Mechanical Properties of Fluids

Mechanical Properties of Fluids :- We know that matter exists in three states solid, liquid and gas. Solid is a state of matter which has a definite shape and volume. Liquid has a definite volume but no shape of its own. It takes the shape of the container in which it is placed. Gas has no definite volume and shape. It takes the shape and volume of the entire container containing it. This kind of behavior is because of the intermolecular force, which is maximum in solids, less than liquids and least in gases. Liquids and gases deforms easily under the application of shear (tangential) stress, no matter how small the shear stress may be.

Fluid(Mechanical Properties of Fluids) :-

A fluid is a substance that cannot sustain a shear stress when at rest.

Or

Fluid is defined as a substance which begins to flow when external force is applied on it.

Thus, fluid comprises of liquids and gases (or vapour phase matter).

 

Hydrostatics :- The branch of Physics which deals with the study of Fluids at rest is called hydrostatic.

Hydrodynamics :- The branch of Physics which deals with the study of Fluids in motion is called hydrodynamics.