1. Examples: Olive oil has 0.85 g / cm 3 (or 0.85 g / mL). 1 mL of olive oil has a mass of 0.85 grams. Iron has 7.8 g / cm 3. 1 cm 3 of iron has a mass of 7.8 grams. Maple wood has 0.7 g / cm 3. 1 cm 3 of maple wood has a mass of 0.7 grams. Glass has 2.5 g / cm 3. 1 cm 3 of glass has a mass of 2.5 grams.

2. Sink or Float in Water? MaterialDensity (g/cc)Sink or Float? 4. Copper8.9 3. Brass8.4 2. Steel7.6 1. Aluminum2.7 6. Acrylic1.2 5. Oak0.8 7. Nylon1.1 9. Pine0.4 10. Poplar0.6 8. PVC1.3 12. Polypropylene0.9 11. Ironwood1.2

3. Floating / sinking rule for fresh water: If the object’s density is LESS THAN 1 g/cc, then it will FLOAT If the object’s density is GREATER THAN 1 g/cc, then it will SINK

4. So how can a ship that weighs several tons float on water??? Hint: Look at the simplified cross-section of a boat below:

5. Most of the inside is open space. So most of the volume of the boat is made up of air! So when you take into account all the metal and the air, the average density of the boat is less than 1 g/cc!!

6. What about other liquids? The density of rubbing alcohol is about 0.8 g/mL The density of polypropylene is 0.9 g/cc Polypropylene will SINK in rubbing alcohol because polypropylene is more dense than rubbing alcohol.

7. General Rule: A substance will SINK in a substance that is less dense than itself. A substance will FLOAT in a substance that is more dense than itself.