WILL IT FLY?
- Thread starter Jotaru
- Start date
Byrdman
Ranger God
Aerospace guy (admittedly wrong about my first assumption. Anyway, wind effects the pitot tube, but thats because the pitot tube only measures the relative airspeed. However, only the wind component that is parallel with the pitot tube effects it.
Araius
Fatty Pirate
Okay so, I think where the "It won't fly" crew (myself included) was the premise of the treadmill being only a few feet long, thus giving the plane no time to accelerate before taking off. I hadn't read this thread but Kal's comment about the treadmill is as long as you want it to be is the key point. That and Jot's comment about the question really being more about "Will it move?".
Of course it wouldn't fly if, by the time the engines kicked on and allowed the plane to move forward enough to counteract the treadmill, the plane was supposedly to magically take off from almost a dead standstill in relation to the ground. But this whole time I thought that was what the question was.
It's really a matter of completely understanding the question at hand than anything. Good lord am I glad this is over though. Now I can get to more pressing questions like, can one person play FFXI, WoW, and have class and a full-time job, have a life, and still sleep?
Of course it wouldn't fly if, by the time the engines kicked on and allowed the plane to move forward enough to counteract the treadmill, the plane was supposedly to magically take off from almost a dead standstill in relation to the ground. But this whole time I thought that was what the question was.
It's really a matter of completely understanding the question at hand than anything. Good lord am I glad this is over though. Now I can get to more pressing questions like, can one person play FFXI, WoW, and have class and a full-time job, have a life, and still sleep?
Pussenboots
R.I.P.
You are all wrong, reality doesn't exist, it only flew because the Matrix told you so.
TAKE THE GREEN PILL
TAKE THE GREEN PILL
Being little more than a thug with a vocabulary any scientific explanation or numberlike thingies seem to me more likely to fly over my head without the assistance or hindrance of a treadmill.
Looking at it though I'm of the opinion it won't fly in the listed example cause it ain't moving and I don't see it generating the lift required to take off any more than I would flapping my arms while running on a treadmill. I don't think the speed of the wheels have any effect on an airplanes ability to fly in the slightest, they're simply a convenient way to move it most of the time and are occasionally replaced with ski's or catapults with the desired effect to propel a plane forward enough to generate the required lift to take off.
Looking at it though I'm of the opinion it won't fly in the listed example cause it ain't moving and I don't see it generating the lift required to take off any more than I would flapping my arms while running on a treadmill. I don't think the speed of the wheels have any effect on an airplanes ability to fly in the slightest, they're simply a convenient way to move it most of the time and are occasionally replaced with ski's or catapults with the desired effect to propel a plane forward enough to generate the required lift to take off.
Varda
Clothcraft Cat
The problem is the assumption that it will not move. It will. The propeller or jet engine will push against the air and act to push the plane forward. Something would have to counter that push to keep the plane still, and the only thing we have is the friction in the wheels because the treadmill is moving backwards. And that friction is tiny compared to the force of the engine.
Another illustration: Imagine a missile/rocket just above the treadmill. With no wheels, the missile flies forward towards the distant end of the treadmill. Now add a set of wheels to the missile and do it again. It doesn't matter that the treadmill is moving backwards; the missile still moves forward. The airplane case is just like that.
Zeri
Retainer of the House of Ultimague
We've been over this a zillion times in the thread previously. The issue comes with you RUNNING on the treadmill. The energy comes from force against the ground. Not so with a plane.
So let's put you in a wheelchair on the treadmill with a rocket strapped to the back of the wheelchair (or eating large quantities of refried beans may suffice) and then see if you take off. Mind you the rocket has to be the driving force. You're not allowed to use your arms to push the chair. They're too busy flapping like a loon.
If that doesn't land you forward off the treadmill and maybe airborne if you're flapping enough, it'll at least securely square you a place in the local sanitarium.
Umm... It flew right?
18 pages and against my better judgement, I'm not going to wade through 18 pages worth of posts.
Planes fly because there's enough lift. Lift is generated by thrust created by the engines moving the plane forward fast enough to create a pressure differential between the upper half and lower half of the wing. Once this lift is big enough to counter the weight of the plane, the plane flies. So as long as enough air is moving through the the wings, the plane will fly.
I haven't ran on a treadmill in a while... but I *think* you can feel the air flow past you while you're running on the treadmill. I'll test it out tomorrow when it stops raining and I can go to the gym.
http://travel.howstuffworks.com/airplane.htm
http://www.allstar.fiu.edu/aero/fltmidfly.htm
http://www.google.com/search?hl=en&...num=0&ct=result&cd=1&q=how+planes+fly&spell=1
I hate Fluid Dynamics as well. I find thermodynamics much more interesting.
18 pages and against my better judgement, I'm not going to wade through 18 pages worth of posts.
Planes fly because there's enough lift. Lift is generated by thrust created by the engines moving the plane forward fast enough to create a pressure differential between the upper half and lower half of the wing. Once this lift is big enough to counter the weight of the plane, the plane flies. So as long as enough air is moving through the the wings, the plane will fly.
