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Here's a brain tickler.. (Page 6)
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itistoday
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Mar 3, 2007, 03:20 PM
 
Originally Posted by iLikebeer View Post

Yes, I read it, and I agree with the entire post. Again, I'm only pointing out why it's so confusing to some. The wheels will skid, otherwise there could be no forward movement in relation to the ground. That post you pointed to had nothing in it about that though.

You can't look at the wheels as disconnected from the airplane in the context of the problem. They don't exist in different dimensions. Either the wheels spin 1:1 with the conveyor and friction is somehow so great as to keep it from taking off. NO. Or the wheels spin at a 1:1 with the conveyor with a lot of skidding and black marks as the plane accelerates to take off.

That's my entire point. There is a disconnect with the people that say no because the airplane shouldn't be able to accelerate if the wheel and conveyor speed is the same. The skidding because of the overwhelming power of the jets allows the plane to take off within the parameters of the initial riddle.

*sigh*... If you really read that post and you still think that the speed of the wheels or conveyor belt has anything to do with whether or not the plane will take off... well then I give up as I wrote enough on it already. 1:1, 10:1, 1:10, it doesn't matter, the plane will take off. You must think about the problem in terms of the forces acting on the plane, you will then see that the wheels having little to do with anything. Talk to a physics teacher about it.
     
iLikebeer
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Mar 3, 2007, 03:23 PM
 
Originally Posted by jokell82 View Post
You are completely wrong. Go try it sometime instead of just thinking about it.
Care to elaborate why I'm wrong? Show me a conveyor belt that can actually accelerate with the wheel and i'll try it.

Unfortunately they don't exist, so we have to think about it. I'll help you think harder.

If you have a skate attached to a string on a moving conveyor belt, they are moving 1:1. If you pull the skate forward, it is no longer 1:1. The wheel is moving faster than the conveyor belt. If you want to say the wheel is 1:1 in that scenario, then a wheel moving over regular ground is also 1:1. The only way for the wheel on the skate to move forward on the conveyor belt is for it to skid, slip, or bounce. Otherwise the speeds are not 1:1.
     
analogika
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Mar 3, 2007, 03:27 PM
 
Originally Posted by iLikebeer View Post
You can't look at the wheels as disconnected from the airplane in the context of the problem. They don't exist in different dimensions. Either the wheels spin 1:1 with the conveyor and friction is somehow so great as to keep it from taking off. NO. Or the wheels spin at a 1:1 with the conveyor with a lot of skidding and black marks as the plane accelerates to take off.
Why would the wheels leave skidmarks? THEY'RE SPINNING.

This is what ball-bearings are for. If you put a roller-skate on a long string on a conveyor-belt, and hold on to the string, it will stay put no matter how fast the conveyor belt is moving.

If you pull forward at that string, the roller-skate will move forward, no matter how fast the conveyor belt is moving. The wheels will spin a little faster, is all.

Now replace the "string" with a jet engine and add wings to the roller-skate.

You'll have one hell of a roller-skate, and damned if it won't fly - somewhere.
     
itistoday
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Mar 3, 2007, 03:28 PM
 
Originally Posted by iLikebeer View Post
Care to elaborate why I'm wrong? Show me a conveyor belt that can actually accelerate with the wheel and i'll try it.

Unfortunately they don't exist, so we have to think about it. I'll help you think harder.

If you have a skate attached to a string on a moving conveyor belt, they are moving 1:1. If you pull the skate forward, it is no longer 1:1. The wheel is moving faster than the conveyor belt. If you want to say the wheel is 1:1 in that scenario, then a wheel moving over regular ground is also 1:1. The only way for the wheel on the skate to move forward on the conveyor belt is for it to skid, slip, or bounce. Otherwise the speeds are not 1:1.

