Not seen this for a while and never on this NEW forum...
Sorry by the way...
Yes, it will.
[center]The End[/center]
Yes. I mean no. Yes. No.
Yes. Absolutely. Yes. Actually, No. Yes, No.
Yes, but the wheels will go round faster or summink.
No no no no no no no....
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Not this. Not again. No. Please....
Depends on how you word the question.
how powerful is the plane?
Is it an African plane or a European one 😐
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This has been on the tv programme "Myth Busters" They fixed a massive piece of papaer to the back of a car, with a remote control plane on it. The car set off and got some speed up and the plane took off.
Thread closed!!!!!!!!!!! I bet its not!!!!!!!!! 😳 🙄 😯 🙂
Is it sharp?
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What about a helicoptor on a turntable?
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WELL?
Edit: beaten by WCA!
If its on a conveyer belt then it must still be in the factory, so its not finished yet. It will fly, but not yet. Patience is whats required
jet enngine or turbo prop ??????
I can't believe I've never heard this argument before! Which way is the conveyor going. Is the aircraft powered or not?
Scenario 1. ac not powered but conveyor moving it quickly enough through the air to create lift then it will take off, then stall.
Scenario 2 ac moving under its own power at the same speed that the conveyor moves in the opposite direction. No air over wings, no lift, no take off.
I live next to 2 airfields and know lots of aerospace engineers so i obviously know what I'm on about. If you disagree with me you will feel my rock and power washer.
Either you're a poor troll Devs, or.......
Devs - you've got to assume the brakes are off and they are frictionless... actually, i'm not even going to go there.
zokes - MemberEither you're a poor troll Devs, or.......
zokes, how did you work that one out, he's the first person on this thread to speak any real sense (though in fairness, he could have worded what he said a bit better).
AIR SPEED over the planes wings is ALL THAT MATTERS, the wheels on a plane are totally unconnected to the planes ability to get airborne. Conveyor belt moving at 200mph in a normal atmospheric environment (ie. not a vacuum) will result in enough air speed over the wings of most planes to make them take off, though if the engines aren't running, it will stall and hit the ground.
Regarding helicopter on a turntable. Well, even at 78rpm it's not likely. I'd much rather be the pilot in the plane on the conveyor belt than the poor dizzy bastard in the helicopter! 😉
How about a pogo stick on a bouncy castle?
devs... it's a conveyor that matches the plane speed in the opposite direction, so your scenario 2. Unfortunately you are wrong in that you think it won't take off though.. 😀
mboy... so certain again huh? 😉
Good grief
The world is flat! Flat I tell thee!
There are some thick ****s in this world.
It's just like driving your car and the steering wheel coming off. We all know this thread is going to be painful, but we're in it and we're just going to have to wait for the sickening crunch. 😉
Some people don't seem to have noticed my first reply. So, I'll repeat it:
[center][b]THE END[/b][/center]
devs... it's a conveyor that matches the plane speed in the opposite direction, so your scenario 2. Unfortunately you are wrong in that you think it won't take off though.. [:D]
It won't. The ac is standing still with regards to the air. It has no airspeed. There is no air [1] going over the wings to provide any lift so it cannot take off.
[1] Except for maybe some prop wash but this alone is not enough to make a plane take off otherwise they would be capable of vertical take off from a standing start.
It takes off!!!!!!!!!!!!!
[center][b]THE END!!![/b][/center]
Devs, seriously, it will.
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And indeed
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Accept defeat.
There're [url= http://www.google.com/search?q=plane+conveyor+belt ]lots of explanations on the web as to why it will take off[/url]. There's a [url=
of a model airplane on a conveyor belt, which takes off[/url]. [url= http://www.youtube.com/watch?v=YORCk1BN7QY ]Mythbusters made what was in essence a giant conveyor belt from which a plane took off[/url].
Why do people insist on arguing that it won't take off?
miketually.. it's because they 'know' better than everyone else of course... 😀
Or because they live near an airfield and so know lots of pilots?
Having read up on this now. If the wheels were frictionless i.e. the ac stood still if the conveyer moved backwards then the ac could take off put that is not how the question is worded. Forward speed does not equal conveyor speed in that case. To all the nay sayers take a kite down the park and run with it till it takes off. Then go down the gym and run on a running machine with the kite. When it takes off come back here and post the results.
