A solid horizontal cylinder of mass 13.1 kg and radius 1.22m rotates with an angular speed of 2.99 rad/s about a fixed vertical axis through its center. A 0.258kg piece of putty is dropped vertically onto the cylinder at a point 0.853m from the center of rotation, and sticks to the cylinder. What is the final angular speed of the system. Answer in rad/s Now, I know the solution to this question involves conservation of momentum. mgh=the sum of rotational and translational kinetic energy i'm guessing the mass to be used initially is that of the cylinder, while the mass to be used to calculate the P.E from the height, is the mass of the cylinder and putty. Can anyone confirm this?