Again, even in that situation the wheels have little to do with why the skate moved forward. The skate does not move forward because of the wheels, it moves forward because you pushed it. Had the conveyor belt sped up with the speed of the wheels to maintain a 1:1 ratio with them, the skates would have still moved forward because you pushed it, can you not see that? The wheels on the skates would just spin faster.
     
iLikebeer
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Mar 3, 2007, 03:31 PM
 
Originally Posted by itistoday View Post
*sigh*... If you really read that post and you still think that the speed of the wheels or conveyor belt has anything to do with whether or not the plane will take off... well then I give up as I wrote enough on it already. 1:1, 10:1, 1:10, it doesn't matter, the plane will take off. You must think about the problem in terms of the forces acting on the plane, you will then see that the wheels having little to do with anything. Talk to a physics teacher about it.
Did you even read my posts? I said the same thing. It doesn't matter how fast the wheels go, the plane will take off. I was answering why it confuses the people that say no. But many of the people that say yes, they get it right but still have some details wrong. That is why the arguments usually continue for so many pages. The people that say yes show half the right answer, but ignore the disparity between being able to accelerate and the conveyor keeping up with the wheel speed. Skidding is what would happen.
     
jokell82
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Mar 3, 2007, 03:38 PM
 
Originally Posted by iLikebeer View Post
Skidding is what would happen.
No, it's not.

All glory to the hypnotoad.
     
iLikebeer
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Mar 3, 2007, 03:38 PM
 
Originally Posted by analogika View Post
Why would the wheels leave skidmarks? THEY'RE SPINNING.

This is what ball-bearings are for. If you put a roller-skate on a long string on a conveyor-belt, and hold on to the string, it will stay put no matter how fast the conveyor belt is moving.

If you pull forward at that string, the roller-skate will move forward, no matter how fast the conveyor belt is moving. The wheels will spin a little faster, is all.

Now replace the "string" with a jet engine and add wings to the roller-skate.

You'll have one hell of a roller-skate, and damned if it won't fly - somewhere.
No. think of this. If I sit a skate on the ground and pull. The wheels spin faster. If the ground accelerates at the same speed as the wheels, it stays in place. The only way for the skate to move forward is for the skate wheel to be spinning faster than the ground moves.
skate speed . ground speed . direction skate moves
0 . 0 . none
5 . 0 . forward
5 . 5 . none
5 . 2 . forward
5 . 4 . forward
the only way for the wheel speed and conveyor speed to be the same with the skate moving forward is if it skips, hops, or uses some kind of quantum physics to dimension hop. You can pull the skate forward on the conveyor, but the wheel speed is faster than the conveyor at that point.
     
jokell82
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Mar 3, 2007, 04:06 PM
 
Instead of just spouting off bs like it's fact, why don't you try it? Because you are very wrong.

All glory to the hypnotoad.
     
itistoday
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Mar 3, 2007, 04:09 PM
 
Originally Posted by iLikebeer View Post
Did you even read my posts? I said the same thing. It doesn't matter how fast the wheels go, the plane will take off. I was answering why it confuses the people that say no. But many of the people that say yes, they get it right but still have some details wrong. That is why the arguments usually continue for so many pages. The people that say yes show half the right answer, but ignore the disparity between being able to accelerate and the conveyor keeping up with the wheel speed. Skidding is what would happen.
Yes, I read your posts and I see that you are mistaken in your understanding, I also replied to your example here trying to show you why this is so.
     
iLikebeer
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Mar 3, 2007, 04:23 PM
 
Originally Posted by itistoday
Again, even in that situation the wheels have little to do with why the skate moved forward. The skate does not move forward because of the wheels, it moves forward because you pushed it. Had the conveyor belt sped up with the speed of the wheels to maintain a 1:1 ratio with them, the skates would have still moved forward because you pushed it, can you not see that? The wheels on the skates would just spin faster.
That is completely true except the bolded part. Wheels can still skid while moving and that is the only way it would be possible. The wheels have nothing to do with the takeoff, i understand that. You're not understanding what I'm not saying. The wheels wouldn't just move faster. The conveyor would also move faster.

