1.
Three masses are placed on the xx-axis: 300 g300\,\text{g} at origin, 500 g500\,\text{g} at x=40 cmx = 40\,\text{cm} and 400 g400\,\text{g} at x=70 cmx = 70\,\text{cm}. The distance of the centre of mass from the origin is