"Travis Marlatte" wrote in message
hlink.net...
Peter, I think you lost the relative perspective.

No, I didn't.

Given the original riddle, the treadmill only moves backward at the same
rate the plane moves forward.

The rate at which the treadmill moves is entirely irrelevant. An airplane
does not transmit any force through it's wheels. They simply rotate
whatever speed is required to account for whatever speed the airplane has
relative to the surface the wheels are in contact with.

It doesn't matter one bit WHAT speed the treadmill moves, according to the
original riddle or otherwise.

If the plane was developing exactly enough thrust to counteract the
headwind, it will not move and neither will the treadmill.

The headwind is just an example. The actual wind could be anything. Yes,
if the headwind is exactly the same speed as the airspeed, the airplane
won't move. My only reason for setting the headwind equal to airspeed, as
an academic point of reference, is that if it's not, the airplane isn't
going to stay sitting on the treadmill for very long, making the "riddle"
even less interesting.

Pete