1. The problem statement, all variables and given/known data Two circular disks, each of area 4.10×10-4 m2, are situated parallel to one another. The distance between them is small compared with their radii. Both disks are uniformly charged; their charges per unit area are σ = 5.00×10-5 C/m2 for one and -σ = -5.00×10-5 C/m2 for the other. Compute the force exerted by one on the other. 2. Relevant equations E=σ/ε F=qE 3. The attempt at a solution E=σ/ε=5.00×10-5 C/m2/8.85x10-12 =5.649717514x106N/C Charge on one plate = σ*Area=5.00×10-5 C/m2*4.10×10-4 m2=2.05x108C F=qE=2.05x108C*5.649717514x106N/C =0.1158N I have tried both the positive and negative version of this answer, both are wrong. I have no idea what I'm doing wrong here....the distance between the plates isn't given, so I can't use coulomb's law (but they're not point charges anyways) Help?