Will it take off?

[TraceZ]

I'd say we have beat this horse to death. 117 beatings so far.

the horse was gone a long time ago. There is just a pile up dust and bone fragments where there was once a dead horse.

[Joe 1320]

the horse was gone a long time ago. There is just a pile up dust and bone fragments where there was once a dead horse.

I close my eyes......... only for a moment and the moment's gone.........


Dust my friends.......

[fastTa]

The scale changes nothing. As the airplane gets larger, so do all the forces including the thrust of the engine(s). The proportions remain unchaged for the most part. I recall the last time I flew on a large passenger jet being very impressed with the force that was pushing me back into my seat when we lifted off.

When a 747 taxis, it uses a very minimal amount of throttle. The engines barely have to even try to move that large airplane across the ground... it is nearly effortless for them.

No offense, but now I understand clearly the source of your vast confusion. Still luv ya man!

I thought about this even more and here is the deal. It will ALL depend on the mass and most importantly the weight of the said aircraft. The lighter the aircraft the more it is a plausible event. The heavier the plane, and more importantly when approaching the size of a commercial aircraft, this becomes staggeringly less plausible.

[fastTa]

Agreed....poor horse is 6 feet under.

[Sean 94z28]

I'll make my final comments too.

The only way to keep the plane from flying in the system described would violate the original statement. That is why it is illogical.

The only way to keep the plane grounded against the thrust of the engines is with zero wheel speed. Any tire rotation at all means that the air speed and conveyor speed are not the same (violation).

There is some amount of force (very small compared to the engines capability) required to start a still plane moving. Once the wheels move, "free-wheeling begins" and any acceleration by the conveyor only spins the wheels faster and has virtually zero effect on the forward momentum fo the plane. Unfortunately, zero wheel speed from the observer means the plane is traveling backwards on the conveyor and therefore has a negative airspeed. Meaning the conveyor speed (or wheel speed) is not equal to plane speed. This violates the question parameters.

Here is another real problem I see. Think about the table cloth magic trick. Slow-pieces don't move, fast-everything stays in place. Airplane engines generate so much forward thrust, that a conveyor accelerating that quickly (even with a motionless plane) would start the wheels turning. There is an acceleration limit where the wheels will start to spin, instead of the plane moving.

The parameters of the question can never logically be met and any attempt to do so (ie. Mythbusters) will definately result in a flying plane. I am 100% sure of this. No conveyor system could ever stop the wheels from turning against the planes opposing thrust. If you could ever build such a theoretical system, the planes speed would not be equal to the conveyor speed.

I just brought the horse back to life, didn't I. hehehe

[Joe 1320]

I just brought the horse back to life, didn't I. hehehe

Wadda ya think guys? Let's put his post count back to 10.

[wolfdogs]

i have 3 golden retrievers and a wolfdog...........................

[Trans Am]

Ok, so this is going around the 'net. HUGE threads of people arguing back and forth...




The question is:

Will the plane take off or not? Will it be able to run up and take off?


The plane WILL take off. The wheels do not affect the thrust of the airplane, they just support it. People cant seem to grasp the concept that they are free rotating wheels and this is not a wind tunnel we are talking about.

it wont take off

[Trans Am]

lol

[thomas]

Its simple.. Theres no air moving over the wings so theres no lift so the plane does not fly..

[Jeff_in_Atl]

Its simple.. Theres no air moving over the wings so theres no lift so the plane does not fly..

The question says the plane "moves" in one direction. If it moves, there will be air flowing under and over the wing.

[bru333]

The question says the plane "moves" in one direction. If it moves, there will be air flowing under and over the wing.

and the plane has to be moving forward through the air mass or the wheels would not turn.

[thomas]

unless I read it wrong(probably did) The plane is really stationary. The only thing really moving is the belt that the planes on. right?


Let me go read it again, this time slowly

[Dave M]

unless I read it wrong(probably did) The plane is really stationary. The only thing really moving is the belt that the planes on. right?


Let me go read it again, this time slowly

you read it right, but you're forgetting, like I did at first, that the wheels spin freely and are not connected in any way to the acceleration of the plane. If the conveyor started moving under the plane by itself, the plane wouldn't move backwards, it would stay staionary while the wheels spun bacwards. Now apply thrust from the engines and the plane moves forward, just like it always would because the wheels play no part in moving the plane forward and bakward. Thrust from the engine moves the plane, regardless of what te ground or wheels are doing. The plane would move forward and fly like always.

[Sean 94z28]

unless I read it wrong(probably did) The plane is really stationary. The only thing really moving is the belt that the planes on. right?

Well if that is the case, then the plane and belt are not moving at the same speed. The plane is standing still and the belt is moving X. The problem states that their speed is exactly the same. They can never move the same "speed". If either is moving (plane or belt), then the other is either preceeding it or catching up.