1. A disk with radius of 0.3m and a mass of 4kg is free to rotate about an axle through its center. A cord wrapped around the circumference supports a weight with mass 5kg. a) What is the acceleration of descending mass if it is released? b) 5 seconds after release what is the rotational energy of the disk? 2. I disk = (1/2)MR2 3. I know that Idisk = (1/2)(4)(.3)2 is 0.18. After that I am lost.