tbourner Posted February 7, 2008 Share Posted February 7, 2008 No movement = no take-off. Nobody here (I don't think) is stupid enough to think that a plane can take off if it's not moving through the air, even those that don't fully understand the distance travelled equations and that the larger surface on the top of the wing creates a lower pressure creating lift etc., we all know a plane needs to move through the air in order to take off. The point is, we're discussing whether or not the plane moves forwards with respect to the Earth (and therefore air). I'm quite enjoying playing devils advocate here actually It's a fun discussion, but you're still wrong. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 Forget speed for a minute. Put a chalk mark on the belt, and a corresponding mark on the ground next to the belt, and a corresponding mark on the plane. When all this stuff kicks off, the belt moves right ? The chalk mark will move from its point marked on the ground. Lets say it moves 100m. It can only move at the same time as the plane, and as stated the plane moves in the opposite direction...so the chalk mark on the plane is now also 100m away from the chalk mark on the ground, but 200m away from the chalk mark on the belt. So the plane has moved forward. Now add speed, and more distance. the chalk marks on the belt and plane get further apart, but the distance from the chalk mark on the plane and ground, and from the chalk mark on the belt and the ground are always equal. The plane will move further away from the chalk mark on the ground, accelerate and take off. Again. But every time the plane moves forwards, the ground moves backwards so the plane still doesn't go anywhere. The chalk mark arguement doesn't work because the mark on the earth would stay still whereas the one on the runway will move. If the one on the runway moves then that doesn't prove that the plane is moving, just that the runway is in motion. This motion is counteracted by the plane, and so the forces are equal, hence the plane won't move. For this example to be accurate, you'd have to have a chalk mark on the wheel of the plane. Quote Link to comment Share on other sites More sharing options...
Homer Posted February 7, 2008 Share Posted February 7, 2008 It will take off Quote Link to comment Share on other sites More sharing options...
Ric Posted February 7, 2008 Share Posted February 7, 2008 It will take off I think its boiled down to yes theoreticaly it will take off, BUT Are there tyres, bearings, engines strong enough to actually get for example a 747 or any other large passenger bearing aircraft in the air? Nevermind a conveyor belt that would hold and rotate with a plane on it Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 I think its boiled down to yes theoreticaly it will take off, BUT Are there tyres, bearings, engines strong enough to actually get for example a 747 or any other large passenger bearing aircraft in the air? Nevermind a conveyor belt that would hold and rotate with a plane on it But the plane can't move as it can't begin the acceleration at full weight as every time the engines push the plane, the runway moves. It will never get up to a speed where lift takes the plane upwards and negates the effects of gravity on the wheels. It just can't move from stationary in this situation Quote Link to comment Share on other sites More sharing options...
Thorin Posted February 7, 2008 Share Posted February 7, 2008 this thread still going. Either some people are REALLY stupid, or they're just winding people up now Quote Link to comment Share on other sites More sharing options...
Alex Posted February 7, 2008 Share Posted February 7, 2008 I'm closing this thread because the discussion over the facts is complete. If I don't close it, we'll be going on forever arguing the toss. If after 300+ posts you're still confused there's not a lot more that can be done. Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 7, 2008 Share Posted February 7, 2008 this thread still going. Either some people are REALLY stupid, or they're just winding people up now Quote Link to comment Share on other sites More sharing options...
RiceRocket Posted March 4, 2010 Share Posted March 4, 2010 Thread saved. Quote Link to comment Share on other sites More sharing options...
Ewen Posted March 4, 2010 Share Posted March 4, 2010 Thread saved. Was it that long ago ? Crikey time flies...unless its on a treadmill. Quote Link to comment Share on other sites More sharing options...
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