hmmm.... physics question for you guys....

[SeventhSon]

Re: hmmm.... physics question for you guys....

ok, i'm throwing my hat in with the boys that say the plane will fly. lou, you're pretty smart for a knuckle dragger!

[lerxstcat]

Re: hmmm.... physics question for you guys....

Okay, problem solved! You want the JCPF (Physics) Forum!
So go down to the end of the hall, take a left, and it's your second right, next door to the JCAF (Astrology) Forum.
Make sure not to go in there, as they'll tell your fate will decide whether the plane will take off! [img]/images/graemlins/crazy.gif[/img]

[Sandman0170]

Re: hmmm.... physics question for you guys....

[img]/images/graemlins/what.gif[/img]

[xenophobe]

Re: hmmm.... physics question for you guys....

lol... some hillariously FUCKTARDED answers in this thread [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img]

The only thing that will happen is that the plane's tires will be spinning twice as fast as it starts moving down the conveyor belt to take off.

There is a question of how efficient the bearings on the landing gear wheels are, factoring in a friction co-efficient that would require slightly more thrust to make the plane initially move forward (from the moving tarmac), but once the initial forward momentum of the plane starts, this would be negligible.

lol... it wouldn't take off or move. [img]/images/graemlins/bs.gif[/img] Hahahaha... fucking funniest shit ever. [img]/images/graemlins/poke.gif[/img]

EDIT: Funnier than the Dross Cockroah thread even! [img]/images/graemlins/laugh.gif[/img]

[img]/images/graemlins/popcorn.gif[/img]

[AfterForever]

Re: hmmm.... physics question for you guys....

great topic.. I had fun reading all this haha

[zeegler]

Re: hmmm.... physics question for you guys....

[ QUOTE ]
lol... some hillariously FUCKTARDED answers in this thread [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img] [img]/images/graemlins/laugh.gif[/img]

The only thing that will happen is that the plane's tires will be spinning twice as fast as it starts moving down the conveyor belt to take off.

There is a question of how efficient the bearings on the landing gear wheels are, factoring in a friction co-efficient that would require slightly more thrust to make the plane initially move forward (from the moving tarmac), but once the initial forward momentum of the plane starts, this would be negligible.

lol... it wouldn't take off or move. [img]/images/graemlins/bs.gif[/img] Hahahaha... fucking funniest shit ever. [img]/images/graemlins/poke.gif[/img]

EDIT: Funnier than the Dross Cockroah thread even! [img]/images/graemlins/laugh.gif[/img]

[img]/images/graemlins/popcorn.gif[/img]

[/ QUOTE ]

My faith in the intelligence of man has been (somewhat) restored! [img]/images/graemlins/headbang.gif[/img] [img]/images/graemlins/headbang.gif[/img]

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

The things I've read in this thread....

First of all Bernoulli's Principle is not the explanation for flight in se. Try calculating and designing a wing for an airplane supported by Bernoulli, simple hilarity! [img]/images/graemlins/laugh.gif[/img]

The plane would NOT take off, it would remain on the exact same spot (if the theory that is given in the question was indeed practically possible: a plane countermoving at a certain speed on a treadmill going in the opposite direction at the same speed).

Flight of an airplane is achieved by many different factors, but the most important one is lift, as mentioned.

Now let me explain a bit: a plane reaches lift because of air that travels under but particularly over the wing. Because of Bernoulli you'd need a 50% larger top of the wing than the downside to achieve the most minimal of lift, that is unfeasable, though. What really happens is the air on top does move a slight bit faster, a vacuum appears over the top of the wing, this vacuum is filled in IMMEDIATLY by the air even higher than the air already on the top of the wing, so the vacuum pulls in air from above, creating A) an action/reaction equation not dissimilar to Newton and B) lower air pressure (relative to under the wing), pure logic dictates that more speed = more air = more displacement = more lift (hence minimal take-off speeds and the need for engines, namely to create forward motion (or backward motion in some parallel/symmetrically winged stuntplanes)). And as such (albeit simplistically stated) lift is created.

Air speed, relative speed, weight of the plane and sizes of the wings all matter greatly of course. For example, a small cessna needs to create 2,5 ton/s air deplacement for its rougly 3000lbs frame, a jumbojet as is mentioned here is about 800 000lbs, do the math!

Your point of the weels having minimal impact on the planes forward bearing is interesting to say the least. However there is an equally interesting paradox: the plane is reliant on its weels until it reaches sufficient speed = enough airflow = sufficient lift, however since it's still bound to its weels to keep it on the conveyor belt and counteracting gravity and the conveyor belt is moving in the opposite direction at the exact same speed (at no point does the plane move faster or slower than the belt). Now it's necessary to use some sort of archimedal point, let's say the ground, under the conveyor belt or besides the conveyor belt through this we can also consider another archimedal, solid point: the air surrounding the plane. Asides from the minimal airflow created by the belt itself and the engines (Matt's main theory) the air would remain virtually the same. Of course engines are designed nowadays to not only pull in air into themselves for propulsion but also to offset air to above and below the wing to aid in achieving more lift, this however has to be seen as complementary and not sufficient on its own.

The plane remains on the exact same spot (for example it will have the exact same GPS coordinates), no sufficient airflow is created by movement (the main instigator of airflow and lift), the plane does not move forward, the plane does not achieve lift, the plane DOES NOT TAKE OFF!

In other words, I'll repeat the same: the plane won't take off, it'll only be drawing a crowd of people going "what in the name of holy fuck are those dumbasses doing with that Boeing and that gigantic conveyor belt".

[hippietim]

Re: hmmm.... physics question for you guys....

I think it will take off. My pilot coworker explained one key thing to me that sort of puts it into perspective. Airspeed and ground speed are completely different. A plane can be flying just fine and be making little or no progress on the ground. So a plane flying 50 miles an hour into a 50 mile an hour wind is making no forward progress so the the ground speed is zippo. So it stands to reason that even if the plane is making no forward progress on the conveyor it can still fly. The props and jets are the things that pull the air thus causing flight.

Oh and Lou, you are still wrong about the skateboard on the mother of all compensating conveyors [img]/images/graemlins/laugh.gif[/img]

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

But to achieve that flight, it needs enough initial momentum to achieve lift and be able to fly, once airborne I agree with your statement completely. It's the phase before that that has me a bit numbskulled.

[ QUOTE ]
Of course engines are designed nowadays to not only pull in air into themselves for propulsion but also to offset air to above and below the wing to aid in achieving more lift, this however has to be seen as complementary and not sufficient on its own.

[/ QUOTE ]

So I agreed with you partially, however I still believe engines are not sufficient alone and will as such not create enough lift for the plane to magically hover off the belt and start flying forward.

That this is true is proven by the most essential and most famous part, in fact the part that still makes and airplane what it is: the wing and its necessity.

1)Lift counteracts the gravitational pull (weight)(vertically)
and

2)Thrust (by the engines!) counteracts the drag (horizontally)
(Thrust has to cause forward motion initially to be able to achieve sufficient lift for take-off)

Both 1 and 2 are essential, none is reached here. (Well, thrust IS reached, but because of it NOT reaching sufficnet lift (think of the paradox) the weels stay on the conveyor belt and the force is transferred that way, the plane is generating thrust but is experiencing no forward motion.

(Also notice on helicopters they have their blades to provide upward momentum and lift but they also have other engines (mostly jet) to provide forward propulsion)

[Endrik]

Re: hmmm.... physics question for you guys....

THE PLANE WILL NOT TAKE OFF PERIOD.


I'm very good at physics, I was the best in my school, I've made tons of tests wich had WAY harder questions than this and most of the test results were at least 98% right.
This one is too easy, something harder please

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

Yeah me too Endrik, eventhough I hated math and all the friggin' equations, I found it a relatively easy subject. I had 100% on my christmas exams and 96,7% on my finals for physics. And people say Flandria has one of the best educational systems in the world! [img]/images/graemlins/tongue.gif[/img] [img]/images/graemlins/tongue.gif[/img] [img]/images/graemlins/tongue.gif[/img]

Alright alright enough snobism! [img]/images/graemlins/laugh.gif[/img]

[Endrik]

Re: hmmm.... physics question for you guys....

ahaa, I hated math too, but I was the best in Physics and Molecular Biology, I was pretty good at Chemistry too. I was the first one in three years in my school who got the big relative physics test an A, 100% correct answers.
Phyisics are easy, just plain and simple logic.

[GodOfRhythm]

Re: hmmm.... physics question for you guys....

I agree wholeheartedly, I would have gone to medschool (8yrs) and would have wanted to specialize in neurology or genetics (another minimum of 6 yrs) but the longetivity and extremely high subjectload put me off, but most of all CHEMISTRY put me off, the first three years are constant labwork, organic and anorganic carbonchemistry and whatnot, it's definitly achievable but I hate it with a paaaaaaasiion!

[Endrik]

Re: hmmm.... physics question for you guys....

yeah, these things are easy but it doesn't mean I like to do it....24/7 working in the lab...NO FUCKIN' WAY, I'm studying the easier shit like culture/social/languages stuff, It's more fun, a lot of chances to travel the world and a lot of chicks are studying that same thing so I can have more fun [img]/images/graemlins/laugh.gif[/img]

[buzzsaww]

Re: hmmm.... physics question for you guys....

lol [img]/images/graemlins/laugh.gif[/img]