I haven't ran on a treadmill in a while... but I *think* you can feel the air flow past you while you're running on the treadmill. I'll test it out tomorrow when it stops raining and I can go to the gym.
http://travel.howstuffworks.com/airplane.htm
http://www.allstar.fiu.edu/aero/fltmidfly.htm
http://www.google.com/search?hl=en&...num=0&ct=result&cd=1&q=how+planes+fly&spell=1
I hate Fluid Dynamics as well. I find thermodynamics much more interesting.
If you are running on a treadmill and feel the wind on your face, you either have a.) a window open, b.) a fan on somewhere around you, or c.) a 70 year old man gently blowing on your ear right before he goes after your naughty bits. Only c would make you go airborne.
With all that aside, this exercise was meant to show that an airplane does not propel itself the same way a human or car does. Fluids never really make an appearance into the problem except for the fact that you are asked to answer whether or not the plane takes off. The real question, though, is whether or not the plan moves.
With all that aside, this exercise was meant to show that an airplane does not propel itself the same way a human or car does. Fluids never really make an appearance into the problem except for the fact that you are asked to answer whether or not the plane takes off. The real question, though, is whether or not the plan moves.
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Really? I would have assumed that the ground speed increase would create additional friction as the rubber tires heated from the additional speed, albeit marginally.
I would also be curious as to the maximum speed the wheels where able to travel. In order to produce the lift, the plane would need to reach standard ground speed required for takeoff plus whatever speed the treadmill was travelling.
In either case I would assume that the airplane would take off and that the previous scenarios would not be enough to the force generated by the turbines.
See, like I mentioned, I'm basically a literate thug who isn't wearing animals skins and hitting things with rocks only due to the close proximity of the local mall.
Still in the example cited with the magically adjusting treadmill compensating on the fly for any change to the plane's... ummm forward go'ey motion. Velocity, Momentum, Scientificky Old Greekish wordy mish mash you care to insert. I shall confidently call it the forward go'eyness with a straight face cause I can pull it off. Especially while wearing something pleasantly furry and bearing a convenient rock.
Anyway without forward go'eyness I can't see it taking off. If it was just a matter of the turbines being on they'd shoot off perfectly well on thier own like one of Lucas' pod racers. Or you wouldn't even really need wheels at all, planes would just lift off as soon as you flicked the starter switch with no need for such things as run ways. Aircraft Carrier's wouldn't need catapults.
Now I hesitate to believe there happens to be a treadmill capable of counteracting entirely the thrust of turbine engines, but that's not a factor in the example. It's simply a given that is supposed to be accepted as part of the hypothetical question.
Unless I read it wrong, which is entirely possible, and if so will require me to hit the question with a rock and an accompanying grunt
Still in the example cited with the magically adjusting treadmill compensating on the fly for any change to the plane's... ummm forward go'ey motion. Velocity, Momentum, Scientificky Old Greekish wordy mish mash you care to insert. I shall confidently call it the forward go'eyness with a straight face cause I can pull it off. Especially while wearing something pleasantly furry and bearing a convenient rock.
Anyway without forward go'eyness I can't see it taking off. If it was just a matter of the turbines being on they'd shoot off perfectly well on thier own like one of Lucas' pod racers. Or you wouldn't even really need wheels at all, planes would just lift off as soon as you flicked the starter switch with no need for such things as run ways. Aircraft Carrier's wouldn't need catapults.
Now I hesitate to believe there happens to be a treadmill capable of counteracting entirely the thrust of turbine engines, but that's not a factor in the example. It's simply a given that is supposed to be accepted as part of the hypothetical question.
Unless I read it wrong, which is entirely possible, and if so will require me to hit the question with a rock and an accompanying grunt
Nobody disputes this. If you can see it taking off with forward go'eyness, then maybe we're on to something.
Oh, I can totally see it taking off WITH forward go'eyness, but that doesn't seem to be present in the question as given.
The inquiry itself seems to make the idea of forward go'eyness moot as the magic treadmill negates it. Unrealistic as it may be it's still the premise accepted when answering the question as initially stated within theoretical imagination land.
I'm trying to wrap my head around the wheels simply being a distraction and their simply being a point where you can lift them and have enough thrust to keep going anyway, but it's warring with my notion of needing a runway in the first place.
This thread needs an abridged version>.>
The inquiry itself seems to make the idea of forward go'eyness moot as the magic treadmill negates it. Unrealistic as it may be it's still the premise accepted when answering the question as initially stated within theoretical imagination land.
I'm trying to wrap my head around the wheels simply being a distraction and their simply being a point where you can lift them and have enough thrust to keep going anyway, but it's warring with my notion of needing a runway in the first place.
This thread needs an abridged version>.>
abridged version: it's not a car. the external force moving the plane forward comes from the air/engine, not the wheels/ground. The plane moves forward as normal.
The thing that turns me off to this whole conversation is that all the people who say this never say anything about the treadmill. Even if the wheels aren't attached to an axle attached to a chassis, doesn't the treadmill impart some kind of force backwards to the plane? I can accept that the force may be small but I have no conception of how small or large it might be.
-benny
Nekio
{Gilfinder}
The only force that the treadmill exerts on the plane is that of the rotational friction between the wheel and the axle, and that force is very small. On the other hand, the jet engines exert a very strong force on the plane in the opposite direction, just like a rocket as Kalia said.
The NET force on the plane is the difference between the two, which is a strong force in the direction of the jets, which will push the plane forward causing it to take off eventually.