A capacitor consists of two parallel plates measuring 12.0 cm x 12.0 cm each and the distance between them is 4.50 mm. Half of the space between these plates only contains air, but the other half is filled with Plexiglas® having a dielectric constant of 3.40 (see figure). An 18,0 V battery is connected to the plates. (a) How much is the capacity of this combination? (b) How much energy is stored in the capacitor? (c) If we remove Plexiglas® and nothing changes, how much energy will be stored in the capacitor