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Thread Statistics | Show CCP posts - 2 post(s) |
YouGotRipped
Ewigkeit
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Posted - 2008.09.15 09:00:00 -
[241]
Edited by: YouGotRipped on 15/09/2008 09:06:01
 Originally by: Reven Cordelle
Originally by: Crumplecorn
People who wander in towards the end and repeat that the plane won't take off look particularly stupid.
Kinda just reinforces the fact people don't even read half of the thread before posting.
I wonder if the "Plane don't take off" crowd are part of the "Flat-Earth Society"?
Ah yes, page 9, almost there.
You people find a subject that proves to you that you're more intelligent than others and you tread it to death because there's something in it that makes you feel special.
This particular guy that I'm quoting is not satisfied with that alone but seeks other means of self gratification.
And of course there are also the trolls that love to claim the contrary of whatever is generally accepted just to mock the guys above.
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Nathanial Victor
Minmatar
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Posted - 2008.09.15 09:06:00 -
[242]
the answer either way assumes some things, but in the right conditions BOTH yes and no are acceptable (which is why its such a mind boggling question)
/me prepares to put one foot in the 'it wont' crowd
its simple. the wings need lift, to do that it needs a particular amount of air moving over (and under) the wings
the argument is flawed as the conveyor wont inhibit the craft to take off, it cant. or can it? 
if the plane can't generate ANY forward momentum, then the only chance it has of taking off is the wind coming off the props (not likely but depending on weight, possible w/ a model). so there is the 'NO it can't' crowd
/me puts the other foot in the 'yes it will' crowd
fact is the conveyor used in experiments like myth busters wasn't dynamically changing and perfectly proportional to the forward momentum of the craft.
it only makes sense the only way it IS possible is that the wheels moving against the conveyor belt are free moving and that the craft propels itself past the speed the conveyor is moving, thus providing lift and taking off
this can likely seem to happen almost instantaneously as once it overcomes that conveyor speed, the engines are likely running so high, the first chance it overcomes that conveyor speed it will be very quickly accelerating and taking off.
the answer is 'it depends'  , either way, for a airplane to take off, it needs to generate lift, this is not done by cranking the engines up, its dont by wind OR forward momentum
"one more spam thread will get you a warning.
- Thanks Hutch. "
isn't a warning of a warning a warning? or just a warning of a warning? didnt he just get 'the warning'?
my head hurts |
Nathanial Victor
Minmatar
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Posted - 2008.09.15 09:12:00 -
[243]
to be even more of a pain in the arse, i'll contest that it DOES matter whether your speaking of jet propulsion or propeller (some would say it doesn't matter)
a light prop craft can and will generate enough wind over the wings to supply lift, a jet engine mounted below the wings will NOT. IF your conveyor perfectly matches craft speed, a jet plane simply cannot take off
"one more spam thread will get you a warning.
- Thanks Hutch. "
isn't a warning of a warning a warning? or just a warning of a warning? didnt he just get 'the warning'?
my head hurts |
Crumplecorn
Gallente
Eve Cluster Explorations
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Posted - 2008.09.15 09:24:00 -
[244]
Where do you people get the idea that a conveyor matching the aircraft's speed will have any measurable effect on it?
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DesuSigs |
Nathanial Victor
Minmatar
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Posted - 2008.09.15 09:35:00 -
[245]
Edited by: Nathanial Victor on 15/09/2008 09:37:45
Originally by: Crumplecorn
Edited by: Crumplecorn on 15/09/2008 09:29:42
Where do you get the idea that a conveyor matching the aircraft's speed will have any measurable effect on it?
where does anyone get the idea that a craft can take off without any forward momentum or lift on the wings?
i dont see anyone mentioning craft weight either. do you think that would have ANYTHING to bear on the conversation?
there are too many variables and unknowns to simply chop the argument down to: will a plane on a conveyor belt take off? and think it will always be 'yes' or 'no'
to answer your question and make it a bit simpler: the answer, in the real world, will be YES taking away so many variables. the plane will overcome the speed of the conveyor.
it must or it wont take off (barring a prop giving lift to the wings)
if there were no limits on the speed the conveyor and the aircrafts wheels could move, you would simply approach infinity and NO, the craft would NOT take off
"one more spam thread will get you a warning.
