The answer should be put on the original post.

The plane will fly, and it will take off using just as much runway space as it would without the conveyer belt (minus the wheel friction). This is because the turbines thrust the plane foward, not the wheels. It uses the same concept if you think of the plane being hung on a zipline by two cables, one at the front and one at the rear. The plane will still move foward along the zipline because the turbines move the plane, not the wheels. So even though the conveyer belt is "keeping up" with the speed of the wheels turning, it will still move along the conveyer belt and take off.

I know it has been answered already.. but i had to