Airplane on a treadmill

[Barihawk]

i would say its simple

 

once it gets enough speed it would just lift off the tredmill

 

 

 

But if the treadmill matches it's speed, it won't be going forward. Therefore, the wings will not be exerted Bernoulli force, and lift can not happen.

 

 

 

The jets only make the craft move forward, they do jack squat in regards to actually making it fly.

[Collective]

i would say its simple

 

once it gets enough speed it would just lift off the tredmill

 

 

 

But if the treadmill matches it's speed, it won't be going forward. Therefore, the wings will not be exerted Bernoulli force, and lift can not happen.

 

 

 

The jets only make the craft move forward, they do jack squat in regards to actually making it fly.

 

The treadmill only exerts force on the wheels, which spin freely. The plane will move forward and take off with the wheels spinning twice as fast as they would on a runway.

[assassin_696]

i would say its simple

 

once it gets enough speed it would just lift off the tredmill

 

 

 

But if the treadmill matches it's speed, it won't be going forward. Therefore, the wings will not be exerted Bernoulli force, and lift can not happen.

 

 

 

The jets only make the craft move forward, they do jack squat in regards to actually making it fly.

 

 

 

There is no power going to the wheels though, the thrust comes from jet engines spewing air out of the back. If you had a rocket on a treadmill with wheels, the rocket would move forward irrelevant of the speed of the treadmill, and if that rocket had wings it would fly.

[Barihawk]

Ah, ok. Now I see your point. The treadmill would match the speed of the wheels, that's where it tricked me.

[indy500fan]

Anyway is there supposed to be an answer and if so what is it? (apologies for not reading through the entire thread).

 

 

 

The answer is: it's a loaded question. If you use the logic that I used above your post, then you'd have to assume the wheel and conveyor can go infinite speeds. I'm not sure, I just know it's a loaded question and can be interpeted in a few ways.

 

 

 

In my head, it takes off.

 

 

 

Yep, in mine it does too. I can think of the question as being regarded three different ways, one it will take off no matter what, the next it will almost definitely take off, and the last it won't take off (but the treadmill is going at incredible [10,000mph+ speeds]).

 

 

 

It really screwed up my mind, all the sudden going from "lol of course it won't take off" to "wow, the last 100 times I looked at this and brushed the question aside I could have been wrong?"

 

 

 

Just was a weird feeling.

[britrockdude]

Can you post another thread with another one of these? I'm liking the brainteasing. :

[Echofish]

For a minute I thought the title was meant to be 'Treadmill on an airplane' :P

 

 

 

 

 

 

 

 

 

Okay, to be honest I got nothing better to say but that... *hides*

[scn64]

Can you post another thread with another one of these? I'm liking the brainteasing. :

 

 

 

Do you mean another question on a different subject, or just links to other versions of this same question?

 

 

 

I don't have any questions based on different subjects at the moment, but if you type "airplane on a treadmill" into Google you'll see a ton of links associated with this same question.

[britrockdude]

Thanks for that! I can't believe it, somebody put $2 on google answers to find out!

 

 

 

Quite a few sites dedicated to it, and the discussion of it.

 

 

 

Next brainteaser: If a tree falls in the forest? yadda yadda yadda?

[Lovelydude]

This is just a question this rised up for me, and I'm curious about it... And didn't want to make a new topic.

 

 

 

Let's say you're on a plane..or a train. Or an (automobiles!) bus. If you were to jump, would it move underneath you?

 

 

 

Welcome to relativity :)

 

 

 

(no)

 

 

 

Oh, and the plane takes off by the way.

 

 

 

If the vehicle was moving, you would remain travelling forward, but decellerate to a stop (assuming you didn't return to the vehicle after jumping).

[Sir_Alex85]

Thanks for the answers guys. ;P

 

 

 

I was always curious about that.

[No_OnE]

I won't state which side of the argument I stand on...yet. But some would argue that the plane will still move forward because, unlike a car, it does not rely on it's wheels to move forward. It's jets create it's forward motion and the treadmill cannot directly influence the jets.

 

Though this quote has probably been replied to and the answer has already been stated, I'm going to restate it.

 

 

 

The plane would not move even with the jets because the jets propel the plane which would then move on it's wheels which would be matching the speed of the treadmill. In a sense, the plane would be moving forward while the "ground" moves backward at the same speed, thus creating zero change in position.

[Collective]

Though this quote has probably been replied to and the answer has already been stated, I'm going to restate it.

 

 

 

...

 

You could restate it 100 times, but it would still be wrong.

 

 

 

The wheels will be spinning twice as fast as they otherwise would, but the plane would still move forward and take off.

[MyPurpleCrayon]

The answer just seems simple to me, of course the plane would take off.

 

 

 

Although it isn't actually "moving" at that speed, it's still going towards and into the air at that speed.

[Randox]

Seeing as the planes thrust is not driven by the wheels, teh tredmill would just make the wheels go faster and have no affect on the airplanes velocity.

[RebelAssassin]

the plane can go as fast as it wants, but if it isnt generating any air lift it isnt going anywhere.

[scn64]

the plane can go as fast as it wants, but if it isnt generating any air lift it isnt going anywhere.

