A man of 50 kg mass is standing in a gravity free space at a height of 10 m above the floor. He throws a stone of 0.5 kg mass downwards with a speed 2 m/s.When the stone reaches the floor, the distance of the man above the floor will be

Since the man is in gravity free space, force on man + stone system is zero. Therefore centre of mass of the system remains at rest. Let the man goes x m above when the stone reaches the floor, thenMman×x=Mstone ×10x=0.550×10  or  x=0.1mTherefore final height of man above floor = 10 + x = 10 + 0.1 = 10.1 m