1. The plane moves forward.
2. If undercarriage doesn't break off, the only way for the wheels to move forward is for them to move faster than the ground.
3. Wheels do a sort of a reverse peel out at same increasing speed as the conveyor.

I know the plane takes off (most likely, if the runway is long enough for the plane to overcome the extra force), but it is physically impossible without the tires skidding along as the thrust pushes it forward.

I would love to see a computer model of this.
     
jokell82
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Mar 3, 2007, 04:30 PM
 
Originally Posted by iLikebeer View Post
I know the plane takes off (most likely, if the runway is long enough for the plane to overcome the extra force), but it is physically impossible without the tires skidding along as the thrust pushes it forward.
The length of the runway has absolutely nothing to do with it because there is essentially NO extra force applied to the plane. You are simply incorrect about your assumptions.

All glory to the hypnotoad.
     
hayesk
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Mar 3, 2007, 04:57 PM
 
Yes, the plane would take off. The engines push air out the back to generate forward momentum. They don't rotate the wheels to move forward. It doesn't matter how fast the conveyor belt was moving.

Now if there was a giant fan in front of the plane that matches the air speed from the back of the engines, then it would stay put.
     
itistoday
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Mar 3, 2007, 05:21 PM
 
Originally Posted by hayesk View Post
Now if there was a giant fan in front of the plane that matches the air speed from the back of the engines, then it would stay put.
That would be cool... however the behavior isn't entirely predictable. If the thrust generated by the engines was equal to the force of the wind on the plane, then the plane would hover in midair.

Now, (and this is a separate thought from the previous sentence) I'm not sure if you can get a situation where the engines are no longer accelerating the air going into them (as in your scenario), that would be some strange phenomenon, perhaps "horizontal terminal velocity"... I'm not sure if that would happen, although it is possible I think.
( Last edited by itistoday; Mar 3, 2007 at 05:29 PM. )
     
iLikebeer
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Mar 3, 2007, 05:22 PM
 
Originally Posted by jokell82 View Post
The length of the runway has absolutely nothing to do with it because there is essentially NO extra force applied to the plane. You are simply incorrect about your assumptions.
lol, no you're wrong.
In any decent aircraft systems and components class, you'll learn that the function of the undercarriage/wheels is to support the aircraft on the ground to reduce friction for takeoff and increase friction to stop the plane upon landing.

Although the brakes wouldn't be applied, the wheels would add an extra skidding force opposite to the thrust vector. Most likely it would increase until the wheels got hot enough to melt a thin layer of rubber and letting it hydroplane, decreasing the drag vector. I have no idea how much longer it would make the takeoff roll, but it would increase it some percentage. If it increases it too much and the conveyor is the size of whatever runway was being used before, safety margins might decrease enough to not let the pilot takeoff.

Originally Posted by hayesk
Now if there was a giant fan in front of the plane that matches the air speed from the back of the engines, then it would stay put.
Not exactly, that's kind of undefinable. Hi-bypass ratio turbofans on commercial planes accelerate a large mass of air a smallish amount (as compared to turbojets or rockets.) If the fan accelerated the air to the exhaust speed, by design, the engine would take in that high-speed air, compress it, fuel it, explode it, and exhaust it at a higher speed than the air the fan is blowing. This would work up until certain airspeeds depending on the type of engine/inlet/blade design...
     
analogika
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Mar 3, 2007, 05:41 PM
 
Originally Posted by iLikebeer View Post
lol, no you're wrong.
In any decent aircraft systems and components class, you'll learn that the function of the undercarriage/wheels is to support the aircraft on the ground to reduce friction for takeoff and increase friction to stop the plane upon landing.
NO!

That is precisely and ENTIRELY up to the brakes, and the other braking mechanisms of the aircraft - flaps, reverse thrust, whatever.

