For a physics issues investigation I chose to investigate what effects lightning could have on an aeroplane while in flight if it was struck and then go on to discuss some possible implications of engineers not taking into account the power of positive lightning.
Just in-case you don't know what positive lightning is, my understanding of it at least is that when charges accumulate in clouds (I won't go into how) in most cases the underside of the cloud is negatively charged and the top of the cloud is positively charged. Basically positive lightning is a lot more powerful than negative lightning as it has a higher voltage and current.
Q1. How would you determine the potential difference between the underside of the cloud (given an overall charge) and the ground (given the overall charge) and hence the electric field strength. $E = V/d$ ? But how would I calculate the voltage?
Q2. I understand that $V = IR$. And this is why the voltage of a positive lightning strike is higher than a negative strike as the resistance for the positive strike is higher (it has to go out to the side of the cloud and THEN down). But why is the current higher? If $I = V/R$ and the resistance is higher, wouldn't the current be lower?
(This question probably isn't as high a level as many of the other questions on this site so you should find it quite easy to answer.)