Originally Posted by
Vessbot
Sure you can. If your last sentence is true, then it is not a meaningful analysis that in Scenario A the Cessna went from 90 to 110 groundspeed when turning East to West. Did you look at scenario A? Do you think that's meaningful or meaningless?
From a physics standpoint, it is completely meaningless. You are making the identical mistake that Ian was making. In your Scenario A, From the frame of reference of the ground, the airplane went from a velocity +110 knots to a velocity of -90 for a total change in velocity of 200 knots.