Question

A man of mass 80 kg stands on a wooden plank of mass 40 kg.The plank is lying on a smooth horizontal floor.Initially both are at rest.The man starts walking on a plank towards north and stops after moving a distance of 6m on the plank.Then
(1)the plank will slide to north by a distance of 4m
(2)the plank will slide to south by a distance of 4m
(3)the plank will slide to the south by a distance of 12m

Answer 1

I am thinking 2 because the weight calculation