yes, i was just clarifying airspeed vs. groundspeed and how groundspeed doesn't necessarily matter.

with the conveyor belt, the plane will have ground speed as a normal take off. the plane will travel down the conveyor belt like the ground wasn't even moving and the wheels will just be spinning twice as fast. the ground has no effect on forward thrust of the plane, and the conveyor belt's only force on the plane is the friction it puts on the bearings and tires.