Properties of Fluids

To understand the different properties of fluids, we have to first understand what exactly is meant by the term fluids. By definition, anything that can flow is a fluid. The water we drink, the air we breathe are all examples of fluids. Essentially, all liquids and gases are fluids.

Properties of fluids

Since fluids are, like solids, also a form of matter, they have certain properties. The study of the properties of fluids in fluid mechanics helps us to utilize them for useful purposes.

Different Properties of Fluids

Though each fluid is different from others in terms of composition and specific qualities, there are some properties which every fluid share.

These properties can be broadly categorized under:

  • Kinematic properties such as velocity and acceleration.
  • Thermodynamic properties of fluids such as density, temperature, internal energy, pressure, specific volume and specific weight.
  • Physical properties of fluids such as appearance, color and odor.

Here we will look into some of the basic properties of fluids.


Density of a fluid is its mass per unit volume. It is the ratio between the two. Unit of Density of fluids is kg/m3.

The formula for deriving density is : MassVolume

The density is dependent on a number of factors such as pressure, temperature and its chemical combination.



The property of fluids that determines the state of hotness or coldness of it. Temperature is measured in either Kelvin, Celsius or Fahrenheit. Kelvin is the most common one that is used because of its independence from the properties of the substance.


The pressure of a fluid is the force applied by it per unit area. The unit of pressure of fluids is N/m2.

Specific Volume

In fluid mechanics, specific volume is the reciprocal of density. It can be expressed as the volume that a fluid occupies per unit mass. Specific volume is denoted by the letter ‘v’ and can be derived by calculating  VolumeMass. Its unit is m3/kg.

Learn about the Mechanical Properties of Fluids, fluid mechanics notes and more by solving the NCERT Solutions.

Practise This Question

A metallic ring connected to a rod oscillates freely like a pendulum. If now a magnetic field is applied in horizontal direction so that the pendulum now swings through the field, the pendulum will