Hi I have a few problems from 'Physics for Scientists and Engineers' by Serwat and Jewett, chap 10 Prob. 51 A cylinder of mass 10 kg rolls without slipping on a horizontal surface. At the instant its centre of mass has a speed of 10 m/s. Determine (a) the translational kinetic energy of its centre of mass (b) the rotational kinetic energy about its centre of mass (c) its total energy. (a) turns out to be 500 J and (c) is the sum of E.K. rotational and E.K. translational however (b) is a mystery for me, I would appreciate someone helping me out. Thanks.