A turntable rotates about a fixed vertical axis, making one revolution in 10 s. The moment of inertia of the turntable about the axis of rotation is 1200 kg.m2. A man of mass 80 kg, initially standing at the centre of the turntable, runs outwards along the radius. What is the approximate angular velocity of the turntable when the man is at a distance of 2 m from the centre?