"T o d d P a t t i s t" wrote in message
...


But anyone who does *not* violate the stated assumption (and
consequently thinks this is *not* about real airplanes and
real treadmills) can argue the plane cannot take off because
its speed relative to the air is zero. To get that
conclusion, however, they've got to assume an engine that is
so weak, it couldn't take off on a real runway, or friction
so much higher than reality as to again prohibit a takeoff.

Well, I choose a treadmill with zero internal friction. [If the treadmill
can be the length of the runway, I can make it frictionless.]

Now, lock up the brakes and advance the throttle(s) to 100%. Thrust is going
to overcome drag and move the airplane forward. Nothing in Aerodynamics 101
says thrust is related to wheel rotation. The treadmill belt is going to
maintain the zero rotation speed of the wheels by slipping forward instead
of rearward. When the aircraft reaches takeoff speed, it flys. Problem
solved.