physics
posted by Anonymous .
A solid, horizontal cylinder of mass 12.0 kg and radius 2.30 m rotates with an angular speed of 6.70 rad/s about a fixed vertical axis through its center. A 1.60 kg piece of putty is dropped vertically onto the cylinder at a point 0.600 m from the center of rotation and sticks to the cylinder. Determine the final angular speed of the system

momentum is conserved
initial momentum=final momentum
I*wi = (I+1/2 massputty*r^2)wf
solve for wf.
Look up the moment of inertia I for the cylinder.