Skill's weekend teaser
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megamuel
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I answered the same as you Richard! I have accepted that I was wrong but, although it has been explained many times (in detail), I am still slightly baffled 
Lets say a plane is travelling accross a normal runway at 50mph, now swap that runway for the conveyor belt runway which moves at the same speed in the opposite direction. The plane will be travelling at 50mph in relation to the runway, but what about the ground next to the runway? Say there is a speed camera (one that uses a radar signal not markings on the runway) on the ground next to the conveyor belt runway, and it captures the planes speed. It will be 0mph right? If the runway matches the speed of the plane. So it goes faster, runway goes faster etc etc until it gets to the speed needed to make air. The air will be travelling through the jets at whatever speed. The second the plane leaves the runway, how fast would it be on the radar? Would it just start to accelerate from 0mph? This is why I asked about the rollers, if it was on rollers instead of conveyor runway would this be the same?
Oh my, I'm confused Please don't snap at me skill, I don't know why I was created with such a simple mind
Sam.
Lets say a plane is travelling accross a normal runway at 50mph, now swap that runway for the conveyor belt runway which moves at the same speed in the opposite direction. The plane will be travelling at 50mph in relation to the runway, but what about the ground next to the runway? Say there is a speed camera (one that uses a radar signal not markings on the runway) on the ground next to the conveyor belt runway, and it captures the planes speed. It will be 0mph right? If the runway matches the speed of the plane. So it goes faster, runway goes faster etc etc until it gets to the speed needed to make air. The air will be travelling through the jets at whatever speed. The second the plane leaves the runway, how fast would it be on the radar? Would it just start to accelerate from 0mph? This is why I asked about the rollers, if it was on rollers instead of conveyor runway would this be the same?
Oh my, I'm confused
Please don't snap at me skill, I don't know why I was created with such a simple mind Sam.
hwsteele
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Man I missed the WHOLE THING!!! that sucks.
Oh well I had fun with my kids this weekend instead.
Skill, glad to see that you are still with us and have not been banned!
Told you about those steroids and the difference they make.
I must say I was WRONG about this...half way.
I knew the plain would start moving once it's engines were turned on but in my quick reading I missed the part about the really big tread mill.(I was eating at the same time too.)
All I could see in my head was the plain getting sucked under that horrid beast after it starts to move forward and falls off the front. Kinda like me only I always fly off the back and skin my knee.
Then I started to read through and saw the "whole" truth and understood.
I hope I get to join next weeks little brain teaser MUCH earlier.
Oh well I had fun with my kids this weekend instead.
Skill, glad to see that you are still with us and have not been banned!
Told you about those steroids and the difference they make.
I must say I was WRONG about this...half way.
I knew the plain would start moving once it's engines were turned on but in my quick reading I missed the part about the really big tread mill.(I was eating at the same time too.)
All I could see in my head was the plain getting sucked under that horrid beast after it starts to move forward and falls off the front. Kinda like me only I always fly off the back and skin my knee.
Then I started to read through and saw the "whole" truth and understood.
I hope I get to join next weeks little brain teaser MUCH earlier.
megamuel
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I get it again now! The plane won't be at 0 mph relative to the ground. The air will will be forced through the engines at such a speed so that the plane will move relative to the atmosphere and the runway could never move fast enough to counteract that. It has no difference if the runway is stationary, moving forwards or backwards at any speed, the plane will still move and take off as normal (unless it is in a vacuum). Woohoo. Now I'm really done with this. I am going to explore how fast my didjerido can move in relation to my girlfriends cha cha. Then I shall sleep like a baby. Goodnight all,
Sam.
Sam.
Skill Leverage
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Isnt it amazing how people can be told the correct answer, told that it's sitting in textbooks and papers written by people far more intelligent than any of us, there's a bloody video of it happening in real life, and yet they STILL choose to believe their own ill-informed opinion....
Trendie you are the man as always; a car on rollers during an MOT is not the same as a plane, because of course a car implements its drive through the contact of its wheels with the ground; therefore, the rollers directly counteract its forward motion, and the car cannot move.
What these people cannot get their heads around is that a plane does not function in this way, thus it's a completely different kettle of fish. The reason I did this is not to prove the answer (I already knew it of course), but to show that people like Bramble simply refuse to accept opinion that's not their own, no matter how compelling the evidence may be; they simply choose to ignore or misunderstand the information as it suits them.
Not a good way to go about anything in life, particularly trading I'm sure.
