At time t=0, the switch in the following circuit is closed. R=10000Ω while C=100μF

  1. Determine the time required for the initial voltage across the capacitor to fall to 1/e of its initial value.
  2. Determine what resistor would be required to decrease the time required to fall to 1/e of its initial value to 0.4 seconds.
  3. Determine the time required for the initial voltage across the capacitor to fall to 1/10 of its initial value using R=10000Ω