1. Aim: How is an objects density determined?
Density Notes
Aim: How is an objects density determined?

2. Why does this happen?
Watch the following video clip then answer the question above:

3. What is Density?
Which one is more dense, a bowling ball or a soccer ball?
Even though they are both approximately the same size and shape, the bowling ball is much more dense.

4. Density
It depends on the mass of particles and how closely packed they are.
Formula can be found on the 1st page of the ESRT
Density: Mass
Volume

5. Find the Density of the cube
8 cm
Mass = 480 grams
480 g
240 cm3
= 2 g/cm3
3 cm
10 cm

6. Density Triangle
Volume

7. Density Facts
The Density of a substance remains the same regardless of size, shape, or mass of sample.
Example: The density of a piece of aluminum is 2.7g/cm3.
If you cut the AL bar in half, what would be the density of each piece ?
2.7g/cm3

8. Density Facts Continued
In what phase are most natural substances the densest?
Solid Phase (ex. Aluminum, lead, steel)
However, there is one exception. Water!
In what phase is water the most dense? And how do we know this?
Liquid- Ice cubes (solid) float in a glass of water (liquid).

9. Changing phases of matter animation

10. Ice floats because it is less dense then the liquid.

11. Only 10 % of Ice floats above the water, while 90% floats below
Only 10 % of Ice floats above the water, while 90% floats below. One of the main reasons why the Titanic sunk.

12. Density Facts Continued
Warm air rises because it is less dense, and cold air sinks because it is more dense.
Lets see Density in action

13. Two Ways To Change Density
Temperature
As temperature increases density decreases because molecules move further apart.
Indirect Relationship
2. Pressure
As pressure increases density increases because molecules move closer together.
Direct Relationship
Car getting crushed