Question 7. A coin kept on a rotating gramophone disc just begins to slip if its centre is at a distance of 8 cm from the centre of the disc. The angular velocity of the gramophone disc is then doubled. Through what distance, the coin should be shifted towards the centre, so that the coin will just slip? (a) 2 cm (b) 6 cm (c) 16 cm (d) 4 cm Answer
The coin is also rotating along with the disc . The C.F force acting on the coin is opposed by the force of friction for equilibrium ,F= mv2 r =mrω2 in both cases , the maximum (limiting ) force of friction remains the same.... Answer The correct Answer is C
