Author Topic: Does it fly??  (Read 1966 times)

KnacK

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Does it fly??
« on: July 26, 2006, 02:27:34 PM »
The Question:

A plane is standing on a runway that can move (some sort of band conveyer). The plane moves in one direction, while the conveyer moves in the opposite direction. This conveyer has a control system that tracks the plane speed and tunes the speed of the conveyer to be exactly the same (but in opposite direction).

Does the plane ever take off, and why or why not?

Spook

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Re: Does it fly??
« Reply #1 on: July 26, 2006, 02:32:43 PM »
no becuase they are going the same speed in opposite directions?

QED

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Re: Does it fly??
« Reply #2 on: July 26, 2006, 02:35:03 PM »
I would say not unless you got some serious headwind.  The "runway" by rolling in the opposite direction directly negates any speed the plane on the ground is making.

P!nk

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« Reply #3 on: July 26, 2006, 03:01:34 PM »
Post removed
« Last Edit: July 26, 2010, 02:33:26 AM by P!nk »

KnacK

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Re: Does it fly??
« Reply #4 on: July 26, 2006, 03:03:10 PM »
what about pressure differential across the wings?

aka LIFT

jitspoe

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Re: Does it fly??
« Reply #5 on: July 26, 2006, 03:04:57 PM »
KnacK, how many times do I have to tell you not to post your homework questions on the forum?!

KnacK

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Re: Does it fly??
« Reply #6 on: July 26, 2006, 03:08:21 PM »
*KnacK goes back to the books....

loial21

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Re: Does it fly??
« Reply #7 on: July 26, 2006, 03:39:06 PM »

Smokey

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Re: Does it fly??
« Reply #8 on: July 26, 2006, 05:10:43 PM »
if there going the same speed, then no. The runway or w/e will cancel out any speed the wheels of the airplane is making. The plane needs upward force to take off. without speed it cant.

jitspoe

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Re: Does it fly??
« Reply #9 on: July 26, 2006, 05:15:37 PM »
Except the plane doesn't use its wheels to go forward -- it has jet engines or a propeller.

Smokey

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Re: Does it fly??
« Reply #10 on: July 26, 2006, 07:01:24 PM »
hmmm........

S8NATHOME

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Re: Does it fly??
« Reply #11 on: July 26, 2006, 07:45:18 PM »
Airplanes fly by generating lift. Thier wings generate this lift.
Do we really need to get into the whole shape of the wing, air pressure differentials, and why the wings generate lift?

The plane will not fly on your conveyor...ever...well...unless a sustained headwind of around 160 knots all of a sudden arises.

OK...it apears some morons might still not get it...so...
Air must move across the wing in order to generate the lift mentioned above. The shape of the wing causes air to move faster over the top of the wing than it does under the wing. This causes a lower pressur over the wing. As this lower pressure becomes enough to lift the plane, it flies.

The engines can counter the conveyor at the speed of light if it could and there would still be no airflow across the wing (besides any wind in the enviroment).

Read on...good stuff...
http://www.plumcreekmarketing.com/articles/02whyplanes.html

P!nk

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« Reply #12 on: July 26, 2006, 08:20:19 PM »
Post removed
« Last Edit: July 26, 2010, 02:33:23 AM by P!nk »

jitspoe

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Re: Does it fly??
« Reply #13 on: July 26, 2006, 08:27:08 PM »
Quote
OK...it apears some morons might still not get it...so...
Kind of ironic. :)

And I see P!nk cheated. ;)

P!nk

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« Reply #14 on: July 26, 2006, 08:29:06 PM »
Post removed
« Last Edit: July 26, 2010, 02:33:20 AM by P!nk »

jitspoe

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Re: Does it fly??
« Reply #15 on: July 26, 2006, 08:31:37 PM »
True.  I'm surprised how many people think the plane wouldn't move, though.

S8NATHOME

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Re: Does it fly??
« Reply #16 on: July 26, 2006, 08:40:42 PM »
the question was not "would the plane move" it was "would the plane take off"
the answer is no

if the answer is anything other than "no" prove it. I prove the "no".

jitspoe

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Re: Does it fly??
« Reply #17 on: July 26, 2006, 08:47:06 PM »
If the plane can move, it can take off.

Edit: Unless you replace "conveyer" with "air current".

medley crew 2

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Re: Does it fly??
« Reply #18 on: July 26, 2006, 08:52:25 PM »
wouldnt the turbines move the plane even if the conveyor was pushing the wheels back? i mean, since the wheels have no motor, they could move at whatever speed without slowing the plane down. the plane would go fast enough to take off i think, the wheels would just be spinning at twice the speed the plane was moving, but would that really prevent it from taking off?

S8NATHOME

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Re: Does it fly??
« Reply #19 on: July 26, 2006, 08:53:07 PM »
kiss my ass...stupid riddle