1. September 29, 2014 Do-Now: Come in quietly and take out your notebook. Write your HW into agenda and answer the follow question. Answer the following questions reviewing metric system WRITE THE METRIC UNIT FOR EACH QUANITY BELOW Kilograms Seconds Liters Meters Cubic centimeters Do-Now: Come in quietly and take out your notebook. Write your HW into agenda and answer the follow question. Answer the following questions reviewing metric system WRITE THE METRIC UNIT FOR EACH QUANITY BELOW Kilograms Seconds Liters Meters Cubic centimeters HW Pages 74 and 75 in workbook

2. Density Objective: How is density determined?

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 Density is the amount of mass in a given a space Density = Mass Volume

5. Hot Air More energy, molecules are moving faster Molecules are more spread apart Which sample shows warmer air? Hot Air More energy, molecules are moving faster Molecules are more spread apart Which sample shows warmer air?

6. The two rooms are the same size. 50 people come to one party and 37 people come to the other party. Which one is more dense

7. Let’s put it all together… DENSITY is the ratio of the mass of a substance to the volume of the substance UNITS: commonly expressed as grams per cubic centimeter for solids and liquids and grams per liter for gases

8. Find the Density of the Cube 10 cm 3 cm 8 cm Mass = 480 grams Volume= LxWxH= 10x3038= 240 cm3 Volume= LxWxH= 10x3038= 240 cm3

9. Density Problems Calculate the density of a rock that has a mass of 40 grams and a volume of 5 cm 3. 40g/5 cm 3 = 8 g/cm 3

10. 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 2.7 g/cm 3. If you cut the Al bar in half, the density of each piece is still 2.7 g/cm 3 Even if you roll the aluminum into a sheet the density will still remain the same

11. Density of Aluminum D = 2.7 g/cm3 By simply cutting the bar in half, the density remains the same!!!

12. What will change the density of an object? Temperature As the temperature of a substance INCREASES the density DECREASES due to the expansion of the substance Inverse Relationship Most substances EXPAND when heated and CONTRACT when cooled

13. Warm air rises because it is LESS dense Cold air sinks because it is MORE dense

14. Material DENSER than water will SINK in water Material LESS DENSE than water will FLOAT Materials with a density EQUAL TO water may remain at ANY LEVEL When several objects of different densities float on water, the LEAST DENSE objects float HIGHEST.

15. A B C D Water: 1 g/ml Object D: 2 g/cc Object C: 1 g/cc Object B: 0.4g/cc Object A: 0.8g/cc Why is object D sinking Why is object A floating Why is object D sinking Why is object A floating

16. How do we measure the MASS of an object?

17. How do we measure the VOLUME of a cube?