Re: Will it take off?

[quote=jamesalvarez;622026]yeah, and whatever the conveyor belt does , it doesn't effect the air speed the airplane can -still- generate![/quote]

I think we're on two different pages here. Forward motion/air resistance is what generates air speed. It isn't generated by the plane or the plane's engine per se, although the engine propels the plane forward so it can get the air resistance the wings need to lift the plane off the ground.

Unless the conveyor belt is coupled with a wind tunnel to give the wings the air they need, the plane is grounded.

Re: Will it take off?

im not saying the airplane would rise vertically, it would look like a normal takeoff, just with a conveyor belt udnerneath - the engine generates air velocity on the wings by being attached to the airplane, pulling the airplane through the air. a plane doesnt take off by using its wheels to generate forward motion, it uses engines to drag the plane through the air.

Re: Will it take off?

the plane ISNT moving along the converyor belt, it is basically stationary in this argument

Re: Will it take off?

if the conveyor belt somehow generates equivilent wind speed of inflight wind speed, then yes, the plane would take off vertically but to maintain a stable take off and not move backwards or forwards would be friggin hard to impossible. i get what you're saying though, james... in this particular case, i think we were assuming nothing is generating wind speed for the plane to rise thus making it impossible to really take off.

Re: Will it take off?

Why is this so difficult to grasp?

Re: Will it take off?

can my c ar fly if i drive it really fast and hit a jump ?

Re: Will it take off?

try it out and let us know

Re: Will it take off?

[QUOTE=threehills;621810][I] A plane is standing on a movable runway(t?[/QUOTE]

Yeah - its not clear how big the runway is but i assume its runway size if its called a runway...

and also if the plane was stationary and the runway moved in proportion to the speed then surely the runway would just not move? it would not make sense as a problem

"he conveyor has a system that tracks the speed of the plane and matches it exactly in the opposite direction."

whence the plane has to move to generate conveyor speed...

in this problem there is no situation where the plane is stationary with the conveyor belt moving underneath it. unless the conveyer belt is moving in propoertion to wheel speed - but weve already ascertained that airplanes ues get engines not wheel engines to go forward.

Re: Will it take off?

does all this mean that if you put a plane in a wind tunnel, and put the e-brake on, and then pumped up th wind, then the plane will take off in a stationary position in regards to moving forward???(i.e. just rise in the air from a stopped position)

answer that and this guy will come to your door and giv e you a can of moutain dew.

[IMG]http://blogs.zdnet.com/ip-telephony/images/mrwizard.jpg[/IMG]

Re: Will it take off?

[QUOTE=thesightless;622045]does all this mean that if you put a plane in a wind tunnel, and put the e-brake on, and then pumped up th wind, then the plane will take off in a stationary position in regards to moving forward???(i.e. just rise in the air from a stopped position)

answer that and this guy will come to your door and giv e you a can of moutain dew.

[IMG]http://blogs.zdnet.com/ip-telephony/images/mrwizard.jpg[/IMG][/QUOTE]

yeah if the air velocity matches the velocity generated by the engiens -through- the air

first time ive felt compelled to post on this board - lol - hello

Re: Will it take off?

"An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force."

so, if the plane reaches a certain speed on the conveyor belt, that means it will start hovering and could take any direction it would desire?

do you realize how stupid that sounds??? this would mean that if you run fast enough on a threadmill with your arms spread you could defy the laws of gravity,

plus, im just gonna use common sense here, lets say they could do that, wouldnt that be at least experimented on a daliy basis by our armed forces, planes that could take off without using runnways?!?!?

Re: Will it take off?

Nevermind ... couldn't delete this post.

Re: Will it take off?

[quote=Cj Tari;622057]this would mean that if you run fast enough on a threadmill with your arms spread you could defy the laws of gravity, [/quote]

Truth.

[IMG]http://www.akacrasher.com/stuff/matrix-retard.jpg[/IMG]

Re: Will it take off?

[QUOTE=jamesalvarez;622031]im not saying the airplane would rise vertically, it would look like a normal takeoff, just with a conveyor belt udnerneath - the engine generates air velocity on the wings by being attached to the airplane, pulling the airplane through the air. a plane doesnt take off by using its wheels to generate forward motion, it uses engines to drag the plane through the air.[/QUOTE]

see ^

:lol:

Re: Will it take off?

