Four bodies of masses `1,2,3,4 kg` respectively are placed at the comers of a square of side `a`. Coordinates of centre of mass are (take `1kg` at the origin,`2kg` on X-axis and `4kg` on Y-axis)

Options

A. `((7a)/10,a/2)`
B. `(a/2,(7a)/10)`
C. `(a/2,(3a)/10)`
D. `((7a)/10,(3a)/2)`

Answer

B

Explanation

`x_(cm)=(m_(1)x_(1)+m_(2)x_(2))/(m_(1)+m_(2)) , y_(cm)=(m_(1)y_(1)+m_(2)y_(2))/(m_(1)+m_(2))`