(It is, of course, possible, that the wheels and their bearings are designed to reach a precise speed - that of liftoff+x - and no faster, but that would be rather difficult to do, and fairly pointless. IANAE.)

What YOU are arguing, that they both REDUCE friction and INCREASE friction depending on the situation, is patently ridiculous. How the hell would the wheel bearing know that the ground it's touching is now the *landing* strip rather than the *takeoff* strip?
     
f1000
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Mar 3, 2007, 05:44 PM
 
Originally Posted by hayesk View Post
Now if there was a giant fan in front of the plane that matches the air speed from the back of the engines, then it would stay put.
No, it would levitate off the ground.
     
iLikebeer
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Mar 3, 2007, 05:51 PM
 
Originally Posted by analogika View Post
NO!

That is precisely and ENTIRELY up to the brakes, and the other braking mechanisms of the aircraft - flaps, reverse thrust, whatever.

(It is, of course, possible, that the wheels and their bearings are designed to reach a precise speed - that of liftoff+x - and no faster, but that would be rather difficult to do, and fairly pointless. IANAE.)

What YOU are arguing, that they both REDUCE friction and INCREASE friction depending on the situation, is patently ridiculous. How the hell would the wheel bearing know that the ground it's touching is now the *landing* strip rather than the *takeoff* strip?
You got me there. You're absolutely right, that is the function of the brakes.
BUT, in this situation, the wheels WOULD act as brakes. Some people don't understand that. I'm not saying it won't take off, I'm arguing the wheels would act as a little model rocket parachute on a Saturn V. It's there doing something, but has almost no effect.

I can see some of you guys asking a professor why you got points taken off when you have the right answer. "Your answer is right, but your work is wrong. -5"
     
itistoday
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Mar 3, 2007, 05:59 PM
 
analogika, I'd just leave this guy alone, this is hopeless and it's going no where.
     
analogika
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Mar 3, 2007, 06:03 PM
 
Originally Posted by iLikebeer View Post
You got me there. You're absolutely right, that is the function of the brakes.
BUT, in this situation, the wheels WOULD act as brakes. Some people don't understand that. I'm not saying it won't take off, I'm arguing the wheels would act as a little model rocket parachute on a Saturn V. It's there doing something, but has almost no effect.

I can see some of you guys asking a professor why you got points taken off when you have the right answer. "Your answer is right, but your work is wrong. -5"
In my world, wheels have bearings.

In your world, wheels leave skidmarks even though they're spinning on bearings.

I'm not sure what a physics professor would say to that, especially since we're completely ignoring the idiotic phrasing of the question in favor of at least theoretically *possible* reality.

If half the effort is trying to make even halfway reasonable sense of the question (and this thread and the one I linked to are proof of that), then the negligible braking effect of well-lubed bearings designed for the single purpose of ELIMINATING FRICTION (as far as reasonably possible) is not something I'd consider worth focussing on.

Especially since you're claiming truly bizarre, conflicting things within a single sentence.
     
iLikebeer
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Mar 3, 2007, 06:23 PM
 
ok, I'm going to the beach. I'll explain it better later tonight when I get home and have more time. Wheels having bearings have nothing to do with this, unless these special bearings distort reality into another dimension. Wooo, and I'll use simple math to show you what I mean.
     
f1000
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Mar 3, 2007, 06:29 PM
 
I've started a new thread with a mathematical solution to the problem. I'd appreciate if people would refrain from posting in it until I've completed my explanation, which might take awhile as I've got many other things to do.

http://forums.macnn.com/89/macnn-lou...n/#post3316304
     
itistoday
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Mar 3, 2007, 06:53 PM
 
Originally Posted by iLikebeer View Post
ok, I'm going to the beach. I'll explain it better later tonight when I get home and have more time. Wheels having bearings have nothing to do with this, unless these special bearings distort reality into another dimension. Wooo, and I'll use simple math to show you what I mean.