[quote=Cj Tari;622057]

do you realize how stupid that sounds??? this would mean that if you run fast enough on a threadmill with your arms spread you could defy the laws of gravity, [/quote]

[quote=threehills;622164]Truth.

[IMG]http://www.akacrasher.com/stuff/matrix-retard.jpg[/IMG][/quote]

That's fucking gold. :lol:8)

Re: Will it take off?

[quote=jamesalvarez;622960]see ^

:lol:[/quote]

You're still wrong.

Re: Will it take off?

Yes the fucker will take off as the jets thrust are against the earth not the conveyor belt there fore it will move forward.

It's like putting your hand behind the plane and pushing it forward, your hand is acting as the thrust of the jet. Once you get enough speed it will take off.

ps. I started this thread on another forum and it turned out to be the biggest bitch fight ever recorded on the forum...something like 180 pages... lol

Re: Will it take off?

it's so logical! :D

Re: Will it take off?

My faith in humanity decreases with every post in this thread.

Re: Will it take off?

[quote=MJDub;623152]My faith in humanity decreases with every post in this thread.[/quote]

yup

Re: Will it take off?

i,m getting drunk right now so in about 30 minutes anything will take off :'(

Re: Will it take off?

lol, pisana understands, the rest of you obviously do not have logic as your forte, meh who needs it really anyway.

heres a couple of threads after typing 'plane conveyor' were they have solved it:

[url]http://www.physforum.com/index.php?showtopic=2417&st=9240&#entry346427[/url]

[url]http://www.kottke.org/06/02/plane-conveyor-belt[/url]

"But of course cars and planes don't work the same way. A car's wheels are its means of propulsion--they push the road backwards (relatively speaking), and the car moves forward. In contrast, a plane's wheels aren't motorized; their purpose is to reduce friction during takeoff (and add it, by braking, when landing). What gets a plane moving are its propellers or jet turbines, which shove the air backward and thereby impel the plane forward. What the wheels, conveyor belt, etc, are up to is largely irrelevant. Let me repeat: Once the pilot fires up the engines, the plane moves forward at pretty much the usual speed relative to the ground--and more importantly the air--regardless of how fast the conveyor belt is moving backward. This generates lift on the wings, and the plane takes off. All the conveyor belt does is, as you correctly conclude, make the plane's wheels spin madly."

case closed - although i am willing seriously to bet anyone any amount of money that i am right :D

Re: Will it take off?

sigh.

Re: Will it take off?

^^^ right? lol

Re: Will it take off?

[quote=jamesalvarez;623175]the rest of you obviously do not have logic as your forte[/quote]

I'm a pilot, and what I said 3 pages ago still stands as substantiated fact.

Re: Will it take off?

[QUOTE=MJDub;623196]I'm a pilot.[/QUOTE]

so what i used to play flight simulator when I was about 8 years old - you don't need to understand physics to fly a plane, drive a car, or to hit a ball with a golf club. for instance in the latter, most people don't even know why swing and timing etc is so important; they just see the results. you don't need to understand biochemistry to make a good cake.

do you regularly take off from conveyor belts? and please, are you actually considering and thinking about the other arguments?

do me a favour and read this, its a comprehensive argument-

[url]http://txfx.net/2005/12/08/airplane-on-a-conveyor-belt/[/url]

Here is yet another good argument from someone who thought the opposite initially and credit to them, rethought it and admitted they were initially wrong:

[url]http://www.illuminatingscience.org/plane-on-a-conveyor-belt/[/url]

i don't think anyone is stupid for not getting it, but come on, its all there now!:roll:

Re: Will it take off?

[QUOTE=MJDub;621944]Let me bring my piloting expertise into this one (yes I'm a private pilot).

Say you were about to take off and you had a wind that was going parallel to the runway. Conventional wisdom would say that you would want to take off with the wind, no? But conventional wisdom doesn't apply to aerodynamics. You want to take off into the wind (a headwind) because air resistance is what gets the airplane off the ground. Since there is more wind/air coming over the leading edge of the wing (i.e. what creates lift), even though you're technically not going as fast with relation to ground speed, [U][B]the air speed is all that matters[/B][/U]. So if you were to takeoff with the wind (a tailwind), you would need to be going much faster ground speed wise to get the same amount of air over the leading edge of the wings, and unless you're taking off on the space shuttle landing strip, you would probably run out of runway before you got to rotation speed (speed the airplane can lift off the ground and climb).

