tipsy Jock Posted February 22, 2006 Report Share Posted February 22, 2006 An aircraft is standing on a runway that can move (a conveyor belt). The aircraft moves in one direction, while the conveyor moves in the opposite direction. This conveyor has a control system that tracks the aircraft's speed and tunes the speed of the conveyor to be exactly the same, but in the opposite direction. There is no wind. The pilot begins to add thrust to the engines...The question is:Will the plane take off or not? Link to comment Share on other sites More sharing options...
anzo Posted February 22, 2006 Report Share Posted February 22, 2006 No...the plane will be satationary and would require speed and air resistance to fly. If its on a conveyor only the wheels will move if its done perfectly as you said. Link to comment Share on other sites More sharing options...
nmt_oli Posted February 22, 2006 Report Share Posted February 22, 2006 yes it will, as planes are driven by thrust, not the wheels, so the conveyor will get faster and faster, but the plane will still move and take off. Link to comment Share on other sites More sharing options...
tipsy Jock Posted February 22, 2006 Author Report Share Posted February 22, 2006 No...the plane will be satationary and would require speed and air resistance to fly. If its on a conveyor only the wheels will move if its done perfectly as you said.You're gonna have to think harder than that Took me ages to figure out Link to comment Share on other sites More sharing options...
anzo Posted February 22, 2006 Report Share Posted February 22, 2006 An aircraft is standing on a runway that can move (a conveyor belt). The aircraft moves in one direction, while the conveyor moves in the opposite direction. This conveyor has a control system that tracks the aircraft's speed and tunes the speed of the conveyor to be exactly the same, but in the opposite direction. There is no wind. The pilot begins to add thrust to the engines...The question is:Will the plane take off or not?so yes it will fly, if the conveyor is turned get again it'll go in the same way as the plane! Link to comment Share on other sites More sharing options...
Sameer Posted February 22, 2006 Report Share Posted February 22, 2006 Surely the plane isn't going to fly because it's just in one place. I always thought it used the wind resistance as well as the speed to take off (using flaps to counter the wind). If it's just in one place (regardless of thurst and speed of wheels, and all that) it's still just standing there, and it doesn't have the technology of a helicopter to just start flying from a standing point.Seems pretty weird to me. But I don't know how planes work so I guess I'm wrong. Link to comment Share on other sites More sharing options...
Haz Posted February 22, 2006 Report Share Posted February 22, 2006 Yeah it will, but the wheel wheel be spinning twice as fast as usual. Link to comment Share on other sites More sharing options...
nmt_oli Posted February 22, 2006 Report Share Posted February 22, 2006 Yeah it will, but the wheel wheel be spinning twice as fast as usual.correct! Link to comment Share on other sites More sharing options...
anzo Posted February 22, 2006 Report Share Posted February 22, 2006 so yes it will fly, if the conveyor is turned get again it'll go in the same way as the plane!Aheemmm.... Link to comment Share on other sites More sharing options...
nmt_oli Posted February 22, 2006 Report Share Posted February 22, 2006 (edited) Anzo- think! the conveyor wont be going the same way as the plane, still can't see how you worked that one out.also people- the plane wont stay stationary. This conveyor has a control system that tracks the aircraft's speed and tunes the speed of the conveyor to be exactly the same, but in the opposite directionSO:If the plane is stationary, the conveyor will be stopped. If the plane moves - note- the riddle is telling us the plane moves! - at 5 mph forward, the conveyor will run at 5mph backwards, the wheels of the plane will be spinning at 10mph.That is assuming no friction, if you take into account friction, it still works a similar way, but more comlicated to explain.The pilot begins to add thrust to the engines...So- the plane is being driven forwards by its engines, which work by thrusting air, nothing to do with the wheels, so it will still move, and accelerate, and eventually take off. Edited February 22, 2006 by nmt_oli Link to comment Share on other sites More sharing options...
andyroo Posted February 22, 2006 Report Share Posted February 22, 2006 For lift to be acheived air needs to be moving over the wings. The plane increses thrust, but the conveyor belt will also increase speed in the opposite direction. The plane will remain stationary and no air will move over the wings. Meaning it wont take off, or for tht matter, go anywhere. Link to comment Share on other sites More sharing options...
endofreak Posted February 22, 2006 Report Share Posted February 22, 2006 yes it will, as planes are driven by thrust, not the wheels, so the conveyor will get faster and faster, but the plane will still move and take off.What he said. No matter how fast the conveyor goes, the plane will still move as it is being propelled by the Jet engines and not the wheels. Link to comment Share on other sites More sharing options...
nmt_oli Posted February 22, 2006 Report Share Posted February 22, 2006 Thank you endo freak! Link to comment Share on other sites More sharing options...
