Planes' forward force (lift) comes from the engine pushing against surrounding air.
Planes' upward force (lift) comes from wings passing through the same air.
Planes' rearward force (drag) comes from air resistance and the friction of wheel bearings on the runway.
The engine pulls the plane forward, as its' thrust is far greater than drag.
The wheels contribute to the drag when it's on the ground - doubly so because they're turning twice as fast as normal,
since the runway matches the plane's speed in the negative direction -
but they're on bearings, so it's still a tiny amount, much less than air resistance as the plane's speed builds.
(Note: The original problem does not factor in wheel bearing resistance)
As the plane's forward speed builds (thrust > drag = acceleration),
the wings move through the air faster, and lift increases,
and eventually equals and surpasses the weight of the aircraft.
Takeoff.
Every forum this damn thing pops up.