Velocity is a vector. Therefore, it depends on the direction. Pilots need to know the direction of wind, not just the speed. If the pilot is going South, and there's 5 mph wind going South, they'll be happy, but if the wind is going 5 mph North, they'll be going against the wind.
The electric field is given by volts/distance:
. The breakdown voltage of dry air is about 3x10^6V/m. So solving for V we get
or
A. physical
they represent real things except at a much smaller scale so they are relatable to humans.(..)