A flexible cable is wound in one row round a drum with a radius . The weight of a unit of cable length is . The entire cable weighs . The drum moves by inertia without slipping along a horizontal surface, and the cable is wound off it. At the initial moment, when the cable was completely wound on the drum, the velocity of the drum centre was .
Find the velocity of the drum centre at the moment of time when a part of the cable with a length lies on the surface, neglecting the radius of the cable cross section(in comparison with ) and the mass of the drum.
For diagram, refer: Drum - Mechanics problem on Flickr - Photo Sharing!
How to solve it?