A 20.0-F capacitor is charged by a 150.0-V power sopply, then disconnected from the power and connected

Question:

A 20.0-µF capacitor is charged by a 150.0-V power sopply, then disconnected from the power and connected in series with a 0.280-mH inductor. Calculate:
(a) The oscillation frequency of the circuit;
(b) The energy stored in the capacitor at time t = 0 ms (the moment of connection with the inductor);
(c) The energy stored in the inductor alt = 1.30 ms.