A lightning flash transfers 8.0 C of charge and 8.5 MJ of energy to the Earth . i) Between what potential difference did it travel?

/in /by

A lightning flash transfers 8.0 C of charge and 8.5 MJ of energy to the Earth .
i) Between what potential difference did it travel?
ii) How much water could this boil, starting from temperature of 20.0 Degree Celcius ?
(Given c of water = 4186.0 J/kg C , Latent heat of fusion : 2.256 x 10^6 J/kg)