It's all a matter of physics.

[Anime Gee]

Read the question and really think about it before you answer.

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).

The question is:

Will the plane take off or not?

There's a huge debate on another forum about this. I want to see what my fellow colleagues think. :crube:

[Galkar]

It most certainly would not. There would be no lift to make it rise, be it via bernoulli's principle, or by the angle of the wings. The only difference between this scenario and one where the belt stays still is that the wheels are turning, and there would be a TINY bit of breeze generated by the moving belt.

EDIT: Note that it is when I am absolutely sure of something that I am mostlikely to make a mistake.

Edited November 28, 2005 by Taekwondeal

[Crube]

Read the question and really think about it before you answer.

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).

The question is:

Will the plane take off or not?

There's a huge debate on another forum about this. I want to see what my fellow colleagues think.

WORDS.

Edited November 28, 2005 by Dr. Crube

[David]

The plane should take off. Partially depends on where the propelling force is in relation to the force exerted by the conveyor belt. Plane could crash nose-first into the ground. xD

Though I've forgotten everything from Physics, except that my teacher said someone broke his spine and he became a diamond expert. I have no idea what that has to do with Physics, but that's the only thing he said that's stuck.

Edited November 28, 2005 by Deathmate Type:B

[thebornotaku]

depends. if the plane is moving due to engines (jet or propeller) it should generate enough force to eventually take off.

[Arcane]

At first glance, it would seem to me that the plane would not take off. Planes lift off from air moving over and under the wings, and technically the plane would not be moving, therefore there would not be much air flowing over the wings.

[Crube]

Yeah... I just realised the stupid plane would still be in place, thus producing little to no air flow at all...

[Galkar]

Exactly. As the plane is not actually moving, there would be no air moving over the wings which is what creats the lift, except for a little bit from the propeller maybe.

[thebornotaku]

but you see, the purpulsion moves air. so there would be more than just a little bit, because it has to move air to gain speed.

[Crube]

Exactly. As the plane is not actually moving, there would be no air moving over the wings which is what creats the lift, except for a little bit from the propeller maybe.

More words. :crube:

Edited November 28, 2005 by Dr. Crube

[Crube]

Now that I actually think of it. If the belt was moving at precisely the same speed as the airplane... the speeds cancel each other out. The plane will never make it.

[thebornotaku]

But still... that small burst of air could make it fly. Why do you think cars hydroplane over water?

that has more to do with the fact that rubber and water don't grip too well. plus i would imagine that a small burst of air wouldn't make a car hydroplane, but rather sudden excessive wheel spin (rapid acceleration) and sudden braking.

yeah.

[Belial]

No forward movement = no airflow on the wings = no lift produced by the pressure difference under the wing = no flight.

Simple.

Now if this was a Harrier, this would be a totally different question, but I'm assuming we're talking about a simple single prop plane.

[Kreutz]

Ok, I'll settle this with one statement: The fucking plane isn't moving, so the fucking plane isn't moving.

[thebornotaku]

Ok, I'll settle this with one statement: The fucking plane isn't moving, so the fucking plane isn't moving.

that seems pretty logical, actually.

[Crube]

that seems pretty logical, actually.

Because it is? Anyway, I fixed my shit responses before he came in here. :crube:

[David]

If the plane isn't moving because of the conveyor, it's speed becomes 0, and then the conveyor would stop, since the conveyor attempts to match the speed of the plane.

So then plane will take off, because the rate at which the plane accelerates is likely much higher than the rate at which the conveyor can de-accelerate it when it attempts to match the plane's new increasing speed?

/gg?

Edited November 28, 2005 by Deathmate Type:B

[Crube]

If the plane isn't moving because of the conveyor, it's speed becomes 0, and then the conveyor would stop, since the conveyor attempts to match the speed of the plane.

So then plane will take off, because the rate at which the plane accelerates is likely much higher than the rate at which the conveyor can de-accelerate it?

/gg?

No... the speed of the conveyor will slowly decrease along with the plane.

[Siendra]

I would like to know in what world sixty-six hours of work a week is "full time."

No, really. I hate the store I'm working at: You have 17 staff members, give me some fucking time off.

Edit: Fuck. Why does teh board keep redirecting me to this thread? FUCK YOU. *KICKS*

[Crube]

I would like to know in what world sixty-six hours of work a week is "full time."

No, really. I hate the store I'm working at: You have 17 staff members, give me some fucking time off.

Random Thoughts is right above us*

Real Edit: No clue.

Edited November 28, 2005 by Dr. Crube

[thebornotaku]

If the plane isn't moving because of the conveyor, it's speed becomes 0, and then the conveyor would stop, since the conveyor attempts to match the speed of the plane.

So then plane will take off, because the rate at which the plane accelerates is likely much higher than the rate at which the conveyor can de-accelerate it when it attempts to match the plane's new increasing speed?

/gg?

that actually makes some sense.

plane's speed becomes zero, convery tries to compensate, plane moves forward creating airflow, and given the conditons are right, flight is achieved.

[David]

So.... each time the conveyor slows down to the velocity of the plane, the constant force of the plane's engine will give it a higher velocity of that of the conveyor, the plane would move a slight distance forward until the conveyor matches it's velocity again (and then at that point the conveyor will slow down to match the new velocity of 0)... the cycle would repeat until the plane leaves the runway and takes off of some other surface (unless there's a wall where the runway ends)

[Galkar]

This is making assumptions though about the capabilities of the conveyor belt that we don't actually know.

[Belial]

While you're making assumptions, why not assume that there is a 140 knot headwind. Then the plane would most likely achieve lift.

[Kreutz]

While you're making assumptions, why not assume that there is a 140 knot headwind. Then the plane would most likely achieve lift.

:happy: