The area of the plates of a flat air capacitor is 100 cm^2 and the distance between them is 5 mm. A potential difference of 300 V is applied to the plates. After disconnecting the capacitor from the voltage source, the space between the plates is filled with ebonite (ε = 2.6). 1) What will be the potential difference between the plates after filling? 2) What is the capacitance of the capacitor before and after filling? 3) What is the energy of the capacitor before and after filling?

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