FLUID- Any substance which can flow and is unable to resist shear force or a substance which continuously deform under shear force and it can also flow. Example- Liquid, gas etc.
NOTE: 1) SUBSTANCE- Anything which have finite mass, occupies space and can be felt. 2) FLOW- Relative change of position of particle with respect to time.
Fluid have a mass. Fluid does not have any definite shape, it occupies shape of the vessel. Fluid can flow under its own weight.
Mechanics- It is the study of forces and it’s effect.
Fluid mechanics- Study of forces and it’s effect on fluid is called Fluid Mechanics.
Note: 1) Study of fluid at rest is called Fluid Statics. 2) Study of fluid in motion is called Fluid Dynamics.
Mechsiast 