I do not understand, how can plasma travel at 3.3% the speed of light in the air? Wouldn't it still need to fight the pressure of the air and by that definition

I do not understand, how can plasma travel at 3.3% the speed of light in the air? Wouldn't it still need to fight the pressure of the air and by that definition the moment a projectile at 3.3% the speed of light bounces against of speck of air that plasma will immediately release most of it's energy dispersing in various directions?