Ah, I figured it out. The upper and lower series each have half the value of the charge that I calculated. Then using V=QC, Vad=140V and Vac=70V, so Vad-Vac=70V.
1. The problem statement
The capacitors in the figure are initially uncharged and are connected, as in the diagram, with switch S open. The applied potential difference is Vab = + 210 V.
What is the potential difference Vcd?
Homework Equations
(series) 1/C = 1/c1 + 1/c2 + ...
Thanks for suggesting that I didn't need to integrate. I was stuck trying to work out an integral, but once I saw I didn't need one, the problem was very simple.
For the maximum speed, I just solved KE + PE = 0 for velocity, and that was correct.
Homework Statement
A ring of diameter 7.90 cm is fixed in place and carries a charge of 5.90 \muC uniformly spread over its circumference. How much work does it take to move a tiny 3.80 \muC charged ball of mass 1.90 g from very far away to the center of the ring? Also, What is the...