volume=h(cross section of pillar of fluid)×a(breadth of pillar)
mass=volume×density
TAKING DENSITY AS d mass=a×h×d
weight=mass×acceleration due to gravity
weight of liquid column (force also)= a×h×d×g
pressure=force÷area
pressure=a×h×d×g÷a
pressure=h×d×g
The laws of fluid pressure are
1) Pressure at a point in a fluid increases with depth
2) Pressure increases with increase in density of a fluid
3) Pressure in a fluid is same in all directions
4) Pressure at a horizontal plane at the same depth experiences equal amounts of pressure at all points of the horizontal plane
liquid seeks it's own level
Force acting normally per unit area is called THRUST THRUST acting on a unit area is called pressure
Formula pressure=force÷area
SI unit of force is
Newton per metre square or Nm² Also called Pascal (Pa)
Fluids exert pressure as they are molecules are always crashing into each other and the walls of the container hence applying pressure on the walls of the container this is called as lateral pressure
Atmospheric pressure
air in the atmosphere also exerts pressure this is known as atmospheric pressure
in places of high altitude pressure is low places of lower pressure is high
we would have been Crushed by the enormous pressure the atmosphere exerts but our blood exerts pressure counteracting with the atmospheric pressure thus not letting us being crushed
hydraulic Jack takesadvantage that water is incompressible and hence we can move heavy objects without applying much pressure