1. The problem statement, all variables and given/known data Two capacitors, C1 and C2, are separately charged to 166 C and 348 C, respectively. They are then attached in parallel so that the + plate of one goes to the - plate of the other, and vice versa, as shown on the diagram below (notice how C2 was rotated 180 degrees before the capacitors were connected). C1 has a capacitance of 39.8 F, and C2 has a capacitance of 174 F. What is the final voltage across C1? http://lon-capa.mines.edu/res/csm/csmphyslib/type56_capacitors/AttachedInParallel.jpg [Broken] 2. Relevant equations V(C1+C2) = Q1 - Q2 V = (Q1-Q2)/(C1+C2) V = .851 V 3. The attempt at a solution My question is, why are the charges subtracted? What goes on in this circuit to make that happen? Why does this happen when capacitors are aligned in this manner? Also, why is the final voltage reported as positive, when it should be negative?