A disk with a hole in the middle has a c value of 0.68 about its center. Its center of mass is moving at 10 m/s at the top of an incline which is 18 meters long at an angle of 30 degrees. It rolls without slipping down the incline. If its mass is 5 kg and its radius is 0.6 meters, what is its rotational kinetic energy (about its center) at the bottom of the incline in Joules?