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| Thread ID: 93430 | 2008-09-16 06:00:00 | Aircraft Taking off problem | Thomas01 (317) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 705609 | 2008-09-16 06:00:00 | I see that tonight Myth Busters on Prime are having a look at that argument so often discussed in this forum. Can an aircraft take off if the runway is a conveyor belt going in the opposite direction? |
Thomas01 (317) | ||
| 705610 | 2008-09-16 06:13:00 | Its a repeat, and the episode can be viewed on youtube. In short, They "discovered" the propeller pulls the plane forward (and up) and whatever was happening with the wheels made no impact. |
Metla (12) | ||
| 705611 | 2008-09-16 06:27:00 | An aircraft flies when the propellor pulls it through the air at a certain speed. In small aircraft this could be around 60-100km/h before there is enough airflow over the wing to generate sufficient lift to make the aircraft fly.As the air is not moving the aircraft has to accelerate to this speed relative to the air. What the wheels are doing is completely irrelevant. In the case of an aircraft on a conveyor belt it just means that when it reaches sufficient airspeed to fly, the wheels will be spinning a lot faster than normal. A consideration in a similar vein is an aircraft on floats taking off from a river. What is the difference taking of down stream as opposed to taking off upstream? |
tut (12033) | ||
| 705612 | 2008-09-16 07:25:00 | As is the case with most of the episodes, their experiment was flawed. | roddy_boy (4115) | ||
| 705613 | 2008-09-16 07:41:00 | NO NO NO don't start this again!!!!! lol | Jester (13) | ||
| 705614 | 2008-09-16 07:53:00 | The practical value of this (impossibly expensive) conveyor escapes me; however conveyancing always seemed counter-productive and overpriced. ;) |
R2x1 (4628) | ||
| 705615 | 2008-09-16 07:58:00 | Yes Yes Yes :banana:banana It is completely illogical to propose that an aeroplane will take off when one stipulation of the problem is that the wheels rotate at the same speed as the conveyor to the effect that the plane stays in the same spot. Even with infinite conveyor speed and infinite wheel rotation, the wings require air to flow over them - and that airflow has to be generated somehow. Either wind, or forward movement of the plane - which the problem prohibits. :eek: |
Winston001 (3612) | ||
| 705616 | 2008-09-16 08:15:00 | Exactly. GL getting Billy T to actually read a post that counters his points though. E: The whole thing depends on the wording of the question though. |
roddy_boy (4115) | ||
| 705617 | 2008-09-16 08:25:00 | This problem was on the x10Hosting forums as well. I was the first to state "it will not take off". :D The plane will not take off at all. A plane relies on the air rushing underneath the wings to take off. To achieve this, it needs to be physically moving. A conveyor belt will not allow it to move, and it will simply stay 'still'. This is also why helicopters do not need runways - they can generate their own lift via the propellers. It is also why planes are not able to hover - they require constant motion. |
pcuser42 (130) | ||
| 705618 | 2008-09-16 08:27:00 | Yes Yes Yes :banana:banana It is completely illogical to propose that an aeroplane will take off when one stipulation of the problem is that the wheels rotate at the same speed as the conveyor to the effect that the plane stays in the same spot. Even with infinite conveyor speed and infinite wheel rotation, the wings require air to flow over them - and that airflow has to be generated somehow. Either wind, or forward movement of the plane - which the problem prohibits. :eek: But the engine provides the forward energy, not the wheels. |
dolby digital (5073) | ||
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