A small metal piece is kept on a rotating disc of 4 cm from the axis of rotation. The speed of rotation of the disc is gradually increased. Find (i) the angular speed of the disc at which the metal piece just begins to slip and (ii) the number of revolutions per minute made by the disc with this angular speed (μ = 0.2).

A small metal piece is kept on a rotating disc of 4 cm from the axis of rotation. The speed of rotation of the disc is gradually increased. Find (i) the angular speed of the disc at which the metal piece just begins to slip and (ii) the number of revolutions per minute made by the disc with this angular speed (μ = 0.2).