SL
Trendie you are the man as always; a car on rollers during an MOT is not the same as a plane, because of course a car implements its drive through the contact of its wheels with the ground; therefore, the rollers directly counteract its forward motion, and the car cannot move.
What these people cannot get their heads around is that a plane does not function in this way, thus it's a completely different kettle of fish. The reason I did this is not to prove the answer (I already knew it of course), but to show that people like Bramble simply refuse to accept opinion that's not their own, no matter how compelling the evidence may be; they simply choose to ignore or misunderstand the information as it suits them.
Not a good way to go about anything in life, particularly trading I'm sure.
SL
megamuel
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Have your sedatives worn off now SL? Good thread again. I'm gonna get it right next week man. You watch me! Its easy, the answer is the one which I think is definately not the answer. Now don't you try any reverse psychology on me you cheeky little swine!
Sam.
Sam.
TheBramble
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What is it with this fascination for the contact the plane has (or has not) with what it's standing on?
We are GIVEN: whatever it is standing on will counteract totally any forward motion through means/mechanisms we are not interested in.
As the plane moves forward under power the runway moves under it to precisely the same extent IN THE OPPOSITE direction thus totally cancelling out any forwad movement.
If the teaser is EXACTLY as stated in post #1 then the plane does not move forward from it's starting position even blowing full power. It therefore never moves through the air and also therefore never generates sufficient |(any actually) lift.
Put the plane away. Get rid of the runway. YOU Trendie are standing on a rather long rug. It's actually infinite in length. You are told that every step you take forward will result in someone tugging the rug from under your feet to exactly the same length of each pace as you move forward.
How far are you going to get?
Will it make ANY difference how much effort you put into it or how fast you run?
Skill Leverage
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For the eight hundredth time, at no point has anyone ever said this. This is what you do not understand, and this is why you are wrong.
Skill Leverage
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How does a person exact force with which to move forward by walking?
by friction, WITH THE GROUND.
Like the car during its MOT, a completely different concept. Hahaha, you really can't get your head around this can you? Pretty funny really.
megamuel
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Bramble,
Clear your mind and think about this again. I too was confused about this and I've only just got it. It doesn't matter what the runway or the wheels are doing. Its the air going through the jet engines that makes the plane move and fly. If the runway is moving forwards or backwards, at any speed - it does not make a difference. The runway could speed up 1 million mph in the opposite direction to the plane, but the plane would still fly of at its normal speed. If the wheels exploded and fell off there would be a large amount of friction added which would alter things... But the question is a hypothetical one. I can see the image you have in your head - of the plane and the runway, and the plane being stationary, but really the plane could never be stationary once the engines kicked in.
I'm sorry that I am not very good at explaining things, but I really think you should conceed on this one! You, I, and 15 other voters have been proved wrong!
Sam.
Clear your mind and think about this again. I too was confused about this and I've only just got it. It doesn't matter what the runway or the wheels are doing. Its the air going through the jet engines that makes the plane move and fly. If the runway is moving forwards or backwards, at any speed - it does not make a difference. The runway could speed up 1 million mph in the opposite direction to the plane, but the plane would still fly of at its normal speed. If the wheels exploded and fell off there would be a large amount of friction added which would alter things... But the question is a hypothetical one. I can see the image you have in your head - of the plane and the runway, and the plane being stationary, but really the plane could never be stationary once the engines kicked in.
I'm sorry that I am not very good at explaining things, but I really think you should conceed on this one! You, I, and 15 other voters have been proved wrong!
Sam.
Skill Leverage
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People's fascination with this is that it's the KEY CONCEPT in this problem; a concept which you do not understand due to having stubborn, low-grade brain matter. You have been told many times, by many people, that the plane does not gain forward motion through its contact with the ground, thus the conveyor belt has no effect; this is basic, basic, basic Physics, but you do not understand it, and are embarassing yourself in a fairly huge way.
Keep going though, I'm sure at some point the penny will drop. I think the longest it took someone in my Phys class was three days, before they said 'I'm an idiot'. I'd say about 10% of people got it straight away, 60% of people had the first thought 'it stays still', then thought about it and realised the truth after 2 minutes of thinking about net forces on the plane(I was in this category), then the rest are, well, you.
SL
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TheBramble
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Skills, your constant theme is I suspect a regurgitation of web-based ‘solutions’ to this teaser. It tends to be fuzzy, illogical and you either deliberately miss the point (you can’t really defend that which you haven’t thoroughly studied) or you accidentally misunderstand pretty much everything I say. You are consistent, which is to your credit. However, you are wrong, but you’re sticking so hard to your beliefs because I imagine by now you’ve invested so much ego in the process. If so, that’s your struggle and none of my business. I don’t want to cause you any more pain or suffering.