- Thanks Hutch. "
isn't a warning of a warning a warning? or just a warning of a warning? didnt he just get 'the warning'?
my head hurts |
Crumplecorn
Gallente
Eve Cluster Explorations
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Posted - 2008.09.15 09:47:00 -
[246]
Originally by: Nathanial Victor
Edited by: Nathanial Victor on 15/09/2008 09:37:45
Originally by: Crumplecorn
Edited by: Crumplecorn on 15/09/2008 09:29:42
Where do you get the idea that a conveyor matching the aircraft's speed will have any measurable effect on it?
where does anyone get the idea that a craft can take off without any forward momentum or lift on the wings?
No-one is suggesting that. Read the thread again.
Originally by: Nathanial Victor
i dont see anyone mentioning craft weight either. do you think that would have ANYTHING to bear on the conversation?
No. If you double the weight of the plane, it is twice as hard for the engines to move it, but it would also be twice as hard for the conveyor belt to move it. So the question becomes, are we dealing with an aircraft capable of taking off at all? I think it's implied that we are.
Originally by: Nathanial Victor
there are too many variables and unknowns to simply chop the argument down to: will a plane on a conveyor belt take off? and think it will always be 'yes' or 'no'
No, there are not. The only thing being on a conveyor changes is the rotation rate of the wheels. It only changes one variable compared to real life.
Originally by: Nathanial Victor
to answer your question and make it a bit simpler: the answer, in the real world, will be YES taking away so many variables. the plane will overcome the speed of the conveyor.
it must or it wont take off (barring a prop giving lift to the wings)
if there were no limits on the speed the conveyor and the aircrafts wheels could move, you would simply approach infinity and NO, the craft would NOT take off
How would it approach infinity? Know a lot of aircraft that travel at infinite velocity, do you?
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DesuSigs |
Kwuggy
Amarr
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Posted - 2008.09.15 10:04:00 -
[247]
Kay, hopefully this will help all you no-sayers to see what wheels do for airplanes.
Pretend that the airplane was hovering instead. Only an inch above the ground, with no use of engines for it or whatever (pretend it's magnets if you have to). Now, position it on the conveyor belt. Will it matter what speed the conveyor is moving at? No, because the wheels aren't touching the belt.
That's the principle of the wheels, theoretically the belt could move HELLA fast, 4-5 times faster than the plane could ever fly, and the plane still wouldn't move backwards (if the wheel friction is low enough). The weels are just to keep the body of the airplane from scratching the ground. Remove the friction and the conveyor can move any direction and any speed it feels like, without being able to move the airplane.
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Evanade
Rionnag Alba
Triumvirate.
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Posted - 2008.09.15 10:38:00 -
[248]
Haha, this still going?
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sok alt - main got banzored |
Crumplecorn
Gallente
Eve Cluster Explorations
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Posted - 2008.09.15 11:06:00 -
[249]
Originally by: Evanade
Haha, this still going?
Threads with conveyor belts always take off.
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DesuSigs |
Dimitryy
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Posted - 2008.09.15 12:49:00 -
[250]
Originally by: Akita T
Edited by: Akita T on 11/09/2008 15:13:22
__
Seriously, I never heard of it before today (although it's supposedly quite a heated "internet argument"), and it was just an obscure reference in the latest XKCD "footnote" (but the discussion thread in the forums was quite... ahem... lively).
Still, I almost couldn't believe it IS an argument at all in the first place.
I mean, I knew there's plenty of dense people who never paid any attention in basic physics, but to hear that people who CLAIM to be pilots or engineers are arguing about the incorrect answer is just... ungh.
If you are like me and never heard of the thought experiment until today, I'll spare you the google search time and just post it here... I'm curious what the rationale any of you can provide for the WRONG answer.
" An airplane is standing on a (very/sufficiently) long, powerful and fast conveyor belt.
The airplane pilot attempts to take off moving forward.
The controller of the conveyor belt is making the conveyor belt move in the opposite direction with the same speed.
Can the plane take off, yes or no ? "
Clarification picture
NOTE: added picture as picture too, since it appears nobody's really bother to look at it.
Obviously, the RIGHT answer is that it DOES take off, that's what theory says.
