Plane on a treadmill

[Ho3n3r]

The treadmill can do a million km/h. It won't make a difference.

Ninja'd.

And I'm embarrassed to have argued the opposite earlier. It's so logical.

 

[BandwidthAddict]

You're not seeing the difference between your legs and the planes engines.

He's not understanding the difference between legs and free-wheeling wheels.

Legs cannot compensate for increased speed without the animal exerting effort to move them faster and then only up to a fixed limit. Free-wheeling wheels do not have an upper limit so can just move faster to ignore the effect of the treadmill.

 

[nakedpeanut]

Dude..

FREE SPINNING WHEELS!!!
The wheels will speed up proportionally and thus match the delta of the planes velocity and that of the treadmill!!

Stationary
Plane = 0 m/s
Treadmill = -50m/s
----------------------
Wheels = 50m/s

Plane moving
Plane = 50m/s
Treadmill = -50m/s
----------------------
Wheels = 100m/s


(using negative to show direction)

But no one said this imaginary treadmill has a speed limit it could just increase and match the plane the whole time because it's an imaginary treadmill. People are bringing in a treadmill with a certain speed now because they know they're stupid.

 

[rietrot]

But no one said this imaginary treadmill has a speed limit it could just increase and match the plane the whole time because it's an imaginary treadmill. People are bringing in a treadmill with a certain speed now because they know they're stupid.

It doesn't matter how fast the treadmill rotates the weels of the plane will just go faster. The treadmill won't brake the forward motion of the plane.

 

[bwana]

But no one said this imaginary treadmill has a speed limit it could just increase and match the plane the whole time because it's an imaginary treadmill. People are bringing in a treadmill with a certain speed now because they know they're stupid.

There is no [-]spoon[/-] treadmill…

 

[Kerrits]

Hang on, people who say that the plane won't fly, how do you picture the setup?

The way I see it, the runway is replaced by a crazy long treadmill, and the jet uses its engines to propel the plane forward. Then it's obvious that the plane can take off.

 

[Vegeta]

Hang on, people who say that the plane won't fly, how do you picture the setup?

The way I see it, the runway is replaced by a crazy long treadmill, and the jet uses its engines to propel the plane forward. Then it's obvious that the plane can take off.

Yes! because then the plane will actually move along the long treadmill.

Ag guys its all about lift, lift needs to be greater than weight. A plane will take off even without an engine if enough lift is generated.
A giant fan will lift a plane even if the plane has no engine at all. Airspeed being the crucial factor. For that you need air(wind) or movement. It really has NOTHING NOTHING NOTHING to do with the god dam treadmill!!! If you have a perfect treadmill that keeps the plane still in a windless room the plane is going to stay in one place, if you have a different idea of this setup then sure in your setup it might fly but again the bloody treadmill has nothing to do with it!

 

[Sinbad]

Yes! because then the plane will actually move along the long treadmill.

Ag guys its all about lift, lift needs to be greater than weight. A plane will take off even without an engine if enough lift is generated.
A giant fan will lift a plane even if the plane has no engine at all. Airspeed being the being the crucial factor. For that you need air(wind) or movement. It really has NOTHING NOTHING NOTHING to do with the god dam treadmill!!!

So, given the original scenario, you agree that the treadmill will not stop the plane taking off.

 

[FNfal]

Explain how the treadmill stops the plane moving.
Make reference to newton's laws, and the principles of friction.

Just woke up , heavy night out , not going to happen even got the low pressure wrong . :erm:

 

[LazyLion]

But no one said this imaginary treadmill has a speed limit it could just increase and match the plane the whole time because it's an imaginary treadmill. People are bringing in a treadmill with a certain speed now because they know they're stupid.

The treadmill was just introduced into the scenario to see if people actually understand how planes really work.
It doesn't matter what speed the treadmill runs at - it could be 1 million kms and the wheels of the plane would also turn at that speed.
But it's only when the plane turns on it's engines that it begins to roll forward and eventually take off.
BECAUSE THAT'S HOW PLANES WORK.

 

[FNfal]

http://hyperphysics.phy-astr.gsu.edu/hbase/fluids/airfoil.html

"Bernoulli or Newton's Laws for Lift?

Which is best for describing how aircraft get the needed lift to fly? Bernoulli's equation or Newton's laws and conservation of momentum? This has been an extremely active debate among those who love flying and are involved in the field. If the question is "Which is physically correct?" then the answer is clear -- both are correct. Both are based on valid principles of physics. The Bernoulli equation is simply a statement of the principle of conservation of energy in fluids. Conservation of momentum and Newton's 3rd law are equally valid as foundation principles of nature - we do not see them violated. This physical validity will undoubtedly not quell the debate, and this treatment will not settle it. But perhaps it can at least indicate the lines of the discussion."

 

[Cray]

Just woke up , heavy night out , not going to happen even got the low pressure wrong . :erm:

So explain it, how does the treadmill cancel out the thrust of the engines? And while you are at it, explain how seaplanes can take off from a liquid surface.

 

[Vegeta]

But it's only when the plane turns on it's engines that it begins to roll forward and eventually take off.
BECAUSE THAT'S HOW PLANES WORK.

But then I suppose we're all saying the same thing in contorted ways. The plane needs to move through air or air needs to move over & under it's wings the engines nor the treadmill has anything to do with it as I explained earlier.

 

[Cray]

But then I suppose we're all saying the same thing in contorted ways. The plane needs to move through air or air needs to move over & under it's wings the engines nor the treadmill has anything to do with it as I explained earlier.

Air moving over the wings generates lift, the engines develop thrust to create the forward motion of the plane through the air.

 

[Alton Turner Blackwood]

Planes need to generate lift around the wings before it will be able to climb, for lift you need wind. If the plane remains stationary relative to the ground on a windstill day, it won't be able to takeoff.

This is the reason why planes takeoff into the wind.

Not only does it need to be faster than the wind in the opposite direction, it needs to be a lot faster to generate enough lift around the wings to rotate - I'm assuming this is a commercial passenger plane.

 

[Ho3n3r]

But then I suppose we're all saying the same thing in contorted ways. The plane needs to move through air or air needs to move over & under it's wings the engines nor the treadmill has anything to do with it as I explained earlier.

But the treadmill is the whole premise of the argument. Without it, we'd have a plane on a runway.

 

[LazyLion]

But then I suppose we're all saying the same thing in contorted ways. The plane needs to move through air or air needs to move over & under it's wings the engines nor the treadmill has anything to do with it as I explained earlier.

Nope, you still don't understand. You need the engines to create THRUST. The THRUST is what draws the air over the wings.

 

[Cray]

Planes need to generate lift around the wings before it will be able to climb, for lift you need wind. If the plane remains stationary relative to the ground on a windstill day, it won't be able to takeoff.
.

*If* the plane remains stationary relative to the air then no lift is generated and the aircraft remains on the ground. However, the treadmill does not in any way counter the thrust of the engines which act to move the plane forward.

 

[FNfal]

So explain it, how does the treadmill cancel out the thrust of the engines? And while you are at it, explain how seaplanes can take off from a liquid surface.

There is cancelling out of the thrust, the treadmill will exert force same as the engine will exert force , assuming the force is the same .
You will not achieve flight unless you have enough air flowing over the wings to achieve flight , solid or liquid ..

 

[Sinbad]

There is cancelling out of the thrust, the treadmill will exert force same as the engine will exert force , assuming the force is the same .
You will not achieve flight unless you have enough air flowing over the wings to achieve flight , solid or liquid ..

How does the treadmill cancel out the thrust? It exerts negligible force on the plane.