Download I. Density

Aim: What is Density?
Do Now:
In your notebooks, explain what you think
determines an objects density?
And then, try to explain how you would find
an objects density (formula/steps/process)?
I. Density: The amount of matter in a
specific volume.
- A physical property of matter.
- Measured in g/cm3 or g/ml.
- Every object has it’s own unique
density.
**
Density
of
an
object
remains
D = M
the same no matter how many
V
pieces it’s broken into **
Using the one density formula you can rearrange
the variables to solve for mass and volume.
Density =
Mass
Volume
Volume =
Mass = Density x Volume
Mass
Density
M
D
V
II. Buoyancy vs. Density
• Buoyancy is an objects ability to float in
water.
- determines if an object will sink, float
or remain neutral in water.
What does neutrally
buoyant look like?
1.3 g/ml 2.9 g/ml -
4.3 g/ml -
5.4 g/ml -
• Which color liquid
is most dense?
• Which color liquid
is least dense?
• Where would a
metal sphere with a
density of 3.0g/ml
land?
Example: Compare the density of H2O
(water) to the density of an ice cube.
THINK
An ice cube floats in H2O because it has a
density that is…
a) Equal to the density of water
b) Greater than the density of water
c) Less than the density of water
d) None of the above
III. Density of Water and Ice
- As water freezes it expands. (increases
volume)
- This make ice less dense than water
ice
ice
Ice always floats
the same in water
no matter the
size or shape.
IV. Frozen Lakes
- Water is most dense at 4oC in the Liquid
phase. Just before it freezes into ice.
-100C air temp.
ICE
00C
40C
Why does a steel ship float in water?
Densities in grams / cm3
D (water) = 1.0 g / cm3
D (wood) = 0.8 g / cm3
D (steel) = 7.8 g / cm3
D (lead) 11.3 g / cm3
D (air) .0012 g / cm3
Answer:
A ship has a steel shell that is hollow inside.
The volume is mostly air. The ship and air
together have a density less than water.
• Closure:
From the back table, top bin; take a density
review worksheet from the top bin to work on in
class with your partner using your notes.