Not only that, but it's apparently been done IN PRACTICE too :
Linkage (thanks Archonus for the link).
LOL Me and a freind debated this for like an hour, it turns out it depends on what kind of airplane. If it has a propeller, the speed in relation to the ground doesn't make any difference, b/cause it throws the air over the wings, generating lift. If it's a jet aircraft, it does matter, because jet engines don't throw air over the wings, they speed the plane up enough that the airflow over the wings lifts it. So yeah... Crazy...
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Suze'Rain
Caldari
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Posted - 2008.09.15 13:08:00 -
[251]
Originally by: Dimitryy
LOL Me and a freind debated this for like an hour, it turns out it depends on what kind of airplane. If it has a propeller, the speed in relation to the ground doesn't make any difference, b/cause it throws the air over the wings, generating lift. If it's a jet aircraft, it does matter, because jet engines don't throw air over the wings, they speed the plane up enough that the airflow over the wings lifts it. So yeah... Crazy...
*breaks keyboard headbutting the table*
For what its worth, a propeller does'nt "throw air over the wings".
another term for a propeller was an "airscrew". the blades have an airfoil section, much like a wing, which generates lift as it passes through the air. except as it's mounted and rotating, that lift then trasfers to forward motion. same as a helicoper blade rotating produces lift making that rise upwards.
Either way, jet or prop, it makes no difference to groundspeed, so, erm, may I suggest you do a little more research of this whole wonderful science called "physics" before you debate it in future, mate?
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Evanade
Rionnag Alba
Triumvirate.
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Posted - 2008.09.15 13:15:00 -
[252]
Put it this way:
If an airplane starts to take off it slowly gains speed and eventually has enough velocity so that it can take off. That's on a normal concrete runway.
Replacing the runway with a conveyor belt doesnt change anything about this. Despite the fact that the 'surface' on which the plane stands is moving it will still attain the same velocity eventually compared to the solid ground under the belt, albeit slightly slower due to the extra resistance caused by the wheels having to turn faster.
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sok alt - main got banzored |
Slade Trillgon
Siorai Iontach
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Posted - 2008.09.15 13:19:00 -
[253]
Originally by: Crumplecorn
Originally by: Evanade
Haha, this still going?
Threads with conveyor belts always take off.
This one not only took off, but it is now reaching the upper regions of the atmosphere. 
Slade
Originally by: Crumplecorn
NerfBat is now known as the WaveMachine.
DesuSigs
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Crumplecorn
Gallente
Eve Cluster Explorations
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Posted - 2008.09.15 13:58:00 -
[254]
Anyone who brings up the difference between propeller driven and jet driven aircraft has already failed, as there is no difference between them which has any bearing on a meaningful response to this problem.
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DesuSigs |
Dimitryy
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Posted - 2008.09.15 14:03:00 -
[255]
Edited by: Dimitryy on 15/09/2008 14:05:14
Originally by: Evanade
Put it this way:
If an airplane starts to take off it slowly gains speed and eventually has enough velocity so that it can take off. That's on a normal concrete runway.
Replacing the runway with a conveyor belt doesnt change anything about this. Despite the fact that the 'surface' on which the plane stands is moving it will still attain the same velocity eventually compared to the solid ground under the belt, albeit slightly slower due to the extra resistance caused by the wheels having to turn faster.
Then i still dont understand how the airplane gets lift. I understand that the plane will be moving at the speed it needs to relative to the ground, but since the air above the wing is standing still, thus giving no lift, how is it taking off? It seems you could show this exact situation by holding a plane still in the air and spinning the wheels really fast, i dont understand why it would take off.
Edit: what i mean by "air is standing still" is that it is not passing over the wing in any way, so there should be no lift.
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Evanade
Rionnag Alba
Triumvirate.
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Posted - 2008.09.15 14:10:00 -
[256]
Edited by: Evanade on 15/09/2008 14:12:25
Edited by: Evanade on 15/09/2008 14:11:37
Originally by: Dimitryy
Edited by: Dimitryy on 15/09/2008 14:05:14
Originally by: Evanade
Put it this way:
If an airplane starts to take off it slowly gains speed and eventually has enough velocity so that it can take off. That's on a normal concrete runway.
