A disc of mass M and radius R is rotating with angular velocity `omega_(0)` about a vertical axis passing through its centre (O). A man of mass `(M)/(2)` and height `(R)/(2)` is standing on the periphery. The man gradually lies down on the disc such that his head is at a distance `(R)/(2)` from the centre and his feet touching the edge of the disc. For simplicity assume that the man can be modelled as a thin rod of length `(R)/(2)`. Calculate the angular speed `(omega)` of the platform after the man lies down.