Will the Plane Take-Off - Merged with MythBusters Show Thread
12-17-2007, 08:01 PM
#721
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12-17-2007, 09:09 PM
#722
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12-17-2007, 10:47 PM
#723
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Originally Posted by curls
Every variant of the original riddle says or implies that the treadmill matches the speed of the PLANE, not the PLANES WHEELS. IE: Matches the speed of the fuselage. If this is the case, then the plane flies 100% normally. If, however, the treadmill matches the rotational speed of the wheels (ground speed of the plane as indicated by wheel rotation), then yes the question is broken.
I HIGHLY suspect that the riddle was/is worded to get people thinking about a planes' method of thrust and of how a conveyor wouldn't affect that method, and was not worded in order to make it impossible to answer. AFAIK, there are no riddles without answers, and no riddles where the answer is "the riddle is broken by nature of its question".
I HIGHLY suspect that the riddle was/is worded to get people thinking about a planes' method of thrust and of how a conveyor wouldn't affect that method, and was not worded in order to make it impossible to answer. AFAIK, there are no riddles without answers, and no riddles where the answer is "the riddle is broken by nature of its question".
12-17-2007, 11:04 PM
#724
I shoot people
I forget who's argument is what... why can't we have a open poll on this?!?!
12-17-2007, 11:10 PM
#725
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Originally Posted by Whiskers
Is it snowing in Hell?
12-17-2007, 11:30 PM
#726
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Originally Posted by Gpump
Dom, Dan, and Srika - read the above comment and help yourselves to a great big helping of stfu. Or, re read my last post where I tried to clarify my stance which curls probably did a better job of than me, admittedly. But I prefer the stfu option.
12-23-2007, 01:07 PM
#727
I shave my change purse
PREVIEW:
<embed width="448" height="361" type="application/x-shockwave-flash" wmode="transparent" src="http://i252.photobucket.com/player.swf?file=http://vid252.photobucket.com/albums/hh4/werdy1234567/tradmill.flv"></embed>
<embed width="448" height="361" type="application/x-shockwave-flash" wmode="transparent" src="http://i252.photobucket.com/player.swf?file=http://vid252.photobucket.com/albums/hh4/werdy1234567/tradmill.flv"></embed>
12-23-2007, 01:15 PM
#728
I shoot people
so, when's the open poll gonna be put up? That thing ain't going anywhere
12-23-2007, 01:29 PM
#730
Go Giants
I hope they do it right....
12-24-2007, 12:58 AM
#735
Senior Moderator
Originally Posted by The Dougler
2000ft tarp + coefficient of friction with the ground is certainly greater than 10,000lbs.
01-23-2008, 09:06 PM
#738
i cannot beleive that there are 30 pages of this thread. there IS no argument here. there is no way in a hell a plane can take off from a standstill unless it is a harrier type plane with engines that can fire downward or those helicopter adjustable wings.
how anyone can actually beleive a plane will take off from a standstill just because the wheels are spinning quickly underneath it is beyond all reasonable comprehension. I didnt think so many people...many grown adults no less...could have such a limited or flat out LACK of any understanding of physics.
plane needs air moving rapidly under the wings to take off....simple concept people....
how anyone can actually beleive a plane will take off from a standstill just because the wheels are spinning quickly underneath it is beyond all reasonable comprehension. I didnt think so many people...many grown adults no less...could have such a limited or flat out LACK of any understanding of physics.
plane needs air moving rapidly under the wings to take off....simple concept people....
01-23-2008, 09:18 PM
#739
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Originally Posted by BubbaMarkTL
i cannot beleive that there are 30 pages of this thread. there IS no argument here. there is no way in a hell a plane can take off from a standstill unless it is a harrier type plane with engines that can fire downward or those helicopter adjustable wings.
how anyone can actually beleive a plane will take off from a standstill just because the wheels are spinning quickly underneath it is beyond all reasonable comprehension. I didnt think so many people...many grown adults no less...could have such a limited or flat out LACK of any understanding of physics.
plane needs air moving rapidly under the wings to take off....simple concept people....
how anyone can actually beleive a plane will take off from a standstill just because the wheels are spinning quickly underneath it is beyond all reasonable comprehension. I didnt think so many people...many grown adults no less...could have such a limited or flat out LACK of any understanding of physics.
plane needs air moving rapidly under the wings to take off....simple concept people....
