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I'm still hoping that someone can prove to me, once and for all, if that plane on the treadmill can lift or not? I say it will not..But..?Awh, come on now, myth-busters has defined it as lifting, and the majority of that physics community I was on then seemed to think it should too?==the exact quote;A plane is standing on runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction).The question is:Will the plane take off or not? Will it be able to run up and take off? ==end.Jump right in, but prove your point sientiflicly please, I do have some standards? I think?
Quite so, and to get it from a 'standing position' you need
"Quite so, and to get it from a 'standing position' you need "A F***ing great engine pushing it, and nothing but air resistance holding it back.(whatever the wheels and the ground are doing)
Still I withhold that what makes lift is the speed relative the surface. Without that speed you won't get any downward pressure, aka 'lift' of the aircraft.
Well, that's where we diverge BC.
Quote from: yor_on on 31/03/2011 20:26:17Still I withhold that what makes lift is the speed relative the surface. Without that speed you won't get any downward pressure, aka 'lift' of the aircraft.No, the lift is created by airflow over the wings. The ground has nothing to do with it. http://www.youtube.com/watch?v=JslkmigogKYThe aerofoil in this video has no 'speed relative to the surface'. Well, except for when it goes up.
Well, if it was ice and skates that plane would find it a lot easier to get into a 'real motion' relative the earths 'starting-mark'
No, it would not!! You seem to be making a very bad assumption about how much friction wheels produce. They are hardly any different from ice skates.The amount of thrust that the engines have to produce to overcome the rolling resistance of the wheels is negligible compared with the thrust required to accelerate the mass of the plane and the thrust required to overcome wind resistance.
I'm not speaking about friction?You are Geezer.I'm speaking of the mass, the weight resting on the wheels before it gets its lift.
This is not a good comparison The wheels will turn, skates don't.Sh* nobody but me that sees it?As for the rest, let's take that as a new question as it's not the same.Because with skates it would be different, as you say.
Am I to understand this to mean that, according to you, there is no difference between 10 kg resting on three wheels, or 10 tons?
The inertia will differ, and it won't disappear just because it starts to roll Geezer. It's there along with the mass. Even though it will lessen with speed and lift I guess.