Replacing the runway with a conveyor belt doesnt change anything about this. Despite the fact that the 'surface' on which the plane stands is moving it will still attain the same velocity eventually compared to the solid ground under the belt, albeit slightly slower due to the extra resistance caused by the wheels having to turn faster.
Then i still dont understand how the airplane gets lift. I understand that the plane will be moving at the speed it needs to relative to the ground, but since the air above the wing is standing still, thus giving no lift, how is it taking off? It seems you could show this exact situation by holding a plane still in the air and spinning the wheels really fast, i dont understand why it would take off.
Edit: what i mean by "air is standing still" is that it is not passing over the wing in any way, so there should be no lift.
The plane will still be moving relative to the solid ground and thus to the air, creating lift, and moving very fast relative to the conveyor belt. The effect of the belt on the speed of the plane is nil, efect on wheel speed is alot.
The situation you project is WRONG as the plane IS moving forward, just the wheels are spinning fatser than in the normal situation.
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sok alt - main got banzored |
Merin Ryskin
Peregrine Industries
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Posted - 2008.09.15 14:20:00 -
[257]
Originally by: Suze'Rain
*breaks keyboard headbutting the table*
For what its worth, a propeller does'nt "throw air over the wings"..
[nitpick]
Actually it does, to some degree. This is why, to give one example, prop planes are much more resistant to low-level wind shear, increase power and you immediately have more lift from the wings. Get a sudden downdraft and start sinking too fast in a big jet (engines under or behind the wings) and it might kill you, while I just push the throttle in a bit and hardly even notice.
Not that it's enough to get the plane off the ground, of course, otherwise those short-field takeoffs (hold the brakes as you put in full power) might get kind of interesting...
[/nitpick]
Originally by: Dimitryy
Then i still dont understand how the airplane gets lift. I understand that the plane will be moving at the speed it needs to relative to the ground, but since the air above the wing is standing still, thus giving no lift, how is it taking off? It seems you could show this exact situation by holding a plane still in the air and spinning the wheels really fast, i dont understand why it would take off.
The airplane gets lift because it isn't standing still relative to the air. The moving belt has no way to apply any meaningful force to the airplane to counter the forward force from its engines, so the plane moves forward with the following speeds:
Relative to the air around it: 1x speed
Relative to a fixed point on the ground next to the runway: 1x speed
Relative to a point on the moving belt: 2x speed
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Kolmogorow
Freedom Resources
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Posted - 2008.09.15 14:34:00 -
[258]
"The airplane pilot attempts to take off moving forward."
What is he moving forward? Himself? Walking through the cabin? No, no, no, I don't believe that the plane will take off...
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Dimitryy
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Posted - 2008.09.15 14:36:00 -
[259]
Edited by: Dimitryy on 15/09/2008 14:38:28
Maybe i'm missing something with the original question, or the physics of acceleration, not quite sure. How would it be moving at 1x speed with the air and a stationary point on the runway? Lets say its pulling 120mph; thus the convayor belt is moving 120mph in the opposite direction. If it was moving at 1x speed with relation to the runway, it would be going 120mph forward, but since the convayor belt is there, it would have 0 forward momentum. If it has 0 forward momentum, no air passes over its wings, right?
For example, if it's started 10ft from a hanger, an hour later it will still be 10 ft from a hanger, not moveing b/cause of the conveyor belt matching it's speed. Now how would the fact that it's wheels are moving 120mph equate to air moving over it's wings at 120mph?.
EDIT: Holy shit i get it now. TY to everyone who helped explain it lol
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P'uck
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Posted - 2008.09.15 14:37:00 -
[260]
Edited by: P''uck on 15/09/2008 14:38:45
Originally by: Merin Ryskin
[nitpick]Actually it does, to some degree. This is why, to give one example, prop planes are much more resistant to low-level wind shear, increase power and you immediately have more lift from the wings. Get a sudden downdraft and start sinking too fast in a big jet (engines under or behind the wings) and it might kill you, while I just push the throttle in a bit and hardly even notice.
Not that it's enough to get the plane off the ground, of course, otherwise those short-field takeoffs (hold the brakes as you put in full power) might get kind of interesting...[/nitpick]
OMG you just injected an infinite amount of confusion into the thread!
