Chapter 4, Problem 4.14P

Suppose that at t= 0, we connect an uncharged 10 $\{\mu \text{F}$ capacitor to a charging circuit consisting of a 2500-V voltage source in series with a 2 $\{M\Omega$ resistance. At t= 40 s, the capacitor is disconnected from the charging circuit and connected in parallel with a 5 $\{M\Omega$ resistor. Determine the voltage across the capacitor at t =40 s and at t= 100 s. (Hint: You may find it convenient to redefine the time variable to be t’ = t-40 for the discharge interval so that the discharge starts at t’ = 0.)