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corrado33 t1_isqrph2 wrote

Fun fact: This is also somewhat related to why the "airplane on a treadmill" idea would never work.

Airplanes don't care about groundspeed, only airspeed. (At least, in terms of "can this airplane maintain altitude/take off.")

So long as the wheels were properly lubricated, the plane wouldn't really notice the treadmill under it and would take off like the treadmill wasn't there regardless.

Propellers push the airplane through the AIR, not along the ground. The fact that the airplane happens to be sitting on the ground at the time is of no consequence.

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draftstone t1_isr3osh wrote

Next time people someone talks to you about this, ask him why a floatplane can takeoff if it has no wheels. What makes contact to the ground has no effect other than possibly slowing you down due to friction.

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Reddit_Is_Bollox t1_iss8r1b wrote

So what are you saying - the airplane-on-a-treadmill does work or doesn't work?

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RandoCalrissian11 t1_issi7db wrote

The reply made it seem like they thought the treadmill wouldn’t work, but the reply was correct saying the treadmill is irrelevant in the equation.

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corrado33 t1_issxase wrote

The treadmill would NOT stop an airplane from taking off is the point I'm making.

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Admetus t1_ist33xj wrote

As long as airspeed is high enough. Put a plane on a treadmill in a wind tunnel I'm sure it can take off.

It's probably a gap in education regarding physics making people assume that relative ground speed has anything to do with taking off.

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danielcw189 t1_ist4rsy wrote

Put a plane on a treadmill in the normal world. let the plane try to take off. It will.

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pjabrony t1_ist70za wrote

Much like the Monty Hall Problem, the "airplane-on-a-treadmill" problem creates controversy because of how the problem is defined.

If you had a proper runway of proper runway length, but you turned it into a treadmill, that would not affect the takeoff of the airplane because it doesn't care how fast its wheels are spinning for takeoff purposes.

But, if you just had a treadmill the length of the airplane and you tried to use that to allow the airplane to get up to speed so it could take off without a long runway, that would not work.

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Doggydog123579 t1_isu56qh wrote

The second interpretation does not make physical sense as the plane will immediately leave the treadmill. The only way to make that short of treadmill work is to put it in a wind tunnel, at which point the airplane takes off anyways.

It creates controversy because people think the wheels are important to it moving, not because of the treadmill size.

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pjabrony t1_isu9abt wrote

> The second interpretation does not make physical sense as the plane will immediately leave the treadmill.

I understand that, but I think not everyone does which is why there's a question.

Put it this way: if you put a car on a treadmill, which does operate by the wheels' grip on the road, and you spun the wheels and the treadmill up to high speed, the car wouldn't have gone anywhere. Then say you quick-stop the treadmill. Would the car take off at a high speed? Could you get a lower zero-to-sixty time this way?

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swolypinger t1_it09zil wrote

Most likely the wheels wouldn't have enough grip at high rpms to do anything other than wheelspin until they had slowed down a bit.

That's the same reason f1 drivers dont just slam on the gas at the statt of a race, they would just burnout and go nowhere

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PizzaQuest420 t1_isr9dng wrote

i've never heard of this idea, do you talk to a lot of little kids or something?

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tsunami141 t1_isrjwzc wrote

> do you talk to a lot of little kids or something?

I think it’s more like physics nerds lol

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AirborneRodent t1_isrmobc wrote

It's an old meme from 2007 or so. It's up there with the blue/black dress on the list of memes that caused the most arguments on the internet.

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nrin005 t1_isruajz wrote

This is a very very common question online

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