Will the plane take off?? Finally going to be answered.***

[joetama 5,000+ posts]

or if the treadmills faster and the plane goes backwards.//content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

NO!!!

 

Please stop posting until you understand what you are saying!!!

 

[IamDeMan 5,000+ posts]

You are an idiot.
nG

Because I said they will botch it or because of the beautiful explanation you gave me in contrast to my answer //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

Re-capping after the thorough and detailed explanantion of Tama and squeak I realize my mind played tricks on me and couldn't get the thought of wheels actually driving something out to really see the answer. I hereby change my stance and FULLY understand what you to are saying. It makes absolute sense now.

the plane won't remain stationary (lifting off depends on how fast the wheels can go). It will travel down the tread mill. The prop isn't in contact with the tread mill and is applying the thrust to the plane. I am still not sure without knowing how much force the wheels applying during takeoff whether the plane will get enough speed to create lift but it will move.

As has been mentioned, anyone who thinks optherwise needs some physics books.

As for nGs idiot comments, I don't find that to be the case for any thinking it won't take off. I am willing to bet that most just aren't looking at the equation correctly. So in closing I say nG can lick my taint clean like the *** he is. I am so glad I voted him back in for this kind of harassment //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[mapolley07 10+ year member]

i'm not arguing the physics presented earlier, but that's not the problem presented here. Say your average groundspeed for takeoff is 150 mi/hr. the problem is putting the plane at standard takeoff speed, but on a conveyor moving backward at 150 mi/hr. the plane is moving relative to the belt at the speed normal takeoff would occur, but in relation to the surroundings it is staying still. the question is that, in this particular situation, would the plane gain lift.

the answer is no, because no airspeed is generated. the plane would take off or move backward depending on an inequality of forces, but the true question is what happens with balanced forces. the plane cannot and will not takeoff from the conveyor unless a variable is introduced

 

[93EXT 10+ year member]

Idiot.

nG

Its sunday, not supposed to think, try working instead of living on a forum.//content.invisioncic.com/y282845/emoticons/crazy.gif.c13912c32de98515d3142759a824dae7.gif

theres bearings in the wheel, bearings have drag, drag will slow its down, if fast enough it can go backwards.

I say nG can lick my taint clean like the *** he is. I am so glad I voted him back in for this kind of harassment //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I'm glad you did too //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[joetama 5,000+ posts]

Because I said they will botch it or because of the beautiful explanation you gave me in contrast to my answer //content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif


Re-capping after the thorough and detailed explanantion of Tama and squeak I realize my mind played tricks on me and couldn't get the thought of wheels actually driving something out to really see the answer. I hereby change my stance and FULLY understand what you to are saying. It makes absolute sense now.

the plane won't remain stationary (lifting off depends on how fast the wheels can go). It will travel down the tread mill. The prop isn't in contact with the tread mill and is applying the thrust to the plane. I am still not sure without knowing how much force the wheels applying during takeoff whether the plane will get enough speed to create lift but it will move.

As has been mentioned, anyone who thinks optherwise needs some physics books.

As for nGs idiot comments, I don't find that to be the case for any thinking it won't take off. I am willing to bet that most just aren't looking at the equation correctly. So in closing I say nG can lick my taint clean like the *** he is. I am so glad I voted him back in for this kind of harassment //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

The wheels apply no force relative to the problem. Positive or negative. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

Just pretend the airplane is already in the air and their are no wheels.

(Actually the wheels do provide some 'negative' acceleration if we consider forward positive acceleration. But, it will be so small it will pretty much just act as 0 for this idea)

 

[IamDeMan 5,000+ posts]

//content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif
Indeed... I took physics 4 years ago and this still seems like a simple force problem... //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

My last and only Physics class was 14 years ago. Please spare me some slack for not approaching the problem correctly. I do appreciate the time you took to explain it and make me realize it unlike some douchenozzles who equate it to stupidity.

I laugh at all the simpleton morons here...
What tards.

nG

I am willing to bet dollars to donuts that many people find things easy that you struggle in. Not everyones minds examine a problem the same way and many get stuck in a rut. This doesn't mean they are stupid or morons. If they have the ability to learn the correct answer and understand it then intelligence is present. I am glad you can boil it down as easy to say that anyone who doesn't understand this Physics story problem is a moron. Mustmake life easy for you.

rD

 

[mapolley07 10+ year member]

The plane ISN'T moving at 0 mph.
The plane is moving at take off speed (lets say 100 mph) and the treadmill is moving at the same speed in the opposite direction (100 mph). But, this doesn't matter, because these values are relative to ground speed (air speed if you like). If they were relative to each other the plane would be moving a 200 mph.

