hmmm.... physics question for you guys....

[Number Of The Priest]

Re: hmmm.... physics question for you guys....

Yeah, I stopped reading after the first page because it was virtually identical to our forum. [img]/images/graemlins/laugh.gif[/img]

[RobRR]

Re: hmmm.... physics question for you guys....

I have a head ache. [img]/images/graemlins/laugh.gif[/img]

[Newc]

Re: hmmm.... physics question for you guys....

In the event the conveyor in question was as long and wide as a runway, then there exists the possibilty that the motion of the conveyor belt will generate enough airflow towards the plane to cause it to lift, as large/wide/flat objects in motion do produce a noticeable wind force in the direction they travel.

However, in the event the conveyor was only as long and wide as the plane in question, or the conveyor system covered only the wheels, then the conveyor could not generate enough air pressure under the wings/flaps to cause it to lift.

However, the benefit of a runway-length conveyor that could generate enough airflow to gain lift certainly has its advantages - you could line up 30 planes end to end and just let them pop up and go where they wish from a relative standstill, but don't give the FAA any ideas [img]/images/graemlins/laugh.gif[/img]

[VinceV]

Re: hmmm.... physics question for you guys....

[ QUOTE ]
Yeah, I stopped reading after the first page because it was virtually identical to our forum. [img]/images/graemlins/laugh.gif[/img]

[/ QUOTE ]

With that, I will stop posting in this thread. As I can see where it is going to go forever.

I will say that this idea at some point has to have been experimented with. It either did not work, or has no practical applications. Might just be cheaper and easier to build long ass runways.

Until we find out it will probably still be a split group.

It was fun, and I was suprised that almost everyone kept there cool. [img]/images/graemlins/laugh.gif[/img]

[Cleveland Metal]

Re: hmmm.... physics question for you guys....

Our silly military and their silly aircraft carriers...

they could just have floating conveyor belts and planes would magically lift off of them...

You guys are high...

[RobRR]

Re: hmmm.... physics question for you guys....

We arent saying they would lift off of the conveyor, they would travel down the conveyor the same as it would a stationary runway. I think alot of people are misinterpreting this question. Answer this for me correctly then Ill drop the whole discussion.

Answer me this question people, then Im done. What force is stopping the plane from physically moving forward on the conveyor runway? What is physically not allowing the plane to move forward at a high enough air speed to achieve lift?

[Newc]

Re: hmmm.... physics question for you guys....

Probably the notion that the engines are not angled even in the slightest, thus pushing against the solid ground, but rather face straight level out the back of the plane, serving instead to push the plane across the ground until the airflow across the wings is high enough to cause lift.

Assuming the engines are straight/parallel to the ground and have a zero degree angle, only serving to push the plane forward across the ground and not trying to push the plane into the air, and the wheels are on the aforementioned automatic-speed-matching conveyor, then the plane cannot travel forward fast enough to lift from the conveyor.

Remember, no matter how fast the plane moves, the conveyor moves at the same speed in reverse. There is no "IF the plane exceeds the speed of the conveyor" or "IF the headwind is above 110kts" or "IF you get out and push".

[RobRR]

Re: hmmm.... physics question for you guys....

Um, engines dont make a plane fly, lift is generated by air traveling across the leading and trailing edge of the wings. Engines only move the plane forward to achieve that lift via wind speed. You obvously have no aeronautical knowledge, therefore I will not comment or reply to any more of your posts, as your opinion on this matter is apparently null and void.

NEXT? Can anyone answer my question?

[MetalGrasshopper]

Re: hmmm.... physics question for you guys....

[ QUOTE ]
We arent saying they would lift off of the conveyor, they would travel down the conveyor the same as it would a stationary runway. I think alot of people are misinterpreting this question. Answer this for me correctly then Ill drop the whole discussion.

Answer me this question people, then Im done. What force is stopping the plane from physically moving forward on the conveyor runway? What is physically not allowing the plane to move forward at a high enough air speed to achieve lift?

