Three identical spheres, each of mass m are placed at the corners of a right angled triangle with mutually perpendicular sides equal to 2m. Taking their point of intersection as the origin, the position vector of centre of mass is

Options

A. `1/3(hati-hatj)`
B. `2/3(hati-hatj)`
C. `2/3(hati+hatj)`
D. `1/3(hati+hatj)`

Answer

C

Explanation

`x_(CM)=(summ_ix_i)/(summ_i)=(mxx0+mxx0+mxx2)/(m+m+m)=2/3`
`y_(CM)=(summ_iy_i)/(summ_i)=(mxx2+mxx0+mxx0)/(m+m+m) = 2/3 :. ` Position vector of centre mass is `2/3 (hati+hatj)`