -q at y = = -L and the charge Q. That distance is also 2L. kqQ sin (2L) 2L 3) Decompose the force vectors into x and y components. The x components cancel. The y component is: kq sin(30) 4L Fy = F = F = 0 = kqQ 4L sin (30) = = 30 = kqQ 4L (0.5 +0.5) What is the force on the charge Q from + the other two charges? +q -9 -V3L +9 L V3L r=L+3L = 2L F Force of -q on Q F Force of +q on Q +9 -9 3 L L 030 since sin 0 = 2L V3L Q FIX Fly F X +q L L -9 0 X