Need help with practice problem!

S251 : A) A parallel-plate capacitor with circular plates (each with diameter of 16.0 cm) and are 5 mm apart. The capacitor is connected across the terminals of a battery of 100 V. a) Calculate the magnitude of charge Q on each plate in uC? b) Calculate the electric eld E between the two plates. c) calculate the energy stored in the capacitor. (1) If the battery is disconnected between the two plates, then one of the plates is moved by 2 mm toward the other plate. What is the new capacitance of the two plates? e) Calculate the new charge on each plate. f) Calculate the new voltage between the plates of the capacitor