So going back to this "conveyor belt" idea, there is no way that this would work with any conventional aircraft because while your wheels may be spinning like you're going 150 knots, your airspeed is essentially 0. The engine does provide some air over the wings (in a propeller plane for example) but nowhere near the amount and speed of air that is needed to get the plane off the ground. You need forward motion.[/QUOTE]

first paragraph is all correct - second paragraph is the common mistake, because it implies that the wheels are driving the plane forward, when they are not.

Re: Will it take off?

lastly, in 'imaginary' physics world, if the conveyor belt is moving at the same speed as the plane, and this causes the plane to be still, then the conveyor belt will also be still. if the plane moves forward, it means that the conveyor belt is not matching the plane speed. logically the conveyor will never move.

if instead you mean that the conveyor matches the wheelspeed, then imagine if you glue the wheels on your aeroplane so they can't move, you could probably still take off with the conveyor belt still, with the jet engines dragging the glued wheels along

Re: Will it take off?

The main problem with this question is it's a hypothetical situation and there are too many variables that are not specified.

Re: Will it take off?

i also found a video for you :) [url]http://www.youtube.com/watch?v=4owlyCOzDiE[/url]

Re: Will it take off?

[QUOTE=miketpoto;623217]The main problem with this question is it's a hypothetical situation and there are too many variables that are not specified.[/QUOTE]

i agree, it could be more specified, and I sense you are beginning to understand how the question is designed to trick you:

It made you think that I was arguing something that is logically impossible - whence its clear effectiveness in generating arguments!

There is also a paradox, if the conveyor belt matches wheel speed since acceleration isn't instantaneous, then the conveyor will quickly accelerate to infinity. this is because as conveyor speed increases by 1 mph it also increases wheel speed by 1mph, so if wheelspeed starts at 1mph, then conveyor matches it to 1mph, by then wheelspeed is 1+1mph = 2mph and then conveyor must got at 2mph, so wheelspeed becomes 4mph, and this happens as quickly as the conveyor system can update itself to the wheelspeed, so if its instantaneous (which is impossible) then the conveyor will suddenly start moving at infinite speed.

The equilibrium you aer imaging is when the force of the jet engines matches the force of friction from the wheels on the conveyor.

If the problem were this: a conveyor belt matches the jet engines force via force it creats by rotating the wheel backwards, could a plane take off? The answer would be hypothetically no, although i suspect the small wheels on an aeroplane would melt before they matched the jet engines full force.

Re: Will it take off?

please people, next time youre at the gym, and youre running on the threadmill, extend your arms and tell me if you feel the air running under your arms........

no, you know why??? because youre not moviing forward, youre not moving from point a to point b, you are an object vertically at rest, therefore you cannot displace the air around you. Like one of Newton law's says, you cannot ocupate the same space that is occupied by another entity, so, everytime you move, you displace the air around you, this is what makes a plane fly, the air that is being displaced by the planes forward motion. So, if you really really think about it for a second, the plane is occupiing the exact same space all the time, not moving at all, not displacing anything, thus not having any forward motion, or "air under its wings"

and no, the engines are not pumping air trough the wings, there just sucking up air and tunneling it on a concentrated spot, that being the engine, so you have no air displacement, all the air that the engines are sucking is just going trough the engine, thats it, not trough the tips of the wings, or trough the body of the plane.

[IMG]http://www.offthemarkcartoons.com/cartoons/2007-12-12.gif[/IMG]

Re: Will it take off?

[QUOTE=Cj Tari;623224]please people, next time youre at the gym, and youre running on the threadmill, extend your arms and tell me if you feel the air running under your arms........

no, you know why??? because youre not moviing forward, youre not moving from point a to point b, you are an object vertically at rest, therefore you cannot displace the air around you. Like one of Newton law's says, you cannot ocupate the same space that is occupied by another entity, so, everytime you move, you displace the air around you, this is what makes a plane fly, the air that is being displaced by the planes forward motion. So, if you really really think about it for a second, the plane is occupiing the exact same space all the time, not moving at all, not displacing anything, thus not having any forward motion, or "air under its wings"

and no, the engines are not pumping air trough the wings, there just sucking up air and tunneling it on a concentrated spot, that being the engine, so you have no air displacement, all the air that the engines are sucking is just going trough the engine, thats it, not trough the tips of the wings, or trough the body of the plane.

