[Total Heckler]

Imagine a plane is sat on the beginning of a massive conveyor belt/travelator type arrangement, as wide and as long as a runway, and intends to take off. The conveyer belt is designed to exactly match the speed of the wheels at any given time, moving in the opposite direction of rotation.
There is no wind.

Can the plane take off?

Explain why it can, or cannot, take off?

 

[bdamschen]

I got in a drunk argument with a few of my friends over this a while back. The only dude who was backing me up was a nasa scientist.

This was followed shortly by the "do you get more wet when you run from the car to the store in a rain storm or if you walk" argument.

 

[-BB-]

Yes, but I would think that it does slightly depend on the coefficient of friction in the wheels.b Mythbusters did it...

And is this a fashion runway?

 

[bdamschen]

Yes, but I would think that it does slightly depend on the coefficient of friction in the wheels.b Mythbusters did it...

That would have to be a LOT of friction or the brakes would need to be on for the plane not to take off.

 

[buildyourown]

Yes.
A fixed wing doesn't care what the wings or the ground is doing. The engines push the wings thru the air til there is enough lift, regardless of relative or actual ground speed.
See aircraft carrier.

 

[Whoops]

...planes engine doesn't drive the wheels, so wheel speed is irelevant.

Right?

edit - snap

 

[lovebunny]

people are retarded.ITS NOT A CAR!!!!!

 

[IH8Rice]

im glad one of the pilots got it

 

[stevew]

fvck asking stupid questions....offer them blow.

 

[ICEBALL585]

Smart people have way too much time on their hands!

 

[Mr Jones]

...planes engine doesn't drive the wheels, so wheel speed is irelevant.

yes. thrust is applied to the aircraft not the wheels so wheel speed is indeed irrelevant if the wheels are not used accelerate the aircraft.

 

[c101aviojet]

If engine thrust > (wheel + body) drag, it can.

 

[Straya]

This all seems a lot easier the second time around.

 

[I Are Baboon]

It's like watching Loco try to explain bicycle brakes to a customer.

 

[HardtailHack]

If you left the brakes on you'd take off when you run out of treadmill.

 

[MMike]

I have insufficient palm to apply to my face for this thread.

 

[Pesqueeb]

I have insufficient palm to apply to my face for this thread.

Shut up Mr. Whirlybird.

 

[SkaredShtles]

fvck asking stupid questions....offer them blow.

You, sir, are a genius amongst retards.

 

[-BB-]

That would have to be a LOT of friction or the brakes would need to be on for the plane not to take off.

Certainly... Just pointing out that there is another variable in there to consider.
For example if it had monster truck wheels and used the bearings off my bike (they are real "crunchy" right now)

 

[rockofullr]

The situation which is described can not occur. You silly question is silly and invalid. You may as well ask "what if, marmosets?".

If the plane starts it's engines and the trust begins to move it forward the wheels and the conveyor belt will accelerate to an infinite velocity.

Why?

Thrust (if sufficient) will move the plane forward with no regard to the state of the wheels or conveyor belt. Therefore the velocity of the wheels is:

(Vel Wheels) = (Vel Plane) + (Vel Conveyor)

According to the question the conveyor belt will accelerate to match the wheel speed meaning:

(Vel Conveyor) = (Vel Plane) + (Vel Conveyor)

The plane is still going to move forward due to the thrust so now:

(Vel Wheels) = (Vel Plane) + [ 2 x (Vel Conveyor)]

Within a few moments the wheels and conveyor would be accelerating out of controls and when they reach the speed of light they would probably be transported into an alternate reality where internet forum geeks rule the world with jonKranked as their eternal overlord.

 

[CrabJoe StretchPants]

The situation which is described can not occur. You silly question is silly and invalid. You may as well ask "what if, marmosets?".

If the plane starts it's engines and the trust begins to move it forward the wheels and the conveyor belt will accelerate to an infinite velocity.

Why?

Thrust (if sufficient) will move the plane forward with no regard to the state of the wheels or conveyor belt. Therefore the velocity of the wheels is:

(Vel Wheels) = (Vel Plane) + (Vel Conveyor)

According to the question the conveyor belt will accelerate to match the wheel speed meaning:

(Vel Conveyor) = (Vel Plane) + (Vel Conveyor)

The plane is still going to move forward due to the thrust so now:

(Vel Wheels) = (Vel Plane) + [ 2 x (Vel Conveyor)]

 

[bean]

The situation which is described can not occur. You silly question is silly and invalid. You may as well ask "what if, marmosets?".

