Question

a circuit consists of two identical parallel metallic plates connected by identical metallic springs to a 102V battery. With the switch open, the plates are uncharged, are separated by a distance d=7.80mm, and have a capacitance C=2.00microF. When the switch is closed, the distance between the plates decreases by a factor of .500. (a)How much charge collects on each plate
(b)What is the spring constant for each spring?