
Clulup is right...... but only if the treadmill can exert enough force on the airframe to counteract the thrust of the jets (e.g. like in a stationary test of a jet).
So, the real question is then, can the treadmill exert enough force on the airframe via the wheels (its only contact) to keep the plane stationary with respect to the air and the ground?
If we accept that the force in question is due to friction, and that the wheels are designed to reduce that, and that friction does not increase with increased wheel speed (the only thing that the treadmill can influence, its only coupling to the plane) then the answer is that the treadmill can only exert a specific amount of force (thrust in the opposite direction to motion).
The equation is:
F=uR where u is the coefficient of friction and R is the force downward.
As we can see its independent of the speed of movement. Therefore, no matter how fast the treadmill goes, due to friction in the ballbearings, it can only exert a finite amount of force, say 500 newtons in to opposite direction of motion. The jet engine however can exert 60 000 newtons in the other direction, meaning the original problem is flawed, because there is no way, except for a very puny jet engine, for the force of fiction in the wheels of the engine to keep the plane stationary with respect to the ground.
In fact the problem was obviously originally framed by someone who did not understand that the force of friction was independent of the speed of movement (although stationary and moving coefficient of friction are different).
So in fact, Clulup is wrong.
Surur


