THE biggest online debate ever?

[Rob WS6]

Ok, so this is going around the 'net. HUGE threads of people arguing back and forth...

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?

The plane WILL take off. The wheels do not affect the thrust of the airplane, they just support it. People cant seem to grasp the concept that they are free rotating wheels and this is not a wind tunnel we are talking about.

[oh one ls1 SS]

im probally going to sound like a stupid POS but is the plane going to be moving??

[Ian]

I would think the opposite. Yes there is thrust being generated, but there is no air moving over and under the wings. Its like saying the plane is bolted directly to the ground and it tried to take off.


Now see what you've done! we're gonna start debating about it here!

[oh one ls1 SS]

haha thats what i was thinking the plane needs to be moving if it has thrust but its not moving then its like it has the brakes on

[Teds89IROC]

I say no for the reasons Ian said. The airplane isn't actually moving through the air.

~Ted

[GP99GT]

the plane will move, the wheels will be going a million miles an hour though. keep in mind, the plane isnt driven by the wheels, it just rolls on them...the thrust will still push the plane

[oh one ls1 SS]

but the "runway" will be moving in the opposit direction so the plane isnt moving its sitting in the same spot creating thrust hense.. plane isnt moving

[Teds89IROC]

idiot! It will move, just that the wheels will be moving in the opposite direction

~Ted

[Ian]

Originally Posted by GP99GT

the plane will move, the wheels will be going a million miles an hour though. keep in mind, the plane isnt driven by the wheels, it just rolls on them...the thrust will still push the plane

but the plane will not move through the air. It NEEDS air under the wings to take off. I can run 15 mph on a treadmill, but after an hour of doing so, I'm still on the treadmill, not 15 miles away. you see what I'm saying? the thrust is only half of what makes the plane take off, the other half is air flow across the wings creating a hig pressure area under the wing and a low pressure area above it....or vice versa, I dont really remember.

[ar0ck]

I think that the plane will not generate lift. The plane has to be going in a forward motion at a high rate of speed to generate it. But if the track is moving at the same speed the jet will not move anywhere. Yes it is just rolling on the wheels but it has to go somewhere but it wont!

[oh one ls1 SS]

i think we found out why this is the biggest debate

[Ian]

Originally Posted by oh one ls1 SS

i think we found out why this is the biggest debate

It's not even an issue. I'm right. 8)

[Teds89IROC]

the actual jet has nothing to do with the wheels. The plane will move forward and accelerate moving through the air but the wheels will be moving in the opposite direction

~Ted

[oh one ls1 SS]

correction... WE are right

[Ian]

Originally Posted by Teds89IROC

the actual jet has nothing to do with the wheels. The plane will move forward and accelerate moving through the air but the wheels will be moving in the opposite direction

~Ted

are you saying it will take off? because if you are, you're wrong.

[Ian]

Originally Posted by oh one ls1 SS

correction... WE are right

[Teds89IROC]

yes, it will take off. the speed of the conveyer/wheels has nothing to do with the speed/thrust/acceleration of the plane. They are free rotating wheels, they will just be moving in the opposite direction that the plane is moving. YOU are wrong

~Ted

[oh one ls1 SS]

how is it moving?? its ike Ian said its like its on a tredmill its not moving just the wheels and convayer are plane is stationary

[Ian]

The plane will not move even an inch forward from where it was resting before it tried to take off. because it started from a standstill, all the planes weight is supported by the wheels. therefore, when it goes to take off, all the weight will stay on the wheels. it is not moving through the air! If you took a crane and dropped a string with a weight from it to meet the very tip of the nose of the plane, it will not move the entire time because there is no airflow under the wings. Airflow is the key to lift off. Push all you want, but if there isnt any air flowing across the wings, the plane is staying on the ground.

[Ian]

so you're saying if I'm running 15 mph on a treadmill, creating thrust and all that good stuff, that I'll have 15 mph worth of wind in my face?

[oh one ls1 SS]

[Teds89IROC]

Originally Posted by Ian

so you're saying if I'm running 15 mph on a treadmill, creating thrust and all that good stuff, that I'll have 15 mph worth of wind in my face?

If your feet are detached from your body and you can move without friction, yes.

~Ted

[Ian]

Okay, I got another one. Try running on a treadmill with a kite and try to make it fly. yeah, you're running, but there sure as hell isnt any airflow. same thing as what the plane is doing

[Teds89IROC]

Originally Posted by oh one ls1 SS

how is it moving?? its ike Ian said its like its on a tredmill its not moving just the wheels and convayer are plane is stationary

who said the plane is stationary?

~Ted

[Ian]

unless I'm missing the part where they said it was a harrier jet doing all this, it wont take off, you need two things to make a plane take off and one directly affects the other. you need thrust to generate airflow. if you are thrusting, but not moving anywhere, there is no air flow and there is no flight.