Pressure is defined as the perpendicular force per unit area acting on a surface.
P = F/A
si unit =Nm-²
pressure is a scalar quantity,because it has magnitude but no direction.
PRESSURE IN LIQUID
Characteristics of liquid pressure
1.The pressure at all point at the same level within a liquid is the same.
2.The pressure in a liquid increases in direct proportion to the depth of the liquid.
3.The pressure in different liquid at the same depth varies directly with density.
P = hpg
where p = liquid of density
h = dept
g = acceralation due to gravity
the pressure due to liquid is known as HYDROSTATIC PRESSURE.
ATMOSPHERIC PRESSURE
Atmospheric pressure is the pressure exert by the atmosphere on the surface of the earth.
APPLICATIONS
1.The siphon
2.The syringe
3.Bicycle pump
4.Lift pump
5.Force pump
PASCAL'S PRINCIPLE
Pasca'l principle states that the pressure applied to an enclosed fluid is transmitted undiminished to every portion of the fluid and the walls of the containing vessel.
P =F/f =A2/A1
APPLICATIONS
1.The hydraulic press
2.The motor car foot brake
We can measure the relative density of a liquid using the U-TUBE method and HARE'S apparatus.
Both method depend on the pressure exerted by a liquid column ( p = hpg).
