Two resistors, R1 = 8.00 Ω and R2 = 4.00 Ω and two uncharged capacitors, C1 = 0.480 μF and C2 = 0.240 μF are arranged as shown in the figure below.
With a potential difference of 21.1 V across the combination, what is the potential at point a with S open? (Let V = 0 at the negative terminal of the source.)
What is the potential at point b with the switch open?
When the switch is closed, what is the final potential of point b?
How much charge flows through the switch S after it is closed?
I know that the potential is the same across the switch when the switch is closed, but I don't know how you can calculate the charge at the specific point B.
The Attempt at a Solution
I tried Q=CV for V=7.03 and C=.24 microF, and I got Q = 1.69 microC (I thought that because the potential drop at C2 is equal to the potential at B), but that didn't work. Everything else is right, but I just don't know how you do the last part.
Other answer I tried, but were wrong, were 3.38 microC, 6.75 microC, and 0 C (just to see).