1. 9/8 - Warm Up #7 A sprinter ran for 400 meters. Calculate this distance in inches, if 1 in = 2.54 cm and 100 cm = 1 m A cheetah ran at a speed of 75 miles per hr. Calculate this speed in meters per second (1 mile = 1.61 kilometers). You have a gold block with a mass of 45.0 grams. If the density of gold is 19.3 g/mL, calculate the volume.

2. Density Chapter 3.4

3. DENSITY Density – how tightly packed object is in given space How much mass is in a given amount of space DENSITY= MASS/VOLUME D = M/V Mass – -grams Volume - -liters OR cm 3 (or dm 3 ) 1 mL = 1 cm 3

4. Coke vs. Diet Coke An Investigation

5. Investigation 1 can of Coke 1 can of Diet Coke When placed in water… DIET COKE FLOATS COKE SINKS WHY? How is coke different from diet coke?

6. Key Information Water’s density = 1.00 g/mL MEANING… If bottle is LESS DENSE than 1.00 g/mL…it will FLOAT If bottle is MORE DENSE than 1.00 g/mL…it will SINK Diet coke’s DENSITY = LESS than water

7. Similarities and Differences SAME Volume of can = 355 mL DIFFERENCE Mass of cans Diet Coke = 354 grams Coke = 393 grams (way more!!) WHY?.....SUGAR. Diet coke = 0 grams of sugar Coke = 39 grams of sugar

8. Calculating Density Water: 1.00 g/mL Diet Coke: 354 g / 355 mL = 0.997 g/mL LESS DENSE THAN WATER (floats) Regular Coke: 393 g / 355 mL = 1.107 g/mL MORE DENSE THAN WATER (sinks)

9. Density and Temperature Inverse Proportion – as one goes up, the other goes down Opposite: Direct Proportion – as one goes up, the other goes up (and vice versa). With density: as temperature increases, density decreases Ex. Melting butter

10. Why Do Ice Cubes Float? Density dec. as Temperature inc. exceptions? Comparing densities: a solid vs. water Liquid water = 1.00 g/mL Solid objects MORE dense…sink Lead = 11.4 g/mL Solid objects LESS dense…float Ice = 0.917 g/mL

11. Volume in cm 3 cm 3 = centimeters CUBED How to get it: cm x cm x cm = cm 3 Example: If the dimensions of the block are 5.31 cm by 0.51 cm by 1.09 cm what is the volume of the block? (5.31 x 0.51 x 1.09 = 2.95 cm 3 )

12. Warm Up #10: A scientist has a sample of gold with a mass of 45.0 grams. If the density of gold is 19.3 g/mL, calculate the volume of this gold sample, in deciliters. Mr. Lockett has a mystery substance with measurements of 3.0cm, 10.0mm and 5.0cm and mass of 40.5 grams. Find the density of this mystery substance. Compare the above densities to the density of water (1.00 g/mL). Which of the two substances will FLOAT in water? Explain why.

13. Warm Up #11 Mr. Lockett is late to a Star Wars convention. Once he gets out of his car, he sprints to the convention at a speed of 25.0 miles per hour dressed as Boba Fett. How fast is this in km/sec (remember 1.6 kilometers = 1 mile)? A rectangular block of copper metal has the dimensions of 9.4 cm by 5.5 dm by 4.6 cm. From this data, what is the mass of copper (the density of copper is 19.3 g/cm 3 )? You drop an unknown amount of ethanol into your beaker of water. The water level rises from 250.0mL to 350 mL. With this information, calculate the mass of ethanol added to your beaker. (the density is 0.789 g/mL)