The switch above the 12 V source in the circuit of Fig. 8.60 has been closed since just af...

The switch above the 12 V source in the circuit of Fig. 8.60 has been closed since just after the wheel was invented. It is finally thrown open at t = 0.(a) Compute the circuit time constant, (b) Obtain an expression for υ(t) valid for t > 0. (c) Calculate the energy stored in the capacitor 170 ms after the switch is opened.