[/ QUOTE ]

There's no force keeping the plane from moving forward. However, since the ground is moving in the opposite direction in the same speed, the plane's net speed relative to the ground is zero. Since there isn't any net speed (the plane remains stationary), there would be no lift to cause the plane to move up (unless there were a huge gust of wind acting on the wings). It would be like a plane whose tires have no force of friction to produce the reactive force that propels the tires/plane forward. I'm not sure if that's the question, but it's my take on it.

[ApeDosMil]

Re: hmmm.... physics question for you guys....

The answer is 2^12031231231231231231232133233

[hippietim]

Re: hmmm.... physics question for you guys....

Denny Crane.

[diablomozart]

Re: hmmm.... physics question for you guys....

i think the key factor when discussing this (and im sorry i missed out on this one earlier) is that the wheels of the plane are not attached to a transmission...therefore...since they move freely....the plane would sit still even without the jets running...if the conveyor was moving...the jets however push against the air in the back of the plane insinuating forward movement...therefore if the converyor is going 100 mph and the planes thrust is moving at 100 mph the wheels in effect would be moving at twice the speed...hence 200 mph...the stickler is this...does the plane have to have drag against the ground or will the drag against the air in front of it compensate for the lack of drag on the ground...this could be a very interesting experiment...but somehow i see the plane building up enoughdrag to leave the conveyor and when it does...oh boy is there gonna be a speed jump there...lol...god i am rambling...d.m.

[LouSiffer]

Re: hmmm.... physics question for you guys....

Now that I am back, lets see if I can straighten this out. Originally, I said it would not accelerate. I was wrong. It will accelerate and here is why:

The wheels on the plane are neutral, and other than the basic friction that is caused by the weight of the plane onto the bearings of the wheel, they do not have any effect.

Earlier, I stated that thrust is created by the turbine that increases the atmospheric pressure at the nozzle and uses this to "push" off the air behind the engine. A car requires the wheels to be "pushing" off the ground.

If a conveyor pointed south moving at 100 MPH existed and a plane pointed north with its engines set at 100MPH, it will move forward as the air behind the jet is not moving with the conveyor ( assuming it is not hurricane season ).

The wheels will spin at 200 MPH once the plane reaches its 100MPH velocity. This is the 100 MPH of the plane plus the 100 MPH of the conveyor.

Again, this is all the result of the plane pushing off the air behind it and not having to overcome the speed of the conveyer to make up ground. It doesn't need to....remember, the wheels are a neutral part of the equation. If the conveyor was moving in the same direction, the plane would not reach 200 MPH, it would still only hit 100 MPH. The wheels just wouldn't spin at all. I know it is hard to imagine, but, its true.-Lou

[diablomozart]

Re: hmmm.... physics question for you guys....

you explained it better than i did...lol...d.m.

[MetalGrasshopper]

Re: hmmm.... physics question for you guys....

[ QUOTE ]
Now that I am back, lets see if I can straighten this out. Originally, I said it would not accelerate. I was wrong. It will accelerate and here is why:

The wheels on the plane are neutral, and other than the basic friction that is caused by the weight of the plane onto the bearings of the wheel, they do not have any effect.

Earlier, I stated that thrust is created by the turbine that increases the atmospheric pressure at the nozzle and uses this to "push" off the air behind the engine. A car requires the wheels to be "pushing" off the ground.

If a conveyor pointed south moving at 100 MPH existed and a plane pointed north with its engines set at 100MPH, it will move forward as the air behind the jet is not moving with the conveyor ( assuming it is not hurricane season ).

The wheels will spin at 200 MPH once the plane reaches its 100MPH velocity. This is the 100 MPH of the plane plus the 100 MPH of the conveyor.

Again, this is all the result of the plane pushing off the air behind it and not having to overcome the speed of the conveyer to make up ground. It doesn't need to....remember, the wheels are a neutral part of the equation. If the conveyor was moving in the same direction, the plane would not reach 200 MPH, it would still only hit 100 MPH. The wheels just wouldn't spin at all. I know it is hard to imagine, but, its true.-Lou

[/ QUOTE ]

Wow...I feel pwnd. Nicely done dude.