Airplane and Belt Conveyor

[ThreeWheels]

A plane is standing on a runway that can move (some sort of belt 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 the opposite direction). Can the plane take off?"

 

[vided]

i'm going with a i don't think so

 

[MarkLawson]

Nope. It's not a matter of the speed of the wheels turning, but of the rate of airflow over/under the wings that make the plane fly.

 

[vided]

:banghead::banghead::banghead:

 

[Bob Denman]

Nope. It's not a matter of the speed of the wheels turning, but of the rate of airflow over/under the wings that make the plane fly.

:agree: Without movement through the air; the wings provide no lift...

 

[PrairieSpyder]

Nope. It's not a matter of the speed of the wheels turning, but of the rate of airflow over/under the wings that make the plane fly.

:agree: Without movement through the air; the wings provide no lift...

:agree: They tested this on Mythbusters.

 

[aeroshots]

Depends

Yes it can. https://www.google.com/search?q=ver...bFMTnsAX2h4DQAQ&ved=0CCEQsAQ&biw=1350&bih=610

:yes:

 

[MarkLawson]

Yes it can. https://www.google.com/search?q=ver...bFMTnsAX2h4DQAQ&ved=0CCEQsAQ&biw=1350&bih=610

:yes:

Hadn't considered that possibility!

 

[Bob Denman]

:shocked: Okay... you caught us with a trick question! :clap:

 

[ThreeWheels]

:shocked: Okay... you caught us with a trick question! :clap:

It's not a trick. VTOL is not part of the original question.

 

[Bob Denman]

A plane is standing on a runway that can move (some sort of belt 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 the opposite direction). Can the plane take off?"

It doesn't mention HOW it must take off; it just misdirects us, by making us think about the obvious...
We were all drawn to the issue of the wings not having airflow over them...
...While forgetting about the other methods of lift that are available! :clap:

 

[aeroshots]

It's not a trick. VTOL is not part of the original question.

O, okay sorry. I was trying a good humored yet accurate answer to a humorous yet interesting question.pps: You did say plane four times in your question, but I missed the VTOL exemption. I guessed I missed your point in the question. So, what is the answer?

 

[Chupaca]

There you go...!!

to late to give an opinion....great question food for tought answer should have been polled or given in a few days...:thumbup: but I'll keep my three wheels on the ground...:roflblack::roflblack:

 

[jcthorne]

The plane is accelerating with regard to the runway, moving or not. It does not use the wheels as motive force, rather the acceleration of air through the engines provide thrust which happens regardless of the speed of the wheels turning. The belt movement has no net effect other than the minimal rolling resistance of the wheels.

Yes the plane will take off in normal fashion and will move forward at its normal acceleration and lift rates.

 

[Bob Denman]

But it's not moving forward; the conveyer belt is counteracting it's forward speed, by running in the opposite direction.
It'll just sit there... :shocked:

Unless it's a Harrier!

https://www.youtube.com/watch?feature=player_detailpage&v=2pweY5y5eRI

 

[PrairieSpyder]

The plane is accelerating with regard to the runway, moving or not. It does not use the wheels as motive force, rather the acceleration of air through the engines provide thrust which happens regardless of the speed of the wheels turning. The belt movement has no net effect other than the minimal rolling resistance of the wheels.

Yes the plane will take off in normal fashion and will move forward at its normal acceleration and lift rates.

It's not the air through the engine that causes lift, but air moving over the wings. The plane has to move forward through the air in order to achieve lift. It the plane can't move through the air, it won't fly!

 

[bscrive]

The plane is accelerating with regard to the runway, moving or not. It does not use the wheels as motive force, rather the acceleration of air through the engines provide thrust which happens regardless of the speed of the wheels turning. The belt movement has no net effect other than the minimal rolling resistance of the wheels.

Yes the plane will take off in normal fashion and will move forward at its normal acceleration and lift rates.

:agree: We are not talking about a car where the mode of forward movement is the wheels.

 

[Bob Denman]

.......................................................................................Lift...
:agree: The turbines provide the thrust; the wings provide the...

 

[jcthorne]

But it's not moving forward; the conveyer belt is counteracting it's forward speed, by running in the opposite direction.
It'll just sit there... :shocked:

Unless it's a Harrier!

https://www.youtube.com/watch?feature=player_detailpage&v=2pweY5y5eRI

The counter direction conveyer has no effect once the engines are providing enough thrust to overcome rolling resistance of the wheels. It cannot 'counter' the forward acceleration that is the direct effect of the rearward acceleration of the air through the engines. This is nothing like a car that uses the wheels to generate the forward thrust.

 

[jcthorne]

It's not the air through the engine that causes lift, but air moving over the wings. The plane has to move forward through the air in order to achieve lift. It the plane can't move through the air, it won't fly!

Its the acceleration of the air through the engines that provides the forward movement. The plane DOES move forward regardless of the speed of the conveyor belt. Therefore the plane achieves lift in the normal manner.