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| Thread ID: 64128 | 2005-12-04 07:01:00 | Sunday night Brain Bender - Airplane Physics | miknz (3731) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 410192 | 2008-03-27 21:35:00 | Hooray!!! It's finally settled. :clap Can we lock this thread now? :thumbs: :thanks | Richard (739) | ||
| 410193 | 2008-03-27 21:38:00 | The stupidity of some people amaze me. *chants* Lock the thread, lock the thread!! :sleep |
wratterus (105) | ||
| 410194 | 2008-03-27 23:20:00 | The plane still won't take off if the original question's scenario was stuck to. It's obvious that the speed of the wheels on the plane in the experiment travelled faster than the conveyor. How people can't see that is ludricous. Mythbusters bent the rules, or more accurately, weren't capable of making a real-life example. If the speeds matched exactly there'd be no forward movement, hence no wind speed for the wings to give lift. In the hypothetical scenario... the plane won't fly! |
Greg (193) | ||
| 410195 | 2008-03-27 23:29:00 | No - it'll take off, but the wheels will explode as soon as it starts moving. | Erayd (23) | ||
| 410196 | 2008-03-28 00:03:00 | The plane still won't take off if the original question's scenario was stuck to. It's obvious that the speed of the wheels on the plane in the experiment travelled faster than the conveyor. How people can't see that is ludricous. Mythbusters bent the rules, or more accurately, weren't capable of making a real-life example. If the speeds matched exactly there'd be no forward movement, hence no wind speed for the wings to give lift. In the hypothetical scenario... the plane won't fly! I think you need to watch it again. You are clear confusing the wheels with the drive wheels of a car, the thrust from the engines of the plane move it forward, on a REAL conveyor belt the plane will judder over the rollers moving forward "unlike" a car. Mythbusters are 100% and prove it with the exact principle be it not a conventional conveyor belt, makes no difference. |
Battleneter2 (9361) | ||
| 410197 | 2008-03-28 00:17:00 | Myth Busters are the wicked. Great demonstration, The myth is BUSTED. And I love the way the goof balances crap on his nose (the model plane) A couple of weeks back he was balancing a scale model of the Hindinberg on his face, after they must have spent boatloads of hours welding the entire 3m structure together. Classic stuff. |
Metla (12) | ||
| 410198 | 2008-03-28 03:03:00 | I think you need to watch it again. You are clear confusing the wheels with the drive wheels of a carSome things I'm clear about and not confused about: 1) I'm not completely stupid... I know that the wheels aren't powering the aircraft 2) The laws and forces of gravity make the plane stay firmly fixed to the surface it's resting on. You might as well be saying that a plane with its wheels firmly imbedded in concrete will suddenly defy physics and rip itself off the ground, without any forward movement!!! I'll say it once again... the only way the plane can go forward is to have it's wheels move faster than the conveyor, which is clearly what happened in the experiments, and which are completely contrary to the scenario described, eg that the conveyor and wheels travel at the SAME speed. I'll try not say this again though, no matter what is said hereafter... the plane will not fly, given the original scenario. :groan: |
Greg (193) | ||
| 410199 | 2008-03-28 04:57:00 | I reckon you're still not getting it Greg. Here it is again: Imagine a plane is sat on the beginning of a massive conveyor belt/travelator type arrangement, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation. There is no wind. Can the plane take off? Let's assume that the plane starts in a stationary position. This means that neither the conveyor or the wheels are moving. The jets start. Now there is a force trying to push the plane forwards, however for it to move forward, the wheels would have to turn faster than the conveyor is moving. According to the scenario given, this obviously can't happen. As the laws of physics state that "every action has an equal and opposite reaction", there has to be something to counter the force of the jets without moving the plane forwards. That something is the friction in the wheel bearings. The wheels (and the conveyor) will simply spin faster and faster, until the bearing friction matches exactly the force being applied by the jets. The plane is still stationary. Noting that wheel bearings don't have much friction, it wouldn't be long before the jets are applying enough thrust that the bearing friction required to match it cannot be attained without spinning the wheel faster than it can physically cope with. Once this point is reached, centrifugal force literally rips the wheels apart, causing them to 'explode'. The plane is still stationary, but now it has no wheels. As the wheels have now exploded, they obviously have no speed. As a result, the conveyor stops. The plane will start to move forward under the force of its jets, and will take off on its belly, with no wheels. So to answer the original question, yes - the plane will take off, just not in quite the conventional manner. |
Erayd (23) | ||
| 410200 | 2008-03-28 05:01:00 | Yes, upon watching the mythbusters video I wasn't sure exactly how the myth was defined. Was isn't clear is how the speed of the conveyor belt works. I think mythbusters said that they tried to get it at the taking off speed of the plane. They glossed over that part. Of course it is possible such conveyor belt is impossible. Perhaps it is easier just to lock the thread :lol: |
gibler (49) | ||
| 410201 | 2008-03-28 05:09:00 | Yes, upon watching the mythbusters video I wasn't sure exactly how the myth was defined. Was isn't clear is how the speed of the conveyor belt works. I think mythbusters said that they tried to get it at the taking off speed of the plane. They glossed over that part. Of course it is possible such conveyor belt is impossible.It's not possible to accurately construct this scenario in the real world - so it doesn't really matter what mythbusters did, it doesn't apply to this situation. Perhaps it is easier just to lock the thread :lol:Please no.... this thread is a classic, and it's clear there is still more ground to be covered. |
Erayd (23) | ||
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