Two persons each of mass 50kg are standing on a platfrom P of mass 10kg and is placed on a platform Q of mass 20kg...Now A starts moving towards B wrt to P with speed of 5m/s B is at rest...As a result of motion of A Q moves right with vel. of 5m/s....wrt ground....Cal the vel of B wrt ground/..... plz answer to get rated...plz answer fast...Click to enlarge..