A series RC circuit, with R = 10 and C = 4 F, has an initial

A series RC circuit, with R = 10 Ω and C = 4 μF, has an initial charge Q₀ = 800 μC on the capacitor at the time the switch is closed, which results in applying a constant-voltage source V = 100 V. Find the resulting current transient if the charge is

(a) Of the same polarity as that deposited by the source, and

(b) Of the opposite polarity.