The four capacitors in the circuit in Figure are connected across the terminals of a black...

The four capacitors in the circuit in Figure are connected across the terminals of a black box at t = 0. The resulting current ib for t > 0 is known to be

If va(0) = -20 V, vc(0) = -30 V, and vd(0) = 250 V, find the following for t ≥ 0: (a) vb(t), (b) va(t), (c) vc(t), (d) vd(t), (e) i1,(t), and (f) i2(t).