Hello everyone. I need to see if I did this right. the problem is this: Particle 1 of charge 1.0E-6 C and particle 2 of charge -2.0E-6 C are held at seperation L = 13.0cm on an x axis. If particle 3 of unkonwn charge q3 is to be located such that the net electrostatifc force on it from particles 1 and 2 is zero what must be the coordinates of particle 3? Here is my drawing and work: http://img231.imageshack.us/img231/2886/quad5nx.jpg [Broken] So would the answer be X = 31.385 cm Y = 0 cm? Also another quick question... http://img76.imageshack.us/img76/510/22115ph.gif [Broken] shows four situations in which charged particles are fixed in place on an axis. In which situations is there a point to the left of the particles where an electron will be in equilibrium? (Select all that apply.) situation b and a were the only ones that made senes to me. Does that seem right? Thanks!!