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

Question

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 (A) 9.9 m (B) 10.1 m (C) 10 m (D) 20 m

Tardigrade Admin · Accepted Answer

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, then

M_{man} \times x = M_{stone} \times 10

x = \frac{0.5}{50} \times 10

x = 0.1 m

Therefore final height of man above floor

= 10 + x

= 10 + 0.1 = 10.1 m

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

9.9 m

10.1 m

10 m

20 m

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