There is a parallel plate capacitor with plate separation s,length L and charge q. A long di electric plate of thickness s/3and relative permittivity εr is midway between the plates andpenetrates a distance d. Assume the width of all the platesperpendicular to the plane is w.
a.) Calculate the capacitance of this system, neglectingfringing.
b.) Use the method of virtual work to calculate theelectrostatic force, in the direction of increasing d, on thedielectic plate.