scn64

I'll get right on to phoning god about turning the lightswitch 'on' from 'off'. Let me know when this will take place. I want to make sure to close my eyes, things might get pretty bright.

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.

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.

When I read this I immediately thought "fraternity initiation".

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.

I don't want to take credit where it's not due. Mine aren't very good considering I used an online tool to make them. :oops: If you'd like to try it out you can find it at: http://www.network-science.de/ascii/ Basically, I know how to type a word into a text box and click a button. :?

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.

Have you been inside my head? o_0 In other words, those were more or less my thoughts. The plane would probably need air movement under the wings and the scenario you posed (topic starter) seems to leave the air around the system rather stagnant relative to the aircraft. Anyway is there supposed to be an answer and if so what is it? (apologies for not reading through the entire thread). I've never seen an official answer from a well respected group of "experts" or anything. As far as I know, it's just been passed around the internet, mainly on forums like this. As rocketman indicated, I think the question is intentionally written to be confusing (I didn't write it myself). I have my own idea of what would happen but no way of proving it.

Yeah, that's exactly how it was with me. At first I thought there was no possible way it could take off. Now I think the exact opposite.

I still have a lot of quests to complete, skills to advance, and items to obtain. So, yes I would keep playing. If I ever got to the point where I had 99 in every skill, had completed every quest, and had every item I wanted, then maybe I would quit but that would take a very long time.

when you turn on the jet engines the treadmill will increace its speeds to compecent for this [/hide] When the treadmill increases its speed that will merely cause the wheels on the plane to spin faster while the plane continues to move forward. that would only work if there is something holding up the plane, keeping it from going back, the friction could work to make if go forward in one sense, but there will be more pulling back the of the turning of the wheel, dont get me wrong, i see where you going with this :wink: and i can see why you think it would work, but it just wouldn't work As I see it, the jets would be "holding it up". They would be applying a forward force on the plane. As the treadmill runs in the opposite direction, it would be pushing on the bottom half of the wheels. If the treadmill is spinning to the West this would cause the bottom half of the wheels to move towards the West which is the direction they need to move for the plane to move East. But even if the wheels were spinning in the opposite direction, the plane still doesn't rely on it's wheels to push it forward so it wouldn't make much of a difference anyway.

when you turn on the jet engines the treadmill will increace its speeds to compecent for this When the treadmill increases its speed that will merely cause the wheels on the plane to spin faster while the plane continues to move forward.

You'll have to excuse me, but after trying to explain it over 2 pages... Right or wrong, I feel the same way. I'm trying to explain it to you. Obviously, I don't have a giant treadmill, a jet plane, and the necessary equipment to get the treadmill to match the plane speed and attempt to prove what I'm saying. I accept that I could be wrong. But I have spun this around and around in my head and I still come to the conclusion that the plane would move forward.

I don't see the need for insults.

When I first read this question I was on your side. I agreed with you. 50 pages of convincing later, I had changed my mind.

But you have to take in the fact that to get in the air, the plane has to reach the speed on the ground first. A plane is just a big car with wings until it gets enough forward velocity to take off. On this treadmill, it has no forward velocity, so no lift. Yes, but to gain that initial speed, even on the ground, the plane is relying on the same source of propulsion as it does when it's in the air, and that propulsion is not affected by ground movement.

You're analogy has NOTHING to do with this situation. In your analogy, the skater is moving along the treadmill on its own power, just as the jet is. There is no man pushing the jet here. It doesn't matter how it propels itself (for the 3rd time). I want you to understand this most simple of concept, for your sake. Why can't a car move forward when it's suspended in mid-air? Why CAN a jet plane move forward in the same situation?

The jets on the plane are an external force as far as the treadmill is concerned.

It doesn't look like YOU are going to grasp this.

Like I said it doesn't matter what the means of propulsion is. Equate it to the airplane with it's engines on full blast, but no wheels. It's just sitting there. You're not gunna be able to wish it into the air because there is no lift. It's not going to take off. Going back to my example of a man standing on a treadmill with rollerskates, do you agree that he would move forward if pushed from behind?

What?! Look, the plane is not moving forward, thus it is getting no lift. Try to think really hard about it, please. I understand that the pane needs to move forward in order to generate lift and take off. I'm saying that the plane might still move forward despite what the treadmill is doing because the jets do not need to push against the ground. The wheels of the plane would spin at the combined speed of the treadmill and the plane.

Have you never been on a plane before? They don't just hover and take off, they need to reach a certain speed on land before they can. The means of propulsion make no difference. Not if it was a jet, a rocket, or a regular combustable. but since the jets are not pushing against the ground to move would the treadmill have enough effect on the planes movement to stop it? For example, imagine that you're wearing a pair of rollerskates while standing on a moving treadmill. At the same time, a man is standing behind you on the ground, not the treadmill. He holds a wooden stick against your back. Even though the treadmill is spinning in the opposite direction, you still wont move backwards because the stick is not being affected by the treadmill. If the other man were to push the stick forward, you would move forward as well. The argument is that the jets on the plane act as the "stick" since they do not push against the ground to create the planes movement.

It's not going to lift off without any tangent velocity (which it will obviously never get with a treadmill under it). Also, I thought this was more of a philisophical question, not a matter of physics... 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.

The real question is, will the plane move forward. I know that sounds like a stupid question after I stated that the treadmill matches the speed of the plane, but think about how a jet plane propels itself forward.

The Airplane on a Treadmill is a type of physics riddle that usually results in two groups of people taking different sides and calling each other idiots for hours at a time. None the less itÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s a fun thought puzzle and worth taking a look at. The Set Up: LetÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s say that we have a jet airplane (like a 747 for example) trying to take off on a giant runway sized treadmill. The treadmill, which turns in the opposite direction that the plane is facing, is capable of precisely matching the speed of the airplane. HereÃÆââââ¬Å¡Ã¬Ã¢ââ¬Å¾Ã¢s a visual to bring it all together (not drawn to scale obviously ) The Question: Can the airplane take off under these conditions?