1. Density

2.  Density is the amount of matter that an object has in a given unit of volume.  density =

3. Ex. 1  A piece of copper with a volume of 8.25 cubic centimeters has a mass of 73.92 grams. A piece of iron with a volume of 5 cubic centimeters has a mass of 39.35 grams. Which metal has the greater density?

4. Population Density  The population density of a city, county, or state is a measure of how many people live within a given area.  population density =

5. Ex. 2  The population of Vermont in 2009 was 621,760. The state can be modeled by a trapezoid with vertices at (0, 0), (0, 160), (80, 160), and (40, 0), with each unit on the coordinate plane being 1 mile. Find the population density of Vermont.

6. Displacement  A submerged object displaces (pushes away) a volume of liquid equal to the volume of the object.  When the mass of an object equals the mass of the water displaced by the object, the object is neutrally buoyant (neither sinking nor floating) and easy to lift to the surface. One milliliter (1 mL) of water has a volume of 1 cubic centimeter (1 cm 3 ).

7. Ex. 3  A tanker made of 2.5×10 3 m 3 of steel sank to the bottom of the ocean. The density of steel is approximately 8×10 3 kg/m 3. The density of seawater is approximately 1×10 3 kg/m 3.  In cubic meters, what total volume of seawater would need to be pumped out of the ship in order to lift the tanker to the surface?