An air-insulated parallel-plate capacitor of capacitance Co is charged to voltage Vo and then disconnected from the charging battery. A slab with dielectric constant k and thickness equal to the capacitor spacing is then inserted halfway into the capacitor (Fig. 23.16). Determine (a) the new capacitance, (b) the stored energy, (e) the force on the slab in terms of Co, Vo, k, and the plate length L.

An air-insulated parallel-plate capacitor of capacitance Co is charged to voltage Vo and then disconnected from the charging battery. A slab with dielectric constant k and thickness equal to the capacitor spacing is then inserted halfway into the capacitor (Fig. 23.16). Determine (a) the new capacitance, (b) the stored energy, (e) the force on the slab in terms of Co, Vo, k, and the plate length L.