(But it's nice to see there are people out there with a clue)
Originally by: Dimitryy
stuff
Because the belt actually CANNOT counter the movement of the plane enough. It might slow it down by a knot or two, if even. But thats it.
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Dimitryy
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Posted - 2008.09.15 14:44:00 -
[261]
Edited by: Dimitryy on 15/09/2008 14:46:01
Haha i get it. Really seems simple now... the wheels are free moving, cause it's a plane, not a car 
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Evanade
Rionnag Alba
Triumvirate.
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Posted - 2008.09.15 16:05:00 -
[262]
Originally by: Dimitryy
Edited by: Dimitryy on 15/09/2008 14:47:38
Edited by: Dimitryy on 15/09/2008 14:46:01
Haha i get it. Really seems simple now... the wheels are free moving, cause it's a plane, not a car
Now i'm gonna go back and read the postings of others who made the same mistake as me.
You can laugh at them, too
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sok alt - main got banzored |
Pwett
Minmatar
QUANT Corp.
QUANT Hegemony
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Posted - 2008.09.15 20:43:00 -
[263]
*scratches his chin*
In Russia, the plane prevents the conveyor belt from moving.
_______________
Pwett
CEO, Founder, & Executor
<Q> QUANT Hegemony
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P'uck
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Posted - 2008.09.15 20:51:00 -
[264]
Edited by: P''uck on 15/09/2008 20:51:49
No, no, no.
In soviet russia, conveyor belt prevents plane from moving 
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Mea Lustra
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Posted - 2008.09.15 20:54:00 -
[265]
Actually, in Russia it's the conveyor belt that takes off.
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Akita T
Caldari Navy Volunteer Task Force
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Posted - 2008.09.15 21:09:00 -
[266]
Originally by: Dionisius
Now lets see, you are dumb, you made a question with an preconceived answer and mind and launched it in public, then you copy an image that goes along with whats your conception of the right answer, failing to consider all variables and dismissing stuff.
Anyways you posted examples of things that were said and debated already, you are making up stuff that isn't in the original question and still you manage to create scenarios were you are trying to be right , and failing miserably at explaining them.
You sir are dumb beyond all recognition, and well i will point the only right thing you said in this entire thread,
Originally by: Akita T
(...) just for simplicity's sake LET'S ASSUME THERE IS NO WIND BLOWING THAT DAY (...)
Yes , keep it simple as in back to learning your abc's, as i said previously, certain persons are not meant to understand certain questions and its numerous possible answers.
So there, stick to your common folk failbusters tv show and mtv kids stuff, i think those are areas were you are more confortable with along with your trolling friends.
It's pointless even trying to explain it to you since you seem incapable of understanding it (or incapable of not acting like a ***** and actually reading what's been written).
I can say without a shadow of regret : you sir, are in serious need of professional help.
Now, what kind of help, that's really up to debate.
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SHOPS || Mission rewards revamp || better nanofix
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Mea Lustra
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Posted - 2008.09.15 21:19:00 -
[267]
I think he would reject help, just as he rejects logic.
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Crumplecorn
Gallente
Eve Cluster Explorations
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Posted - 2008.09.15 21:32:00 -
[268]
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DesuSigs |
Dmian
Gallente
Starline Engineering Corporation
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Posted - 2008.09.16 09:10:00 -
[269]
Edited by: Dmian on 16/09/2008 09:10:41
9 pages already? 
The meme factor of this topis is amazing!
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Eve Alpha - The font of Eve - Get it here |
MotherMoon
Huang Yinglong
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Posted - 2008.09.16 16:48:00 -
[270]
Edited by: MotherMoon on 16/09/2008 16:51:12
Quote:
fact is the conveyor used in experiments like myth busters wasn't dynamically changing and perfectly proportional to the forward momentum of the craft
the wheels are... oh you know what nvm I've not even going to get into it's been said 1000 times in this thread.
Quote:
Originally by: Dimitryy
Edited by: Dimitryy on 15/09/2008 14:47:38 Edited by: Dimitryy on 15/09/2008 14:46:01 Haha i get it. Really seems simple now... the wheels are free moving, cause it's a plane, not a car Now i'm gonna go back and read the postings of others who made the same mistake as me.
huzzah! \o/
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