Something to ponder... and I don't know the right answer

[Spikeroo]

I'm still not buying it.  Anyone have a jet and a coveyor belt we can borrow?

The air through the engines/turbines is moving, obviously, but this air isn't the air that causes the lift.  The engine moves the plane - the plane moving through the air causes the lift.  The plane can't move, because the conveyer is preventing it.

Enough said from me.  I find these types of posts annoying.  Flint - wtf is wrong with you!!!!!!

 

[Kaneda]

Guys...Cole has spoken.

He retracrted his earlier statement, and now says the plane will fly.

Hah. So, that has to be the answer, cus, Cole is smart (or at least sounds like it).

The plane will fly.



Besides Dropkick, Nighttrain, Cole and, Hey, me.




Some Smart dudes right there (well, maybe except for me.)

Omg... can we please recognize Kaneda... I recall him being the first one to disagree with everyone else 

[Mathius007]

Guys...Cole has spoken.

He retracrted his earlier statement, and now says the plane will fly.

Hah. So, that has to be the answer, cus, Cole is smart (or at least sounds like it).

The plane will fly.



Besides Dropkick, Nighttrain, Cole and, Hey, me.




Some Smart dudes right there (well, maybe except for me.)

Omg... can we please recognize Kaneda... I recall him being the first one to disagree with everyone else 

AND KANEDA TOO!!!!

[Cole]

The air through the engines/turbines is moving, obviously, but this air isn't the air that causes the lift. The engine moves the plane - the plane moving through the air causes the lift. The plane can't move, because the conveyer is preventing it.

 

That's just it!  The conveyer is not doing that.  it could, but since the wheels are not transfering power i.e. work to the plane, having the conveyor match the speed of the plane is not enough.  The conveyor could concievably stop the plane from moving, but it would have to move much much faster than the plane.

And the air is the same air. 

Oh, and kaneda - no recognition, cause you didn't explain yourself very well.  ;P

[Spikeroo]

I guess we can get rid of runways for takeoffs then.  Don't think so - only the Harrier uses it's engines for initial lift at takeoff.

Here's a lesson for you (http://www.aeromuseum.org/Education/Lessons/HowPlaneFly/HowPlaneFly.html):

"The four aerodynamic forces that act upon an airplane in flight are lift (the upward acting force), weight (or gravity, the downward acting force), thrust (the forward acting force), and drag (the air resistance or backward acting force). These four forces are continuously battling each other while an airplane is in flight.

Gravity opposes lift, thrust opposes drag. In order to take off, the aircraft's thrust and lift must be suffucient to overcome its weight and drag. In level flight at constant speed, thrust exactly equals drag and lift exactly equals the pull of gravity. To land, an aircraft's thrust must be reduced safely below its drag, as its lift is reduced to levels less than its weight.

Lift is the aerodynamic force that counteracts gravity and holds an airplane in the air. Most of the lift required by an airplane is created by its wings, but a certain portion is also generated by other parts of the aircraft, such as the fuselage.

Thrust is the force created by a power source that overcomes the airplane's aerodynamic drag (its resistance to passing through the air) and gives it forward motion. This force can either "pull" or "push" the aircraft forward, depending on the type of power source used. Common types include reciprocating (piston-powered) engines driving propellers, and jet engines."

The air is not the same - I love to say it - you are wrong.  The air that the engine acts on, via thrust, overcomes drag.  The air moving over/under the wing creates lift and overcomes gravity.

Updated - You, know, I'm starting to think the plane will fly...after some serious thought - I may actually buy into the fact that all that the conveyor does is make the wheels spin twice as fast.  Better have some damn good bearings.  But, I'm still right about the air Cole...

 

[Kaneda]

I'm bringing this up in my physics class tomorrow. My teachers pretty $$... so we'll see what he has to say

[Cole]

spike about the air.  When i said that the air is the same, I mean the body of air that the plane is occupying.  I know how a plane flys.   and what you said about the drag, the conveyor is creating a minimal amount of extra drag.  The amount translated into the plane would have to depend on the coeff. of friction of the bearings and tires, and size and mass of the tires, etc.

an engine will not fly without a wing, so i now get what you were saying about the air not being the same.  What I was refering to was that the air that ineracts with the wing and the air that interact with the engine is in the same inertial frame.

So basically this question doesn't really give enough information.  But, if assumptions of a normal plane are made it will take off.  If the bearings and tires can create enough drag to keep the plane from going to takeoff speed when the conveyor matches the planes speed .... yada yada yada.

[Kaneda]

Yea physics teacher said the plane will move forward regardless of the wheels. Wheels are just used to reduce friction, jet engines are what create the acceleration. So... it'll move forward, therefore fly, as I said...


i still win

[flintlock]

This thread is so damn funny. I think we need to make it a sticky so all of our visitors can see how leet our Engineers are. For all you guys that are too lazy to read a four page thread you should make an exception on this one.

Cobra has my favorite reply in the history of the clan.

i eat clay 

Cole, the smiley plane is pretty cool too, but I have to go with Cobra.

But my question is this...without all the math beacuse I don't know jack about that.

Can we get away with... max thrust (MT) minus max weight (MW) minus max drag (MD) would equal max speed (MS)?

So for this example we can say MT - MW - MD = 350 mph (MS) because we are talking about speed which is the result of everything else adding, subtracting, coefficienting and whatever.

If the belt can match 350 mph, however many rotations of the tires and belt it takes, (You can't even measure the belt in terms of speed anyway can you? it would be like RPMs or something) wouldn't that keep the plane on the ground? I still think the question is flawed.

Oh yeah and to everyone that got sucked into reading this, you're welcome!

[Mathius007]

Ok.


So...the plane fly's

[WolbEm]

Whats important to note here is that I was right, and that Cole was wrong.   (Kaneda, srry dude, but I get all the props.. 1. becuase Im an owner, 2. you only quesitoned old King Cole.. I kicked his ass.)

I AM KING OF THE MOUNTAIN, BITCH!!!!!

[Cole]

yeah, you you probably cheated by using google!  I challenge thee to a probability problem!

[Paladin_Godfather]

its funny cause all of that doesnt matter if you attach the engine of a Harrier jer onto that 747..... cause it would take off straight up...

I decree spike the winner of the battle of wits... cause he was the first to mention it...

there.... thats logic....

[Cole]

paladin just officially made this post completely retarded with his presence.

[WolbEm]

its funny cause all of that doesnt matter if you attach the engine of a Harrier jer onto that 747..... cause it would take off straight up...
I

Paladin, Dont make me thrash you too...  747 is much heavier than a Harrier. Would never work.

Cole, that was a high school problem, there was no need to google what was so plainly obvious.  hell, even kaneda got it.  

So, what are the stakes on this probability problem?  I promise not to use the internet... which means, neither can you.

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