01-23-2008, 09:18 PM
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Originally Posted by BubbaMarkTL
i cannot beleive that there are 30 pages of this thread. there IS no argument here. there is no way in a hell a plane can take off from a standstill unless it is a harrier type plane with engines that can fire downward or those helicopter adjustable wings.
how anyone can actually beleive a plane will take off from a standstill just because the wheels are spinning quickly underneath it is beyond all reasonable comprehension. I didnt think so many people...many grown adults no less...could have such a limited or flat out LACK of any understanding of physics.
plane needs air moving rapidly under the wings to take off....simple concept people....
how anyone can actually beleive a plane will take off from a standstill just because the wheels are spinning quickly underneath it is beyond all reasonable comprehension. I didnt think so many people...many grown adults no less...could have such a limited or flat out LACK of any understanding of physics.
plane needs air moving rapidly under the wings to take off....simple concept people....
you are missing a vital part of the equation. the plane prop pushes off the air, not the wheels like a car engine. so the conveyor can be moving in the opposite direction at a million miles per hour, and the plane propeller will STILL push off the air, not the conveyor, and push the plane forward. note friction was removed from that equation for simplicity. so i'm not sure what physics you are quoting, but its wrong.
01-23-2008, 09:24 PM
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The confusion/assumption was in the wording of the question. Myself and others took took "moving in the opposite direction at the same speed" to mean the speed of the wheels, not the fuselage. For it to take off the wheels, while in contact with the conveyor belt, will by definition be moving x mph faster than the belt regardless of where the propulsion comes from. Again, see curls explanation. You won a reading comprehension contest - I lost.
01-23-2008, 09:26 PM
#742
Originally Posted by DRM600
the plane will indeed take off from a conveyor belt. the plane is not propelled by powered wheels, but jet engines. the wheels are free-rolling and have no effect on the plane's forward motion other than keeping it off the ground.
youre right....the wheels have nothing to do with it....
but what you are missing is that the jet engines or propellers are merely providing enough power to match the speed of the conveyor belt in reverse....so the plane goes absolutely nowhere and certainly not up into the air....sorry the plane will not take off.
if a plane's takeoff speed is 150 mph then in order to take off, the jet engines would have to be providing enough thrust to make the plane go 300 mph in order to make up for the reverse 150 mph (again, the conveyor is matching the planes take off speed in reverse) and than an additional 150 mph to make the plane actually move forward in spite of the reverse conveyor.
if your conveyor is going 150 mph in reverse and your engines are providing enough power to get the plane to move forward at 150 mph, it cancels itself out, thus the fuselage (and the entire plane) goes nowhere and most certainly does not take off
Last edited by BubbaMarkTL; 01-23-2008 at 09:28 PM.
01-23-2008, 09:30 PM
#743
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the conveyor belt and the plane will be moving independently in opposite directions. the only way the conveyor will affect the plane is that it will cause the wheels to rotate faster than the plane is traveling.
01-23-2008, 09:36 PM
#744
We beat the shit out of this theory. The wheels will be spinning twice as fast as normal as the plane will be moving the same speed in one direction as the treadmill is in the other.
Mike
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01-23-2008, 09:40 PM
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Originally Posted by BubbaMarkTL
youre right....the wheels have nothing to do with it....
but what you are missing is that the jet engines or propellers are merely providing enough power to match the speed of the conveyor belt in reverse....so the plane goes absolutely nowhere and certainly not up into the air....sorry the plane will not take off.
if a plane's takeoff speed is 150 mph then in order to take off, the jet engines would have to be providing enough thrust to make the plane go 300 mph in order to make up for the reverse 150 mph (again, the conveyor is matching the planes take off speed in reverse) and than an additional 150 mph to make the plane actually move forward in spite of the reverse conveyor.
if your conveyor is going 150 mph in reverse and your engines are providing enough power to get the plane to move forward at 150 mph, it cancels itself out, thus the fuselage (and the entire plane) goes nowhere and most certainly does not take off
but what you are missing is that the jet engines or propellers are merely providing enough power to match the speed of the conveyor belt in reverse....so the plane goes absolutely nowhere and certainly not up into the air....sorry the plane will not take off.
if a plane's takeoff speed is 150 mph then in order to take off, the jet engines would have to be providing enough thrust to make the plane go 300 mph in order to make up for the reverse 150 mph (again, the conveyor is matching the planes take off speed in reverse) and than an additional 150 mph to make the plane actually move forward in spite of the reverse conveyor.
if your conveyor is going 150 mph in reverse and your engines are providing enough power to get the plane to move forward at 150 mph, it cancels itself out, thus the fuselage (and the entire plane) goes nowhere and most certainly does not take off
think of it this way. at 0mph nothing is moving. engine starts, plane moves forward at 1mph, so the conveyor moves backward at 1mph. but the plane is still moving forward at 1mph, with the wheels now spinning at 2 mph total. 1mph for the conveyor, and 1mph for the forward motion from the jet engine. increase these numbers to any amount, 150mph, 1000mph, whatever. the plane always takes off, and the wheel speed is always spinning twice the speed of total plane speed.
