Riddle Me This......... - Page 8

the_scotsman · 30-11-2005, 09:45 PM

Quote:

Originally Posted by xdclevo

I have changed my mind after reading the question properly. Like many others, i assumed the plane was standing still, while the conveyer and wheels were doing the moving. Ofcoarse, when the plane gets up enough speed, the air/wings do there usual thing and create flight, irrellavant or what the (trick question) conveyer is doing.

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FINALLY!!!!! lol!

**Captain Stubing** · 30-11-2005, 09:50 PM

The plane landing on a conveyor belt is the opposite situation of a plane starting from a standstill. A landing plane already has momentum.

The wheels on a stationary plane are needed, so when the engines provide thrust, the wheels roll (they've got friction with the ground), until the wings are moving through the air at a speed fast enough to provide lift for the aircraft.

Casper · 30-11-2005, 09:53 PM

I give up.

Go stand in front of the sidewinder on the skateboard on this conveyor and have a cup of tea. I'll light the fuse. Based on some logic here all its going to do is sit there and go nowhere.

rodderz · 30-11-2005, 09:59 PM

It'd bloody hurt thats for sure, then you gotta scream for someone to turn the treadmill off

Rodp · 30-11-2005, 10:01 PM

Quote:

Originally Posted by swanny

The plane landing on a conveyor belt is the opposite situation of a plane starting from a standstill. A landing plane already has momentum.

Ah. But there is a similarity in the reasoning of those who believe the aircraft won't take off.

If a conveyor moving at the same speed (in the opposite direction) as an aircraft at full thrusts wheels are moving, surely those that agree would also have to conclude that a landing aircraft who landed on the same conveyor that then moved (in the opposite direction) as the speed of the wheels would come to an instantaneous stop.

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I just hope none of them are sanctioned to design the new generation of aircraft carriers. :P

I liked the skateboard on the treadmill with someone independent of the treadmill pushing them forward explaination. The engines are a force independent to the wheels hence forward momentum is achieved regardless of the speed of the treadmill.

**Captain Stubing** · 30-11-2005, 10:01 PM

Quote:

Originally Posted by Casper

I give up.

Go stand in front of the sidewinder on the skateboard on this conveyor and have a cup of tea. I'll light the fuse. Based on some logic here all its going to do is sit there and go nowhere.

Sorry Casper, I can't accept all of your reasoning. Who's got the number for Mythbusters???

Casper · 30-11-2005, 10:03 PM

Quote:

Originally Posted by swanny

Sorry Casper, I can't accept all of your reasoning. Who's got the number for Mythbusters???

you honestly cant work out that a sidewinder on a skateboard is going to take off at about mach 3 regardless of how fast the conveyor is going in reverse? Think about it.. its the exact same principle made REALLY easy.

**Captain Stubing** · 30-11-2005, 10:06 PM

No, Casper. Unless the engine of the plane is providing the airflow to provide lift on the wings, it won't work.

A skateboard with a sidewinder is like a plane sitting on a conveyor belt running at full throttle, and giant SourBastard comes up and kicks it, saying "Bluddy move!"

Casper · 30-11-2005, 10:09 PM

I'm lost for words.. thats just... stunning. I'm done with this. I've made it as simple as I can.. most have got it.. some are beyond my help.

**Captain Stubing** · 30-11-2005, 10:12 PM

And I might be wrong... but....

used:

JAJH · 30-11-2005, 10:15 PM

Casper, your theory is a different scenario with the sidewinder. A rocket is relying purely on thrust, not lift to get it airborne, then computer guidance systems allow it to reach it destination. Again, no-one has offered an answer on how to overcome airflow and lift.
And just to try an get a definitive answer on this, tomorrow I will ring some of the eggheads at Qantas or wherever I need to ring and get their take on it, cuase I just ain't sold - if ya got not lift, ya got no takeoff.

**Charliewool** · 30-11-2005, 10:24 PM

Quote:

Originally Posted by the_scotsman

JEEEEEEEEEEEEEEEEEEEEEEZ!!

I read the first 2 pages them came to the last page to reply....

What is so difficult to understand....IT WILL FLY!!!

CASPER summed it up perfectly with the skateboard analogy!

The wheels have NOTHING to do with it, they dont drive the plane forward...when the plane is first started...sure it wont move, but as thrust develops, the plane will be pulled forward THROUGH THE AIR...and will then of course speed up until enough lift is generated the same as any other take off and fly!

DAMN what a frustrating thread!

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Casper's "skateboard" anology??.... Didn't ANYONE watch my vid? And my putting the fan on it etc? (outta 30metre leads now, and the skateboard is in the esplanade) Hate yous all......

**Charliewool** · 30-11-2005, 10:28 PM

By the way... Big Pete should get TIME for this! Grrrrrrrrr

**Captain Stubing** · 30-11-2005, 10:30 PM

ok, putting aside our skateboards, how about selling off all the airport land for re-development, and we can get our planes to take-off by a new method.

We'll attach a huge cable to a ring-bolt on the rear of the 747, anchored to the ground, we'll get him to get the engine revved up for a minute or so, and activate the quick release pin.

Surely that'll get him launched??

JAJH · 30-11-2005, 10:34 PM

And when I have proved to you all that a stationary plane cannot takeoff, I want an apology, especially from the know-it-all, Casper. (gets off soap box)

Perana · 30-11-2005, 10:35 PM

The plane is NOT stationary!!!!!!!!

