33. A potential difference U1 = 1 kV is applied to the plates of a flat air condenser. The area of the plates S = 250 cm2, the distance between them d1 = 1 mm. The plates were extended to a distance of d2 = 3 mm. Determine the energy W1 and W2 of the capacitor before and after the expansion of the plates, if the voltage source before the extension: 1) did not turn off; 2) disconnected.

Detailed solution. Decorated in Microsoft Word 2003. (Target decided to use formula editor)