at this thread
01-23-2008, 09:40 PM
#747
in order to set up such an experiment you need the plane to be on the conveyor and the conveyor to be stopped. then you need to start the conveyor and get the conveyor up to the take off speed of the plane...in reverse of course.
big problem though, the plane would just move backward and fly off the end of the treadmill...SO you need some sort of "pin" or something holding the plane stationary while the conveyor is getting up to speed. at this point the wheels on the plane are going at exactly the takeoff speed of the plane and the conveyor is doing the same, only in the opposite direction, and the plane is going nowhere. The only thing keeping the plane from going backwards is some sort of pin or barrier...again, at this point, there is still no engine engaged on the plane.
now with the pin still in place, you have to start the engine and bring it up to enough power to cause the plane to take off under normal conditions. at this point you could pull the pin and the plane would go nowhere...
the engine would merely be producing enough power to keep the plane stationary on the treadmill without the need for a pin or barrier behind it to keep it in place...nothing more.
big problem though, the plane would just move backward and fly off the end of the treadmill...SO you need some sort of "pin" or something holding the plane stationary while the conveyor is getting up to speed. at this point the wheels on the plane are going at exactly the takeoff speed of the plane and the conveyor is doing the same, only in the opposite direction, and the plane is going nowhere. The only thing keeping the plane from going backwards is some sort of pin or barrier...again, at this point, there is still no engine engaged on the plane.
now with the pin still in place, you have to start the engine and bring it up to enough power to cause the plane to take off under normal conditions. at this point you could pull the pin and the plane would go nowhere...
the engine would merely be producing enough power to keep the plane stationary on the treadmill without the need for a pin or barrier behind it to keep it in place...nothing more.
01-23-2008, 09:47 PM
#748
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ok i'm not gonna keep replying. but your logic is not factoring in the crucial part. you're just not seeing it. its a proven mind twister, and the plane always takes off with wheels spinning twice the conveyor speed. google it and find the explanation.
your pin holding example is perfect. engines off, pin holding the plan in place with conveyor moving backward. now fire up the engines. the engines push off the air and move the plane forward. hell, the wheels can be replaced with blocks of ice, and the plane will still take off. air thrust moves the plane forward regardless of what the wheels are doing because there is no mechanical link between the wheels and jet engine. the jet engine will always, always always push off the air and move the plane forward. every time. no way around it. you are still thinking that the plane pushes off the wheels, which is why you are not seeing the solution. the wheels just keep the plane from resting on its belly, thats it. they dont do any pushing or force involved from the wheels. its all the jet engine air power doing the work.
your pin holding example is perfect. engines off, pin holding the plan in place with conveyor moving backward. now fire up the engines. the engines push off the air and move the plane forward. hell, the wheels can be replaced with blocks of ice, and the plane will still take off. air thrust moves the plane forward regardless of what the wheels are doing because there is no mechanical link between the wheels and jet engine. the jet engine will always, always always push off the air and move the plane forward. every time. no way around it. you are still thinking that the plane pushes off the wheels, which is why you are not seeing the solution. the wheels just keep the plane from resting on its belly, thats it. they dont do any pushing or force involved from the wheels. its all the jet engine air power doing the work.
01-23-2008, 09:50 PM
#749
F1 cart racer
this thread = dead horse.....and it keeps getting hit with a stick
and that truck is a 5.7 tundra, look it up on youtube and it vs a f150, 2500, and something else. you wanna see something pull. and all those commercials of the tundra are real. i've driven the truck and you can smoke the tires through the gears, it is powerful.
and that truck is a 5.7 tundra, look it up on youtube and it vs a f150, 2500, and something else. you wanna see something pull. and all those commercials of the tundra are real. i've driven the truck and you can smoke the tires through the gears, it is powerful.
01-23-2008, 10:09 PM
#750
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01-23-2008, 10:52 PM
#752
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Heres a question....the answer should prove that a plane CAN take off..........
can a plane LAND normally on a treadmill that is moving at the same speed in the reverse direction as the plane?
And by same speed, I mean (and assuming with numbers here...) if the planes approach is 150mph, the treadmill is moving at 150mph at landing, and as the plane brakes, the treadmill's speed will decrease....or actually it doesn't even matter, because either way the plane WILL take off, and land.
The plane will even take off, if say, as soon as it got into motion, this gay theoretical treadmill started going at a constant 600mph
can a plane LAND normally on a treadmill that is moving at the same speed in the reverse direction as the plane?
And by same speed, I mean (and assuming with numbers here...) if the planes approach is 150mph, the treadmill is moving at 150mph at landing, and as the plane brakes, the treadmill's speed will decrease....or actually it doesn't even matter, because either way the plane WILL take off, and land.
