Darkwing wrote:



Nope the plane won't take off.


You'd better not just be trolling...

Friction generated by wheels is almost negligible. Even for very large aircraft like a
747, wheel friction is nearly constant, regardless of speed (at least at sane speeds). It
only depends on the amount of force pushing down on the wheel.

So let's look at all of the forces acting on this airplane. In the horizontal direction,
we have:
Thrust from the engine (nearly constant at these speeds)
Aerodynamic drag (goes up as the square of speed)
Wheel friction (again, nearly constant)

For any object to accelerate in a given direction, the total force acting on it in that
direction must not be equal to zero. For a normal airplane, on a normal runway takeoff,
thrust must obviously be greater than the other two forces, since we see airplanes take
off every day. Even at the moment of takeoff, aerodynamic drag may have increased, but
the airplane still has a fair bit of excess thrust, and (assuming you don't pull up too
steeply) will continue to accelerate.

So now, let's put the plane on the treadmill. Once again, the ONLY forces acting on it
are thrust (which stays the same), drag (which still increases as speed squared, and wheel
friction (which, again, IS CONSTANT! no matter how fast the treadmill runs, until we start
talking about silly cases like 5000mph treadmills). Sticking to sane, airplane-like
speeds for the treadmill (80-160mph or so) We see that, once again, thrust is greater than
the other two. Therefore, the plane MUST accelerate.

I'd like to also point out that I have tried this on an actual treadmill with a small
model airplane. It takes right off, no problem. Now I just need to go fin