The identical spheres each of mass \( 2M \) are placed at the corners of a right angled triangle with mutually perpendicular sides equal to \( 4 \, \text{m} \) each. Taking point of intersection of these two sides as origin, the magnitude of position vector of the centre of mass of the system is \( \frac{4\sqrt{2}}{x} \), where the value of \( x \) is ______.