If the plane starts it's engines and the trust begins to move it forward the wheels and the conveyor belt will accelerate to an infinite velocity.

Why?

Thrust (if sufficient) will move the plane forward with no regard to the state of the wheels or conveyor belt. Therefore the velocity of the wheels is:

(Vel Wheels) = (Vel Plane) + (Vel Conveyor)

According to the question the conveyor belt will accelerate to match the wheel speed meaning:

(Vel Conveyor) = (Vel Plane) + (Vel Conveyor)

The plane is still going to move forward due to the thrust so now:

(Vel Wheels) = (Vel Plane) + [ 2 x (Vel Conveyor)]

Within a few moments the wheels and conveyor would be accelerating out of controls and when they reach the speed of light they would probably be transported into an alternate reality where internet forum geeks rule the world with jonKranked as their eternal overlord.

I was thinking about posting roughly the same thing.

 

[Mr Jones]

The situation which is described can not occur. You silly question is silly and invalid. You may as well ask "what if, marmosets?".

If the plane starts it's engines and the trust begins to move it forward the wheels and the conveyor belt will accelerate to an infinite velocity.

Why?

Thrust (if sufficient) will move the plane forward with no regard to the state of the wheels or conveyor belt. Therefore the velocity of the wheels is:

(Vel Wheels) = (Vel Plane) + (Vel Conveyor)

According to the question the conveyor belt will accelerate to match the wheel speed meaning:

(Vel Conveyor) = (Vel Plane) + (Vel Conveyor)

The plane is still going to move forward due to the thrust so now:

(Vel Wheels) = (Vel Plane) + [ 2 x (Vel Conveyor)]

by (Vel Wheels), do you mean rotational velocity or linear velocity?

 

[Mr Jones]

Rotational velocity can go to infinity for all I care and is irrelevant in this case because linear velocity is required for the fixed wing to take off. Linear velocity in this case is provided by the propulsion system (propeller or turbine).

 

[rockofullr]

by (Vel Wheels), do you mean rotational velocity or linear velocity?

Tangential linear velocity at the contact point between wheels and conveyor belt.

Rotational velocity can go to infinity for all I care and is irrelevant in this case because linear velocity is required for the fixed wing to take off. Linear velocity in this case is provided by the propulsion system (propeller or turbine).

I'm just making a point. Some guy out there thinks he is really smart because he made up this question then laughed and said "How stupid!" when people got it wrong.

The situation proposed is impossible and nonsensical. So whoever came up with the question failed to think it out all the way making them the same as the booth girls... stoooopid.

 

[Mr Jones]

Tangential linear velocity at the contact point between wheels and conveyor belt.



I'm just making a point. Some guy out there thinks he is really smart because he made up this question then laughed and said "How stupid!" when people got it wrong.

The situation proposed is impossible and nonsensical. So whoever came up with the question failed to think it out all the way making them the same as the booth girls... stoooopid.

I agree... but isn't this FUN! I've wasted a whole hour of work arguing with my co workers that the plane will take off. We even took it to the white board. My morning zoomed by so fast!

 

[rockofullr]

I agree... but isn't this FUN! I've wasted a whole hour of work arguing with my co workers that the plane will take off. We even took it to the white board. My morning zoomed by so fast!

Whatever floats your plane

 

[lovebunny]

Tangential linear velocity at the contact point between wheels and conveyor belt.



I'm just making a point. Some guy out there thinks he is really smart because he made up this question then laughed and said "How stupid!" when people got it wrong.

The situation proposed is impossible and nonsensical. So whoever came up with the question failed to think it out all the way making them the same as the booth girls... stoooopid.

alot of flight schools use it on the first day of ground school to present the principals of flight. ive also seen pilots use it as a way to show people how airplanes work. it was probably thought up by some flight instructor years ago and was never meant to get that in depth im sure.

 

[SkaredShtles]

So while you jeenyuses are arguing over the airplane $hit stevew is in a 3-way with the booth babes.