Principles of flight?

[method]

You guys who say it wont fly are missing the point.

The belt will not stop the plane from moving fowards.

The plane works by pushing against AIR not the GROUND

The wheels are there to in theory create no friction between the plane and the ground.

The ground can do what ever the heck it wants under the planes wheels, it wont stop the thing from moving foward and flying!

PLEASE Think of this
Think of yourself on a bike on a long travelator, you push your self fowards using the railing(air in the planes case) at 1kph, the travelator beneth your bike moves backwards at 1kph. Your still moving fowards at 1kph relative to the railing (air) and your moving at 2kph relative to the travelator.

All you who will say it wont fly are assuming the tredmill under wheels will pull the plane back, it wont! It will just make them spin faster. The idea of the wheels are to minimise the friction between the plane and the ground.

And olliboy, dynamics is the phsyics of moving objects, i did a paper on that at auckland university.

[V8MOFO]

You guys are missing the point.

The belt will not stop the plane from moving fowards.

The plane works by pushing against AIR not the GROUND

The wheels are there to in theory create no friction between the plane and the ground.

The ground can do what ever the heck it wants under the planes wheels, it wont stop the thing from moving foward and flying!

PLEASE Think of this
Think of yourself on a bike on a long travelator, you push your self fowards using the railing(air in the planes case) at 1kph, the travelator beneth your bike moves backwards at 1kph. Your still moving fowards at 1kph relative to the railing (air) and your moving at 2kph relative to the travelator.

All you who will say it wont fly are assuming the tredmill under wheels will pull the plane back, it wont! It will just make them spin faster. The idea of the wheels are to minimise the friction between the plane and the ground.

And olliboy, dynamics is the phsyics of moving objects, i did a paper on that at auckland university.

It will just make them spin faster

and what happens when the wheels spin faster? The travelator spins faster. In the questions there is no way around out-accelerating the travelator. You can certainly sit in a fixed position on the travelator relative to the ground around it but you cant accelerate away from it.

[RomanV]

IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.




IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.




IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.



Just in case you missed it the other times I have said.

[V8MOFO]

IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.

yes I know that, but that still dosn't explain how the plane will out-accelerate the travelator. The plane increases speed to 5kmph as does the travelator. The plane does it in 3 seconds, the travelator does it in 3 seconds.

[geishaboy]

IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.




IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.




IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.



Just in case you missed it the other times I have said.

[RomanV]

When the plane is taking off from NORMAL ground, this is what happens.

Wheel speed = plane speed.

plane speed = difference in speed between the plane and the earth.

However....

When you put a travelator under it.
the plane speed still = the difference in speed between the plane and the earth.

The wheel speed = the plane speed x 2.

So the plane is still travelling at 100kph relative to the earth...
but the wheel speed doubles.

That is ALL that happens.
The speed of the travelator doesnt stop the plane from moving... it just makes the wheels spin faster.

It is 100kph(plane speed) + 100kph(travelator speed) equals the wheel speed.... all this means, is that the wheels are spinning twice as fast as the plane is travelling.

not the plane speed (100kph) - the travelator speed (100kph) = 0kph.

[method]

IF THE PLANE WAS STATIONARY, THE WHEELS WOULD NOT SPIN AT ALL.

yes I know that, but that still dosn't explain how the plane will out-accelerate the travelator. The plane increases speed to 5kmph as does the travelator. The plane does it in 3 seconds, the travelator does it in 3 seconds.

The speed at what the wheels spin have nothing to do with the speed of the plane. A plane flys because of the airspeed, not groundspeed. Think that through!

Changing the ground speed wont stop the plane from moving fowards, the travelator could be in reverse at a million miles per hour, thats just means the wheels will be spinning $&#$% fast, the plane will still move fowards.

The ground speed has no effect on the plane assuming the plane started out with 0 airspeed.

[method]

That is ALL that happens.
The speed of the travelator doesnt stop the plane from moving... it just makes the wheels spin faster.

...erse at a million miles per hour, thats just means the wheels will be spinning $&#$% fast, the plane will still move fowards.

THAT is the point your missing

[V8MOFO]

These points are all assuming there's no friction right?

aaaaaand my argument is going downhill now so I am going to stop

[RomanV]

If there was no friction, then the plane would slide off the side of the runway.

It is assuming that the friction generated by the rotation of the wheels is minimal, compared to the thousands of pounds of thrust that it is working against.

It is assuming that the friction is minimal, to the extent that it is negligable.

But, I give up. I dont think I can think of any more ways to explain it, without repeating myself in a slightly different manner.

I am also wondering why Fivebob would post such a question, knowing that it would confuse a lot of people, and frustrate the rest.

*shakes angry fist in Fivebob's general direction*

[MrOizo]

the plane will have velocity
the travelator will not stop it from moving forward

if what some of you were saying was true roller bearings would not work


v

I'm with you on this one

[V8MOFO]

uh huh I agree. I have changed my opinion a few times a few times during this. I dont know what to think anymore. All I know is you lot have a very open mind and are very intelligent, which I respect

[method]

These points are all assuming there's no friction right?

Nah even there was friction it would be so small compared to the 1,000kg+ plane and all the power the engine has. ITs precisely the lack of friction between the plane and the travelator that stops the travelator from causing the plane to move backwards.

That is the beauty of ball bearings and the wheel
Kudos to who ever invented them

[V8MOFO]

These points are all assuming there's no friction right?

Nah even there was friction it would be so small compared to the 1,000kg+ plane and all the power the engine has. ITs precisely the lack of friction between the plane and the travelator that stops the travelator from causing the plane to move backwards.

That is the beauty of ball bearings and the wheel
Kudos to who ever invented them

'I see' said the blind man.

[Mr Revhead]

ha! i just read all that

and for the record i voted yes before reading it.

its quite simple really.

that fivebob fella, always staring something

[MrOizo]

ha! i just read all that

and for the record i voted yes before reading it.

Same here. Voted yes before reading all the babble

still say yes too

[snwtoy]

Anybody still confused needs to try the following experiment:

Take 1 matchbox car.
Take 1 treadmill
Take 1 friend

Friend turns treadmill on and accellerates the belt

Push matchbox car on treadmill against the motion of the belf. Can you push the car from one end to the other?

[no_8wire]

Arh ok...I will succum to the others thinking...its my training I tell you....civil enginneers dont have to worry about wheels and stuff...just forces/elements...

[pidge]

V8MOFO, ignore the conveyor belt!

Look at the forces acting on the aircraft

Assume that the wheels turn freely (to keep the scenario simple for the moment)

You've got the thrust from the engine accelerating the aircraft forwards.

To stop the aircraft accelerating forwards, there must be force equal in magnitude to the engine thrust being applied in the opposite direction.

Where could that come from? It's not wheel drag (they turn freely), and the engines have more than enough thrust to overcome air drag.

Since the aircraft can accelerate forwards, it will take off.

[blitza]

and fivebob pisses himself...

we all know that if the plane was maintained in china, the wheels would fall off before it got far down the belt anyway.

some planes will produce enough thrust to overcome the friction force of the tyres on the ground, they will moove even with brakes locked. ask the chap in chc who was on the headset for a 767 ground run a while back.

you the plane wont take off chaps had a nice scanned piece of paper, but forgot about inertia, this is all aboot mass acceleration after all...

gas turbines (and marine jetpumps for that matter) create thrust by mass acceleration INSIDE the engine, not by pushing on the air behind.

it is still kinda mental that something weighing nearly 400tonnes can swim around in that stuff we breathe every day.

aaaand if the plane was stationary, the wheels would not spin at all.