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

Options

A. 9.9 m
B. 10.1 m
C. 10 m
D. 20 m

Answer

B

Explanation

Since the man is in gravity free space, force on man + stone system is zero. Therefore centre of mass of the system remains Man at rest. Let the man goes x m above when the stone reaches the floor, then
`M_(man) xx x = M_("stone") xx 10, x = (0.5)/(50) xx 10 = 0.1 m`
Therefore final height of man above Stone floor = 10 + r = 10 + 0.1 = 10,1 m