Lets see the BRAINS of RME

[Cherokeester]

Nice to motivate the brain, at least for me sitting at work becoming a vegatable.

 

[Tacoma]

I'm going with no.

 

[Herzog]

What if the conveyor has nothing to do with it.

I'm visualizing a stationary plane because of the conveyor matching the speed... but when you add in the thrust of a jet (now that I think about it) you end up pushing the plane forward no matter how fast the conveyor moves. Which would probably just burn up the tires and bearings in the plane but lets put that variable aside.

Rocket thrust is all about airspeed and not landspeed. I think I may have been wong. Still thinking.

 

[Greg]

What if the conveyor has nothing to do with it.

I'm visualizing a stationary plane because of the conveyor matching the speed... but when you add in the thrust of a jet (now that I think about it) you end up pushing the plane forward no matter how fast the conveyor moves. Which would probably just burn up the tires and bearings in the plane but lets put that variable aside.

Rocket thrust is all about airspeed and not landspeed. I think I may have been wong. Still thinking.

Add this to your thinking...

http://videos.streetfire.net/player.aspx?fileid=35E964D9-38DB-4EFD-BE8D-D6BA1A43A06B

I may have to change my mind, the wording of the question makes it pretty hard to define an answer.

 

[Herzog]

But it seems that there is an entire equation to fill in order to get a plane to fly. Air pressure, thrust, and speed to name a few. If you take out one of those, you may not fly...

 

[Herzog]

Add this to your thinking...

http://videos.streetfire.net/player.aspx?fileid=35E964D9-38DB-4EFD-BE8D-D6BA1A43A06B

I may have to change my mind, the wording of the question makes it pretty hard to define an answer.

Now that's what I'm visualizing. If he were to pull the "conveyor" at the same speed as the moving skateboard, it would never gain enough speed to create lift (if the skateboard were an airplane.)

 

[Cherokeester]

Video pretty much sums it up. The fan is doing the same job as a jet, skateboard moves forward, jet moves forward as normal and takes off.

 

[Spork]

Is it a harrier jet?

 

[Herzog]

Video pretty much sums it up. The fan is doing the same job as a jet, skateboard moves forward, jet moves forward as normal and takes off.

Not really, because for a split second he pulls as fast as the the thrust given from the fan and the skateboard stays stationary... but a human can't possibly synchronize a experiment well enough to have exact results. If it were a computer controlled conveyor capable of countering the amount of thrust a plane could put out, then it would stay stationary (in my mind...)

:sick:

edit:

 

[Cherokeester]

Not seeing the video that way, sorry. Looks to me my like the skateboard moves just as it would on stable ground.

 

[spencurai]

Of course it will take off. The wheels will just spin twice as fast. The jet engines are creating a thrust vector against the air, not the runway. The wheels will have more drag but I believe that it will eventually take off.

You guys that are saying no are thinking of creating thrust through the wheels.

Here are the factors in this equation...

The jets push against the air.

The air pushes back against the jet engines as best as it can but the jets ultimately win creating forward thrust.

The wheels now spin twice as fast as they normally would but there is still a positive forward thrust vector. the moving runway is almost irrelevant, almost but not entirely.

 

[ZUKEYPR]

NO, if they are moving at the same speed in opposite directions the plane is essentially standing still with the exception of it's wheels moving. Plane standing still = no air moving over and under the wings = no lift = no takeoff.

 

[Herzog]

I'm going to have to admit that I maybe wrong. The plane will probably take off because Airspeed != landspeed. The conveyor belt can even move faster than the plane (if permitted) and the plan will still likely take off.

My logic is likely flawed exactly how Spence described.

Example: Run on a treadmill... you stay in one spot if you match the speed. Now put a giant rocket in your arms with the outlet behind you and launch it. No matter how fast the treadmill goes (even if it were capable of going at such speeds) you would be thrust forward.

 

[Spork]

Since we aren't getting too far with the jet engines pushing the plane how about if we have a tug that is not on the conveyer belt pulling the plane what happens?

My thoughts:
The wheels move so the conveyer belt attempts to counter act the movement however since the plane is obviously going to move forward because it is pulled by the tug the belt and plane wheels will both approach infinity becuase the belt cannot counteract the effects of the tug.

 

[Herzog]

Brett - What's your take on it?

 

[Herzog]

Since we aren't getting too far with the jet engines pushing the plane how about if we have a tug that is not on the conveyer belt pulling the plane what happens?

My thoughts:
The wheels move so the conveyer belt attempts to counter act the movement however since the plane is obviously going to move forward because it is pulled by the tug the belt and plane wheels will both approach infinity becuase the belt cannot counteract the effects of the tug.

If it approaches infinity then the simple mechanics of the planes landing gear (tires, bearings, etc...) will fail and all will be lost.

 

[Milner]

A plane is standing on a runway that can move (some sort of band 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 opposite direction).

The question is:

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

If the plane has suffcient forward motion, it will take off, no matter the speed of what ever is under it. It is not driven by the wheels and will simply drive/fly of the belt when suffcient thrust is reached. Happens on aircraft carriers all the time. Even if the belt could be pulled down the runway to match the ground speed of plane, at some point the speed will be great enough to cause lift. Air moving under the wings will create lift. IF the plane is held in one place and not allowed any forward motion (by some contridicting force) (the belt has no force to counter act the thrust), no matter the thrust, then, no it will not fly! But the questions says the plane can move. therefore as thrust builds it will move forward faster and faster, no matter what is under it. Therefore it will move through air and create lift.

 

[CJJ92yj]

I think Spencurai hit it right on the nose. THe plane will be travelling forward due to the jet engine pusshing the plane, and not the wheels pushing the plane as would be in a car. The tire speed against stationary ground will be double due to the conveyor pushing in an opposite direction. The plane will eventually achieve enough speed versus stationary ground to achieve liftoff.

 

[Badcop]

I think Spencurai hit it right on the nose. THe plane will be travelling forward due to the jet engine pusshing the plane, and not the wheels pushing the plane as would be in a car. The tire speed against stationary ground will be double due to the conveyor pushing in an opposite direction. The plane will eventually achieve enough speed versus stationary ground to achieve liftoff.

3 pages later and I agree with those 2, if a train leaves new york at 9 and the same train leaves slc at 4, when will they collide in bolivia?

 

[Brett]

Brett - What's your take on it?

It takes off...like some have said, the wheels have nothing to do with the thrust generated by the planes engines......