Consider, be the position vectors of masses 2 kg, 4 kg and 6 kg respectively. The position coordinates of the centre of mass of 2 kg, 4 kg and 6 kg is (-2, 0, 4).
Therefore position vector of the centre of mass of 2 kg, 4 kg and 6 kg is,
R1 = -2 + 0 + 4
Also,
Therefore,
Therefore,
... (1)
The position coordinates of centre of mass of 2kg and 4kg is (1, 2, 4).
Therefore position vector of centre of mass of 2kg and 4 kg is,
Also,
From (2) from (1), we get
The position vector of 6kg mass is,
Therefore, position coordinate of 6 kg is ( -5, -2, 4).