1. The problem statement, all variables and given/known data Consider earth and a cloud layer 700m above earth to be the plates of a parallel-plate capacitor. If the cloud layer has an area of 1.9 km^2, what is the capacitance? 2. Relevant equations Q = CV V = Ed E = Q/epsiolon*A 3. The attempt at a solution Solving for C gives us C=Q/V. Substituting Ed for V gives us C=Q/Ed. Substituting Q/epsilon*A gives us C = epsilon*A/d. Now I just plug in numbers and I should get the value for C, right? I'm putting in the values given but I am not getting the right answer...any suggestions? Thanks in advance to anyone who helps.