Interesting Electrical question from uni course

[Jimmy]

A  car  travels  at  100kmh?1.  It  will  cut  the  vertical  component  of  the  Earth's  field,  which  is
about

a. Estimate the potential difference across the bonnet if the car is 1.5m wide (state any
assumptions you make).
b. Say which side of the bonnet will be positive, if the car is heading West.

[Rerouter]

first thing i would state as an assumption would be that the car is driving along the equator and that where the car is driving is a uniform feild, at whatever earths relative magnetic feild is at sea level, as you can loose a little of your potential at other points from the magnetic feild not being perfectly spherical, equally the earths magnetic feild is spotchy with some parts stronger and weaker across the surface,

driving west would mean it would be cutting feild lines head on, so the math is very easy from there, with velocity and length, still interesting,

[free_electron]

My car is made from aluminum....

[Rerouter]

doesnt matter, so long as its conductive,

[8086]

Whole bonnet at same potential, trick question