Brian Bleech Posted February 22, 2006 Report Share Posted February 22, 2006 don't know much about planes, but is it something do with once the correct amount of thrust (force??) to lift the weight of plane and the air resistance then the plane will take off.normally the plane needs a runway , but the conveyer belt allows the engines to gain enough thrust without moving maybe Link to comment Share on other sites More sharing options...
anzo Posted February 22, 2006 Report Share Posted February 22, 2006 An aircraft is standing on a runway that can move (a conveyor belt). The aircraft moves in one direction, while the conveyor moves in the opposite direction. This conveyor has a control system that tracks the aircraft's speed and tunes the speed of the conveyor to be exactly the same, but in the opposite direction. There is no wind. The pilot begins to add thrust to the engines...The question is:Will the plane take off or not?I thought it would just be a word thing. It says the conveyor goes the opposite way to the plane, but then it says the tracking system moves the belt but in the opposite direction (now in the same direction as the plane) therefor 'pushing' the plane, and so, it would take off. Link to comment Share on other sites More sharing options...
nmt_oli Posted February 22, 2006 Report Share Posted February 22, 2006 For lift to be acheived air needs to be moving over the wings. The plane increses thrust, but the conveyor belt will also increase speed in the opposite direction. The plane will remain stationary and no air will move over the wings. Meaning it wont take off, or for tht matter, go anywhere.That statement is fundamentally wrong anyway- your saying the planes thrust is speed "the plane increases thrust, but the conveyor will increase speed in the opposite direction" for starters, these two things cant be equated like that, plus if you read my long explanation, the plane HAS to be moving for the conveyor to be moving, so there WILL be airflow over the wings. Link to comment Share on other sites More sharing options...
andyroo Posted February 22, 2006 Report Share Posted February 22, 2006 NO NO NO NO NO!!!A plane has no drive through the wheels, all they do is stop the aircraft scraping along the ground.The engine pulls air towards the aircraft and forces it backwards (if we are talking about jet engines), which pushes the aircraft forwards. This conveyor belt is said to move at the speed the aircraft would be moving if it were oin a normal runway, so in effect its x amount of force + minus (cos its the opposite direction) x amount of force = nothing, tha aircraft is stationary. No air moves over the wings, and so lift cannot be achieved.If you walk up a down escalator at the same speed it moves down, you will remain stationary... think of it like that. Link to comment Share on other sites More sharing options...
011001000110010101110010 Posted February 22, 2006 Report Share Posted February 22, 2006 It will take off. Relative air speed, the plane is moving in relation to the air around it. Link to comment Share on other sites More sharing options...
andyroo Posted February 22, 2006 Report Share Posted February 22, 2006 It will take off. Relative air speed, the plane is moving in relation to the air around it.Your telling me if you walked up a down escalator at the same speed it moves down at, you will reach the top? Or will you have to increase your speed? (and in this example, the escalator would match your speed in the opposite direction, and you would still go nowhere) Link to comment Share on other sites More sharing options...
Brian Bleech Posted February 22, 2006 Report Share Posted February 22, 2006 What he said. No matter how fast the conveyor goes, the plane will still move as it is being propelled by the Jet engines and not the wheels.but the jet engines are attached to the wheels, so until the plane leaves the ground the wheels will be turned by the jet engine, therefore the conveyer belt will move the at the same speed as the wheels!! it just that that statement doesn't make much sense to me Link to comment Share on other sites More sharing options...
nmt_oli Posted February 22, 2006 Report Share Posted February 22, 2006 NO NO NO NO NO!!!A plane has no drive through the wheels, all they do is stop the aircraft scraping along the ground.The engine pulls air towards the aircraft and forces it backwards (if we are talking about jet engines), which pushes the aircraft forwards. This conveyor belt is said to move at the speed the aircraft would be moving if it were oin a normal runway, so in effect its x amount of force + minus (cos its the opposite direction) x amount of force = nothing, tha aircraft is stationary. No air moves over the wings, and so lift cannot be achieved.If you walk up a down escalator at the same speed it moves down, you will remain stationary... think of it like that.you said it yourself- the aircraft doesnot move via the wheels, therefore if you let friction equal zero, then the plane isnt even connected to the conveyor, so it doesnt matter what the conveyor is doing. even if you let friction into the eqaution, it is very negligable.there is no wind, so the engines WILL be providing thust, the plane WILL move forwards. if the situation was a wind tunnel, and the air speed aroudn the plane increased as the thrust incresed, then the plane would remain stationary (but still take off).this IS NOT A CAR. a car would remain stationary on the conveyor, as it drives via the wheels. i repeat A PLANE DOES NOT SUPPLY POWER VIA WHEELS. Link to comment Share on other sites More sharing options...
andyroo Posted February 22, 2006 Report Share Posted February 22, 2006 ANOTHER EXAMPLE>>>>>>>>A rolling road - we all what that is right - you will never, no matter how fast you drive, be able to drive off it as long as it can free roll in the opposite direction to the cars wheels. Same principle here. Link to comment Share on other sites More sharing options...
nmt_oli Posted February 22, 2006 Report Share Posted February 22, 2006 ANOTHER EXAMPLE>>>>>>>>A rolling road - we all what that is right - you will never, no matter how fast you drive, be able to drive off it as long as it can free roll in the opposite direction to the cars wheels. Same principle here.NO ITS NOT!!!!!!!!!!!!!!!!! read my above post. Link to comment Share on other sites More sharing options...
Brian Bleech Posted February 22, 2006 Report Share Posted February 22, 2006 For lift to be acheived air needs to be moving over the wings. The plane increses thrust, but the conveyor belt will also increase speed in the opposite direction. The plane will remain stationary and no air will move over the wings. Meaning it wont take off, or for tht matter, go anywhere.but jet engines suck air in, therefore will (enventually) push enough air over the wings ... maybe Link to comment Share on other sites More sharing options...
andyroo Posted February 22, 2006 Report Share Posted February 22, 2006 Who said the conveyor belt monitors the speed of the wheels? It says it just matches the potential speed the aircraft would be travlling if it were on stationary ground....C'mon this is basic mechanics!!!! Link to comment Share on other sites More sharing options...
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