Water rises to a height of 2.94 cm capillary tube, while mercury depresses by 1.1 cm in the same tube. Find the ratio of the surface tension of mercury to that of water. Given that density of water = `10^3 kg m^-3`, density of mercury = `13.6xx10^3 kg m^-3` angle of contact for water = `0^@` and angle of contact for mercury= `140^@`