[IMG]http://www.offthemarkcartoons.com/cartoons/2007-12-12.gif[/IMG][/QUOTE]

you havn't read any of the counterarguments - why bother arguing if you don't read them? . when you run on a treadmill, you are using your feet - which in sum (human locomotion is more complext) cause your forward motion relative to the -surface- on which you are standing on via the -surface-, i.e. the treadmill. an aeroplane generates accelerating force on the -air- not the surface.

you don't properly understand how jets generate forward momentum. the air sucked into the engines requires energy to do so force = mass x acceleration, and air weighs stuff hence air pressure etc. this force has to be matched in the opposite direction (by Newtons Law which holds pretty tightly in earthbound conditions), so since you are pulling air from the front to the back, the opposite force is that the plane which is attached to the engines accelerates forward generating speed.

or are you having me on? lol and i like your gym arm flapping argument - it really makes me sound stupid that I should be arguing that, but it is not a sound analogy, and whence, petard; hoisted

Re: Will it take off?

Here is another famous problem which generated a massive amount of controversy with even doctors of mathematics got wrong and argued vehemently about:

It's called the monty hall problem, and the answer is, you should -always- switch.

“Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?”

Re: Will it take off?

After this post, I'm done with this thread because you refuse to understand what I'm saying.

First off, because you played flight simulators hardly makes you a pilot (asinine point you're trying to make there, btw). The very first lesson of the ground school (before they even let you near a plane) is focused on basic aerodynamics principles/inner workings of your plane and proving you understand it completely (which you do not), so don't give me this "I'm a pilot too" garbage. I thought that flying a plane would be just as easy as driving a car/making a cake/hitting a ball too, but it is not. You must know everything about the plane you're flying through and through before you are even able to start it up (unlike driver's licenses that are given out relatively willy-nilly to anybody).

Lesson 1: How the damn wing works

[IMG]http://www.ct.gov/kids/lib/kids/images/symbols/wing3.jpg[/IMG]

Higher pressure on the bottom of the wing, because the air is traveling a shorter distance, pushes the wing upward (lift). [B][U]You must be moving forward in physical space to have air move over your wing.[/U][/B] No amount of jet engine power changes this undeniable Newtonian fact (see Cj tarl's post). Conveyor belts prevent air from moving over wings because they prevent forward motion. Therefore, no matter how much you want it to, the plane will not have air moving over its wings, therefore, no lift is created. Period.

Think about it. Aviation has existed for 105 years and has yielded the fucking F-22 Raptor and space shuttle. Would you not think that shortening/removing takeoff roll would be a top priority for the military, especially for the navy? Would they also have already discovered how to do this if we have F-22's and space shuttles? Of course it would be, and of course they would have, but physics (unless you're going the speed of light) has unbreakable laws. That's just reality my friend.

Now I'll let others back me up on this because I'm done with this endless loop of an argument.

Re: Will it take off?

[quote=jamesalvarez;623234]you havn't read any of the counterarguments - why bother arguing if you don't read them? . when you run on a treadmill, you are using your feet - which in sum (human locomotion is more complext) cause your forward motion relative to the -surface- on which you are standing on via the -surface-, i.e. the treadmill. an aeroplane generates accelerating force on the -air- not the surface.

you don't properly understand how jets generate forward momentum. the air sucked into the engines requires energy to do so force = mass x acceleration, and air weighs stuff hence air pressure etc. this force has to be matched in the opposite direction (by Newtons Law which holds pretty tightly in earthbound conditions), so since you are pulling air from the front to the back, the opposite force is that the plane which is attached to the engines accelerates forward generating speed.

or are you having me on? lol and i like your gym arm flapping argument - it really makes me sound stupid that I should be arguing that, but it is not a sound analogy, and whence, petard; hoisted[/quote]

i mean cmon man, are you really sticking with that??

yes, the plane is creating speed, yes but there is no air displacemente, air displacemente is what makes the airplane fly, not the speed that it can achieve by the force of its engines. Its like trying to fly a plane in a perfectly sealed and vacumed space, with no air, even if the plane is going full speed it will not fly, it will adavnce in horizontal form, but by no means will it pick up flight.

