F4 Quick Revision: Pressure

"Revision of the Day Series"

1. Presure is defined as the force acting pependicularly on per unit area
P= F/ A

2. Pressure in liquids:
P = h ρ g

What is the relationship between depth of liquid and pressure?
The more the depth of liquid the more the pressure at the lowest point of liquid

What is the relationship between density of liquid and pressure?
The higher the density of liquid the higher the pressure

3. Atmospheric Pressure:
-The atmospheric pressure is influenced by the altitude
-The higher the altitude from sea level the lower the atmospheric pressure

4. Archimedes principle:
Buoyant Force = Weight of fluid displaced
(B.F= ρVg)

Factors that affect buoyant force in liquid:
-Volume of object/material
larger volume = bigger buoyant force

-Density of the liquid,
denser liquid exerts larger buoyant force

-Gravitational field strength, g

Relation between buoyant force (B.F) & weight of object:
Object floats when, B.F = Weight of object
Object sinks when, B.F < Weight of object

Relation between volume of object & volume of liquid displace:
Volume of immersed object = volume of liquid displace
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Bernoulli Principle:
High speed flow of fluid causes low in pressure.

Bernoulli application:
Aerofoil, carburetors,bunsen burner, insectiside sprayers