I have Stephen Hawking on speed dial, here's what he had to say on the matter.
     
analogika
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Mar 3, 2007, 08:03 PM
 
     
JohnM15141
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Mar 3, 2007, 09:23 PM
 
You can't ignore this fact: there is a force acting opposite of aircraft thrust(Be it jets, rockets or propellors.) This is the force from the friction of the wheels and from the wheel rotation. All vehicles with round wheels overcome this force. At low speeds this force is very small. As the aircraft accelerates this opposing force increases but is still small in comparision to the work required to overcome the inertia of the airplane. At the airspeed required for the aircraft to fly the force from wheel rotation has increased but is not enough to slow the acceleration by much. My point being there is a force, an increasing force, from the wheels rotating over the runway. Replace the runway with a conveyor belt that matches "...the speed of the wheels..." and at some point the increasing force will equal the opposite force of the airplanes thrust. At that point the airplane will be stationary. The wheels and conveyor belt will be turning at some unimaginable speed, but since the conveyor belt is imaginary it can.
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analogika
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Mar 3, 2007, 09:48 PM
 
And YOU can't ignore the fact that the airplane will have lifted off LONG before this "unimaginable speed" has been attained, since that happens at just somewhere between 150-200 mph (250-300 km/h).

So at the point of lift-off, the conveyor belt would be moving backwards at 250 km/h, and the wheels would be spinning backwards at 500km/h.

Would you like to argue that friction in wheels designed to withstand and virtually eliminate friction at speeds of up to 300 km/h on a daily basis will cease to function properly at 500-600 km/h and increase friction by such a substantial amount that they would stop an aircraft designed with enough thrust to fly at 900-1000 km/h from taking off? I find it difficult to believe that *anything* in an aircraft would not be engineered to take at least twice the stress it would regularly (or conceivably) be subjected to in day-to-day use.

But hey, enjoy yourself.
     
d4nth3m4n
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Mar 3, 2007, 10:17 PM
 
6 pages down, 4 to go.
     
iLikebeer
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Mar 4, 2007, 01:34 AM
 
Have a dinner reservation in 15 minutes, but might have time to squeeze this in. Did some simple algebra in the sand.

V1 = speed of treadmill
V2 = speed of wheel
Vac = speed of aircraft

V1 = V2 always (as the question is worded)
V2 = Vac always (speed of wheel is always the same as the aircraft, or 2*PI * RADtire)
once the aircraft starts moving, Vac has to be faster than V1 in order to move forward on the conveyor. BUT WAIT V1=V2=Vac, which is impossible because Vac has to be greater than V1. So how do you fix this in a hypothetical situation. V1 = V2 + Vskiderror = Vac. The faster you go, the more skid speed you have.

Aircraft ...grr finish when i get back.
     
itistoday
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Mar 4, 2007, 01:37 AM
 
Originally Posted by iLikebeer View Post
V1 = V2 always (as the question is worded)
Yes.

Originally Posted by iLikebeer
V2 = Vac always (speed of wheel is always the same as the aircraft, or 2*PI * RADtire)
No.
     
Gossamer
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Mar 4, 2007, 02:10 AM
 
Originally Posted by JohnM15141
You can't ignore this fact: there is a force acting opposite of aircraft thrust(Be it jets, rockets or propellors.) This is the force from the friction of the wheels and from the wheel rotation. All vehicles with round wheels overcome this force. At low speeds this force is very small. As the aircraft accelerates this opposing force increases but is still small in comparision to the work required to overcome the inertia of the airplane. At the airspeed required for the aircraft to fly the force from wheel rotation has increased but is not enough to slow the acceleration by much. My point being there is a force, an increasing force, from the wheels rotating over the runway. Replace the runway with a conveyor belt that matches "...the speed of the wheels..." and at some point the increasing force will equal the opposite force of the airplanes thrust. At that point the airplane will be stationary. The wheels and conveyor belt will be turning at some unimaginable speed, but since the conveyor belt is imaginary it can.
I addressed this about a month ago.

