Plane on a conveyor revisited Options

[james]

Dragging up the past a bit - TV show Mythbusters ran it's much anticipated episode with a practical experiment version of this question on it a couple of nights ago over in the US.

I don't know when it will come on over here but for the curious Kottke liveblogged it and also links to another good explanation from a guy with a Sc.D. in Nuclear Science and Engineering (whatever that is).

And for the hard of attention and understanding - yes of course it takes off.

[jamie]

no, I can see how you are thinking.. Its just if the planes engines were at low power taxying speed say the tread mill would counter the speed, thus leaving the plane stationary. Regardless of whether the power was coming from the engines or the wheels.

As long as the treadmill could keep up, the plane could never jump to the stage where its forward force we greater than the opposing force by the tread mill. The only way it could is by taking its downward gravitational force out of the equation which it could only do by moving forward and getting some airlift...

Anybody else see what I'm saying?!! Anybody?

[paul]

no, I can see how you are thinking.. Its just if the planes engines were at low power taxying speed say the tread mill would counter the speed, thus leaving the plane stationary. Regardless of whether the power was coming from the engines or the wheels.

As long as the treadmill could keep up, the plane could never jump to the stage where its forward force we greater than the opposing force by the tread mill. The only way it could is by taking its downward gravitational force out of the equation which it could only do by moving forward and getting some airlift...

Anybody else see what I'm saying?!! Anybody?

Completely agree mate!



A plane needs forward motion to create airflow over the wings which in turn creats up lift.



Of course I know nothing about it so could be as wrong as you! Especially as Jeff disagrees