A Wednesday conundrum

[Moose.]

A plane is standing on a runway that can move (some sort of giant conveyer belt). 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?

[timmy30]

Are you taking zee pisss?

[jimothy]

Nope. There would be no air movement under the wings to provide the lift.

[timmy30]

jimothy said:

Nope. There would be no air movement under the wings to provide the lift.

Aggggghghhh stop that at once. This bloody thing nearly sent me potty last time!

[chim_knee]

Depends on the direction and speed of any wind, presumably.

[speedchick]

Haven't we been here before?

[lizzieh]

if it's a Harrier Jumpjet it can surely.

Other than that.. don't know.

[timmy30]

Oh here we go

[Ali_Kat]

Still no.

How many pages did this get to before??

[greg_D]

jimothy said:

Nope. There would be no air movement under the wings to provide the lift.

Seconded

[Einion Yrth]

Ali_Kat said:

Still no. How many pages did this get to before??

You're still wrong, and I can't remember for sure, but it was quite a few.

[Ali_Kat]

Einion Yrth said:

You're still wrong, and I can't remember for sure, but it was quite a few.

:P

[Moose.]

I had no idea this was a repost (saw the thread on pprune a figured the PH collective might enjoy it ) I'm sticking with yes it will take off because the wheels on a plane aren't driven and hence the plane will still go along the runway, abet with the wheels spinning much faster.

[timmy30]

Moose. said:

I had no idea this was a repost (saw the thread on pprune a figured the PH collective might enjoy it ) I'm sticking with yes it will take off because the wheels on a plane aren't driven and hence the plane will still go along the runway, abet with the wheels spinning much faster.

Ohhhh you have no idea what you've done. All sodding day and night that thread went on.

How on earth people couldn't see that the plane would not take off was quite beyond all of us enlighted PHers deperately trying to convince the flat earth brigade with our more advanced logic

[Einion Yrth]

Moose. said:

I'm sticking with yes it will take off because the wheels on a plane aren't driven and hence the plane will still go along the runway, abet with the wheels spinning much faster.

Precisely the answer, so we can stop this now before it goes completely insane like last time. If it continues I shall be forced to post the Monty Hall Problem again, and then there'll be trouble.

[scorp]

No, the plane cannot take off because all the force the jet engines produces is sent to the wheels which is counteracted by the converyor.

[tinman0]

Einion Yrth said:

Moose. said: I'm sticking with yes it will take off because the wheels on a plane aren't driven and hence the plane will still go along the runway, abet with the wheels spinning much faster. Precisely the answer, so we can stop this now before it goes completely insane like last time. If it continues I shall be forced to post the Monty Hall Problem again, and then there'll be trouble.

since when does a plane get lift from its wheels?

wings - planes get lift from the wings. its not a difficult concept to understand. it why planes have wings infact - key component. you see, if planes needed wheels for lift - they'd have big fast moving wheels - but they don't - they have big wings.

[scorp]

Wrong, planes at takeoff use thrust to get off the ground, the wings are ineffective at takeoff speeds.

[omitchell]

The plane will take off albeit with the wheels turning at double the speed that the plane is trvelling forwards, this is due to the fact the jet engines provide forward thrust to the airframe and not to the wheels and as such it is irelevant how fast the wheels are turning if at all, the plane will still accelerate regardless unless a force is applied to the plane itself

[greg_D]

the answer lies in relative ground position, if the plane is moving relative to the solid ground at 150+mph then the air over the wings will create lift and it will take off.

i still think that the power of the plane will be propelling it to 150+mph relative to the conveyor belt but in relation to the ground it will still be going 0mph, hence no lift,

the end.