Originally Posted by
Ian W
I choose the ground as my frame of reference then. Aircraft stationary in my frame of reference and in 30 seconds accelerates to 120kts. Or alternately is traveling at 120Kts and in 30 seconds becomes stationary
And what you're not grasping is that going from stationary to 120 knots is the identical change in velocity as going from 60 knots east to 60 knots west, and it requires the identical force exerted on the airplane by the air for the identical period of time, and both scenarios require overcoming the identical amount of inertia.