Originally Posted by Gossamer View Post
Imagine a picture of an airplane with arrows representing forces, and the arrows sizes are proportional to the magnitude of the force. On a normal runway, the arrow representing friction of the wheel bearings is about 2mm, and the arrow representing thrust is about 2 miles long. Now put it on the conveyor belt. The friction arrow is now about 5mm, and the thrust is still 2 miles. Does it still take off? Of course.
The question states: "The conveyer belt is designed to exactly match the speed of the wheels"
The wheel speed has nothing to do with the thrust.
The wheel speed has nothing to do with the thrust.
The wheel speed has nothing to do with the thrust.
The wheel speed has nothing to do with the thrust.
The wheel speed has nothing to do with the thrust.
d4nth3m4n, I was so hoping you would be wrong, but at this rate I've given up hope.
     
analogika
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Mar 4, 2007, 04:18 AM
 
Originally Posted by iLikebeer View Post
Have a dinner reservation in 15 minutes, but might have time to squeeze this in. Did some simple algebra in the sand.

V1 = speed of treadmill
V2 = speed of wheel
Vac = speed of aircraft

V1 = V2 always (as the question is worded)
V2 = Vac always (speed of wheel is always the same as the aircraft, or 2*PI * RADtire)
once the aircraft starts moving, Vac has to be faster than V1 in order to move forward on the conveyor. BUT WAIT V1=V2=Vac, which is impossible because Vac has to be greater than V1. So how do you fix this in a hypothetical situation. V1 = V2 + Vskiderror = Vac. The faster you go, the more skid speed you have.

Aircraft ...grr finish when i get back.
I have no idea what you THINK you're doing, but try and explain in simple English why you think the wheel would be skidding, when it could be spinning. To be traceable for future generations?
     
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Mar 6, 2007, 06:59 AM
 
Originally Posted by Dakar² View Post
**** KrazyKoot for brining this thread back to life.
Looks like my purpose is achieved. My getting the facts wrong have resulted in others getting things right. And yes, the plane will fly since the wheels move faster, IF "the conveyor moves in the opposite direction to the wheels" means that the conveyor is moving from the take-off point to the back of the runway
     
design219
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Mar 6, 2007, 08:16 AM
 
Looks like my purpose is achieved.
Yes, but has anyone bought a conveyor system, or even clicked through the conveyor google ads at the top of this thread?
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Mar 6, 2007, 09:16 AM
 
Originally Posted by analogika View Post
I have no idea what you THINK you're doing, but try and explain in simple English why you think the wheel would be skidding, when it could be spinning.
He is right. The "trick" in the question is the impossible conveyer belt that "matches the speed of the wheel". The wheel turns because it is pushed backwards by the conveyer belt and it turns because it is pushed forward by the moving airplane. Mathematically:

tangential speed of the wheel = speed of the conveyer belt + speed of the airplane

The condition for the conveyer belt however is:

tangential speed of the wheel = speed of the conveyer belt

Both conditions can only be met if the speed of the airplane is 0. This tricks some of you into believing the airplane could never take off. Of course in the real world the airplane's propellers or jet engines would move it, and if it is ever so slightly the conveyer belt becomes mathematically impossible, at which point you can't meaningfully say whether the plane would take off since the situation is impossible. Unless you say the wheels slip (by what amounts to the speed of the plane) which reduces their tangential speed to that of the conveyer belt again.
     
Tiresias
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Mar 7, 2007, 08:18 AM
 
Imagine an airplane that tries to land on a conveyor-belt runway that is moving at an equal speed and in the opposite direction. What's gonna happen?

(A problem of this nature isn't resolved until the thread reaches 16 pages).
     
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Mar 7, 2007, 09:55 AM
 
Originally Posted by Tiresias View Post
Imagine an airplane that tries to land on a conveyor-belt runway that is moving at an equal speed and in the opposite direction. What's gonna happen?
*aneurysm*
     
jokell82
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Mar 7, 2007, 10:02 AM
 
Originally Posted by Tiresias View Post
Imagine an airplane that tries to land on a conveyor-belt runway that is moving at an equal speed and in the opposite direction. What's gonna happen?

