MrRalphMan Posted February 6, 2008 Share Posted February 6, 2008 ok I grabbed this off another forum, but it invoked several different ideas.. Lets try it with you guys... A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in the opposite direction). Can the plane take off and why? Don't run off and Google, but I'll let you know that Mythbusters tried this.. But lets see what you think first... Quote Link to comment Share on other sites More sharing options...
Ric Posted February 6, 2008 Share Posted February 6, 2008 no it doesent, it stays in the same place, like a running treadmil Oh and repost Quote Link to comment Share on other sites More sharing options...
AndrewOW Posted February 6, 2008 Share Posted February 6, 2008 no it doesent, it stays in the same place, like a running treadmil Oh and repost No air is passing over and under the wings to give lift (high/low pressures) etc, plus the engines would overheat too I'd thought. EDIT: So no it won't take off. Just ask supradibbs Quote Link to comment Share on other sites More sharing options...
spidermonkey Posted February 6, 2008 Share Posted February 6, 2008 this has got to be an issue with air flow and density so i guess the plane will not move Quote Link to comment Share on other sites More sharing options...
Blackie Posted February 6, 2008 Share Posted February 6, 2008 Stays in the same place as there is no wind speed going over/under the wings. Quote Link to comment Share on other sites More sharing options...
MrRalphMan Posted February 6, 2008 Author Share Posted February 6, 2008 Oh and repost Well bugger me, I couldn't find it.. Oh well... Quote Link to comment Share on other sites More sharing options...
mikeyb10supra Posted February 6, 2008 Share Posted February 6, 2008 It just stays where it is, the movement below it will just spin the wheels, similar to a rolling road....or have I read the original post inccorectly? and then it will prob burst into flames Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 6, 2008 Share Posted February 6, 2008 It's not a car ffs. The engines work on the air around it which ISN'T moving, the treadmill thing just means the unpowered wheels will spin twice as fast as normal as the plane takes off perfectly normally. Quote Link to comment Share on other sites More sharing options...
Ric Posted February 6, 2008 Share Posted February 6, 2008 It's not a car ffs. The engines work on the air around it which ISN'T moving, the treadmill thing just means the unpowered wheels will spin twice as fast as normal as the plane takes off perfectly normally. If the plane cannot move forwardly (like down a runway) of speeds upto 150mph then how is the wind (lift) going to be created under the wings at 150mph speed. Quote Link to comment Share on other sites More sharing options...
AndyT Posted February 6, 2008 Share Posted February 6, 2008 It's not a car ffs. The engines work on the air around it which ISN'T moving, the treadmill thing just means the unpowered wheels will spin twice as fast as normal as the plane takes off perfectly normally. You must be the 2nd yes then Ian. Quote Link to comment Share on other sites More sharing options...
R Black Posted February 6, 2008 Share Posted February 6, 2008 It cant take off as no air is rushing over the wings thats what makes normal (as opposed to a jump let can vector its thrust)planes airborne Quote Link to comment Share on other sites More sharing options...
spidermonkey Posted February 6, 2008 Share Posted February 6, 2008 It's not a car ffs. The engines work on the air around it which ISN'T moving, the treadmill thing just means the unpowered wheels will spin twice as fast as normal as the plane takes off perfectly normally. is this a jet or propellor plane? i thought the principle of a plane taking off is to create more pressure under the wing than on top(the same reason that a glider needs to be propelled) i could be wrong though;) Quote Link to comment Share on other sites More sharing options...
razza Posted February 6, 2008 Share Posted February 6, 2008 plane stands still, so doesn't create enough uplift under wings as no air moving over them:) Quote Link to comment Share on other sites More sharing options...
Ian C Posted February 6, 2008 Share Posted February 6, 2008 If the plane cannot move forwardly (like down a runway) of speeds upto 150mph then how is the wind (lift) going to be created under the wings at 150mph speed. ITS NOT A CAR THE ENGINES/PROPELLER ACT ON THE AIR How does a plane normally accelerate down a runway for crying out loud, a moped engine on each wheel? I despair. Quote Link to comment Share on other sites More sharing options...
MrRalphMan Posted February 6, 2008 Author Share Posted February 6, 2008 he he he, just like the other forum... Who's going to get bored first and check Mythbusters? Quote Link to comment Share on other sites More sharing options...
