Small quest for the bored...

[MTFDarkEagle]

Yes, the wheel is turning at the same speed as the treadmill. (no cheating), but still doesn't STOP the aircraft. The fittnes centre is a non-valid comparison, because my legs are not freewheeling (hehe). I'm powering my legs. What you are saying is the case with a car, not with a plane, because the wheels can free-wheel

[SNAFU]

is the treadmill stationary?

Thinking the right direction. ;) Lets put the threadmill on a threadmill.... :thumbup:

[SNAFU]

Yes, the wheel is turning at the same speed as the treadmill. (no cheating), but still doesn't STOP the aircraft. The fittnes centre is a non-valid comparison, because my legs are not freewheeling (hehe). I'm powering my legs. What you are saying is the case with a car, not with a plane, because the wheels can free-wheel

 

Hey, now image someone is dragging you over the threadmill, you just move you legs accordingly. Now you move along, now you move faster than the threadmill, but you are not allowed to, cause the conditions of the fittness centre stated: Do move at the same speed as the threadmill but opposite direction. ;)

[MTFDarkEagle]

Dude, it's scientifically proven...

 

Try this: take a piece of paper, place it on the table, and take a lego tyre. Put on of those poles in it, so it can turn freely. (i.e. the pole and tyre can turn independantly of eachother). Next, pull the piece of paper to one side, and take the wheel by it's pole, and pull it very fast in the other direction (off course place the tyre and piece of paper on top of eachother before you start argueing about that too..) Hey presto! movement

[Avilator]

Come on people, why are we even discussing this?:doh:

[MTFDarkEagle]

I'm not discussing, SNAFU is discussing this! He doesn't want to see the point :doh:

[SNAFU]

No, I perfectly understand you. I made the same mistake at first. Its all about the specification.

 

But now go back to the specifications and read what is written there, do not read, what you want to read and what you expect. ;)

 

There is no way to betray the maths. Sure the plane will move and finally takeoff if the wheels turn even the opposite direction of the planes rolling direction and the threadmill in the same direction as the plane. It really doesnt matter in which way the wheels turn, but as soon as the plane moves, the wheels (not the plane) turn faster or slower than the threadmill - bang, quest conditions not obeyed - specifications not met, your company which had signed the contract to provide this plane and the threadmill lost millions of dollars... ;)

 

The only way to takeoff and keep the condition of equal speed, would be to takeoff with loked wheels. ;)

 

Your suggestion of freely turning wheels and threadmill is an assumption your logic/reason made, but it is not written in the specification. ;)

Edited November 22, 2010 by SNAFU

[159th_Viper]

Come on people, why are we even discussing this?:doh:

 

[SNAFU]

I told you, only for bored mathematicians. ;)

[MTFDarkEagle]

+1 viper... Now I'm off to bed.. I give up argueing...

[SNAFU]

No engineers, physicains or mathematicians around here?

 

I ll paint you a drawing tomorrow, DarkEagle, after then I ll give up too. ;)

[MTFDarkEagle]

I'm studying applied physics in fact, together with a commercial pilot training.

 

And I expect the painting in van gogh style :D

[SNAFU]

Wilco ;)

[Frederf]

AHHHHH NOT THIS ONE AGAIIINNNN!!! You've just doomed the forum to 1000 posts of not getting anywhere.

 

Last time I saw this one the treadmill speed condition was written "backward at a speed such that the airplane doesn't move" which is a lot sillier to how this one is written. This one is written in a more sensible way as simply the opposite value of the tangential speed of the rotating wheel(s).

 

The goofy part of this question isn't the plane's ability to move under its own power but what the heck the treadmill's doing. Replace the wheels with skis and no matter what the treadmill does the plane is on its merry way. If the speed of the airplane with respect to the ground/air is X and the backward motion of the treadmill is Y, then the wheel speed must be X+Y. But the treadmill is supposed to be going the same as the wheel so Y=X+Y. Inconsistent. Try with accelerations: Plane accelerates with respect to the ground A. Wheel is also A acceleration with respect to a stationary treadmill. Treadmill accelerates back at A to match wheel. Wheel thus accelerates at 2A which the treadmill mimics. Yeah, it's still inconsistent.

 

The feedback loop of the treadmill going as fast as itself plus a little more instantly violates causality. The treadmill feedbacks to infinite speed at a different rate depending on how much the treadmill lags behind the wheel speed.

 

The question isn't solvable with the mechanics of reality because the behavior of the treadmill lies outside the realm of reality.

[monotwix]

What are the procedures for a commercial pilot if there is a zebra crossing on a treadmill?

[Sticky]

The speed governor of the treadmill is setting the speed of the treadmill to the same, but opposite speed of the rotational speed of the airplane`s wheels,

 

This isnt possible, the condition cant be met, so the question is broken :P

 

But I say that under the given conditions, that the rotational speed of the wheels has to be the same as the treadmill`s surface speed, the plane must not move a bit, other wise the conditions are not obeyed.

 

The conditions doesnt work, that is why the question might seem hard to answer. The plane will move anyway, and gain speed relative to the treadmill and once it has enough lift it will fly :P

 

Its all about the specification.

 

The specification is wrong, not possible, cant be kept, the plane will fly.

[Sticky]

And I cant believe I took the bait. I had a friend who liked these kind of questions, where there is something wrong with the way the question is asked. Did I tell you he was an idiot?

[MTFDarkEagle]

And I cant believe I took the bait.

Join the club..:doh:

[SNAFU]

Yes, the specifications cannot be met. That was the point.

 

But be aware that such specifications in requests for proposals or tender procedures are sometimes that way. In the industry some companys define such specifications to keep their competitors busy and give them booby traps.

 

The traders and business people do not read correctly and make proposals or bids, without asking the engineers. They spent time and waste money finding out, that the specifications are unclear or not to achieve.

 

Then it is a case for the lawyers and it gets expensive... ;)

[mvsgas]

:doh::smartass::D:huh:

Trolling

Trolling is trying to get a rise out of someone. Forcing them to respond to you, either

through wise-crackery, posting incorrect information, asking blatantly stupid questions, or

other foolishness. However, trolling statements are never true or are ever meant to be

construed as such. Nearly all trolled statements are meant to be funny to some people, so it

does have some social/entertainment value.

http://www.urbandictionary.com/define.php?term=trolling

 

4owlyCOzDiE

:P:joystick:

Not related but fun to watch

[SNAFU]

Hey, do not troll my troll-thread. :joystick:

 

At least we are in the troll-sub-forum, where we belong... :helpsmilie:

[monotwix]

I feel like asking the engineer about this one.

 

About the nose diving to be precise.

[SNAFU]

Huh, the wings seem to be a little oversized. ;)

[Frederf]

I actually despise most of Myth Busters's "proofs" because they have the scientific rigor of me waving my hands around. The show and the questions raised are interesting but they often come to overly confident conclusions beyond what is logically sound.

 

It's like that smart alec kid that answers the "what is the sound of one hand clapping?" question by folding their fingers onto their palm really fast, missing the point.

[sobek]

Hey, do not troll my troll-thread. :joystick:

 

At least we are in the troll-sub-forum, where we belong... :helpsmilie:

 

What bugs me most is, why the typo in the sig? :D