[SOLVED] RC Circuits

[snoweangel27]

1. The problem statement, all variables and given/known data

1. I have two questions in regards to RC circuits, the first one is how to calculate the maximum voltage across a capacitor, knowing the charge on a battery and the capacitance.

2. The other question involves this circuit http://i2.photobucket.com/albums/y30/snoweangel27/figure-25-70.gif

where the potential drop across the capacitor is 12V and the Battery is 36 V. R and C are also known. I need to calculate the current in R immediately after the switch is closed.



2. Relevant equations

For the first problem I am sure I am just overlooking something. As far as I know I can't use the equation V = Q/C as that will just give me the Voltage of the battery.





3. The attempt at a solution

In the second problem, I applied Kirchhoff's Law to obtain -I(1)*R(1)-12V+36V=0, where I then solve for I(1), but my answer in not correct, and I am not sure what I am doing wrong.
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution