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airplane vs conveyor belt

Dec. 27, 2007, 11:26 p.m.
Posts: 33673
Joined: Nov. 19, 2002

if the belt matched the speed of the plane it would not take off. Air needs to move over the wing with enough velocity for the preesure below the wind to be greater then the pressure above. the jet engine does nothing but push the plane forwards to create said air velocity. if you are running on a treadmill, do you feel the wind in your face?

If the belt matches the rotational speed of the wheels, the plane cannot take off.

If the belt matches the speed of the plane, the plane can take off.

The reason? The plane has to move forward relative to the air around it, and it can only do this by moving forward on its wheels.

Remember, this is a theoretical question, not a practical one. There have been a lot of debates, but on a BB that consists of airline pilots, engineers, and mechanics, they all agreed that the plane would not take off and also that the question is poorly worded.

Hey GB - if a conveyor is moving backwards at the same speed as the wheels are rotating forward, then the wheel itself can't move forwards. Mythbusters will, of course, miss this fine point, try to take off a plane from a conveyor belt without this limitation, and pat themselves on the back.

Their question is worded differently, and the way it is worded, the plane can take off. I bet this is what they will find.

It is easy to dodge our responsibilities, but we cannot dodge the consequences of dodging our responsibilities.
- Josiah Stamp

Every time I see an adult on a bicycle, I no longer despair for the future of the human race.
- H.G. Wells

Dec. 28, 2007, 1:53 p.m.
Posts: 15
Joined: March 27, 2007

If the belt matches the rotational speed of the wheels, the plane cannot take off.

If the belt matches the speed of the plane, the plane can take off.

The reason? The plane has to move forward relative to the air around it, and it can only do this by moving forward on its wheels.

Remember, this is a theoretical question, not a practical one. There have been a lot of debates, but on a BB that consists of airline pilots, engineers, and mechanics, they all agreed that the plane would not take off and also that the question is poorly worded.

Their question is worded differently, and the way it is worded, the plane can take off. I bet this is what they will find.

DUDE. If the wheels are touching the belt they will move at the same speed regardless of whether the plane itself is moving forward or not. :rolleyes:

Dec. 28, 2007, 1:56 p.m.
Posts: 13016
Joined: Nov. 24, 2002

DUDE. If the wheels are touching the belt they will move at the same speed regardless of whether the plane itself is moving forward or not. :rolleyes:

I pity you. Seriously. New here, eh? Never ever try to argue with guys who think it is fun to work in the forest on some "stunts" in the PISSING rain - those same stunts they will crash on no matter what. Sheeshh.

"You don't learn from experience. You learn from reflecting on the experience."
- Kristen Ulmer

Dec. 28, 2007, 3:03 p.m.
Posts: 0
Joined: Nov. 23, 2005

If the treadmill is supposed to match exactly the speed of the wheel rotation, then the question disqualifies the plane from applying enough force to launch. Wheels rotate at 1000rpm, so does treadmill. If pilot applies more force to take off, and the plane moves forward (no problem for plane to accelerate) then the plane is disqualified because it's wheels are now spinning faster than the treadmill.

Just call me GW, trying to get a handle on this sh[HTML_REMOVED]t disturbing thing so I can find my home in NBR along with the rest of people who dont ride.

Eric

Jan. 1, 2008, 7:36 a.m.
Posts: 696
Joined: May 8, 2005

:cake: this thread turned 2 three hours and six minutes ago :cake:

the plane won't take off.

Disclaimer: the above text is in no way or form intended to harm you. if by any chance you are offended by it, please take a moment to Harden the F*** Up. thank you.

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Jan. 1, 2008, 1:03 p.m.
Posts: 0
Joined: March 10, 2007

oh god this thread is crazy. seriously messed up , people really just want to see it get longer.

bump

Jan. 1, 2008, 1:34 p.m.
Posts: 7769
Joined: Nov. 23, 2002

people really just want to see it get longer.

thats what splinky said to diggs

"Fullness of knowledge always means some understanding of the depths of our ignorance; and that is always conducive to humility and reverence." - Robert Millikan

Jan. 1, 2008, 2:32 p.m.
Posts: 0
Joined: Aug. 5, 2003

the plane will crash and burn and atheists will get offended if you wish them a merry christmas.

Jan. 1, 2008, 2:34 p.m.
Posts: 7769
Joined: Nov. 23, 2002

the plane will take off because god said so.

.

"Fullness of knowledge always means some understanding of the depths of our ignorance; and that is always conducive to humility and reverence." - Robert Millikan

Jan. 1, 2008, 2:36 p.m.
Posts: 0
Joined: Aug. 5, 2003

.

Doxa si kurie doxa si.

Jan. 1, 2008, 9:39 p.m.
Posts: 3
Joined: July 4, 2003

… Its taking off for sure.

Jan. 1, 2008, 10:35 p.m.
Posts: 0
Joined: Feb. 14, 2005

i'm going to go ahead and say again that the plane will take off.

Jan. 2, 2008, 12:25 p.m.
Posts: 0
Joined: Dec. 27, 2002

Who cares about the speed of the wheels or the conveyor belt. You need relative airpseed between the wings and the mass of air that is flowing above and below the wing to generate lift. In this instance the relative airspeed is zero - therfore the plane doenst take off. The running conveyor will generate some airspeed at the conveyor surface or ground level but will in now way provide any lift to the foil (wing). Its that simple.

Jan. 2, 2008, 1:18 p.m.
Posts: 8259
Joined: Nov. 20, 2002

ok, now the same situation, but the plane is taking off from an ecologically sensitive frog pond, what happens now?

Well, well I been movin' down to Florida.
And I'm gonna bowl me a perfect game.
Well I'm gonna cut off my leg down in Florida, child.
And I'm gonna dance one-legged off in the rain.

Jan. 2, 2008, 1:22 p.m.
Posts: 18529
Joined: Nov. 19, 2002

ok, now the same situation, but the plane is taking off from an ecologically sensitive frog pond, what happens now?

montreal or quebec city?

meh

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