But had you taken the trouble to think it through afresh all for yourself, you may have come to another conclusion other than the one that has been handed to you by professors of physics classes and other assorted bods. Oh, and by the way, this IS a practical problem even if it is based on theoretical premises which have very little possibility of being replicated in reality. (Please don’t site myhtbusters again – LOL).
This isn’t an issue of intelligence as I’m reasonably convinced you’re at least partially-brained and I’m certainly no boffin. I just guess it’s one of those things you either ‘get’ or you don’t ‘get’. Like the Monty Hall problem. But this one is far simpler.
Forget EVERYTHING else you think you already know about this teaser and just concentrate on one key fact you posted in your post #1. “The conveyor is set to exactly match the speed of the plane’s wheels, moving in the opposite direction’.
We don’t care how or why – it is just a given.
I’ve seen so many spurious meandering on here and on subsequent research relating to such things as ’the engines being easily able to overcome the friction of the conveyor’ and other such irrelevance. Well, no, not in this theoretical situation. People get really confused trying to mix in their bits of what they think might happen in reality with what is after all a theoretical teaser. Just concentrate on the wheels of the plane being EXACTLY matched in the opposite direction and speed by the conveyor. Focus on that. Forget what you think you already know. If the rotation of the wheels is EXACTLY matched by the conveyor at all times, how can the plane ever move from it’s starting point relative to a fixed reference? It can’t, can it? Mr. Charts summed this up far more ably than me a few posts back.
It doesn’t mater how much power the engines are putting out (or how fast trendie is running on that moving rug) – it ain’t going anywhere in relation to any fixed reference point. Consider, if it’s easier for you, that the conveyor is moving under the plane rather than the plane is moving over the conveyor – net result is the same: No net forward motion. You’ve built that into your teaser in post #1, can’t be any other way.
I suspect you may already know this at some deep, visceral if not intellectual level, but your investment in your public belief is stopping you admitting it. There’s no shame in being wrong – only in knowingly holding onto wrong ideas.
As a little exercise which may help you with your beliefs system, try this.
Stand in front of a mirror with your eyes closed. Open your eyes. Now try and believe God has a positive purpose….
But had you taken the trouble to think it through afresh all for yourself, you may have come to another conclusion other than the one that has been handed to you by professors of physics classes and other assorted bods. Oh, and by the way, this IS a practical problem even if it is based on theoretical premises which have very little possibility of being replicated in reality. (Please don’t site myhtbusters again – LOL).
This isn’t an issue of intelligence as I’m reasonably convinced you’re at least partially-brained and I’m certainly no boffin. I just guess it’s one of those things you either ‘get’ or you don’t ‘get’. Like the Monty Hall problem. But this one is far simpler.
Forget EVERYTHING else you think you already know about this teaser and just concentrate on one key fact you posted in your post #1. “The conveyor is set to exactly match the speed of the plane’s wheels, moving in the opposite direction’.
We don’t care how or why – it is just a given.
I’ve seen so many spurious meandering on here and on subsequent research relating to such things as ’the engines being easily able to overcome the friction of the conveyor’ and other such irrelevance. Well, no, not in this theoretical situation. People get really confused trying to mix in their bits of what they think might happen in reality with what is after all a theoretical teaser. Just concentrate on the wheels of the plane being EXACTLY matched in the opposite direction and speed by the conveyor. Focus on that. Forget what you think you already know. If the rotation of the wheels is EXACTLY matched by the conveyor at all times, how can the plane ever move from it’s starting point relative to a fixed reference? It can’t, can it? Mr. Charts summed this up far more ably than me a few posts back.
It doesn’t mater how much power the engines are putting out (or how fast trendie is running on that moving rug) – it ain’t going anywhere in relation to any fixed reference point. Consider, if it’s easier for you, that the conveyor is moving under the plane rather than the plane is moving over the conveyor – net result is the same: No net forward motion. You’ve built that into your teaser in post #1, can’t be any other way.
I suspect you may already know this at some deep, visceral if not intellectual level, but your investment in your public belief is stopping you admitting it. There’s no shame in being wrong – only in knowingly holding onto wrong ideas.
As a little exercise which may help you with your beliefs system, try this.
Stand in front of a mirror with your eyes closed. Open your eyes. Now try and believe God has a positive purpose….
TheBramble
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OK for the 801st - check your post #1. You categorically state this is the case.