just because you hold a toy remote car in your hand and press the go button to full speed means that the car is moving or creating displacement, it happens the same with the conveyour belt, the backwards movent by the conveyor belt cancels out your forward progress, therefore you are not moving at all, yes you are sucking up air and creating movement but you have to remember that all that forward movent is just cancelled out by the conveyour belt, so you have no forward progress, if you dont have forward progress air is not gonna be hitting your wings, therefore theres no upper and lower air pressure to pick up the plane from land.

just remember that, yes the engine creates movent, and yes the plane has the ilusion of moving forward, but all that movent is cancelled out by the conveyor belt::

its like math

1 + -1= 0

so if the plane is going 10mph and the conveyour belt is going 10mph negative to your trajectory, then it would be 10 - 10 = 0

as easy as that.

sorry but im not gonna argue more, i know youre a smart man and youre trying to prove your point, but youre just wrong man, a plane that doesnt move cant fly, our armed forces have proven that thousands of times, that why theres no "conveyour belt" carriers.

Re: Will it take off?

[quote=MJDub;623238]After this post, I'm done with this thread because you refuse to understand what I'm saying.

First off, because you played flight simulators hardly makes you a pilot (asinine point you're trying to make there, btw). The very first lesson of the ground school (before they even let you near a plane) is focused on basic aerodynamics principles/inner workings of your plane and proving you understand it completely (which you do not), so don't give me this "I'm a pilot too" garbage. I thought that flying a plane would be just as easy as driving a car/making a cake/hitting a ball too, but it is not. You must know everything about the plane you're flying through and through before you are even able to start it up (unlike driver's licenses that are given out relatively willy-nilly to anybody).

Lesson 1: How the damn wing works

[IMG]http://www.ct.gov/kids/lib/kids/images/symbols/wing3.jpg[/IMG]

Higher pressure on the bottom of the wing, because the air is traveling a shorter distance, pushes the wing upward (lift). [B][U]You must be moving forward in physical space to have air move over your wing.[/U][/B] No amount of jet engine power changes this undeniable Newtonian fact (see Cj tarl's post). Conveyor belts prevent air from moving over wings because they prevent forward motion. Therefore, no matter how much you want it to, the plane will not have air moving over its wings, therefore, no lift is created. Period.

Think about it. Aviation has existed for 105 years and has yielded the fucking F-22 Raptor and space shuttle. Would you not think that shortening/removing takeoff roll would be a top priority for the military, especially for the navy? Would they also have already discovered how to do this if we have F-22's and space shuttles? Of course it would be, and of course they would have, but physics (unless you're going the speed of light) has unbreakable laws. That's just reality my friend.

Now I'll let others back me up on this because I'm done with this endless loop of an argument.[/quote]

you sir are an intelligent man.

and most probably one with a life time supply of peanuts and pretzels, oh and ginger ales.

Re: Will it take off?

So, to sum it up, Mythbusters is full of shit. The End. Tada!

Now, lets return to the rockin boobies thread and see something meaningful taken off.

Re: Will it take off?

the. conveyor. does. not. stop. the. plane. moving. forward.

:DumbAss:

I honestly thought you were puling my leg that you didn't get it by now - have you not checked the links?

the point you are making is the same one over again :shock::

there needs to be forward momentum to generate lift on the wing.

i do not "refuse to understand what you are saying" I understand it perfectly well - have i missed anything? now prove you understand me, what have I mistaken?

what i and anyone who thinks about it is saying is:

the conveyor does not stop the plane as a machine from generating forward momentum

Have you not read those links I posted? I mean [I]please[/I]

CJ tari, i reckon youre just trying to wind me up lol. or are you serious?:what

Re: Will it take off?

Err dude, the conveyor DOES STOP the plane moving forward. They're both at the same speed but in opposite directions. You know, vectors?

Those engines aren't strong enough to pull the plane forward ontop of the motion provided by the wheels, those engines only pull air over the wings.

So at the very best, the plane might generate some lift, but as MJ pointed out, it's also not enough for the plane to take off.

You need the forward momentum + the wing lift, but we have no forward momentum.

Stick your arms up, duct tape hair dryers to them. No go. But maybe if you run and leapt off a building. Youtube please.