1. Density

2. The Density of a substance is determined by its Mass (weight) compared to its Volume (space occupied).
Some facts:
-If two things have the same weight (mass), then the one that takes up less space is the denser of the two
Density doesn’t just involve solids; Gases and liquids
also have specific densities based on how and what
they are made out of.
Which weighs more?
A gallon of water or
A gallon or paint?

3. We can find out the density of anything as long as we know its
____________ and ____________.
Mass
Volume
……...Then we divide the mass by the volume. The resulting number will be the density.
Remember:
D = M / V
The density of water is 1
Sometimes we can find out about density by putting different substances together:
What happens when we mix oil and water??

4. Denser materials always try to sink and less dense materials
Why?
Even though we may not know the density of oil, we know that is less than water.
Denser materials always try to sink and less dense materials
always try to rise.
This is not just true for liquids!

5. Sometimes the density of substances can be changed
How?
Applied Pressure or a change in temperature
Examples:

6. What Weighs More: Styrofoam Steel or
This is truly a meaningless question because we aren’t told the amount!
We are temped to say that steel is heavier, but this is because we are really thinking about density, rather than weight.

7. Density is a far more important property to consider when dealing with anything in the physical world….
It is also important to understand that there are a wide variety of densities in our universe.
Take a look at a few….
Space
Air

8. Water Gasoline Copper Gold The U.S.S. Ronald Reagan 1 0.7 8.92 19.32
<1

9. Neutron Star (Pulsar) Earth Saturn Coke Diet Coke 5.5 .7 1.08 .977,
5.5
Saturn .7
Coke
1.08
Diet Coke
.97