 

 

 

We're not saying the plane would just sit in one location and magically take off. We're saying that the plane would move forward, despite how fast the treadmill is going. Because of this forward movement, it could generate lift and take off almost as if there was no treadmill at all. The treadmills movement is just making the wheels spin faster while the jets are "pushing" the plane forward from behind.

[No_OnE]

Though this quote has probably been replied to and the answer has already been stated, I'm going to restate it.

 

 

 

...

 

You could restate it 100 times, but it would still be wrong.

 

 

 

The wheels will be spinning twice as fast as they otherwise would, but the plane would still move forward and take off.

 

So the wheels would be moving faster than the speed of the treadmill moving back? If that's the case, then yes, the plane would move forward and eventually take off if it's going fast enough. If the wheels are moving the same speed as the treadmill then there would be no change in position for the plane and the plane would never take off. It's like a person walking on a tread mill. The person is moving forward at the same speed the treadmill is moving back so the person doesn't feel any air hitting his face because he is not changing position. Though, if like you say, the plane is moving faster than the treadmill then it will take off. In either scenario, the answer is obvious.

[indy500fan]

So the wheels would be moving faster than the speed of the treadmill moving back? If that's the case, then yes, the plane would move forward and eventually take off if it's going fast enough. If the wheels are moving the same speed as the treadmill then there would be no change in position for the plane and the plane would never take off. It's like a person walking on a tread mill. The person is moving forward at the same speed the treadmill is moving back so the person doesn't feel any air hitting his face because he is not changing position. Though, if like you say, the plane is moving faster than the treadmill then it will take off. In either scenario, the answer is obvious.

 

 

 

The person on a treadmill, or even a car if you want an example with wheels, doesn't have any other force moving them forward besides for the contact with the treadmill. A plane has engines, the wheels make no difference at all.

[scn64]

Though this quote has probably been replied to and the answer has already been stated, I'm going to restate it.

 

 

 

...

 

You could restate it 100 times, but it would still be wrong.

 

 

 

The wheels will be spinning twice as fast as they otherwise would, but the plane would still move forward and take off.

 

So the wheels would be moving faster than the speed of the treadmill moving back? If that's the case, then yes, the plane would move forward and eventually take off if it's going fast enough. If the wheels are moving the same speed as the treadmill then there would be no change in position for the plane and the plane would never take off. It's like a person walking on a tread mill. The person is moving forward at the same speed the treadmill is moving back so the person doesn't feel any air hitting his face because he is not changing position. Though, if like you say, the plane is moving faster than the treadmill then it will take off. In either scenario, the answer is obvious.

 

 

 

The wheels are spinning freely. As the treadmill turns faster and faster it only makes the wheels spin faster. It's like if you held a hotwheels car on a moving treadmill. The wheels on a Hotwheel car do not provide power of any kind to the car. Your hand would be the "power" for the car. If you pushed forward with your hand, the treadmill would only cause the wheels to spin faster while the car moves forard.

 

 

 

Even if you were pushing your hand forward at a slower speed than the treadmill is moving, the car would still move forward.

[No_OnE]

The wheels are spinning freely. As the treadmill turns faster and faster it only makes the wheels spin faster. It's like if you held a hotwheels car on a moving treadmill. The wheels on a Hotwheel car do not provide power of any kind to the car. Your hand would be the "power" for the car. If you pushed forward with your hand, the treadmill would only cause the wheels to spin faster while the car moves forard.

 

 

 

Even if you were pushing your hand forward at a slower speed than the treadmill is moving, the car would still move forward.

 

Ok, so in this riddle, is the thrust from the engines forcing the plane forward or is it giving the plane just enough force to stand still?

[scn64]

The wheels are spinning freely. As the treadmill turns faster and faster it only makes the wheels spin faster. It's like if you held a hotwheels car on a moving treadmill. The wheels on a Hotwheel car do not provide power of any kind to the car. Your hand would be the "power" for the car. If you pushed forward with your hand, the treadmill would only cause the wheels to spin faster while the car moves forard.

 

 

 

Even if you were pushing your hand forward at a slower speed than the treadmill is moving, the car would still move forward.

 

Ok, so in this riddle, is the thrust from the engines forcing the plane forward or is it giving the plane just enough force to stand still?

 

 

 

In my mind, the thrust is forcing the plane forward. This is where the wording of the question can be confusing though and I'm still not sure exactly what the original author meant. He says the treadmill matches the speed of the plane. I think it would make more sense to say the treadmill is matching the force of the jets.

 

 

 

If the treadmill is simply matching the speed of the plane, then the only way the treadmill would ever be moving was if the plane was moving too. And if the movement of the treadmill somehow caused the plane to stop, then the treadmill would no longer be moving.

[No_OnE]

So basically, the solution to this riddle is:

 

 

 

1. The power of the jets is forcing the plane forward and enabling take off.

 

 

 

2. The power of the jets is forcing the overall speed of the plane to match that of the treadmill which causes zero movement. Take off is impossible.

[das1330]

No lift means no takeoff, unless you have a VERY powerful airplane such as a fighter that has a big enough thrust to weight ratio to takeoff without needing lift.

[indy500fan]

No lift means no takeoff, unless you have a VERY powerful airplane such as a fighter that has a big enough thrust to weight ratio to takeoff without needing lift.

 

 

 

Thank you for that very informative post!