Question

Three identical spheres each of mass $M$ are placed at the corners of a right angled triangle with mutually perpendicular sides equal to $3 m$ each Taking point of intersection of mutually perpendicular sides as origin, the magnitude of position vector of centre of mass of the system will be $\sqrt{ x } m$ The value of $x$ is

Answer 1

The correct answer is 2

rcom​=3MM(0i^+0j^​)+M(3i^)+M(3j^​)​
rcom​=i^+j^​
∣rcom​∣=2​=x​
x=2