That plane/conveyor problem - filmed solution
Discussion
For those who still can't see that the plane will take off, someone's made a film to prove the point that it would......
http://videos.streetfire.net/player.a
Apologies if this was shown before.
paulie-mafia said:
That skateboard / fan set-up bears no relation to the plane scenario. The skateboard doesn't have wings or anything to give it lift and the guy tugging the paper from underneath it is doing so in an inacurate manner that doesn't exactly match the opposing force of the fan / skateboard as it needs to.
Must......resist........urge......to.......respond
-DeaDLocK- said:
paulie-mafia said:
That skateboard / fan set-up bears no relation to the plane scenario. The skateboard doesn't have wings or anything to give it lift and the guy tugging the paper from underneath it is doing so in an inacurate manner that doesn't exactly match the opposing force of the fan / skateboard as it needs to.
Can't believe I'm doing this, but hey ho -
The contention in the original pointless threads wasn't really about lift. Lift is generated by movement of air under and over the wings, and movement of air is generated by forward travel. People simply could get their head around the fact that he plane would move forward in the first place, which is where the trouble arose.
In proving that it does actually move forward, this video is a very good demonstration of the physics involved. Once it moves forward, then you have lift and you have take off.
The fact that it isn't a real speed-matching conveyor belt doesn't matter - the guy could have pulled the piece of paper faster than the speed the wheels where turning but the skateboard would still move forward.
Sorry guys. Had to.
Fine work Deadlock. Now someone quickly lock it before the flatearth society come back and start posting....
ehyouwhat said:
Let's face it though guys, those on one side of the argument are not going to convince those on the other side today are we?
No, and it's unlikely that those of us who know it will take off will have the time to explain it to those that don't, before they get taken back to their special school.
I think the simple fact that escapes the doubters is that the horizontal retarding forces exerted by the wheels are minute compared to the forward thrust generated by the jet engine. In fact, the wheels could be rotating backwards and the plane at full thrust would still move forwards. Irrespective of how you read the question, a plane with free-wheeling wheels is going to take off regardless of what the conveyor belt or wheels are up to. The only way the conveyor belt could signifanctly inhibit the forward motion of the plane would be if the conveyor suddenly grew a large pair of clamps and grabbed hold of the plane.
hugoagogo said:
orgasmicliving!! said:
i think your question is stupid and does not provide enough facts to make it even remotely relevant. is the conveyor spinning? at what speed? matched to what? and, since you are posing a different question, why exactly do we need to go off on this tangent?
clearly as stated,
in your scenario you reckoned the engines could be at full thrust, the conveyor would be going at some undisclosed speed, matching that of the wheels which stops the aircraft from moving. keep the belt at that speed, instantly swap wheels for skids
what happens next?
simple
the question is as stupid as your answer
Actually the question is really just a simple one, but designed to get the initial response of nearly everyone who gives it just the briefest thought; that the plane won't take off - we're all so used to thinking of the wheels being driven as in a car. Once you think for slightly longer, and realise the wheels are effectively decoupled from the horizontal thrust from the engines, it's apparent the plane will reach Vlof irrespective of the comedy shenanigans of the magical conveyor.
xjsjohn said:
mini_ralf said:
orgasmicliving!! said:
mini_ralf said:
ehyouwhat said:
No! FFS have you actually read anything I've said?! The plane needs AIRSPEED, which it gains by way of the engines pushing against the air around them. So log as the air under the wings is moving fast enough the plane will take off, and in this instance the plane gathers that speed via way of the engines pushing against the air. Similarly if you sent air at a few hundred miles an hour head-on towards a stationary plane, the plane would take off.
Now I see where you're going wrong... The only airflow is through the engines and not over the wings hence no lift generated. The engines themselves don't generate lift.
Bacon & egg baguette from the excellent truckers cafe down the road. Superb thank you!
sounds class, you should be generating enough "airflow" yourself soon
So perhaps a new question is in order:
"If mini_ralf dons a pair of rollerskates and eats 10 bacon & egg baguettes - will the velocity of expelled anal gases (Vchuf) be sufficient to overcome rolling resistance and propel him back to whatever planet he and OrgasmicLiving came from?"
Edited by GingerNinja on Tuesday 12th December 14:18
orgasmicliving!! said:
ehyouwhat said:
I can see why some people cannot grasp how exactly a plane moves, I really can. At the beginning of the first thread many months ago I was firmly in the 'won't take off' camp of thought. But then I realised that the wheels of the plane are not what powers the plane, therefore the wheels can be moving however they want but the plane will be pushed forward by the engines. This forward movement (geographically, relative to the air and all of the ground except the runway) will in turn lead to air rushing past the wings, which creates lift, etc.
Edited by ehyouwhat on Tuesday 12th December 14:16
sorry, you are wrong. nobody is claiming that the wheels power the plane. where are you getting that from?
the wheels rolling over the ground (circular motion) results in the plane's linear motion. if they don't roll, then the plane will slide forward until they shred. we are not talking about that exception case here. instead we are talking about wheels rolling on a conveyor belt going in the opposite direction. meaning no linear motion.
Incorrect. The wheels roll over the ground as a RESULT of the planes horinzontal motion.
orgasmicliving!! said:
GingerNinja said:
orgasmicliving!! said:
ehyouwhat said:
I can see why some people cannot grasp how exactly a plane moves, I really can. At the beginning of the first thread many months ago I was firmly in the 'won't take off' camp of thought. But then I realised that the wheels of the plane are not what powers the plane, therefore the wheels can be moving however they want but the plane will be pushed forward by the engines. This forward movement (geographically, relative to the air and all of the ground except the runway) will in turn lead to air rushing past the wings, which creates lift, etc.
Edited by ehyouwhat on Tuesday 12th December 14:16
sorry, you are wrong. nobody is claiming that the wheels power the plane. where are you getting that from?
the wheels rolling over the ground (circular motion) results in the plane's linear motion. if they don't roll, then the plane will slide forward until they shred. we are not talking about that exception case here. instead we are talking about wheels rolling on a conveyor belt going in the opposite direction. meaning no linear motion.
Incorrect. The wheels roll over the ground as a RESULT of the planes horinzontal motion.
This is where you are entirely 100% delusionally wrong. The wheels will only move IF the plane has forward motion - the conveyor REACTS to the wheels. So in order for the conveyor to do anything, the wheels on the plane have to move, and in order for them to move, the plane HAS to move forward you see - as the wheels will ONLY ever rotate/accelerate as a result of forward motion of the plane.
Brink said:
Tris.E said:
GingerNinja said:
For those who still can't see that the plane will take off, someone's made a film to prove the point that it would......
http://videos.streetfire.net/player.a
Apologies if this was shown before.
THE PLANE WILL STAY ON THE GROUNG WHY CANT YOU SEE THAT IT WILL??????????????
Ok, Ginge, how do hellicopters take off then? Does the pilot have to spin a wheel next to his seat? What about the Shuttle? Does that have a secret wheel somewhere that winds up to a galaxic speed to make ordit?
As I said eariler, Boo!lux.
Ladies and Gentlemen, it is with great pleasure that I can introduce to you the nonsensical star of Viz; Roger Irrelevant.
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