(A problem of this nature isn't resolved until the thread reaches 16 pages).
If I had to guess, it would probably stop in a shorter distance since the braking of the wheels would be assisted by the conveyor. But it wouldn't just stop once it hit the conveyor...

All glory to the hypnotoad.
     
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Mar 7, 2007, 06:23 PM
 
Originally Posted by Tiresias View Post
Imagine an airplane that tries to land on a conveyor-belt runway that is moving at an equal speed and in the opposite direction. What's gonna happen?

(A problem of this nature isn't resolved until the thread reaches 16 pages).
equal speed as the tires? because it nearly already does that, that's why there's all that rubber at the end of the runway.

equal speed as the plane? ZOMG, THE LANDING GEAR WILL SHEAR OFF!
     
design219
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Jan 31, 2008, 07:04 PM
 
Originally Posted by kc311v2 View Post
Imagine an airplane is sitting on a massive conveyor belt, as wide and as long as a runway. The conveyer belt is designed to exactly match the speed of the wheels, moving in the opposite direction. Can the airplane take off?
Ok, a zombie thread, but we have new evidence!

The Myth Busters did this the other night and proved the plane could take off. Of course, they stated the problem a little clearer by saying "speed of the plane" instead of "speed of the wheels" as in the original post.

YouTube - Mythbusters - Plane on conveyor belt!
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My stupid iPhone game: Nesen Probe, it's rather old, annoying and pointless, but it's free.
Was free. Now it's gone. Never to be seen again.
Off to join its brother and sister apps that could not
keep up with the ever updating iOS. RIP Nesen Probe.
     
JohnM15141
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Jan 31, 2008, 07:49 PM
 
So, actually, they solved a different problem then the one here...


Originally Posted by design219 View Post
... they stated the problem a little clearer by saying "speed of the plane" instead of "speed of the wheels" as in the original post.
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smacintush
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Jan 31, 2008, 08:03 PM
 
Originally Posted by JohnM15141 View Post
So, actually, they solved a different problem then the one here...
And you STILL think that would matter…?

Edit: Actually, as long as the belt is in good contact the wheels WILL go the same speed as the belt. Think about it. All this talk about theoretical unlimited acceleration is just retarded.

Here is a relevant post from youtube:

AHAHAHAHHAH
ALL YOU PEOPLE WHO SAID IT WOULDN'T TAKE OFF.
Kill yourselves now.
HAHAHAHAHHAHA
Emphasis mine.
Being in debt and celebrating a lower deficit is like being on a diet and celebrating the fact you gained two pounds this week instead of five.
     
JohnM15141
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Jan 31, 2008, 09:59 PM
 
Hey, don't hate me cause I'm much smarter than you...

Originally Posted by smacintush View Post
And you STILL think that would matter…?
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"He who is tired of Weird Al, is tired of life"
Homer J. Simpson, the 90's
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Chuckit
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Jan 31, 2008, 10:10 PM
 
Originally Posted by smacintush View Post
And you STILL think that would matter…?

Edit: Actually, as long as the belt is in good contact the wheels WILL go the same speed as the belt.
Not if the plane is moving forward — unless it's grinding its wheels off, the wheels will move at the speed of the belt + the speed of the plane. It seems to me that's why phrasing matters — the "speed of the wheels" version is not describing what actually happens.
Chuck
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jokell82
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Jan 31, 2008, 10:19 PM
 
Originally Posted by Chuckit View Post
Not if the plane is moving forward — unless it's grinding its wheels off, the wheels will move at the speed of the belt + the speed of the plane. It seems to me that's why phrasing matters — the "speed of the wheels" version is not describing what actually happens.
Actually the wheels move at the exact same rate as the belt. If not they'd be skidding.

