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#617850 - 03/01/07 03:28 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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Originally posted by NY Madman: Originally posted by Paul H:
[b]I am still of the middle. No one here has absolutely convinced me...... Don't worry about what side of the debate you were on. The question itself is intentional designed to immediately confuse people....[/b]That is 100% true. The first time I pondered this question I momentarily thought "no". But as I thought deeper, I realized the irrelevance of the belt. I posed this question to both of my brothers and they both gave the correct answer. One is a music teacher and the other is not degreed but lightly technical. TJ asked some non-technical people who were able to come up with the correct answer, also. Some people can reject their initial hangups and swallow the pride of being initially wrong to reach the sensible conclusion. Anybody who claims to be an engineer who does not understand this question should be ashamed of themselves. This is a very simple problem which requires very little technical knowledge, but (apparently) plenty of common sense. Originally posted by NY Madman:
...You are correct though when you say there will be problems with the wheels. While looking at another site that claimed to have a lot of pilots, there were guys who gave data regarding the amount of stress and abuse the wheels could take. A standard passenger airliner couldn't take the abuse and stress placed on the wheels. They would come apart and the plane would crash... hence no takeoff........ That is not true. Aircraft tires and landing gears are required (by the FAA) to be tested to a factor of safety of 1.5 for 200 cycles. So that means a 200 mph tire and bearing should easily be able to withstand some extra wheelspin. Additionally, taking off is much less stressful than landing due to the lack of impact. The plane is also achieving lift as it achieves airspeed, thus lessening the load on the landing gear, wheel and tire. Tires being tested do not have this advantage because they are tested under full load by a machine. Regardless, that's just a copout by somebody who doesn't want to embrace the a different answer because they feel they'll lose face by admitting it. ..... It sounds like most people have taken the time to read what has been posted and come to terms with the simple answer. .
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#617851 - 03/01/07 03:34 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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Originally posted by Chris Mc: Where are Lizz's nudie pics? I was stranded in a snowstorm outside Albuquerque on I-40 for a few days and missed this thread... There in there somewhere. I forget which page though. Just read through the entire thread I'm sure you'll find them. ![wink wink](/forums/images/graemlins/default/wink.gif)
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#617852 - 03/01/07 03:56 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Posts: 7756
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I like the one with the pony. ![laugh laugh](/forums/images/graemlins/default/laugh.gif)
_________________________
- TJ 2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes.... Friends don't let friends drive stock. http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif
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#617854 - 03/01/07 06:02 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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I admit I didn't read all 52 pages, just 15, so maybe it was mentioned in the remaining pages, but I just want to add a few things. Definitions- wind speed: speed of the air relative to the plane, 100mph wind speed means the wind is moving 100mph across the wings.
- Global Perspective: This is the perspective being observed from the outside world, an example would be some one not standing on the tread mill watching the plane try to take off
- Scenario perspective: Perspective from the plane, relative to the treadmill
- Relative speed: speed of the treadmill as observed from the Scenario perspective, aka the plane
- Absolute speed: speed of the treadmill as observed from the Global perspective.
Assumptions- conveyor belt only moves the ground below the plane, not the air around the plane, and moves in the opposite direction the plane is trying to move.
- weather is ideal and wind is calm (0MPH).
- group speed = air speed since the plane is on the ground.
- wheels are freewheeling, ie there is little if any rotational friction between the wheel and the object it is attached to.
- plane would be able to take off if the tread mill was kept stationary.
Facts- lift if determined by the wind speed over the wings.
- Thrust produced by the engines (prop or turbine) applies a force against the air.
- Thrust is dependent on wind speed, the higher the wind speed the lower the thrust, and vice versa.
- Force from the thrusters is what propels the plane and not the wheels.
