Airplane: Does it take off?

[zztype]

Re: Airplane: Does it take off?

Oh, no. If you go back to the original post in this thread, we're not talking practical application. It's all theoretical. And in the HYPOTHETICAL proposal, the plane would attempt to move forward, but the runway treadmill would be adjusted to precisely match the speed of the plane.

The plane does not move forward in the original post. So therefore, the plane cannot take off. The physics of flight prevents this from happening.

So does the guy get a speeding ticket?

[Pomai]

Re: Airplane: Does it take off?

I've said it before, and I'll say it again...

THE AIRPLANE TAKES OFF AND FLIES.

[GeckoGeek]

Re: Airplane: Does it take off?

The plane does not move forward in the original post.

The original post doesn't state that. That's your interpretation.

but the runway treadmill would be adjusted to precisely match the speed of the plane.

Please define the following:

"Speed of the airplane": as referenced to what? The ground? The Air? The treadmill surface?

"Speed of the treadmill": Same question, what is the speed referenced to?

Note: To build any kind of system to test this, both must be defined.

[craigwatanabe]

Re: Airplane: Does it take off?

Oh, no. If you go back to the original post in this thread, we're not talking practical application. It's all theoretical. And in the HYPOTHETICAL proposal, the plane would attempt to move forward, but the runway treadmill would be adjusted to precisely match the speed of the plane.

The plane does not move forward in the original post. So therefore, the plane cannot take off. The physics of flight prevents this from happening.

So does the guy get a speeding ticket?

Hypothetically anything can happen, well that's my hypothesis anyway

[Leo Lakio]

Re: Airplane: Does it take off?

(Extra credit: Will HPD radar officer issue a tag for exceeding the speed limit?)

So does the guy get a speeding ticket?

Hypothetically? Well, it would be a foolish thing to do, as the driver would point out in traffic court that (a) his engine was off, and (b) it was the road that was speeding, not the vehicle. But that doesn't mean HPD won't issue a ticket.

[zff]

Re: Airplane: Does it take off?

Oh, no. If you go back to the original post in this thread, we're not talking practical application. It's all theoretical. And in the HYPOTHETICAL proposal, the plane would attempt to move forward, but the runway treadmill would be adjusted to precisely match the speed of the plane.

The plane does not move forward in the original post. So therefore, the plane cannot take off. The physics of flight prevents this from happening.

This is the relevant excerpt from the original question:

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).

Ah, I get it. So you interpret this statement to mean the conveyor belt holds the airplane stationary on the runway. I guess we interpret this bit differently. I took it as this conveyor belt moves backwards at the same speed the airplane is moving forward. So if the airplane is moving forward at 10mph, the conveyor belt would be moving backward at 10mph. If the airplane had a wheel-driven speedometer (like a car), it would read 20mph.

Still, I just don't see how a conveyor belt can hold an airplane in place. Even if you just cracked the throttle open a hair and the airplane was just trying to inch along at 1 mph, the conveyor belt would have to be moving at hundreds of miles an hour to make any difference. The only way the conveyor belt would have an effect is if it went so fast, the tires on the airplane exploded.

[craigwatanabe]

Re: Airplane: Does it take off?

despite the entire concept of will it fly...the really enquiring minds want to know...WILL IT BLEND!

[Pomai]

Re: Airplane: Does it take off?

despite the entire concept of will it fly...the really enquiring minds want to know...WILL IT BLEND!

The combination of the rubber and steel from the conveyor belt with the aluminum, plastic and textiles of the airplane would make for one tasty Pina Colada!

Still, if the speed in RPM of the blender blade matches the speed of the airplane spinning in it, does it ever blend?

[craigwatanabe]

Re: Airplane: Does it take off?

The combination of the rubber and steel from the conveyor belt with the aluminum, plastic and textiles of the airplane would make for one tasty Pina Colada!

Still, if the speed in RPM of the blender blade matches the speed of the airplane spinning in it, does it ever blend?

Hmmm....Hmmmmm....now you got me thinking!!! Mount a Blender on the wheels of an aircraft and set it on puree! I think we may have something here!!!

[salmoned]

Re: Airplane: Does it take off?

Okay, you all are quite silly. An airplane does not put power to it's wheels, so unless the drag [of wheels to ground friction, etc.,] can equal the thrust [created by the engines], the airplane will move forward (have positive ground speed) no matter how fast the conveyor belt is made to move. Even if you were to double the speed of the conveyor with respect to the motion of the airplane, it would still be able to take off [given enough runway]. The wheels on an airplane are ideally friction-free when the brakes aren't applied. This is a question of Newton's laws (Action/reaction).

[craigwatanabe]

Re: Airplane: Does it take off?

But as we've rehashed this from wayyy back, you still need airflow over and under the wings to create lift to get that bird off the ground otherwise you're just spinning your wheels.

[acousticlady]

Re: Airplane: Does it take off?

Okay, you all are quite silly. An airplane does not put power to it's wheels, so unless the drag [of wheels to ground friction, etc.,] can equal the thrust [created by the engines], the airplane will move forward (have positive ground speed) no matter how fast the conveyor belt is made to move. Even if you were to double the speed of the conveyor with respect to the motion of the airplane, it would still be able to take off [given enough runway]. The wheels on an airplane are ideally friction-free when the brakes aren't applied. This is a question of Newton's laws (Action/reaction).

Ummmmm.........couple points..... if the wheels on the plane were friction free, then the wheels wouldn't rotate at all. It is the friction between the wheel and the ground that allow the wheels to rotate. The wheels rotating reduce the amount of thrust needed to accelerate the plane. Not that the forward thrust alone wouldn't make the plane move, but the amount of thrust needed to move the plane increases greatly. And how would you get friction free wheels anyway? Make a runway of ice? This actually is a question of action/reaction. However, the action/reaction is between the wheel and the runway - aka, friction.

The other comment I'd like to make is with regards to this whole conveyor belt/ plane take-off thingy. Blaine and CW are absolutely correct in stating that it is the air moving over and under the wing that creates the lift - Bernoulli's principle. So conveyor belt or no, it is getting the air particles to move faster over the wing than under the wing. When there is enough of a speed DIFFERENCE between the two, it will create an upward force (lift). The faster the wing moves through the air, the more of a difference there is. Theoretically, it doesn't matter how that difference is obtained.

The on-going argument as to how the conveyor belt will affect the take-off is a relativity problem. Each one seems to be viewing the problem from a different perspective. And therein lies the dilemma. The speedometer of the plane will only read what is would on regular ground. Imagine walking on a moving sidewalk. If you have a speedometer on your foot, it would only read your motion. Not the motion of the belt. Only the person standing off the sidewalk would see you moving at a faster/slower speed.

[craigwatanabe]

Re: Airplane: Does it take off?

BUT WILL IT BLEND!!!

[acousticlady]

Re: Airplane: Does it take off?

BUT WILL IT BLEND!!!

Ohhh...... I don't know about that..........

[DiverDown808]

Re: Airplane: Does it take off?

I can't beleive we're still arguing about this.

The answer is so obvious....The plane overheats, the pilot gives us all the finger, and the plane blows up.