1. Standards of Measurement Section 1-2

2. Units and Standards Units must be included in order for a measurement to make sense.Units must be included in order for a measurement to make sense.  Ball of string just says 150 (no unit) is it 150 feet, inches, meters?  Metric units include meters, centimeters, kilograms, grams, etc Standard is an exact quantity used for comparisonStandard is an exact quantity used for comparison

3. Example  No meter stick  Will the desk fit through the door?  Measure with my hands  Measure with your hands  No standard!

4. International System of Units  Abbreviated SI from the French Le Systeme Internationale d’Unites  Improved version of the metric system  Each SI measurement has a Base unit Length – meterLength – meter Mass - kilogramMass - kilogram

5. SI Prefixes  Based on Multiples of 10  Milli  Centi  Deci  Meter gram liter  Kilo

6. Converting SI Units  Bridges  Top of Bridge = Bottom of Bridge  1 meter = 10 dm  1 meter = 100 cm  1 meter = 1000 mm  1000 meters = 1 km

7. Convert the following:  1.255 liters to ml  3075 cm to m

8. More conversions:  11cm to mm  675 m to km  345 mm to km

9. Measuring Distance  Base unit = meter  Size of the object determines the unit  Activity pg.17  13mm is easier to understand than 0.013m

10. Measuring Volume  Volume = the amount of space an object occupies.  Volume = L x W x h (for solids)  Liquid volumes are measured in liters and milliliters.  1 Liter = 1dm 3  1 Liter =1000 ml  1 cm 3 = 1 ml

11. Conversions  1.5 liters to ml  1.5 liters to cm 3

12. Measuring Matter  Mass = quantity of matter in an object. Ping pong ball and golf ball have the same volume, but much different massesPing pong ball and golf ball have the same volume, but much different masses  Density = mass per unit volume Unit for density could be g/cm 3Unit for density could be g/cm 3  If an object has a mass of 10g and a volume of 2 cm 3 Density = 10g/2cm 3 or 5g/cm 3Density = 10g/2cm 3 or 5g/cm 3

13. Measuring Time and Temp.  Base unit for time is seconds  Base unit for temp. is Kelvin Most scientific work is done using celsiusMost scientific work is done using celsius 0 Kelvin is the coldest possible temp. also know as “absolute zero”0 Kelvin is the coldest possible temp. also know as “absolute zero” 0 kelvin= -273 0 C (273 degrees below the freezing pt. of water)0 kelvin= -273 0 C (273 degrees below the freezing pt. of water)