A 10^-8 F capacitor (10 nanofarads) is charged to 100 V and then disconnected. One can model the charge leakage of the capacitor with a RC circuit with no voltage source and the resistance of the air between the capacitor plates. On a cold dry day, the resistance of the air gap is 5 x 10^13 ohms; on a humid day, the resistance is 8 x 10^6 ohms. How long will it take the capacitor voltage to dissipate to half its original value on each day?

A 10^-8 F capacitor (10 nanofarads) is charged to 100 V and then disconnected. One can model the charge leakage of the capacitor with a RC circuit with no voltage source and the resistance of the air between the capacitor plates. On a cold dry day, the resistance of the air gap is 5 x 10^13 ohms; on a humid day, the resistance is 8 x 10^6 ohms. How long will it take the capacitor voltage to dissipate to half its original value on each day?