2. SI measurement Le Système international d'unitésLe Système international d'unités The only countries that have not officially adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularlyThe only countries that have not officially adopted SI are Liberia (in western Africa) and Myanmar (a.k.a. Burma, in SE Asia), but now these are reportedly using metric regularly Metrication is a process that does not happen all at once, but is rather a process that happens over time.Metrication is a process that does not happen all at once, but is rather a process that happens over time. Among countries with non-metric usage, the U.S. is the only country significantly holding out.The U.S. officially adopted SI in 1866.Among countries with non-metric usage, the U.S. is the only country significantly holding out. The U.S. officially adopted SI in 1866. Information from U.S. Metric Association

3. Standards of Measurement When we measure, we use a measuring tool to compare some dimension of an object to a standard. For example, at one time the standard for length was the king’s foot. What are some problems with this standard?

4. Stating a Measurement In every measurement there is a  Number followed by a  Unit from a measuring device The number should also be as precise as the measurement!

5. Mass vs. Weight Mass: Amount of Matter (grams, measured with a BALANCE)Mass: Amount of Matter (grams, measured with a BALANCE) Weight: Force exerted by the mass, only present with gravity (pounds, with a SCALE)Weight: Force exerted by the mass, only present with gravity (pounds, with a SCALE) measuredmeasured Can you hear me now?

6. Some Tools for Measurement Which tool(s) would you use to measure: A. temperature B. volume C. time D. weight

7. Learning Check Match L) length M) mass V) volume ____ A. A bag of tomatoes is 4.6 kg. ____ B. A person is 2.0 m tall. ____ C. A medication contains 0.50 g Aspirin. ____ D. A bottle contains 1.5 L of water. M L M V

8. Learning Check What are some U.S. units that are used to measure each of the following? A. length B. volume C. weight D. temperature

9. Solution Some possible answers are A. length inch, foot, yard, mile B. volume cup, teaspoon, gallon, pint, quart C. weight ounce, pound (lb), ton D. temperature  F

10. Metric Prefixes Kilo- means 1000 of that unitKilo- means 1000 of that unit –1 kilometer (km) = 1000 meters (m) Centi- means 1/100 of that unitCenti- means 1/100 of that unit –1 meter (m) = 100 centimeters (cm) –1 dollar = 100 cents Milli- means 1/1000 of that unitMilli- means 1/1000 of that unit –1 Liter (L) = 1000 milliliters (mL)

11. Metric Prefixes

13. Units of Length ? kilometer (km) = 500 meters (m)? kilometer (km) = 500 meters (m) 2.5 meter (m) = ? centimeters (cm)2.5 meter (m) = ? centimeters (cm) 1 centimeter (cm) = ? millimeter (mm)1 centimeter (cm) = ? millimeter (mm) 1 nanometer (nm) = 1.0 x 10 -9 meter1 nanometer (nm) = 1.0 x 10 -9 meter

14. Learning Check Select the unit you would use to measure 1. Your height a) millimeters b) meters c) kilometers 2. Your mass a) milligramsb) grams c) kilograms 3. The distance between two cities a) millimetersb) meters c) kilometers 4. The width of an artery a) millimetersb) meters c) kilometers

15. Solution 1. Your height b) meters 2. Your mass c) kilograms 3. The distance between two cities c) kilometers 4. The width of an artery a) millimeters

16. Equalities State the same measurement in two different units length 10.0 in. 25.4 cm

17. 1. 1000 m = 1 ___a) mm b) km c) dm 2. 0.001 g = 1 ___ a) mg b) kg c) dg 3. 0.1 L = 1 ___a) mL b) cL c) dL 4. 0.01 m = 1 ___ a) mm b) cm c) dm Learning Check

18. English and Metric Conversions If you know ONE conversion for each type of measurement, you can convert anything!If you know ONE conversion for each type of measurement, you can convert anything! You must memorize and use these conversions:You must memorize and use these conversions: –Mass: 454 grams = 1 pound –Length: 2.54 cm = 1 inch –Volume: 0.946 L = 1 quart

19. Mass vs. Weight Mass: Amount of Matter (grams, measured with a BALANCE)Mass: Amount of Matter (grams, measured with a BALANCE) Weight: Force exerted by the mass, only present with gravity (pounds, measured with a SCALE)Weight: Force exerted by the mass, only present with gravity (pounds, measured with a SCALE) Can you hear me now?

20. Some Tools for Measurement Which tool(s) would you use to measure: A. temperature B. volume C. time D. weight

21. Learning Check Match L) length M) mass V) volume ____ A. A bag of tomatoes is 4.6 kg. ____ B. A person is 2.0 m tall. ____ C. A medication contains 0.50 g Aspirin. ____ D. A bottle contains 1.5 L of water. M L M V

22. Learning Check What are some U.S. units that are used to measure each of the following? A. length B. volume C. weight D. temperature

23. Solution Some possible answers are A. length inch, foot, yard, mile B. volume cup, teaspoon, gallon, pint, quart C. weight ounce, pound (lb), ton D. temperature °F