2. Measurement Systems English System (USA) –based on feet, pounds, gallons –Complex Metric (SI) system (everyone else) –Simpler –Based on powers of 10

3. a decimal system of measurement based on 10 Prefixes of SI used in this class: Kilo= 1000 Deci= 1/10 or 0.1 Centi= 1/100 or.01 milli= 1/1000 or.001

5. Measurements Must have both a number and a unit: –Ex: 4m Size of object determines size of unit used

6. Length Distance between 2 points

7. 1km = 1000m 1m = 100cm 1cm = 10mm

8. Mass Mass: amount of matter in an object –Measured with a balance –Units = g or kg

9. Volume Volume: Amount of space taken up by an object. Units = liters (L), milliliters (mL), cm 3

10. Measuring Volume 3 Methods : 1.Volume of Regular solids (cubes, rectangles). V = length x width x height Volume = 5 cm x 5 cm x 5 cm = 125 cm 3 5 cm

11. 2.Volume of a liquid Pour and measure –Use graduated cylinders

12. Reading a Graduated cylinder Record value at bottom of meniscus In this case 52.8 ml

13. Measuring Volume 3. Irregular solid (rock) by water Displacement Volume of water displaced = volume of object

14. Volume by water displacement

15. Density

16. Density = Mass/Volume Units = g/ml or g/cm 3

17. M DV

18. Buoyancy Ability of a fluid to exert an upward force on an object placed in it

19. Density & Buoyancy If object is less dense than the fluid it’s in, it floats If object is more dense than the fluid it’s in, it sinks Density of water = 1.0 g/mL

20. Temperature Measured with a thermometer SI base unit is Kelvin

21. Kelvin vs. Celsius Scale Celsius Scale: Water freezes at 0° C Water boils at 100° C

22. Kelvin Scale 0 K is called absolute zero. At 0 K all particles stop moving. Kelvin/Celsius Conversion K = °C + 273

23. Graphing Data

24. Why use Graphs? provides easy method of organizing data (picture) 3types of graphs 1.Bar: used for comparing data 2.Circle: shows how parts relates to a whole 3.Line: shows changes that occur between related variables

25. Bar Graph

26. Circle Graphs Parts always add up to 100%

27. Line Graphs Most scientific graphs are line graphs Lines can be straight

28. Line graphs Lines can also be curved