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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 | ||
| 410202 | 2008-03-28 05:11:00 | Never mind the ground to be covered, it is the ground to be uncovered that raises the anxiety quotient..:o | R2x1 (4628) | ||
| 410203 | 2008-03-28 07:13:00 | 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. :groan: www.youtube.com www.youtube.com On Part 2 at 2.15 minutes the takeoff speed is determined as 25MPH which is the speed the Tarpaulin is towed in the opposite direction, this is exactly the same as """conveyor and wheels travel at the SAME speed""" You needed to take my advice and watch it again. The BIG tell tell sign here is the fact that the plane still takes off NORMALLY. I guess if you can't get it now, you simply never will. |
Battleneter2 (9361) | ||
| 410204 | 2008-03-28 07:34:00 | For the plane to reach take-off speed with the conveyor moving at 25mph, the wheels were moving at 50mph so it isn't possible to construct a scenario per the original question of the speed of the conveyor being the same as the speed of the wheels. As we saw, and has been explained, the plane will take off but you cannot construct an apparatus that is designed to offset the potential forward momentum of the jet/propeller with the conveyor belt - I believe someone mentioned this way back when and suggested the wheels will simply spin faster - that is exactly what happened. | andrew93 (249) | ||
| 410205 | 2008-03-28 11:02:00 | Ok, I've got to page eight and this thing seems to be going around and around so in case this hasn't been finalised this is how it is. Imagine you have a group of three people. One of those people is sitting on a bike which itself is on a treadmill. The bike is steadied by the two people standing on the ground either side of the rear or the bike. The treadmill is turned on. If there is no significant friction in the bearings of the bike the two people standing beside the bike will be able to quite happily support the rider and bike while the wheels turn beneath the rider. If the speed of the treadmill is increased the same will happen. Now, if those supporters exert a forward push to the bike and rider then the bike and rider will move forward on the treadmill even though the wheels are turning even faster. The supporters of course represent the thrust of the engines. The wheels are simply acting as a free wheeling support to the rider or in the original question the plane. If the rider was peddling the bike and trying to drive the bike forward through the wheels then that would be different because his effect on the wheels would be counteracted by the treadmill exactly like someone who uses a treadmill to exercise. BUT where the propelling force is separated from the treadmill such as our two supporters or via a propeller or jet then that vehicle be it bike or plane WILL move forward. Put wings on our bike and a couple of rockets up our riders.... urm... seat and he/she might even get airborne. |
Robinz (9362) | ||
| 410206 | 2008-03-28 13:01:00 | ...the bike and rider will move forward on the treadmill even though the wheels are turning even faster. The supporters of course represent the thrust of the engines...You've stuffed up. The original scenario doesn't allow for the wheels to be moving faster than the conveyor; the conveyor changes speed to exactly match that of the wheels at any given point in time. | Erayd (23) | ||
| 410207 | 2008-03-28 18:46:00 | The wheels have got nothing to do with it. There is no power to the wheels, they just spin. It's the prop/jet that makes the plane fly not the wheels. :rolleyes: |
B.M. (505) | ||
| 410208 | 2008-03-28 18:58:00 | You've stuffed up. The original scenario doesn't allow for the wheels to be moving faster than the conveyor; the conveyor changes speed to exactly match that of the wheels at any given point in time. That is all quite irrelevant as BM says, the conveyor changing speed is put in there simply to cause exactly the obfuscation that has bamboozled so many. As was said earlier, way way back, what about a plane with skids on snow, or a plane with skids and a conveyor belt made of ice??? I can't really believe what I'm still reading in this thread, especially those words from he who thought that the pipes seen sticking out of house roofs were lightning rods :):) |
Terry Porritt (14) | ||
| 410209 | 2008-03-28 19:39:00 | That is all quite irrelevant . . . I can't really believe what I'm still reading in this thread, especially those words from he who thought that the pipes seen sticking out of house roofs were lightning rods :):) They are only part time lightning arrestors . The rest of the time they are potential (?) bird roosts for wayward sparrows having a bit on the side . |
R2x1 (4628) | ||
| 410210 | 2008-03-28 19:45:00 | Ok, I've got to page eight and this thing seems to be going around and around so in case this hasn't been finalised this is how it is. Imagine you have a group of three people. One of those people is sitting on a bike which itself is on a treadmill. The bike is steadied by the two people standing on the ground either side of the rear or the bike. The treadmill is turned on. If there is no significant friction in the bearings of the bike the two people standing beside the bike will be able to quite happily support the rider and bike while the wheels turn beneath the rider. If the speed of the treadmill is increased the same will happen. Now, if those supporters exert a forward push to the bike and rider then the bike and rider will move forward on the treadmill even though the wheels are turning even faster. The supporters of course represent the thrust of the engines. The wheels are simply acting as a free wheeling support to the rider or in the original question the plane. If the rider was peddling the bike and trying to drive the bike forward through the wheels then that would be different because his effect on the wheels would be counteracted by the treadmill exactly like someone who uses a treadmill to exercise. BUT where the propelling force is separated from the treadmill such as our two supporters or via a propeller or jet then that vehicle be it bike or plane WILL move forward. Put wings on our bike and a couple of rockets up our riders.... urm... seat and he/she might even get airborne. Don't you pay attention to the commercials? The bike and rider will fly because the scientifically enhanced features of the treadmill ensure so much weight loss that the rider just flies through the day. (Darkness involves a bit of a let-down, that's why it is called nightfall.):eek: |
R2x1 (4628) | ||
| 410211 | 2008-03-28 20:14:00 | For the plane to reach take-off speed with the conveyor moving at 25mph, the wheels were moving at 50mph so it isn't possible to construct a scenario per the original question of the speed of the conveyor being the same as the speed of the wheels . As we saw, and has been explained, the plane will take off but you cannot construct an apparatus that is designed to offset the potential forward momentum of the jet/propeller with the conveyor belt - I believe someone mentioned this way back when and suggested the wheels will simply spin faster - that is exactly what happened . The wheel speed is not important, be it 1mpr ot 200mpr, this is where most people are misunderstanding . On a more traditional conveyor belt with "rollers" the plane will gudder over each roller and take of normally . People need to consider not all planes even use wheels to take off, as in snow or waters where they use skids . Mythbusters proved it beyond any type of doubt . |
Battleneter2 (9361) | ||
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