An Indian rubber cord 10m Long is suspended vertically. How much does it stretch under its own weight? (Density of rubber $=1500 \mathrm{kg}/{\mathrm{m}}^3,\mathrm{Y}=5\times {10}^8 \mathrm{N}/{\mathrm{m}}^2,\mathrm{g}=10 \mathrm{m}/{\mathrm{s}}^2$)