There are a number of properties of liquid that are of use to us. The foremost among them is its volume, even though the shape is not fixed, volume is. Volume is a measure of space occupied by a liquid and is useful for a number of engineering and scientific systems, say sewer design or pipe size selection in conveyance of clean water to homes, etc. Boiling point and latent heat of vaporization are also needed. Boiling point decides how much heat is required to turn the liquid into gaseous phase, obvious applications are in cooking and electricity production. Surface tension determines the shape of the liquid, while viscosity is the resistance to flow. Higher the viscosity, smaller is the flow. An application of this is in automobile engines, higher viscosity of fuel during winters provides lesser fuel efficiency as compared to summer.
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