All glory to the hypnotoad.
     
Chuckit
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Jan 31, 2008, 10:30 PM
 
Originally Posted by jokell82 View Post
Actually the wheels move at the exact same rate as the belt. If not they'd be skidding.
I don't think so. If they moved at the same rate as the belt but the plane was moving forward, then they'd be skidding. Just like if you're not on a conveyor belt and your wheels are moving the same speed as the ground (not at all), you're skidding.
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jokell82
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Jan 31, 2008, 10:39 PM
 
Originally Posted by Chuckit View Post
I don't think so. If they moved at the same rate as the belt but the plane was moving forward, then they'd be skidding. Just like if you're not on a conveyor belt and your wheels are moving the same speed as the ground (not at all), you're skidding.
You think wrong. It's impossible for the wheels to move faster than the belt. The only force acting on the wheels is the belt, so there is no way for the wheels to move faster than the belt.

All glory to the hypnotoad.
     
Chuckit
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Jan 31, 2008, 10:54 PM
 
Originally Posted by jokell82 View Post
You think wrong. It's impossible for the wheels to move faster than the belt. The only force acting on the wheels is the belt, so there is no way for the wheels to move faster than the belt.
That's relative to the plane, isn't it? If we take the plane as our stationary point, then yes, the wheel and the belt are both moving at the same speed backwards from us. It's much like if we take our car as a stationary point, the speed of our wheels matches the speed of the ground — but in actuality, to a stationary observer, the ground isn't moving at all. Am I wrong here?
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d4nth3m4n
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Jan 31, 2008, 10:55 PM
 
Originally Posted by jokell82 View Post
You think wrong. It's impossible for the wheels to move faster than the belt. The only force acting on the wheels is the belt, so there is no way for the wheels to move faster than the belt.
uh, no.

e: wait, relative to what?
     
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Feb 1, 2008, 05:31 AM
 



the end
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Feb 1, 2008, 08:07 AM
 
Originally Posted by centerchannel68 View Post
Anybody who says otherwise just does not understand the very basics of why an airplane flies.

Sorry to but in here but...


A few years ago I worked on an school reference book in conjunction with engineers at BAE Systems Airbus division, and these guys know ALL about wings.

Anyway we had produced a work project on drag and lift. Proof reading the text BAE systems made us rewrite the section. Apparently the "official answer" as to why planes fly is "We're not sure". It's like Newtons gravity. The sums work but the actual effect in operation is not understood. BAE Systems were concerned to put their engineering name to anythng that claimed that the classic understanding of flight was correct.

We had to insert some additional text regarding other reasons why planes might fly.

On a side note, the official reason why ships float is also "we're not sure".

Ponder that next time you are mid Atlantic in either form of transport.
     
d4nth3m4n
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Feb 1, 2008, 11:12 AM
 
Originally Posted by Andrew Stephens View Post
Sorry to but in here but...


A few years ago I worked on an school reference book in conjunction with engineers at BAE Systems Airbus division, and these guys know ALL about wings.

Anyway we had produced a work project on drag and lift. Proof reading the text BAE systems made us rewrite the section. Apparently the "official answer" as to why planes fly is "We're not sure". It's like Newtons gravity. The sums work but the actual effect in operation is not understood. BAE Systems were concerned to put their engineering name to anythng that claimed that the classic understanding of flight was correct.

We had to insert some additional text regarding other reasons why planes might fly.

On a side note, the official reason why ships float is also "we're not sure".

Ponder that next time you are mid Atlantic in either form of transport.
please don't quote inflammatory posts from banned users more than 7 months ago. especially when later in the thread he changes his position.

this is a bit of a flashpoint topic, and i'm starting to think that those who don't think it will fly will continue to think that no matter what they're presented with. let's just let this one die.

e: sounds like i'm picking you apart, i'm not. just kind of a general annoyance with trying to explain this to idiots on other forums.
     
 
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