When a 360-nF air capacitor (1 nF = 10-9 F) is connected to a power supply, the

Question:

When a 360-nF air capacitor (1 nF = 10-9 F) is connected to a power supply, the energy stored in the capacitor is 1.85 X 10-5 J. While the capacitor is kept connected to the power supply, a slab of dielectric is inserted that completely fills the space between the plates. This increases the stored energy)' by 2.32 X 10-5 J.
(a) What is the potential difference between the capacitor plates?
(b) What is the dielectric constant of the slab?