The plane will even take off, if say, as soon as it got into motion, this gay theoretical treadmill started going at a constant 600mph
01-23-2008, 11:00 PM
#753
Originally Posted by salvo24
Heres a question....the answer should prove that a plane CAN take off..........
can a plane LAND normally on a treadmill that is moving at the same speed in the reverse direction as the plane?
And by same speed, I mean (and assuming with numbers here...) if the planes approach is 150mph, the treadmill is moving at 150mph at landing, and as the plane brakes, the treadmill's speed will decrease....or actually it doesn't even matter, because either way the plane WILL take off, and land.
The plane will even take off, if say, as soon as it got into motion, this gay theoretical treadmill started going at a constant 600mph
can a plane LAND normally on a treadmill that is moving at the same speed in the reverse direction as the plane?
And by same speed, I mean (and assuming with numbers here...) if the planes approach is 150mph, the treadmill is moving at 150mph at landing, and as the plane brakes, the treadmill's speed will decrease....or actually it doesn't even matter, because either way the plane WILL take off, and land.
The plane will even take off, if say, as soon as it got into motion, this gay theoretical treadmill started going at a constant 600mph
01-23-2008, 11:08 PM
#754
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i'm just reading back thru pages 18-21, and holy crap i wanna bash things. its so frustrating hearing the same thing over and over. the plane takes off, identical to how it would on a normal runway. it still has to travel a couple thousand feet down the runway, all the while this conveyor underneath spinning opposite direction. but the thrust still pushes the plane 2500 feet down the runway until it reaches lift speed and takes off.
someone said it best. notice how people are changing their minds from "wont take off, to yes it will" but nobody is switching the other way, nobody is going from "yes it will fly, to no it wont." wonder why.
someone said it best. notice how people are changing their minds from "wont take off, to yes it will" but nobody is switching the other way, nobody is going from "yes it will fly, to no it wont." wonder why.
01-23-2008, 11:15 PM
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Well the common sense of a kid who is about to get a B.S. at FSU shows that the wheels of a plane are free spinning, so the thrust caused from the engines pushes the fuselage, which in turn, the wheels just spin to carry it. I can see how the plane would need extra engine power, as the wheels will move twice as fast (speed of the plane plus the opposite force of the treadmill) which in turn will create more friction.
Other examples:
if a plane could just randomly hover over the ground no wheels, turn on the engine, plane would move forward...right? Harrier and the new JSF....hover planes, thrust against the ground pushes it up....the engines create foward thrust pushing it forward, wheels make no difference
Lastly, ever see a video of a plane taking off from an aircraft carrier? If it doesn't get enough speed, it dips off the deck, and as it gets enough thrust, it flies up, clearly showing, the engines create the forward motion of the plane, not the wheels
put a car on a treadmill, yes, it will not move.
Other examples:
if a plane could just randomly hover over the ground no wheels, turn on the engine, plane would move forward...right? Harrier and the new JSF....hover planes, thrust against the ground pushes it up....the engines create foward thrust pushing it forward, wheels make no difference
Lastly, ever see a video of a plane taking off from an aircraft carrier? If it doesn't get enough speed, it dips off the deck, and as it gets enough thrust, it flies up, clearly showing, the engines create the forward motion of the plane, not the wheels
put a car on a treadmill, yes, it will not move.
01-23-2008, 11:22 PM
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Forgot to add this...
Originally Posted by salvo24
Well the common sense of a kid who is about to get a B.S. at FSU and has flown a Cessna once shows that the wheels of a plane are free spinning, so the thrust caused from the engines pushes the fuselage, which in turn, the wheels just spin to carry it. I can see how the plane would need extra engine power, as the wheels will move twice as fast (speed of the plane plus the opposite force of the treadmill) which in turn will create more friction.
01-23-2008, 11:23 PM
#757
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I admit to being wrong... it will take off... with one exception...
The wheels will be spinning freely but either way the treadmill will have to be of great length so that the plane can actually pull on the wind long enough to create lift from under the wings... the wheels will be spinning twice as fast as the plane pulling on the wind because the treadmill will be moving in the opposite direction... but for how long will it have to pull on the wind to creat lift to actually take off??? Will the treadmill be blown up in scale without making it longer then it really is, just like if you shrunk a plane...
The problem here would be the length of the treadmill...
that would determine the take off or no take off...
Last edited by spooky3ce; 01-23-2008 at 11:25 PM. Reason: credit for my change of mind goes to crazymjb...
01-23-2008, 11:30 PM
#758
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the length of the treadmill doesnt matter. the plane will take off in exactly the same distance that it would on a normal runway. 2 scenarios, first a regular runway and regular plane. takes off in 2500 ft. now the moving conveyor runway. plane still takes off in 2500 ft. no difference.
01-24-2008, 10:13 PM
#759
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Mythbusters teaser for the new episode
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