A capacitor of capacitance C = 500 nF is charged to a voltage of 900 V and is then discharged through a resistance R = 200 kS when a switch is closed. (i) Find the initial charge stored in the capacitor. (ii) Find the initial discharge current when the switch is closed. (iii) Find the voltage across the capacitor in a time t = 25 s after the start of discharge. (iv) Find the time constant of this capacitor resistor network combination. (v) Work out an equation to show the time it takes for the charge in the capacitor to drop by one-half of its starting value and find this time.