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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 | ||
| 410092 | 2005-12-05 22:42:00 | I don't appreciate being called a flip flopper :blush: Sorry Plod, no offence intended, it seemed the easiest way to classify those who changed their minds once or twice during their analytical thought processes and general cogitations. Cheers Billy 8-{) :o |
Billy T (70) | ||
| 410093 | 2005-12-05 23:26:00 | For those who are still doubtful, think about cause and effect . The wheels rotate because the plane is moving . The plane isn't moving because the wheels are rotating . When your normal plane on your normal runway starts the takeoff run, it does that because the pilot has released the brakes and put on throttle . The engines provide thrust . That is a force . That has the effect of accelerating the plane . As long as the wheels are touching the runway, they are rotating . They rotate because there is friction and the axles are moving forwards . They can't help it . If the plane is moving fast enough and there has been heavy rain, the wheels might hydroplane . The wheels would be sliding . The pilot won't be happy about it, but all he can do is keep the throttle on . The plane will still take off . The rotation of the wheels isn't necessary, if the friction is small enough . All that's needed is enough thrust to accelerate the plane to takeoff speed . All in all, Helen's "knowlege economy" hasn't got very good prospects . :( |
Graham L (2) | ||
| 410094 | 2005-12-05 23:52:00 | Billy, were those flip/floppers you referred to asymmetrical and free running? ;) | B.M. (505) | ||
| 410095 | 2005-12-06 00:00:00 | Billy, were those flip/floppers you referred to asymmetrical and free running? ;) Eccles and Jordan (www.du.edu/~etuttle/electron/elect36.htm) or Eccles and Bluebottle? | Graham L (2) | ||
| 410096 | 2005-12-06 00:58:00 | Ohhhhhh Neddy, we wont go there . :groan: Look at the trouble we’ve had getting this beastly plane to fly and there’s still a dozen that won't get on! :D |
B.M. (505) | ||
| 410097 | 2005-12-06 01:09:00 | You certainly said a mouthful there Greg . Ignorance of aerodynamics and the principles of flight are the major barrier, plus an inability to understand that the principles of flight relate to air and thrust, not the runway or hypothetical movement of the ground the plane takes off from . Speed of the surrounding air and the level of thrust available are the only criteria that matter in this question . The connection to the ground is through virtually zero-friction and zero rolling-resistance wheels . The runway can do what it likes . The ability to fly depends solely on aerodynamics and reaction forces (thrust) . The inteface with the ground simply provides a means of moving while on the ground, and a relatively friction-free transport mechanism to enable the former factors to reach the AIR speed necessary to generate lift . Ground speed and airspeed are two different things as has been previously pointed out . In a very high headwind, a plane can have zero or even negative ground speed . The friction of freely rotating wheels on a runway is insignificant, so whether the ground stands still, moves forward or moves backward is totally irrelevant . Three thoughts: What do you think would happen if a plane flew in and landed on this hypothetical and very mobile reverse-runway while the first plane was trying to take off? Humour me and accept that the runway is long enough for both planes to use it simultaneously . Would it lose the power of flight the instant its wheels touched the deck? What do you think would happen if the runway ran forwards instead of backwards and a plane flew in and landed, and the pilot applied the brakes? Suppose it was a normal runway but built inside a ginormous wind-tunnel . Same plane, ordinary runway . The wind-tunnel controls are programmed to match the rolling speed of the wheels with an equivalent tail-wind . Will the plane achive lift-off? Sometimes looking at a question from several other perspectives helps to clear your thinking . The plane can fly, it is as simple as that . Cheers Billy 8-{) Um . . . "mouthful"? moi? *gasp* :eek: Sorry Billy Boy, I thought it was your diatribe that was usually regarded as "mouthful" |
Greg (193) | ||
| 410098 | 2005-12-06 01:13:00 | Me pilot mate rang me a few minutes after I posted last night, I am a believer now it flys, it flys. The wheels mean jack **** I knew he'd come round, pilots usually know how planes work :p |
george12 (7) | ||
| 410099 | 2005-12-06 04:33:00 | Sorry Billy Boy, I thought it was your diatribe that was usually regarded as "mouthful" Get a life Greg, you don't want to end up an irritable old fart like ninja when you grow up. :p Cheers Billy 8-{) |
Billy T (70) | ||
| 410100 | 2005-12-06 05:19:00 | Billy, Greg and ninja - if you guys don't lose the attitude and leave off the mud-slinging, I'm closing this thread. Now that would be a real shame because apart from your childish egotistical carry-on others are enjoying the debate. | Jen (38) | ||
| 410101 | 2005-12-06 05:44:00 | There will now be a two minute silence for rethinking...... Tony |
TonyF (246) | ||
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