RE: Can It Take Off??  
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RE: Can It Take Off?? - 1/13/2006 5:39:16 PM   
jamieduff1981


 

Posts: 131
Joined: 12/29/2005
From: ELLONScotland, UNITED KINGDOM
Status: offline 		Well all this thread has shown is a list of who NOT to ask for help if you're a university student studying a maths based degree, such as Physics, Engineering etc.

The values named by Rat 1 are arbitary. The letters or numbers selected are irrelevant, so long as they are understood MATHEMATICALLY to be equivalent in magnitude.

Anyone who disagrees with the equations offered by Rat 1 simply sucks at mathematics, sorry.

I'm quite sure there are some people who could perform:

I am confident that some people in here could perform something basic and arrive at the wrong answer:

How about this for fun:

1 + 5 x 6 - 3 / 2 + 15

Anyone who gets 31.5 is wrong.

The correct answer is of course = 44.5


(in reply to Rat1)
       Post #: 426

RE: Can It Take Off?? - 1/13/2006 6:10:21 PM   
CHassan



Posts: 1230
Joined: 8/26/2002
From: Beavercreek, OH, USA
Status: offline 		If you are a University Student coming to RCU for help with a math problem you are in the wrong place anyway.
I stand by my math. From my point of view it is correct. I can also say Rat 1 math is correct. Does this mean I don't have a clue?

By the way I got 44.5 also.

But again I ask, how do the wheels ever get rolling?

< Message edited by CHassan -- 1/13/2006 6:12:27 PM >

_____________________________

The knack of flying is learning how to throw yourself at the ground and miss.
--Hitchhikers Guide to the Galaxy--

(in reply to jamieduff1981)
       Post #: 427

RE: Can It Take Off?? - 1/13/2006 6:14:22 PM   
cyclops2


 

Posts: 1834
Joined: 12/23/2005
From: Frenchtown, NJ, USA
Status: offline 		Can you understand that WHEEL speed has NOTHING to do with AIRSPEED ?
WHEEL speed is AIRSPEED in land bound vehicles when all 4 wheels leave the ground.
A plane does not lift off the ground at any fixed ground speed. It FLYS when it has either fast enough airflow over the wings or thrust that is greater than the weight of the plane.
Also known as a vertical hand launch.
Nothing else causes planes to " FLY ".

(in reply to CHassan)
       Post #: 428

RE: Can It Take Off?? - 1/13/2006 6:22:18 PM   
PowerPlay


 

Posts: 181
Joined: 9/6/2002
From: Glendora, CA, USA
Status: offline 		Well you're wrong because I got 49.5, which means that you are wrong because I didn't get 31.5 , you are wrong about my wrong answer, so I'm right, of course.

And on that brilliant dissertation I'm out of here, Cheerio

(in reply to jamieduff1981)
       Post #: 429

RE: Can It Take Off?? - 1/13/2006 6:23:52 PM   
flyinryan2


 

Posts: 35
Joined: 1/10/2006
From: st paul, MN, USA
Status: offline 		IT WOULD NOT TAKE OFF. Think of airspeed. it has ZERO. it is moving as fast as the belt in tire speed but is moving nowhere relative to the wind. WOULD NOT GO ANYWHERE.

(in reply to BMatthews)
       Post #: 430

RE: Can It Take Off?? - 1/13/2006 6:38:18 PM   
jamieduff1981


 

Posts: 131
Joined: 12/29/2005
From: ELLONScotland, UNITED KINGDOM
Status: offline 		CHassan,

glad you got 44.5

You ask "how do the wheels ever get rolling" or words to that effect.

That's the sceptic's arguement. If the wheels roll, the belt matches it, right?

So either: The plane initially moves and the wheels roll and after a short delay the belt reacts - hence the belt hasn't matched the wheel speed and the whole exercise has been a waste of time

Or: the belt acts instantly. In this case, as soon as the plane tries to edge forward, thanks to it's thrust against a static atmosphere (on an initially stationary belt) the belt tries to match the wheel speed, both wheel and belt speed go instantly to infinity (because the plane's thrust doesn't go away and the plane will continue to try to roll forward faster than that belt below it). Once it reaches infinity (which can't really happen) everything equals infinity and it's still been a complete waste of time.

Only if the belt fails to match the wheel speed can the plane actually make any progress and gain airspeed in a near static atmosphere which is independant to the belt.

The key to the sceptic arguement is the "exactly matches" statement regarding the belt and the wheels. This can't happen as the belt will always be reactionary. Even mathematically it's reactionary because the wheels wont move until the plane moves. If the plane moves then it's wheels have gone faster than the belt.

Nothing else really matters. There will be friction from the wheel bearings, gyroscopic forces from the wheels, a moving boundary layer from the belt etc etc etc. That's all true in real life.

