[Solved] Three objects A. B and C are kept in a straight line on a frictionless horizontal surface. These have:masses m, 2m and m, respectively. The object A moves towards B with a speed 9 m/s and makes an elastic collision with it. Thereafter, B makes completely inelastic collision with C. All motions occur on the same straight line. Find the final speed (in m/s) of the object C. - - JEE (Advanced) 2009 Paper-2