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 2m/s. when the stone reaches the floor, the distance of the man above the floor will be

Answer 1

we have to apply concept of centre of mass.
a/c to question, there is no Gravity in the space, centre of mass will remain stationary.

use for formula, $x_{cm}=\frac{X_{man}M_{man}+X_{stone}M_{stone}}{M_{man}+M_{stone}}$
 
$0 =\frac{X_{man}M_{man}+X_{stone}M_{stone}}{M_{man}+M_{stone}}$

$X_{man}M_{man}+X_{stone}M_{stone}=0$

$X_{man}=\frac{X_{stone}M_{stone}}{M_{man}}$

$X_{man}$= – 0.5(10)/50 = – 0.1 metre.

hence, when stone reaches 10 metres down, man moves 0.1 metres up with respect to inital position.

Thus, distance between man and floor is 10.1 metres.

Answer 2

Answer:

10.1 m

Explanation:

Hope it helps u :)