Two parallel plates have a capacitance value of 0.17F when they are 1.5 mm apart. They are

Two parallel plates have a capacitance value of 0.17μF when they are 1.5 mm apart. They are connected permanently to a 100-V power supply. If you pull the plates out to a distance of 4.5 mm,
(a) What is the electric field between them?
(b) By how much has the capacitor’s charge changed?
(c) By how much has its energy storage changed?
(d) Repeat these calculations assuming the power supply is disconnected before you pull the plates further apart.