physics
posted by JM .
A fully charged 98 uF capacitor is discharged through a 125 ohms resistor. How long will it take for the capacitor to lose 75% of its initial energy

The time constant is RC = 0.0123 seconds
To lose 75% of its energy, the voltage on the capacitor must fall in half.
V/Vo = e^(t/0.0123) = 0.500
Solve for t.