Conveyor belt controversy put to rest :-)

[delta november 0]

>>>What I don't understand is that this isn't a terribly>>>difficult physics problem! :-lol >>>>I do have to grin a bit, when I see so many references to a>>rather "simple" physics problem, as though much of the>public>>are physics wizards.. :D >>Larry, this is simple eighth grade physics... ;)>>It may be essentially reduced to a case of four forces acting>on a single object: the aircraft.>>Force#1 is that which is imparted by the treadmill and>transmitted to the aircraft via the wheels. Since the friction>coefficient is negligible, the net force transmitted is>effectively ZERO.>>Force#2 is the force from the propellor. Since that force is>several magnitudes greater than the net opposite from Force#1,>it may be treated as though Force#1 does not exist.>>Force#3 is the force of gravity, which is a constant for our>purposes.>>Force#4 is that which is transmitted to the aircraft via the>'lift' from the wings (and let's not get sidetracked on>this topic!).>>Ergo, the presence or absence of Force#1 is reduced to>irrelevancy. The aircraft will take off, assuming the>pilot isn't too drunk to fly... ;)Bill;All I can say is I'm glad you chose the Priesthood instead ofaeronautical engineering :-lol

[michal 44]

>/ think that occurred. This is another one of those Hollywood fairy talesPeople who know physics don't need Hollywood fairy tales or Mythbusters programs. Only ignorants of this world will argue to death that the airplane won't fly. No similar experiment even on the grandest scale will overcome this ocean of stupidity.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[mgh 89]

Agreed!!!!Newton's Laws show without doubt that the aircraft will take off.

[Avcomware 1]

Hi.And you are swimming right in it. You seem to be very opinionated about things that you have no idea about. If things would have been that simple, do you dot think that others would have used this technique? You are probably in the group that thinks that a simmer can land a plane without any prior training in a real aircraft also. La la land. TV

[Vineguy 26]

Got this from an aeronautical engineer.This morning over coffee I had a chance to talk to Mitch and he put it very clearly....it's all relative to wind. And given those reference points you'd have zero wind resistance. Without achieving "displacement of life horizontally you can not achieve liftoff". If the plane were to increase relative speed in comparsion to the speed of the treadmill, and as he said it would have to be greatly increased relative speed it would be possible to acheive lift off, but he'd have to calculate exactly what that would be and you'd have to know the weight, type and of course all of the other known factors in order to do that

[lcseale53 0]

There are two - and only two - forces competing here, which are very simply thrust (rapidly spinning propeller in this case) and drag (wheel bearing and surface contact friction). We assume lift exceeds weight because it is, after all, an airplane.If the thrust generated by the prop overcomes the aforementioned friction, the airplane accelerates to flying speed.If the wheel bearing friction is greater than the generated thrust, the airplane is either stationary or moves backward with the conveyor/treadmill. Those are the only two considerations (obviously discounting gale force winds, etc.) period.Given reasonable maintenance we can expect a wheel bearing to function continuously at speeds in excess of - say - 100 knots, so a conveyor moving at that same 100 knots would not stop the airplane from accelerating to flying speed...but it might speed up luggage handling at some of the airports I've been through. Leon

[Guest airbus2]

People who think the plane could not take off will have difficulty explaining how a plane moves through the air after gear retraction!Dave

[michal 44]

>You seem to be very>opinionated about things that you have no idea about.Because I am a physicist by education. None of my colleagues who have at least MS in Physics doubted two seconds that this airplane will fly. I suspect your expertise is limited to bits, CPUs and how to tune FSX. Please stay away from subject you have no clue about - you only make a fool out of yourself.Michael J.http://img142.imageshack.us/img142/9320/apollo17vf7.jpg

[Avcomware 1]

Hi.I

[Manny 1,293]

Avcomware,Isn't it amazing? he calls himself a physicist. WOW! :)Manny

[Manny 1,293]

>People who think the plane could not take off will have>difficulty explaining how a plane moves through the air after>gear retraction!>>DaveThats cause..the RAM Air (IAS) is greater than stall speed. Now, imagine another aircraft hooked to this one was pulling it at the same speed in the opposite direction (The force of the conveyor belt). the IAS = 0 and ..it would fall.If he was sitting on a True Conveyor belt, that is moving the aircraft backward at the same speed the properler thrust is moving the aircraft forward, the RAM air/IAS = 0. Hence no fly.In that video, the alleged "conveyor" belt was not doing its job moving the aircraft backward. Cause conveyor was touching the ground and the wheel had friction with the ground. The cloth was simplu sliding underneath and so it was not a conveyor belt.Manny

[Avcomware 1]

Hi, Manny.It

[DadJokeCinema 145]

This is the part where every single one of you says a silent thank you to me for only locking this thread and not banning all of you.

[Guest airbus2]

>Thats cause..the RAM Air (IAS) is greater than stall speed.>Now, imagine another aircraft hooked to this one was pulling>it at the same speed in the opposite direction (The force of>the conveyor belt). the IAS = 0 and ..it would fall.>>If he was sitting on a True Conveyor belt, that is moving the>aircraft backward at the same speed the properler thrust is>moving the aircraft forward, the RAM air/IAS = 0. Hence no>fly.Ahh - but if a plane is on a conveyor belt, what is holding it back?Nothing! The engines push the plane forward.Imagine a rocket flying above a conveyor belt - it still goes forward.Now put that rocket on a skate board (a skateboard as you know has free spinning wheels) The rocket would still move forward, the only effect would be that the wheels on the skate board would spin at rocket speed + conveyor belt speed. Dave

[mgh 89]

Let's get back to basic principles.Newton's 2nd Law is:Force = Mass * Accelerationrecasting that gives:Acceleration = Force / MassConsider a stationary aircraft. If the throttles are opened the Force is the Thrust and the aircraft will accelerate and continue to increase speed, unless a magic force appears from somewhere which is exactly equal and opposite to the Thrust and also varies with it - if the pilot halves thust thrust this magic force would have to halve also.Where could this magic force come from? The answer is nowhere because it doesn't exist.