Riddle Me This.....Before My Brain Implodes!

No it cant, The plane has to have momentum and air pressure under the wings to get off the ground.

This is one of the stupidest arguments i've ever heard.

If The propulsion was powerfull enough to lift the plane from the conveyor "witch basically has the plane at stand still" Then there would be no need for runways in the first place. But the propulsion is not that strong so a runway is necessary.

If you had the conveyor rotating in the same direction as the planes path then you could maybe have a shorter runway. like when you run on the long conveyors at the airport. It would sling the plane into the air quicker , and less distance would be needed to take off.

No. Unless the conveyer is also moving the atmosphere, there's no relative motion.

What lifts the plane is movement against the wings. Ya know, aerodynamics, faster movement below than above, creates vacuum, genetrates lift, blah blah. No gas blowing against the wings = no lift.

Now, if you were to rig giant ass fans in front of the wings...

Edit: INSTA-POSTEDDDD

Uh, no it won't be able to. No air flow over the wings = insufficient lift to overcome gravity. So unless there's also 100MPH winds blowing over the plane...

[edit] Double insta-post!

Well now, I'm no rocket scientist, but I'm pretty sure the plane needs to actually be moving to create the lift to get off the ground. I'm trying to remember my Discovery Channel/TLC/History Channel education here, but a plane gets lift by moving air over both the top and bottom of the wing, with the shape of the wing creating negative pressure on the upper surface, thereby creating lift. If the plane isn't actually moving through the air, all the engine thrust in the world won't get it off the ground.

Damn, I shouldn't have checked that new email. I got beat to the answer.

kortniechan said:

No it cant, The plane has to have momentum and air pressure under the wings to get off the ground.

Click to expand...

, however, it's the air moving above the wings that causes the lift. The airfoil shape creates less pressure above the wings, causing lift.

A demonstration from middle school - take a piece of paper and hold it by one end in front of you. Blow directly across the top of the paper. The handing edge of the paper will lift, due to less pressure above the paper.

But, we're just nit-picking now. The plan has to be moving through space in order to fly.

Dammit, I guess everyone beat me to this, but I'd also like to chime in with a "How could anyone not immediately know the answer for this, you rere!"

Hmm, actually, thinking more about it, you're right Deathmaker. The conveyor belt can spin as fast as it wants and it's not going to affect the plane much beyond spinning the wheels, since the plane isn't pushing against the conveyor belt to gain momentum. And I seriously doubt the friction of the wheels spinning is going to overcome the thrust of the engines. So it will take off, and it will be travelling twice as fast as normal (relative to the conveyor belt).

Deathmaker said:

OK, there's a debate going on over the following question on another forum I frequent, which apparently came from another forum, which came from another forum, etc. I'm hoping someone knows the answer & can provide the definitive explanation. Here's the question:

I'm of the opinion that it can take off due to the fact that the drive/propulsion is coming from the engines acting against the surrounding air and not as a result of traction with the conveyor (as a car on a rolling road or a runner on a treadmill).

Answers on the back of a postcard please.
​

Click to expand...

Since traction and friction are not of importance here, I guess the question can be put in another way to make it clearer "A plane is suspended by 4 strings 2 on the wings and 2 on the body can it lift its nose if on maximum engine strength supposing atmospheric condition remain absolutely normal?"

Planes measure speed relative to airspeed, not wheel speed. This is so because sometimes there's a weird thing that happens that makes the air and the ground not going at the same speed. You might know this strange phenomenon from its common name: WIND.

The conveyor will simply make the wheels turn twice as fast as they would. The plane will accelerate the same (its engines aren't connected to the ground in any way or shape) and take off.


Next question.

Wheels move this way
<------
conveyer moves this way
------>
Both at the same speeds right? that means the wheels are not much of use here hence the only friction and traction actually taking place will be between the engines and the air which are responsible for pushing the plane ahead right? That justifies the question I had placed before!

The question as posed has an obvious answer: the plane takes off. The forward velocity of the plane is provided by the engine, which is not connected to the wheels. The wheels will turn freely, allowing the plane to move forward and take off, even with the conveyer-belt-runway fighting it.

However, the question is often stated differently, in ways that could have a different answer.

Alright, dead horse or not, this needs to end now.

Aircrafts work by having these things called Wings. Wings generate lift. Lift is generated by having gas (most likely the surrouding air) move across the foils. A pressure difference is created, and the wings "move" to fill the void.

Now, part two of this comes from another magical thing called relativity. If I was in a train that's moving at 20 m/s, and I walk 3 m/s towards the back of the train, an observer on the train would say that I'm moving at 3 m/s. However, a dude standing next to the train tracks would say that I'm moving at 17 m/s.

Same thing here. To the surrounding atmosphere (aka your source of wind), the plane is moving at 0 m/s. To an observer standing next to the conveyor, there is no forward velocity. Barring any hurricane or an already extremely windy day, there's no lift generated. A plane cannot magically lift up when its wheels are spinning fast enough. It needs to have a consistent amount of moving gas blowing across its wings, and moving very fast against a body of gas happens to be a great way of doing it. The engines/propellers alone do not generate the wind necessary to lift off, they only allow the plane to accumulate enough kinetic energy to allow the wings to generate lift.

EDIT: Balls, treadmill example was already mentioned...phooey

When you're running, you're pushing on the ground/treadmill with your feet. A plane pushes on the air and its own generated hot gases, not on the ground/conveyor.

What's so hard to understand ? The conveyor does not affect the plane's speed at all (beyond the little friction on the wheels' axises).

Let me state this in simpler words: the conveyor belt in this stuppid riddle does not stop the plane from moving.

kthxbye.

On a treadmill, you're pushing against the conveyor. A plane pushes against the air, so it's going to move regardless of how fast the conveyor is moving. It will just make the wheels spin faster.

To be impartial, to truely test this, one must make a massive conveyor belt, with the sensors (to make it move as fast as the plane in the opposite directions), and use a real plane, and to see what happens.