A gramophone record is revolving with an angular velocity ω. A coin is placed at a distance r from the centre of the record. The static coefficient of friction is μ. The coin will revolve with a record if

Q: A gramophone record is revolving with an angular velocity ω. A coin is placed at a distance r from the centre of the record. The static coefficient of friction is μ. The coin will revolve with a record if

(a) r ≥ μg/ω²

(b) r = μgω²

(c) r < ω²/μg

(d) r ≤ μg/ω²