# DENSITY, BUOYANCY, VISCOSITY

```DENSITY
There are three states of
matter:
solid
liquid
gas
Density – the amount of
matter that occupies space
Solids
Molecules
close
together
Liquids
Molecules
further
Gas
apart
To determine density, you
must divide the mass by
the volume.
D = m&divide;v
Mass is measured in
grams using a triple beam
balance…
or a digital scale.
We can determine the mass of
the box using the digital scale.
750 g
Volume of a regularly-shaped
object can be measured using
a ruler.
If the object has smooth
sides where a ruler can be
used to measure the length,
width, and height, it is
considered regular-shaped.
Volume = length x width x height
2 cm
5 cm
15 cm
V=lxwxh
V = 15 cm X 5 cm X 2 cm
V = 150
3
cm
Determine the volume of
the cube.
3 cm
V=lxwxh
V = 3 cm X 3 cm X 3 cm
V = 27
3
cm
Volume of a
liquid is
measured
in mL using
cylinder or
a beaker.
Objects that do not have
smooth sides to measure are
called irregular-shaped.
To measure the volume of
these objects we use water
displacement.
Water is put
into a
cylinder and
the volume of
the water is
measured.
50
40
30
20
10
The object is
placed in the
cylinder.
50
40
30
The volume of
the water and
the object is
determined.
20
10
The first volume is
subtracted from the second
volume.
40 mL – 29 mL = 11 mL
The volume of the object
is 11mL.
Density does not depend on
the amount of the substance.
The density of the block is 16 g/cm3
If it is cut in half, what
happens to the density?
Density of block is
16 g/cm3
Density of block is
16 g/cm3
Sulfur Hexafluoride &amp; Density
Sulfur Hexafluoride &amp; Density
The density of water is
1g/mL.
If an object
with a density
of less than
1g/mL is
placed in the
water, it will
float.
If an object with
a density of
greater than
1g/mL is placed
in the water, it
will sink.
DENSITY
Alcohol
Oil
Water
COLUMN
Can you give
an estimation
of the density
of the alcohol
and the oil?
Density = 1g/mL
DENSITY
COLUMN
Alcohol
Oil
Water
Density = 1g/mL
The density of
the oil is less
than 1 g/mL.
The density of
the alcohol is
less than the
density of the
oil.
DENSITY
COLUMN
Alcohol
Density = .75 g/mL
Oil
Density = .96 g/mL
Water
Estimate
the
density of
the piece
of wood.
The density
Density = 1g/mL of wood is
.8 g/cm3.
DENSITY
COLUMN
Alcohol
Density = .75 g/mL
Oil
Density = .96 g/mL
Water
Estimate
the
density of
the piece
of ice.
The density
Density = 1g/mLof ice is
.9 g/cm3.
```