1. The problem statement, all variables and given/known data An isolated 5.60 microfarad parallel-plate capacitor has 4.90 mC of charge. An external force changes the distance between the electrodes until the capacitance is 2.00 microfarads. 2. Relevant equations W = Fd c = Q/V 3. The attempt at a solution My first instinct was to solve to the potential of the system in it's initial conditions: C = Q/V 5.60*10^-6 F = .0049C/V V = 875 V Now is where I become a little confused. I'm not sure how I can solve for the distance between the plates in the final condition. Also, I'm not sure what values stay constant as the plates are separated. Any help is much appreciated!