Physics Rotational Mechanics Level: Misc Level

A rotating 5 kg solid flywheel (disk) has a radius of 50 cm and an angular velocity of 20 rads/second. The wheel is brought to rest and all of the rotational energy of the flywheel goes into heating a surrounding water bath.If the water temperature increases 0.2 degrees celcius, what is the mass of the water surrounding the flywheel?