The only part of the plane that touches the treadmill is the wheels. The wheels have NOTHING to do with the plane flying (you know the wheels touch nothing once the plane is in the air //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif)

What makes the plane fly is the movement of air over the wings. What causes the movement of air is the movement of the plane. What causes the movement of the plane is the force generated by the engines. The treadmill has no effect on the movement of the air, the plane(except minimal amounts of friction generated by the wheels spinning), or the engines.

that is assuming both the treadmill and the plane are traveling in the same direction. think of the moving sidewalks in the airport. they move you at about 3mph, give or take. if you get on the sidewalk and stand still you are moving forward at 3mph. if you walk in the same direction of travel as the sidewalk at 3mph, you effectively double your speed and move 6mph. But if you walk in the opposite direction of travel from the sidewalk at 3mph, your forward movement and the sidewalk's backward movement negate each other and you have a net velocity of 0mph.

the plane would be traveling opposite the direction of the treadmill, so the velocities would negate each other and the plane would have an effective velocity of 0mph (in relation to the surroundings)

 

[IamDeMan 5,000+ posts]

I guess I'm just not seeing how any lift can be created if the plane is moving at 0 miles per hour. If the plane does not move forward how can there be any wind? I'ma confused.//content.invisioncic.com/y282845/emoticons/crap.gif.7f4dd41e3e9b23fbd170a1ee6f65cecc.gif

the plane will move forward though, thats the rub.

 

[rollerdj 10+ year member]

after much thought. if the plane is tied down so it can't move anywhere, then there is no way it can take of. unless the prop can make enough wind over the wings to get so lift. if they just let the plane go. then i agree with joe. the prop is the means of power, not the wheels. there for, it will still move forward over the "treadmill" even though the "treadmill" is moving bacwards. allthough i would love to see this big treadmill.

 

[IamDeMan 5,000+ posts]

The wheels apply no force relative to the problem. Positive or negative. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif
Just pretend the airplane is already in the air and their are no wheels.

(Actually the wheels do provide some 'negative' acceleration if we consider forward positive acceleration. But, it will be so small it will pretty much just act as 0 for this idea)

Well more correctly I mean the friction involved in making them turn. There will be some friction, I will assume it is low enough not to matter though. Otherwise we'd have more issues with planes just working without treadmills lol.

 

[93EXT 10+ year member]

its going to be an expensive focking treadmill....

And I also wonder how much throttle they are going to need to get up to speed.

 

[squeak9798 5,000+ posts]

the plane is moving relative to the belt at the speed normal takeoff would occur, but in relation to the surroundings it is staying still.

//content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif

No, the plane would be moving forward, relative to the surrounds, at 150mph.

the plane cannot and will not takeoff from the conveyor unless a variable is introduced

Wrong.

See all of the prior explainations.

 

[mapolley07 10+ year member]

i think that people are trying to over complicate this problem.

say you are running on a treadmill. the treadmill belt is moving backward at the same velocity you are running forward, and in relation to your surroundings, you are not moving. your velocity is ZERO. obviously you are not gaining airspeed. this is the same situation that the airplane would be in on a conveyor runway. The plane would fail to gain velocity and airspeed, thus preventing aerodynamic lift.

now if you were on the treadmill and you ran the same direction as the treadmill belt, you would be doubling your speed (until you fell off), which would double the airspeed that you would gain by running without the aid of the treadmill. this would work for a plane because you could halve the runway length needed to attain liftoff speed

 

[IamDeMan 5,000+ posts]

The plane isn't pushed by the wheels to create its thrust people. The prop does that. No resistance is applied by the treadmill and the spinning wheels. If there is no resistance then what will prevent the plane from moving forward?

Answer me that question?

It is actually basic if you get the idea of the wheels being the driving force completely out of your head. In fact as suggested, pretend they are'nt there and the plane is floating above the treadmill. Because thats exactly what it is doing.

 

[joetama 5,000+ posts]

i'm not arguing the physics presented earlier, but that's not the problem presented here. Say your average groundspeed for takeoff is 150 mi/hr. the problem is putting the plane at standard takeoff speed, but on a conveyor moving backward at 150 mi/hr. the plane is moving relative to the belt at the speed normal takeoff would occur, but in relation to the surroundings it is staying still. the question is that, in this particular situation, would the plane gain lift.
the answer is no, because no airspeed is generated. the plane would take off or move backward depending on an inequality of forces, but the true question is what happens with balanced forces. the plane cannot and will not takeoff from the conveyor unless a variable is introduced

I think you are missing this idea. The wheels pretty much are just rollers.

Think about it in terms of thrust. If the treadmill is moving at 150 mph the air is moving at 0 mph and the wheels are of almost 0 friction the air plane will stand still. Due, to the slight amount of friction the plane would move slightly backwards. However, once the thrust from the motors is turned on the plane will eventually reach equilibrium and then accelerate forwards relative to the ground and take off.

Ok, here is another way of saying it.

If the plane is at equilibrium (0 mph relative to the ground) the wheels speed of the plane (in the example you stated) is 150 mph. But, who really cares what the wheels speed is, it has no affect on the plane (other than the small amount of friction generated by it) the plane is not moving at 150 mph.

Let me add this...

The airplane isn't directly coupled to the treadmill. It is relatively coupled. Meaning that it is attached by a free moving body used to reduce friction.

If the overall airspeed is 0 there obviously will not be take off. But, as stated in the original problem the plane is moving at take off speed, the treadmill is moving at exactly the opposite speed. I would have to assume from this statement that the airplane is not directly attached and that the thread mill has really no affect on the plane.