Quote:
Originally Posted by Cole
All these pulley debates remind me of the great physics question:
If you put an airplane on a treadmill that matches the wheel speed of the airplane perfectly so that no forward motion of the plane is achieved, will it take off?
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Ok, I'm late to this party but I
have to correct this.
The question is predicated on a flawed assumption.
The presence of a treadmill is irrelevant. The airplane doesn't use its wheels to achieve forward motion. The fact that they're rolling on a treadmill is irrelevant.
When you apply power to the engine, Jet, turboprop, plain ol' reciprocating engine bolted to a propeller, the plane will move forward.
It doesn't matter what the wheels are doing. It doesn't matter if it's on a treadmill that's going 1000 miles per hour.
The wheels are freewheeling. You can't make enough drag through the treadmill to stop the plane. That's the minimal rotational drag of a wheel bearing vs the forward thrust of the plane.
It's a question that hands you a flawed assumption and asks you to answer a question based on the flawed assumption. That's the definition of a trick question.
Imagine this scenario.
Imagine you're on roller skates on a treadmill, and someone hands you a rope. If you pull the rope, you go forward. It doesn't matter if the treadmill is going a billion miles an hour. You go forward when you pull the rope. The treadmill can not match your forward speed, the same way a treadmill can't "match" an airplane's forward speed, they are not applying the same force. They can't apply the same force. It's impossible. They are applying different forces to different mediums that don't balance out.