I swear you're just trolling now. The conveyor can apply a certain amount of friction to the wheels. The prop/turbine can provide much more force (more) directly to the fuselage of the aircraft. The force applied to the bottom of the wheels/tires causes them to spin on their respective axes (axises?) but not hold the fuselage back. Greater thrust than resistance causes the plane to move forward. As the plane moves forward the conveyor speeds up, yet is only causing friction with the bottom of the spinning tires. The prop/turbine is creating greater friction with the air. The aircraft continues to move forward at a greater rate. then, of course, as air moves over the wing (because the plane is not stationary, it is moving) the effect of gravity is less and less as the plane accelerates, resulting in less friction on the tires. Eventually lift is achieved, and the plane can go look for an inverted conveyor with a boat underneath it.