A solid, horizontal cylinder of mass 10.4 kg and radius 1.13 m rotates with an angular speed of 6.81 rad/s about a fixed vertical axis through its center. A 0.251 kg piece of putty is dropped vertically onto the cylinder at a point 0.864 m from the center of rotation, and sticks to the cylinder. Determine the final angular speed of the system.
It is very tempting to use conservation of energy here, but beware!!
The collision is inelastic, therefore the energy is not conserved!!
The value which is conserved is the angular momentum.
So we have the initial angular momentum of the cylinder given by:
The solution finds the final angular speed of systems around a horizontal cylinder.