Kinetic energy — UPSC Physics Optional CSE 2000 Paper I

Ram and Shyam are two skaters weighing 40\text{kg} and 60\text{ kg} respectively. Ram travelling at 4\text{ m/s} meets Shyam travelling at 2\text{ m/s} in opposite direction and collides head-on.

(i) If they remain in contact what is their final velocity ?

(ii) How much kinetic energy is lost ?