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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 | ||
| 409972 | 2005-12-04 08:43:00 | No it will not. In effect the aircraft is standing still. | JJJJJ (528) | ||
| 409973 | 2005-12-04 08:46:00 | On a second thought, I think the plane would not be able to take off. This is because its forward velocity is canceled out by the conveyor belt, therefore no air flow would be able to pass through the wing, which means no upward thrust would be provided. Cheers :) |
Renmoo (66) | ||
| 409974 | 2005-12-04 08:50:00 | i would say no because what the question is telling us is that the conveyor will move in the opposite direction to match whatever speed the planes is attempting ot move forward at, thus the plane will not move forward in space, this means there will be no air flow over the wings and thus no flight | lagbort (5041) | ||
| 409975 | 2005-12-04 09:18:00 | :D The score so far: pine-o-clean 10/10 greg 10/10 BM 10/10 gibler 10/10 Terry Porritt 10/10 drcspy 0/10 but full marks for Bernouli knowledge of differential pressure over an aerofoil. JJJJJ 0/10 shame on you being a pilot. JamesKan 0/10 Lagbort 0/10 Now I'm going laughing to bed and hope I can get to sleep :) |
Terry Porritt (14) | ||
| 409976 | 2005-12-04 10:10:00 | grrrrrrrrrrr..................HOW with the wheels doing 100mph in one direction and the conveyor belt doin the same speed in the other direction.....thus the effect is that the plane is standing still...................... HOW/WHERE are you getting airflow over the wings from ?........thrust is irrelevant........thrust simply provides the forward motion so that the plane has airflow over the wings......... in fact it aint the wheels that provide the forward movement it's the thrust.............the wheels simply allow the plane to roll forward..........so....when thrust is applied.......and the plane starts to travel down the conveyor belt.....then soem mysterious feedback/monitoring system fires up the conveyor belt in the opposite direction at the same speed the wheels are goin.............. if the net effect of the application of thrust and the movement of the conveyor belt is to cancel each other out and the plane is standin still then it cant take off.........it NEEDS airflow........not just thrust....... |
drcspy (146) | ||
| 409977 | 2005-12-04 10:19:00 | and bearing this in mind: consider that if the wheel bearing friction was zero, like if the wheels had air bearings instead of grease lubricated roller bearings, then no frictional force would be transmitted through to the plane and it would just sit there with the runway conveyor moving past underneath it. sooooooooo............if it's just gonna sit there 'effectively' not moving how the hell are you gonna get airflow over the wing ? t |
drcspy (146) | ||
| 409978 | 2005-12-04 10:31:00 | Still 0/10 | Safari (3993) | ||
| 409979 | 2005-12-04 10:45:00 | So, which side do you think you are on, drcspy, with regards to your signature :D ? Cheers :) |
Renmoo (66) | ||
| 409980 | 2005-12-04 10:48:00 | The plane will take off, the only difference being that the wheels will be rotating at something like twice the speed. (conveyor -100 knots, aircraft driven by jet or propellors +100 knots, wheel rotation speed equivalent to 200 knots.) The above assumes that 100 knots is sufficient for this hypothetical aircraft to actually take off. All the other stuff is flim-flam to confoozle you into forgetting how planes fly. Think about a flying boat, it takes off into the wind, which reduces its required take-off speed, but the direction of the tide is immaterial, the actual airflow over the wings determines the lift. You just have to assume that the plane's engines have sufficient thrust in reserve to overcome any extra drag induced by the hair-brained question. Cheers Billy 8-{) |
Billy T (70) | ||
| 409981 | 2005-12-04 10:50:00 | The plane will not take off. If you could anchor the plane to the runway with a long rope out behind, put the engines on full steam ahead, would the plane leave the ground. NO. If it did they would be using this method for plane take off now, less tyre wear, less use of the runway etc. imagef1.net.nz |
Rob99 (151) | ||
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