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Old December 14th 06, 01:21 AM posted to rec.aviation.piloting
Travis Marlatte
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Posts: 233
Default So...about that plane on the treadmill...

"Montblack" wrote in message
...
("Darkwing" wrote)
Thank you for your reply. Here is my .02, it would seem that the plane
never actually moves in respect to the observer no matter how fast the
treadmill moves, the plane will just take off like it is hovering and
then
slowly accelerate away?



Not unless the plane's "wheels" are coupled to the shaft of a gyro's
rotor.

Try this one:

You're in a Class B airport terminal.
You're on roller-skates, Rollerblades, a skateboard... whatever.

You find yourself on an (evil) moving sidewalk - facing the wrong way.
The (evil) sidewalk ALWAYS matches your wheels' forward speed.

Someone moves a huge Hollywood 'film set' fan, in a few feet behind you.
They point the fan at your back and turn it on.

You hold open your jacket to make a sail (...like kids at the ice skating
rink have done for ages)

1. Will you get blown down to the far end of the moving sidewalk - your
destination?

2. Will you remain in the same spot - relative to the wall - no matter how
hard the giant fan blows?

3. Forgetting the fan, if you try pulling yourself forward using the
stationary handrails, will you in fact move forward? Or will the (evil)
moving sidewalk thwart your forward motion by speeding up? Or will your
upper body pull itself forward, while your feet remain behind ...(or
stationary, relative to the wall and the handrail)?

4. How is this the same as the airplane and the treadmill question? How is
it different?


Montblack


It's basically the same question with the same ambiguities. The crux of most
of the hilarious debate is really over what defines the speed of the
treadmill. It seems like a more interesting puzzle if the treadmill (or evil
moving sidewalk) tries to match the forward speed of the object on the
wheels resulting in the wheels simply spinnning at twice the speed of the
forward movement of the object.

The other interpretation, which leads to an impossible solution, is that the
treadmill moves to counteract all forward motion - which results in a
treadmill accelerating to infinite speed (or until the wheels explode which
ever comes first).
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Travis
Lake N3094P
PWK