- air is a fluid
ProofThe tread mill doesn't effect the speed of the wind:Lets just say for the sake of argument that the tread mill does move the air around the plane at the same rate as the treadmill. If the plane is trying to go down the run way and is stationary from the global perspective the the wind will increase in speed as it passes over the wings. This equivalent wind speed will cause enough lift for the plane to take off, this scenario is essentially the same as if it was going down a normal run way. So we know that the tread mill does not effect the planes air speed because if it did it would be able to lift off. If we look at a force diagram, the engines produces thrust forward by "throwing" air backwards and pushes against the air already present which produces a force pointing in the forward direction, this is because of newtons third law, equal and opposite reaction. So a force backwards produces a force forwards. The ONLY way for the plane to stand still from the global perspective is to have another force applied to the plane that would counter act this forward force, other wise the plane will move forward since F=ma (Force = mass X acceleration). Here are some possible options that could produce the required force to prevent: - Air resistance, which is determiend by surface area and wind speed
- Excessive friction between the plane and the ground, for example Wheel Brakes are applied, or wheels are not present wheels.
- Plane is chained to a solid anchor
As seen by the fact that a high enough wind speed would creates lift and allow the plane to take off we can rule out wind, as enough wind the keep the plane stationary would surely allow it to take off. Now if we make the assumption that the plane would be able to take off if the treadmill is kept still like a normal run way we can safely assume that plane has little resistance relative to the force generated by the thrusters. And that there is nothing nothing else binding the plane such as it being anchored. So we are safe to assume the airplane is not held by any external constraints. Plus we know the wheel brakes are not applied because otherwise the plane would not be able to move anyways and the question is a trick question So without any kind of constraints it is impossible for a plane to not move from a global perspective when it is at full throttle because there is no resistance to the forward force and because thrust and wind speed are inversely proportional therefor there will be a force acting on the plane moving it forward increasing the wind speed over the wing allowing for take off. ... In summary The planes method of propulsion acts on the global perspective and not on the relative perspective allowing it to move in the global perspective as well, even if the wind was acted form a relative perspective it would be able to take off since it would have a high enough wind speed. so yeah, the plane can take off regardless...
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#617855 - 03/01/07 06:32 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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Originally posted by Chris Ritchey:
... In summary The planes method of propulsion acts on the global perspective and not on the relative perspective allowing it to move in the global perspective as well, even if the wind was acted form a relative perspective it would be able to take off since it would have a high enough wind speed.
so yeah, the plane can take off regardless... Cool, five trucks to you! Love the format, it must have taken you a while to punch that out. Another for the Flies Club. Lord of the flies Kill the PIG! ETA - Whoo Who, 53 and counting! ![[Argue]](graemlins/argue.gif)
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#617857 - 03/01/07 07:01 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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With all the CF'ers either enlightened or chased out, this is probably as far at this thread goes, maybe one more page.
I'm still not sure where Madman stands, though. His posts mentioned something about "neutrality" and being a "devil's advocate," and I never heard him say (since he proclaimed "neutrality") that the plane would fly. Maybe he did, but I've missed it. Bluesky, I think, is still "sticking to his guns".
But honestly, how much farther does this thread need to go? I mean, there's probably a dozen or two different analogies and tons of redundancy.
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#617858 - 03/01/07 07:16 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Member
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Registered: 08/03/01
Posts: 7756
Loc: Lawrenceville, NJ, USA
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Most likely, as each hold-out gets his Eureka Moment, slaps his forehead...realizing the real factors...he will probably just clam up, and not post again. Mad may be an exception, because I believe he really feels a need to show open mindedness....the kindler, gentler Madman, etc. Otherwise....mor mumbling about tire ratings and so forth, to act like OTHER THAN THAT, they got it...etc. ![laugh laugh](/forums/images/graemlins/default/laugh.gif)
_________________________
- TJ 2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes.... Friends don't let friends drive stock. http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif
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#617859 - 03/01/07 07:22 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Member
Registered: 18/02/02
Posts: 1632
Loc: Reading, MA
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I'm not sure that madman doesn't actually get it.
After reading his post about playing Devil's advocate (and then rereading the posts after he posted that) I think he might understand but have been posting just for the sake of argument.
Initially when I read that "devil's advocate" I thought it was just about my "carrier" scenario - which in and of itself was flawed.
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Jeffrey I'm just trying to put my tires on the rocks of life.
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#617860 - 03/01/07 10:00 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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I was disappointed that this thread was not at the top of the page. So, do I get a present for being with the "will fly crowd." LOL.
