Notes
What is Mass?
•How much stuff
(matter) an object has
What is Volume?
•Amount of space an
object takes up
Density is…
•Distribution of a
quantity over a certain
amount of space
•Mass per unit Volume
Important
Density =
Mass
Volume
Story Time
Archimedes
Story of the King’s Crown
•King of Syracuse sent
a huge nugget of gold
to be made into a
crown
Story of the King’s Crown
•King thought the
crown was mixed with
silver
Story of the King’s Crown
•The blacksmith could
have stolen some of
the gold and mixed
the rest with silver
Story of the King’s Crown
•Asked Archimedes to
figure out if all the gold
given to the
blacksmith was in the
crown.
Story of the King’s Crown
•Archimedes weighed
the crown and the gold
and got their masses.
•They has the same
mass.
Story of the King’s Crown
Story of the King’s Crown
•Let’s just say the
crown was 800 grams
•So… Mass = 800g
Story of the King’s Crown
Density (Crown) =
800 g
Volume
Story of the King’s Crown
•So the Masses match
up…
•Do the Volumes?…
Story of the King’s Crown
Archimedes had to
take a bath to think
about this problem…
Story of the King’s Crown
•He filled the tub up the
whole way, to the brim!
•Then he got in…
Story of the King’s Crown
•Water fell out of the tub!!
•But he noticed
something about the
amount of water that
sloshed out…
Story of the King’s Crown
•The Volume of water
that fell out = Volume
of his body!
V (Water) = V (Archimedes)
B4
After
Therefore…
Story of the King’s Crown
•Archi measured the
Crown’s Volume to be
3
48 cm
•So…
Story of the King’s Crown
800 g
Density (Crown) =
48
3
cm
Story of the King’s Crown
Density (Crown) = 16.6
Density (Gold) = 19.3
Not the same!
3
g/cm
3
g/cm
Story of the King’s Crown
•It was mixed with Ag
3
(Density = 10.3 g/cm )
•The blacksmith was
ripping him off!!
Story of the King’s Crown
•The King had the
blacksmith
BEHEADED
immediately.
Story of the King’s Crown
•Archimedes is
credited with the
Density relationship
Important
Density =
Mass
Volume