The branch of physics concerned with the mechanics of fluids and the forces acting on them is called Fluid mechanics. Chapter 13 Fluid Mechanics deals with the mechanism involved in fluids. Fluid mechanics is Classified into three distinct classes. These are static, kinematics, and dynamics. Out of these, Fluid dynamics are divided into compressible and incompressible flows. These are furthermore split into turbulent and laminar forms.
Pascal's law states that when the pressure in a liquid is altered at a particular point, the change is transferred to the whole liquid without being diminished in magnitude. It is worth noting that the atmospheric pressure at the top of the atmosphere is zero as there is nothing above it to exert the force. Torricelli devised an ingenious way to measure atmospheric pressure. He invented an instrument known as the Barometer.
Further, Archimedes has stated that when a body is partially or fully dipped into a fluid at rest, the fluid tends to exert an upward force of buoyancy. This upward force of buoyancy is equal to the weight of the displaced fluid. Thus, Archimedes' principle is not an independent principle and may be deduced from Newton's laws of motion.
The flow of fluid is, in general, a complex branch of mechanics. In fluid mechanics, if the speed of flow of a liquid is not too huge, then it generally flows with a regular gradation and is therefore called streamline flow. Henceforth, pressure is expressed by the equation, Pressure = Density*Height*g. For liquids, which are nearly incompressible, this equation holds to great depths. Therefore, the equation of continuity and the Bernoulli equation is included in this chapter. There are also few applications of the Bernoulli equation, namely, Aspirator Pump, Hydrostatics, Ventry Tube, and so on.