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#617861 - 03/01/07 10:35 PM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Member
Registered: 09/05/02
Posts: 5232
Loc: Florida
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People are back to talking about the plane? It should fly. ![](http://img392.imageshack.us/img392/1782/plane2ku0.jpg) ............ "The flight of Mr. Robert Wilson has ended now, a flight not only from point A to point B, but also from the fear of recurring mental breakdown. Mr. Wilson has that fear no longer, though, for the moment, he is, as he has said, alone in this assurance. Happily, his conviction will not remain isolated too much longer, for happily, tangible manifestation is very often left as evidence of trespass, even from so intangible a quarter as the Twilight Zone."
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#617862 - 04/01/07 02:46 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Member
Registered: 24/05/01
Posts: 6497
Loc: Dammit! Even CLOSER to Smith a...
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Jebus, I'm gone for a few days, and this entire place goes to shit with lame ass threads. Christ on a stick. ![[Finger]](graemlins/thefinger.gif)
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#617864 - 04/01/07 06:17 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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if you tie a rope to the tail of the plane and to a phone pole, and the treadmill turns the wheels of the plane above the stall speed of the plane, will it fly? ![wink wink](/forums/images/graemlins/default/wink.gif)
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#617865 - 04/01/07 06:45 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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If the treadmill is the one moving the plane wheels, you need to attach the rope to the nose, not the tail, otherwise the plane will just back up in the phone pole.
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#617866 - 04/01/07 07:13 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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Originally posted by XterraAdam: if you tie a rope to the tail of the plane and to a phone pole, and the treadmill turns the wheels of the plane above the stall speed of the plane, will it fly?
Yes. But not until the rope snaps, or the pole breaks. Whichever comes first. The plane flies, but it won't fly very well, or very long, 'cause the rope and/or pole that snapped will come flying forward and bang the hell out of the plane. They're extremely fragile when it comes to being hit with a solid object...
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#617867 - 04/01/07 07:14 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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If the plane takes off on a conveyor belt in Chicago, and another one takes off out of a catapult in Bakersfield 2 hours later, followed by two bullets, one fired form a gun, and the other shot out of Shahram's ass in a high powered beer fart, at exactly what time will the pair of unladen European swallows over Wyoming be sucked into each one of the jet engines?
Discuss.
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#617868 - 04/01/07 07:20 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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I suppose it depends upon which way the plane is facing on the tread mill at the start. The example sounds like the tread mill was expected to accelerate the plane to its equivalent take off speed...and the pole was expected to keep it from rolling forwards...with the assumption that the plane was facing at least in the correct direction for take off. So - you'd have the tread mill rolling at say 180 mph...coming from behind the plane and past it... ...and the pole roped to the tail, to keep it from actually moving.
_________________________
- TJ 2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes.... Friends don't let friends drive stock. http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif
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#617869 - 04/01/07 07:22 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Originally posted by Desert_Rat: If the plane takes off on a conveyor belt in Chicago, and another one takes off out of a catapult in Bakersfield 2 hours later, followed by two bullets, one fired form a gun, and the other shot out of Shahram's ass in a high powered beer fart, at exactly what time will the pair of unladen European swallows over Wyoming be sucked into each one of the jet engines?
Discuss. What kind of beer?
_________________________
- TJ 2001 Xterra '03 VG33, SE 5 spd, 305/70/16's, Revolvers, UBSkidderz, Doubled AAL's, 3"SL/2"BL, winch/bumpers, skids, sliders, OBA, Snorkel, pine stripes.... Friends don't let friends drive stock. http://www.gifsoup.com/view/501230/tj-tackling-crawlers-ridge-o.gif
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#617870 - 04/01/07 08:57 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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Does the beer fart have any odor?
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#617872 - 04/01/07 10:11 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Registered: 17/10/00
Posts: 6013
Loc: Prior Lake, MN
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Checking back in after a week...
Has everyone figured out/agreed that the plane will fly yet? The stress was too much for me, earlier on... like around page 2 or 3.
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kjw & the PNUTMNM
The liver is evil, and must be punished...
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#617873 - 04/01/07 10:12 AM
Re: Know that if you do not post in this thread today the human race may cease to exist
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Anonymous
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ok, if a female flight attendant who did 4 years in the military is on a treadmill going 6mph, how long until she looses her "Navy Issue Ass"?
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