Matt H Posted February 6, 2008 Share Posted February 6, 2008 I clicked no but then realised that the power doesnt get fed to the wheels of a plan, it pushes on the air no the conveyor belt. But then again, i should have clicked blown up, because the wheels will end up moving faster and faster and faster then probably fall off, then the plane would hit the deck, the conveyor belt would sent it flying of the end of itself in the opposite direction and then smash boom Quote Link to comment Share on other sites More sharing options...
MrRalphMan Posted February 6, 2008 Author Share Posted February 6, 2008 ITS NOT A CAR THE ENGINES/PROPELLER ACT ON THE AIR How does a plane normally accelerate down a runway for crying out loud, a moped engine on each wheel? I despair. LMFAO /vbb/images/smilies/bbcode_grin.gif Quote Link to comment Share on other sites More sharing options...
Ric Posted February 6, 2008 Share Posted February 6, 2008 ITS NOT A CAR THE ENGINES/PROPELLER ACT ON THE AIR How does a plane normally accelerate down a runway for crying out loud, a moped engine on each wheel? I despair. the thrust from the engines push it down the run way....... not the wheels i know this. But the movement of the plane down the run way (by thrust) would be cancelled out as the runway is moving backwards, therefore no forward motion will be created thus giving zero lift. Quote Link to comment Share on other sites More sharing options...
Matt H Posted February 6, 2008 Share Posted February 6, 2008 the thrust from the engines push it down the run way....... not the wheels i know this. But the movement of the plane down the run way (by thrust) would be cancelled out as the runway is moving backwards, therefore no forward motion will be created thus giving zero lift. The wheels are free to move as they want though surely, so they would just spin faster and faster......then fall off (as the plane move forward) Quote Link to comment Share on other sites More sharing options...
spidermonkey Posted February 6, 2008 Share Posted February 6, 2008 ITS NOT A CAR THE ENGINES/PROPELLER ACT ON THE AIR How does a plane normally accelerate down a runway for crying out loud, a moped engine on each wheel? I despair. if it is a jet it will thrust the air out behind the wings not under them the propeller will not create enough air pressure under the wing to ensure take off, it has nothing to do with the wheels being powered, it is to do with the volume of air under each wing, or am i reading this all wrong:) Quote Link to comment Share on other sites More sharing options...
Ric Posted February 6, 2008 Share Posted February 6, 2008 easiest way is to imagine You are running on a treadmill but the treadmill is too fast, you run quicker. (whereas a jet would thrust more) but you stay central to the treadmill, and if you held your arms out theres no air traveling under your arms the same speed you are running, rofl. As the question stipulates, the conveyor moves the exact same as the plane but backwards, back to the treadmill speed thought. Quote Link to comment Share on other sites More sharing options...
Matt H Posted February 6, 2008 Share Posted February 6, 2008 if it is a jet it will thrust the air out behind the wings not under them the propeller will not create enough air pressure under the wing to ensure take off, it has nothing to do with the wheels being powered, it is to do with the volume of air under each wing, or am i reading this all wrong:) All wrong Quote Link to comment Share on other sites More sharing options...
Thorin Posted February 6, 2008 Share Posted February 6, 2008 Imagine a toy car on a treadmill with your finger at the back off it. Run the treadmill at any speed you like and push forward on the car. Does the car stay where it is? Quote Link to comment Share on other sites More sharing options...
Gaz6002 Posted February 6, 2008 Share Posted February 6, 2008 I don't think the plane will be going anywhere. I believe that given a hypothetical situation the wheels will spin up to their maximum velocity and then overheat and explode or catch fire. The thrust being created by the engine would be cancelled out (through the friction between the wheels and the runway/conveyor) by the backwards movement of the conveyor, hence no lift will be created as there will be the same volume or air under the wings. Quote Link to comment Share on other sites More sharing options...
Matt H Posted February 6, 2008 Share Posted February 6, 2008 easiest way is to imagine You are running on a treadmill but the treadmill is too fast, you run quicker. but you stay central to the treadmill, and if you held your arms out theres no air traveling under your arms the same speed you are running, rofl. As the question stipulates, the conveyor moves the exact same as the plane but backwards, back to the treadmill speed thought. Perfect example, the power to move you forwards on the tread mill is going through your legs (I.e wheels) but the power from the plane is not being fed through the wheels (I.e Legs) its coming from your arse therefore you will fly forward off the tread mill Quote Link to comment Share on other sites More sharing options...
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