-- If velocity is constant, then there is no net force
on the chair.
-- If there is no net force on the chair, then friction
must exactly balance out your push.
-- The force of friction is exactly equal in magnitude
to your push, and in exactly the opposite direction.
Answer
D. move a small magnet back and forth within a section of the coiled wire.
Explanation:
i put that for the test and i got it right