The wheels don't really need to be frictionless - that's just to avoid people saying [i]"Ah.. but if the conveyor belt was going backwards at an infinite speed then the friction alone would be enough to hold back the plane"[/i]
In reality, with an actual plane and an actual conveyor belt as long as a runway it would easily take off.
go down the gym and run on a running machine with the kite
"go down the gym and run on a running machine with a kite that has jet engines attached to it"
Fixed that for you. 🙂
If the forward speed equaled the conveyor speed, then if the aeroplane is stationary, then so is the conveyor. For the conveyor to have any speed at all, then the aircraft must have forward speed...
If the aircraft has forward speed, then it must be moving through the air...
Now follow that through.
As for the attempted kite analogy, well, unfortunately it's incorrect.
D- (must try harder) 😉
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Of course not. The wings would hit the uprights on the treadmill.
Yes, so long as:
- the plane is capable of taking off on a normal run way
- the converyor belt isn't going so fast that the friction in the landing gear wheel bearings prevents the plane reaching its min speed for take off.
(- the plane doesn't hit the treadmill uprights as per 5th elefant 😉 )
Blimey - haven't heard this one before but it's amazing how confused people can get themselves on something relatively straight forward. "Wood" and "trees" spring to mind.
Oh, and yes it would take off 😉
this has confused me for years.
i just 'got it' thanks to GrahamS' point about the conveyor needing to be as long as the runway
boy do i feel stupid
OK, I think I get this....the question is written such that it makes you reason that the plane will remain stationary.
But actually it says that the plane will [b]move[/b] at a certain speed in one direction, while the conveyor will [b]move[/b] in the opposite direction at the same speed. So, both the plane and the conveyor are moving in opposite directions down the runway.
It's all about RELATIVE velocity.
To an observer on the ground in between the two vehicles, they are both going at takeoff speed, but in opposite directions. However, an observer on the pick-up truck is stationary RELATIVE to the truck and will see the plane move away from him at 2x the takeoff speed; hence it can takeoff.
If the question was worded so that the pilot applied the normal power required for takeoff speed to be attained and the pick-up truck drove at takeoff speed in the opposite direction, then the plane would remain stationary, as all the thrust is going into pushing the plane at +v m/s but the conveyor is cancelling that out with it's -v m/s.
stumpy... you were so so close, but then you mucked it all up in the last paragraph...
If the question was worded so that the pilot applied the normal power required for takeoff speed to be attained and the pick-up truck drove at takeoff speed in the opposite direction, then the plane would remain stationary, as all the thrust is going into pushing the plane at +v m/s but the conveyor is cancelling that out with it's -v m/s.
You were doing so well up until that last paragraph. The extra power needed from the plane is minimal, just enough to overcome the slight increase in friction in the wheel bearings.
Oh yeah......bollocks!! I see where I have made my blunder and I am now going to stub my toe by way of punishment.
😳
Will it bollocks. The plane is effectively stationery, therefore no lift under the wings from air rushing past.
I'm 3 years old btw
The confusion on this comes from one of two sources:
1) people being thick and not understanding how planes work and
2) some versions of the original question being worded in such a way as would render the plane unable to take off despite the required situation being impossible in the real world.
I fully understand all facets of the problem. I have full grasp of every possible angle and can see everything at once.
I have reached Nerdvana.
When the question is explained as in the cases below it's simple:
1) An airplane is sitting at rest on a very powerful treadmill. You are at the controls of the treadmill, while I am at the controls of the airplane. On some signal, I begin to attempt to take flight in the plane, and you attempt to match my speed to try to keep me stationary. Will the plane take off?
2) An airplane is sitting at rest on a very powerful treadmill. You are at the controls of the treadmill, while I am at the controls of the airplane. On some signal, I throttle up the airplane and you turn on the treadmill, and we conspire by our joint effort to try to keep the plane stationary relative to the ground. Will the plane take off?
3) An airplane is sitting at rest on a very powerful treadmill. You are at the controls of the treadmill, while I am at the controls of the airplane. On some signal, I attempt to take flight in the plane, but you match my speed with the treadmill and keep me stationary relative to the ground. Will the plane take off?
In case 1 it will take off providing the treadmill is long enough. Too much confusion and interpretation over the question. Nice to see the really intelligent people explaining their viewpoints with such clarity in terms such as "you're thick."
What if the ac wheel bearings were from Superstar?
devs.
it doesnt matter how powerful the tredmill is.
the only force holding the plane back is the friction in the wheel bearings.
which is a tiny amount, and in no way be noticable.
heck even a [url= http://uk.youtube.com/watch?v=tls-Jli6eQE ]man can pull a jet[/url] plane along the apron.
