1. The problem statement, all variables and given/known data A fully charged 10e-4 F capacitor has a potential difference across it of 9Volts. It is then connected to a resistor of 10 ohms. How long will it take for the current through the resistor to decrease to 1/2 of its initial value? 2. Relevant equations 3. The attempt at a solution I know the answer is 6.9e-4 secs... but I want to know how it was done :/ Anyone?