2, Consider a parallel plate capacitor with area A=1000cm^2, the distance between two plates is d=1.0mm. It is charged to 9V, then battery is removed. Fill 1/2 of the area (a) Find the charge and the energy stored in this capacitor when there is nothing between the two plates. (b) Now we insert a dielectric material (dielectric constant 3.2) into this capacitor, and fill half of it (See Figure 2) Dielectric material Find the capacitance of this new system, work out the energy stored in it, then evaluate how much work you need to do in order to insert the dielectric to this position. Figure 2 (c ) What is the answer to (b) if the battery is remain connected (d) We insert the dielectric material in another way, as shown in Figure 3. Find the capacitance of this new system. 1/2 d materia Figure3