Page 83 -

exert pressure in the direction 1 Pa = N/m 2 normal atmospheric pressure =
of the force applied 100 000 Pa

p = F/S pressure in gas is exerted by
the collision of gas molecules

PRESSURE p
textbooks nis edu kz

solids liquids gases

Fa = ↓liq Vg
Archimedes’ Principle
upthrust force lifting force –
F = gVsub F = Fa Ft
A l ob
pressure of liquid
p = ρgh
Pressure in liquids at the
same level is equal in
all directions. Pressure
increases with depth. conditions for buoyancy

Pascal’s Law –
Liquids and gases
exert pressure
not only in the
direction of force
applied, but in all
directions.

ρobj > ρliq – object sinks Fa < Fg – object sinks

ρobj = ρliq – object is in equilibrium at Fa = Fg – object is in equilibrium at any point
any point within the liquid within the liquid

ρobj < ρliq – object floats on the surface Fa > Fg – object floats on the surface

F A

F T

83