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Lets see the BRAINS of RME

notajeep

notajeep

Just me
Location
Logan
Yes it will take off because the conveyer is only affecting the wheels. the wheels are not in any way connected to the jet engines. this situation would cause the wheel speed to be twice that of a normal jet take off... but other wise have no real affect in the take off, other than to make it roll. There are 2 different things happening here and one will not effect the other. the Jet engines effect the incoming and outgoing air causing the thrust and has nothing to do with the wheels.
 
fattodog

fattodog

frame cracks= More flex!!
Location
Roy, Utah
Badcop said:
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?
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Kinda reminds me of this one; "three people walk into a bar third one ducks!"
:rolleyes:
KENNETH !!
 
CJJ92yj

CJJ92yj

Registered User
Location
Kearnsville
Brett said:
...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?
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First off, it clearly states that the plane moves.

Secondly, the conveyor matches the speed of the plane, not the speed of the air aft the propellor or jet engine.

Thirdly, Newtons law states that for every action, there is an equal and opposite reaction. Rearward thrust = forward movement.

The plane engine pushes against the air, creating forward thrust. The wheels act only as an "idler" type of support. The speed of the wheel is irrelavent. The plane will achieve liftoff almost identically as if it were on stationary ground. The only difference will be a slightly longer time to achieve liftoff airspeed due to the added friction/drag in the wheel bearings. However, a plane gradually loses that friction with more airspeed because of the added lift and resulting loss of weight on the tires to cause said friction. If you were in this plane, you would not be able to notice this slight difference.

Now, it is possible that the tires would shred themselves apart ater achieving such landspeed. If this is the case, you better start praying for a soft landing!
 
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CJJ92yj

CJJ92yj

Registered User
Location
Kearnsville
dang, the more I think about it, it is possible a conveyor would only add to the lift of the plane. Certainly a conveyor moving at th ose speeds would ahve a small amount of turbulence caused by the tread moving through the air in the opposite direction of the plane.
 
reddevil

reddevil

'93 Cherokee
Location
Springville
So if I could breath in thru my mouth, and out my butt.... I could run faster on a tread mill.
Thats what I got out of the last four pages.;>
 
CJJ92yj

CJJ92yj

Registered User
Location
Kearnsville
It's all simply a matter of reading the question in the form in which it was posed. Stop trying to read into it. No need to. The answer is in the question.
 
M

mowlasley

Registered User
Location
Provo, UT
I would posit that forward motion makes no difference. The key to flight is the differential between the speed of the air and the speed of the wing. I have seen planes tethered on the runway in Provo hover above the ground. This happens whenever the wind blows across the wing at a higher speed than the stall speed.

In this case, with the conveyor, the wheels of the plane freewheel, making the conveyor irrelevant. The thrust from the engines is enough to make the plane move forward, causing the wings' speed to be fast enough that the wings don't stall (assuming the plane can fly in normal conditions, i.e. the engines have enough thrust to overcome the wings' stall speed).

Edit: No, I am not an aerospace engineer, but I did sleep at a Holiday Inn Express last night.
 
way2nosty

way2nosty

Registered User
That would depend on variables outside the scope of the quesiton. In case A attributing the lack of any outside influence then - no, the plane couldn't take off, I'll submit as evidence of my point the prinicipal of flow vs volume and volume vs velocity. It isn't really the "flow" of air over or under the wing that produces lift, it is the differential of the velocity of the wind over the wing vs the velocity of the wind under the wing. for you Physicists out there yes... air has mass so it may have velocity. If we examine the process that an aircraft follows to acheive lift, the first part is "acheivieng sufficient velocity to produce enough lift to overcome the weight of the aircraft and its coefficient of drag."

In Case B - Thinking outside the perverbial box, then We assume that the plane isn't in a vacuum and that the potential for there being sufficient outside influencs to create sufficient velocity to create lift

...
 
DevinB

DevinB

I like traffic lights
Location
Down Or'm
fattodog said:
If it were an African plane, it could grip it by the husks!! :D

KENNETH !!
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It's not a question of where it grips it, it's a simple question of weight ratio! A five ounce bird cannot carry a one pound coconut!

Suppose two swallows carried it together?


ZUKEYPR said:
I just want to know how many pairs.......not species, but pairs of animals Moses put on the ark?
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One? :greg:
 
M

Meat_

Banned
Location
Lehi
Herzog said:
is it an unladen plane or is it carrying a coconut?
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:rofl:

Herzog said:
Even with the thrust of the engine, the conveyor counters out any forward movement. With out air creating a high/low pressure (because of the wing design) you get no lift, there for it won't take off. The jet engines sole existence is to create forward thrust.
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The plane isn't driven by the wheels, they are free to move as fast as physically possible. Think of a winch in freespool, it doesn't matter how fast you pull the cable out, it's not going to move the jeep ;)

The engines are pushing on the air, the conveyor is not moving the air (and even if it was, that would make the plane take off even faster). Saying the plane can't take off because the ground is moving is like saying a car can't drive because the wind is blowing.
skylinerider said:
Why are you guys assuming it's a jet? It says nowhere in the question that it is a jet. Not that it matters anyway.
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I didn't ;) Props create thrust as well.
 
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