Ghiadude · 30-11-2005, 10:37 PM

im member number three of TPWTO club... i tried to explain it that many times but you people fail to see how the plane will move forward... i simply cant beleive that two physists can get it so wrong... but then again i always new a degree didnt mean you had common sense

its this simple..i got on a plane... it flew. thrust caused it to move forward, moving forward caused airflow wheels span really really fast, treadmill doesnt mean

Casper · 30-11-2005, 10:38 PM

A stationary plane cant take off. Of course, since the plane wouldnt be stationary.. it will take off. Simple.

max^power · 30-11-2005, 10:39 PM

what a debate, my input: if it was a harrier yes. other planes need air over and under the wings, if it was just the engines what are the wings there for? ;)

you need the wings to be moving through the air at a reasonable pace for the plane to take off.

DOC · 30-11-2005, 10:41 PM

All In good fun guys, heres another Q, lets forget the treadmill, if a plane is being propelled down a normal runway at 10KPH how fast are the wheels going ?

**Captain Stubing** · 30-11-2005, 10:41 PM

Quote:

Originally Posted by big_pete

ok, ive seen this on a couple of forums now, and i dont think a conclusion has been reached for this little problem........

Quote:
A plane is standing on a runway that can move (some sort of band conveyer).

so what do you think????

And we're back to the start of the thread, with a non-moving plane

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JAJH · 30-11-2005, 10:44 PM

Quote:

Originally Posted by Casper

A stationary plane cant take off. Of course, since the plane wouldnt be stationary.. it will take off. Simple.

So, if you happened to be standing next to this so-called plane (not on the conveyor) whilst is was travelling on the conveyor are you saying it would be moving away from you, or would you agree it would remain next to you? If you agree it would remain next to you, then how the hell can it fly?

XA Coupsta · 30-11-2005, 10:44 PM

I seriously cant believe this thread is still going.

Its............annoying!

I wanna be a member too Malakai.

The damn plane IS gonna take off!

Im not going into reasonings as it has been done well enough already........and numerous times.

Casper · 30-11-2005, 10:46 PM

Quote:

Originally Posted by JAJH

So, if you happened to be standing next to this so-called plane whilst is was travelling on the conveyor are you saying it would be moving away from you, or would you agree it would remain next to you? If you agree it would remain next to you, then how the hell can it fly?

It would be moving away from you.. actual forward motion.. The convayor would not stop it from moving forward at all as it has no way of stopping the engine from creating thrust. All the conveyor can do is make the planes wheels move faster than the actual plane is going. It would take off just like normal.. the only difference is the wheels would be travelling faster..

Ghiadude · 30-11-2005, 10:49 PM

Quote:

Originally Posted by DOC

All In good fun guys, heres another Q, lets forget the treadmill, if a plane is being propelled down a normal runway at 10KPH how fast are the wheels going ?

if youre asking how fats they are spinning you would need to know the radius/diam of the wheel... if you want to know how fast the y are moving in relation to the ground 10kph,,, if you would like to know how fast they are traveling relative to a pointon a treadmill belt doing 10kph in the opposite direction they are moving 20kph... if you want to know how fast the plane is moving ...its still doing 10kph relative to the ground that the treadmill is on and its moving 10kph faster than the air around it causing lift... iITS GOING 10KPH!!!

**Captain Stubing** · 30-11-2005, 10:52 PM

Quote:

Originally Posted by Casper

It would be moving away from you.. actual forward motion.. The convayor would not stop it from moving forward at all as it has no way of stopping the engine from creating thrust. All the conveyor can do is make the planes wheels move faster than the actual plane is going. It would take off just like normal.. the only difference is the wheels would be travelling faster..

"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same "

This, in effect, will hold the plane in it's place, until there is enough airflow over and under the wings to cause 'Lift'.

Ghiadude · 30-11-2005, 10:54 PM

Quote:

Originally Posted by swanny

"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same "

This, in effect, will hold the plane in it's place, until there is enough airflow over and under the wings to cause 'Lift'.

no this wont hold theplane back it will spin the wheels back... the plane with its big off jet engines will push against the air aroundit moving the plane forward...relative to the ground

JAJH · 30-11-2005, 10:54 PM

Quote:

Originally Posted by Casper

It would be moving away from you.. actual forward motion.. The convayor would not stop it from moving forward at all as it has no way of stopping the engine from creating thrust. All the conveyor can do is make the planes wheels move faster than the actual plane is going. It would take off just like normal.. the only difference is the wheels would be travelling faster..

I'm sorry Shane, I just don't think you are looking at it relatively. The thrust will move the plane forward and cause the wheels to spin, the conveyor will react at the same speed in the opposite direction. The forward motion of the thrust make the wheels spin but is then negated by the conveyor, it will remain stationary. If you stand next to it, it will NOT move.

Casper · 30-11-2005, 10:54 PM

Quote:

Originally Posted by swanny

"This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same "

This, in effect, will hold the plane in it's place, until there is enough airflow over and under the wings to cause 'Lift'.

No, it wont hold the plane in place at all. The only wiay it could hold the plane in place if if the plane was transmitting it forward thrust through the wheels.. like a car. Then it would be held in place. Since a plane creats thrust via a propellor (or jet or rocket) the convayor belt does not absorb this thrust. The plane will move forward as per normal.

DOC · 30-11-2005, 10:56 PM

Quote:

Originally Posted by tx3dude

if you want to know how fast the y are moving in relation to the ground 10kph,,, !!

ok the wheels are doing 10K now the treadmill going the other way at 10k, so how does the plane move forward ?

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