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Old 03-03-2006, 11:52 PM
enipla enipla is offline
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Join Date: Jul 2001
Location: Colorado Rockies.
Posts: 11,578
Quote:
Originally Posted by Paradoxic
Keep in mind that no system is frictionless. We are assuming real systems, and the conveyer as described is well within present capabilities. It can be built. .
Yeah. And I want my Air Car.

Building it is not the issue.

Quote:
Originally Posted by Paradoxic
Fact 1: The force generated by an engine is limited.
So is the force against the landing gear by the moving runway.

Quote:
Originally Posted by Paradoxic
Fact 2: Friction is a force
No argument there. Learned that falling down and skinning my knee. .[/quote]

Quote:
Originally Posted by Paradoxic
Fact 3: The frictional force of the wheel assemblies against the ground, whenever referred to below, contains the friction of the tires against the ground, as well as the wheel assembly (bearings, axle, etc)
The airplane only needs to double it’s wheel speed to get to proper ground speed to take off. No big deal when we talk about moving conveyer belts.

Quote:
Originally Posted by Paradoxic
THIS is what everyone has ignored, and this data is required in order for the system to be closed.
In what possible way is this a closed system? The airplanes engines interact with the air that has absolutely nothing what so ever to do with the conveyor. The reason the airplane takes off is because it’s an open system. The power to the airplane and the power to the conveyor are so far removed I can’t begin to understand how anyone would consider this a closed system.

Let me ask everyone this.

Put a toy car on your home treadmill. Tie a string to it. Start the tread mill at 1foot per second. Could your pull the car to you at 1fps? Having the toy cars wheels turn at 2fps Could you pull it off the tread mill? If you believe that you could pull the toy car off the tread mill, then the plane can take off.

Quote:
Originally Posted by Paradoxic
Proof: An airplane at the start of a runway as it's about to take off, regardless of whether the airplane is propeller driven, or has engines mounted on it's wings, is at full throttle/full thrust. At the start of the runway, this full throttle/thrust is not sufficient to pull enough air over the wings for the plane to take off - if it did, planes would take off immediately and would not require a runway.
It stunned me that some people thought this could happen. “Ummm…. what are the wings for? Hold the engines on I guess”. Wow.