The question is hypothetical though. It has to be because it states absolute conditions. The word "exactly" makes sure of that. None of these real life limitations matter because the experiment fails as soon as it begins.

In other words, it's a non-starter!

(in reply to flyinryan2)
       Post #: 431

RE: Can It Take Off?? - 1/13/2006 7:28:58 PM   
starwoes



Posts: 121
Joined: 10/6/2005
From: Maple Heights, OH, USA
Status: offline 		I am shutting down this thread ASAP!!!

IT WILL FLY! CASE CLOSED!

(in reply to jamieduff1981)
       Post #: 432

RE: Can It Take Off?? - 1/13/2006 7:38:30 PM   
CHassan



Posts: 1230
Joined: 8/26/2002
From: Beavercreek, OH, USA
Status: offline 		Right, so if you take no liberties in the question, it is impossible to come to any realistic conclusion.

The belt reacts to the wheels. If the wheels move the belt matches. A reaction comes after an action, so by definition the belt will lag.

Unless you can pre program the conveyor (which is also an impossible).

If the belt lags even a little, at infinite speeds would this belt be infinitly slower than the wheels?


_____________________________

The knack of flying is learning how to throw yourself at the ground and miss.
--Hitchhikers Guide to the Galaxy--

(in reply to jamieduff1981)
       Post #: 433

RE: Can It Take Off?? - 1/13/2006 7:54:52 PM   
mesae



Posts: 568
Joined: 12/16/2002
From: Edmond, OK, USA
Status: offline
quote:

ORIGINAL: PowerPlay

Well you're wrong because I got 49.5, which means that you are wrong because I didn't get 31.5 , you are wrong about my wrong answer, so I'm right, of course.

And on that brilliant dissertation I'm out of here, Cheerio



Now I get it, he's from SoCal. That explains everything.

(I know, because I'm from there too.)

44.5

_____________________________

"The purpose of time is to prevent everything from happening all at once."

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RE: Can It Take Off?? - 1/13/2006 7:57:41 PM   
mesae



Posts: 568
Joined: 12/16/2002
From: Edmond, OK, USA
Status: offline
quote:

ORIGINAL: PowerPlay

Well you're wrong because I got 49.5, which means that you are wrong because I didn't get 31.5 , you are wrong about my wrong answer, so I'm right, of course.

And on that brilliant dissertation I'm out of here, Cheerio



Now I get it, he's from SoCal. That explains everything.

(I know, because I'm from there too.)

44.5

_____________________________

"The purpose of time is to prevent everything from happening all at once."

(in reply to PowerPlay)
       Post #: 435

RE: Can It Take Off?? - 1/16/2006 2:42:05 PM   
mulligan



Posts: 1147
Joined: 4/14/2002
From: Sanford, FL, USA
Status: offline 		Idiots.

_____________________________

George Mulligan
www.sanfordaeromodelers.com

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RE: Can It Take Off?? - 1/16/2006 2:43:06 PM   
mulligan



Posts: 1147
Joined: 4/14/2002
From: Sanford, FL, USA
Status: offline 		I really didn't mean the above post... I'm just trying to get the thread shut down

_____________________________

George Mulligan
www.sanfordaeromodelers.com

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RE: Can It Take Off?? - 1/16/2006 4:45:10 PM   
cyclops2


 

Posts: 1834
Joined: 12/23/2005
From: Frenchtown, NJ, USA
Status: offline 		I release you from ever looking at this thread again.

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RE: Can It Take Off?? - 1/16/2006 10:32:29 PM   
air mail rcu


 

Posts: 522
Joined: 8/3/2003
From: Pittsburgh, PA, USA
Status: offline
quote:

ORIGINAL: mulligan

I really didn't mean the above post... I'm just trying to get the thread shut down


You'll have to do better then that. Please.please,please.!!!!!


_____________________________

Take-offs are optional. Landings are mandatory.

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       Post #: 439

RE: Can It Take Off?? - 1/18/2006 4:04:28 AM   
ND_newbie


 

Posts: 58
Joined: 2/7/2003
From: Williston, ND, USA
Status: offline 		44.5?

True, but only if the order of precedence is */+-, /*+-, */-+, or /*-+. Lacking parentheses, who really knows?

Regardless, the plane will fly. Then, at some point, it will stop flying.

Mitchell Schaff
Williston, North Dakota
(though I did live in SoCal for a while....)

(in reply to air mail rcu)
       Post #: 440

RE: Can It Take Off?? - 1/18/2006 4:51:27 AM   
davidfee



Posts: 691
Joined: 6/21/2003
From: San Diego, CA, USA
Status: offline 		The order of operations is: parentheses, exponents, multiplication and division, and lastly addition and subtraction. That is not negotiable.

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       Post #: 441