Lightning As a crude model for lightning, consider the ground to be one plate of a parallel-plate capacitor and a cloud at an altitude of 470m to be the other plate. Assume the surface area of the cloud to be the same as the area of a square that is 0.80km on a side. (Dielectric strength of air is 3.0 \times 10^6 \; \rm V/m)
What is the capacitance of this capacitor?
How much charge can the cloud hold before the dielectric strength of the air is exceeded and a spark (lightning) results?