A small disc of mass 0.

A small disc of mass 0.99 kg is attached to a string on a frictionless table top. The string passes through a small hole in the centre of the table and is attached to a mass of 0.57 kg suspended below the table and above the floor. The disc can thus move in a circular path with the hanging mass acting as a counterweight to keep the path radius (from the centre of the table) constant at 0.61 m. With what speed must the disc move, in m/s, around in its path such that the counterweight does not move?