The problem says that there are two parallel plates having charges of equal magnitude but opposite signs and they are separated by 16cm. Each plate has a surface charge of 31 nc/m2(sorry don't know how to superscript). I need to find the potential difference between the plates. I thought I needed to find the electric field of the plate but modelling it as an infinte plane and then find the potential but I can't seem to get the right answer. I was wondering if someone could help me.