Appendix
Togainabetterunderstandingofthe
process,thetheorybehindtheformulas
andthecorrectionfactorisexplainedhere�
Basic Principles
Mass(g)
Density=
Volume(cm
TheArchimedes'principlestates:
Anobjectimmersedinliquidwillbe
subjecttoabuoyantforce(G)�Thisforceis
equaltotheweightoftheliquiddisplaced
bytheobject�
ThevolumeoftheimmersedobjectV(k)is
equaltothevolumeofthedisplaced
liquidV(fl)�
Thefollowingaredetermined:
1� WeightinairW(a)
2� B uoyancyoftheobjectintheliquid(G)
Thedensityofanobjectis:
massofobject
=
ρ=
volumeofobject
Ifthedensityρ(fl)ofthedisplacedliquid
isknown:
Mass(fl)
V(fl)=
=
ρ(fl)
Thus:
W(a)∙ρ(fl)
ρ=
G
3
)
W(a)
W(a)
=
V(s)
V(fl)
G
ρ(fl)
Calculation
Thedensityofasolidobjectiscalculated
basedontheratio
ρ:W(a)=ρ(fl):W(a)–W(fl)
Thus:
W(a)∙ρ(fl)
ρ=
W(a)–W(fl)
W(a)–W(fl)=G=buoyancyofthesample
Where:
=thedensityofthesolidobject
ρ
ρ(fl) =thedensityoftheliquid
W(a) = t heweightofthesolidobject
inair
W(fl) = t heweightofthesolidobject
inliquid
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