The point you are missing devs is that in case 3 there is nothing the treadmill operator can do to prevent the plane taking off. No matter how powerful the treadmill there is no way he can keep the plane stationary relative to the ground.
It will, of course, take off. However it will then hit a flock of birds, and crash. Hope you've positioned the treadmill near a river, and have a pilot named Cheeseburger?
If you had all read the link above which explains why people get the wrong idea about the question, only a complete idiot would try to attempt 3. Case 1 is the only question which has the answer yes the ac will take off. It's a good one though and has certainly had the old grey matter ticking over. The main problem with this one is getting everybody to see the same question. Now I have had it explained it really is simple.
LS, your statement is a bit daft if you think about it. I have pulled a 20 ton ac along the ground. The effort just about gave me piles. The treadmill would have to be very powerful. Your average gym jobber need not apply
devs, no matter how powerful the treadmill, there is no way it can stop the plane taking off. Ever.
devs... sorry for being so ignorant, but can you explain to a relative moron like myself exactly how you plan to keep an aircraft stationary by just using a rolling treadmill?
Superglue in the wheel bearings, or square wheels, would do it 🙂
aaaaaaggggggggghhhhhhhhhhhhhh
IF PLANE HAS AIR GO OVER WING FAST IT TAKE OFF
IF NO AIR GO OVER WING IT NO TAKE OFF
Pook... muuuuaaaaahahahahahaha
Yes Pook we know.
miketually... maybe a stick through the spokes would work too..
Okay, i think i can provide an explanation that might help those who are still confused.
A plane on a conveyor belt/treadmill is not like a human on a conveyor belt/treadmill. The human has to move their legs to stay still, and if the speed was increased enough they wouldn't even be able to do that, and would fly off the back.
HOWEVER the plane doesn't have legs. It has wheels. And (providing these have frictionless bearings) it can stay still on the conveyor belt/treadmill WHILE USING NO POWER - its wheels will just spin round underneath it. If it turns its engines on, it will move forward, and its wheels will spin even faster.
The idea of the plane on a treadmill of short length just doesn't work. It wouldn't take off, but it would hit the front of the treadmill straight away.
while we are dredging up the past, has anyone got any opinions on cheap disc brake pads?
Okay, i think i can provide an explanation that might help those who are still confused.
Another one that might help:
Strap a rocket to a shopping trolley and put that on the conveyor belt. Would that move along it?
Ooh, anyone got a YouTube video for that one?
TL:DR, but the aircraft going the opposite way to the conveyor theorey is arse!
that would apply if the power was being driven through the wheels, but its not, so it wont :s
as long as the engines apply enough power to overcome the inertia of the plane (the inertia causing it to move backwards on a backwards moving conveyor), the plane will move at the speed the engines dictate, the wheels will just spin, freely, twice as fast as on a static runway.
the engines, apply force to the static air around them, not to the surface the plane is resting on.
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But what if it was in a river?
<insert new level of complication here>
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in your FACE beardface!
simon wanders off muttering to find the sniper rifle and large box of hollow points
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miketually - Memberdevs, no matter how powerful the treadmill, there is no way it can stop the plane taking off. Ever.
Posted 1 hour ago #
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funkynick - Memberdevs... sorry for being so ignorant, but can you explain to a relative moron like myself exactly how you plan to keep an aircraft stationary by just using a rolling treadmill?
MT misses my point entirely. Scenario 3 which I pasted directly from a website that explains the whole thing would only be attempted by an idiot because of the reason you are trying to point out. The treadmill would need to be "powerful" to start the whole thing moving in the first place.
FN Are you taking the piss? Are we still in frictionless wonder land or the real world? In frictionless wonderworld the ac will stay still on a treadmill. In real world you would have to use enough forward thrust to counter the friction of bearing and weight on wheels on ground.
Any more thrust would give forward motion relative to the ground and air and lift would be produced.
What about if a helicopter is weighed in a box and then takes off and hovers. It's still inside the enclosed box so does the box weigh the same?
*becomes unsure as to whether devs is actually a post-ironic troll*
devs... sorry, I must be really thick or something, but are you really saying that the friction in the wheel bearings is enough to keep an aeroplane stationary when it's throttled up to try and take off?
No. Have you tried the fish?
In answer to your helicopter q yes the box should weigh the same as the helicopters rotors will be pushing air down.
How about a BIG fan blowing air at the plane!
How about a BIG fan blowing air at the plane!
From what direction?
Infront and not on a tredmill!
warm air or cold air?
Mmmmm...I'm thinking tepid air