TheBramble
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Forget mechansims and friction ans such things. JUst concentrate on the teaser you posed. You did read it didn't you? You didn't just cut & paste from 'Todgers Today' website did you?
Skill Leverage
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FOR THE 802ND TIME YOU RETARD:
Imagine a 747 sitting on a very large conveyor belt. The belt has the same dimensions as a runway at an airport*, and is set up to exactly match the speed of the plane's wheels, moving in the opposite direction.
IS NOT THE SAME AS SAYING:
The motion of the belt counteracts the forward motion of the plane.
LOL, LOL...lol. This has absolutely nothing to do with anything.
Until you understand these facts you are quite simply laughable. You spout on about looking in the mirror, when you are the one that is wrong, and until I literally march you in to Stephen Hawking's living room and get him to take you through this like a dribbling infant, you will not change your opinion.
You simply refuse to change your opinion, which is not to your credit, at all. You cannot see past the fact that the wheels have nothing to do with the flight of an aircraft; 15-year-olds at school can get this given enough explanation, something you have had more than enough of.
Top minds in the worlds in their fields, published authors of physics textbooks, Mythbusters... who cares, the proof is sitting here, megamuel has seen it Aspire has seen it... you are even dumber than the guys on MuscleTalk. Fact. About 10 different people have tried (simultaneously I will add) to explain these basic concepts to you, but you have about as much intellect and understanding as a handbag, which you are no doubt clutching as you try to understand why it is just you against the whole world at this point.
Oh, and one more thing:
It's 'cite', not 'site'.
SL
Imagine a 747 sitting on a very large conveyor belt. The belt has the same dimensions as a runway at an airport*, and is set up to exactly match the speed of the plane's wheels, moving in the opposite direction.
IS NOT THE SAME AS SAYING:
The motion of the belt counteracts the forward motion of the plane.
LOL, LOL...lol. This has absolutely nothing to do with anything.
Until you understand these facts you are quite simply laughable. You spout on about looking in the mirror, when you are the one that is wrong, and until I literally march you in to Stephen Hawking's living room and get him to take you through this like a dribbling infant, you will not change your opinion.
You simply refuse to change your opinion, which is not to your credit, at all. You cannot see past the fact that the wheels have nothing to do with the flight of an aircraft; 15-year-olds at school can get this given enough explanation, something you have had more than enough of.
Top minds in the worlds in their fields, published authors of physics textbooks, Mythbusters... who cares, the proof is sitting here, megamuel has seen it Aspire has seen it... you are even dumber than the guys on MuscleTalk. Fact. About 10 different people have tried (simultaneously I will add) to explain these basic concepts to you, but you have about as much intellect and understanding as a handbag, which you are no doubt clutching as you try to understand why it is just you against the whole world at this point.
Oh, and one more thing:
It's 'cite', not 'site'.
SL
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Skill Leverage
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Sam, at this point he will doubtless give you some guff about the brakes, which has nothing to do with anything.
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I hate to burst anyones bubble, but the reason why there are so many incorrect answers out there is that the question was phrased incorrectly.
The link provided by Candles has the theoretical set up as,
"If an airplane is on a large conveyor belt and is trying to take off by exerting the thrust needed to move it forward at 100 knots, and the conveyor belt starts moving backwards at 100 knots..."
In this situation, the conveyor belt has a constant linear velocity of 100 knots. The airplane would indeed move forward and could take off normally.
Skill Leverage phrased this situation,
"Imagine a 747 sitting on a very large conveyor belt. The belt has the same dimensions as a runway at an airport*, and is set up to exactly match the speed of the plane's wheels, moving in the opposite direction. What will happen?"
Unfortunately for Skill Leverage, he has the wrong theoretical set up and has stated that the conveyor belt moves at the same (I am assuming linear) speed as the wheels. The airplane could not move in this case even though the wheels do not drive the plane forward. In this theoretical situation, the conveyor will always match the speed of the wheels; ie, it is not a constant speed as in the link above. Hence, anytime forward thrust occurs and the wheels start turning, the conveyor belt matches this speed and cancels the momentum. There is one other caveat, however, and that is where Skill Leverage said that the conveyor is moving in the opposite direction. If the wheels were considered as moving clockwise, then a counterclockwise moving conveyor would still yield no linear movement relative to the wind and produce no lift. If, however, the wheels and conveyor movement were analyzed in a linear fashion, then the plane would actually have a relative movement twice as fast as the linear velocity of the wheels. This would result in the plane able to take off in half the normal distance. Either way, the question is phrased incorrectly for any of the answers to be correct.
You may all begin the debate anew.
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