Will the plane be able to take off?

[ponch]

Good morning. Put down your copies of the morning star and get your eyeballs round this. There must be at least one clever person amongst you bunch of reprobates. Can the plane take off or not? Go wild.

 

[F.U.B.A.R.]

No because there won't be sufficient air flow over the wings to provide lift.

 

[Itsgoneundertheboa]

^ what he said. Plus it's a trick question. Plane isn't moving because it says "sitting". IE it's not moving.

The conveyor belt wheels are designed to match the speed of the wheels = what speed? plane is sitting.

 

[ABPI_]

If the conveyor belt is going as fast as the planes wheels then its not going anywhere its just stationary, im no scientist but does it not rely on the thrust to get off the ground, ie a stationary surface and wide enough space to provide upwards force?

 

[ponch]

I think you are looking at the wrong operative word here lads. Can the plane take off not will the plane take off. It's a Boeing 747 for christ sake!

Where are your calcs?

 

[ponch]

Plane speed going forwards = 500mph
Conveyor belt= -500mph
Speed relative to conveyor belt = 0mph
Speed relative to the ground = ?

 

[smalldubster]

Not enough air under the wings

 

[steewith2ees]

Plane speed going forwards = 500mph
Conveyor belt= -500mph
Speed relative to conveyor belt = 0mph
Speed relative to the ground = 0mph?

- as everyone is suggesting it will just spin the undercarriage.

remove it from the conveyor and yes it can take off.

500mph isn't going to be achieved on the ground though is it. That's about 2/3 - 3/4 the maximum cruising speed.


I know im a fucking pedant. I shouldn't try and rationalise an answer as I can see myself looking like an even bigger dick than usual very fast. Just not quite at 500mph.

 

[F.U.B.A.R.]

I think you are looking at the wrong operative word here lads. Can the plane take off not will the plane take off. It's a Boeing 747 for christ sake!

Where are your calcs?

The thread title says 'Will the plane take off?' Under those circumstances, then not a hope in hell.

 

[ponch]

Velocity of the ground is 0
Velocity of the belt is -100
Velocity of plane is +100

Velocity of plane relative to belt -100 + 100 = 0

Velocity of plane relative to ground 0 + 100 = 100

Whats providing the propulsion here the wheels or the jet engines?

 

[F.U.B.A.R.]

There still isn't the required airflow over the wings to provide lift.

 

[steewith2ees]

The jets are providing the propulsion, but the conveyor belt is designed to exactly match the speed of the wheels, spinning in the opposite direction , which would counter any propulsive force as the conveyor adjusts.

I love just firing badly thought out answers without fetching my list of Newtonian equations. That would be cheating.

EDIT -

OR!

The plane can take off fine as the engines propel it along the conveyor until it reaches V2, where it will be able to rotate regardless of what the wheels and conveyor are doing as they cancel each other out.

8(

 

[F.U.B.A.R.]

The plane's speed relative to the surrounding air is effectively zero. Without air movement over the wings there is no lift. Plane cannot take off, but tyres will eventually burn out.

 

[ponch]

The plane's speed relative to the surrounding air is effectively zero. Without air movement over the wings there is no lift. Plane cannot take off, but tyres will eventually burn out.

Think of it in reverse if the plane comes in to land at 200mph and the belt is travelling in reverse at 200mph does the plane stop dead when it hits it or does it freely roll?

 

[steewith2ees]

I just don't have the mental capacity to work this out so I'm going to have to build a contraption so I can at least qualify my next wrong answer

EDIT - right the contraptions ready - paper aeroplane with button wheels.

Just need to wait for the gym to open tomorrow now so I can go chuck it at a treadmill.

 

[Don Luigi]

It should be able to take off. The movement of the conveyor belt doesn't matter because the plane is using the jet engines for propulsion, not the wheels.

NSFW:

I'd like to pretend that I figured that out myself but I saw it on a TV show.

 

[steewith2ees]

That's me satisfied then and saves some poor unsuspecting arse crack ending up with a paper dart in it while exercising.

Bed time at last....

 

[KingOfWessex]

I for one will not be getting on this plane.

 

[alasdairm]

The movement of the conveyor belt doesn't matter because the plane is using the jet engines for propulsion, not the wheels.

this.

alasdair

 

[Arnold]

I think a guy called Bernoulli and fubar might be right.