1. Dimensional Analysis Lecture

2. 1.Purpose A.Change units 1. ie: cm into meters or grams into kilograms B. Change numbers once units are converted C. Does NOT change the size of the real life object, changing only how it is represented 3kg of gold is still 3kg of gold even if it’s now called 3,000 g of gold

3. 2. Procedure A. Example: convert 3kg into grams 1. take what you know and change into a fraction: 3kg 1

4. 2. multiply by a fraction: (only use the horizontal line symbol, not the other two types) 3kg x ___ 1

5. 3. place the unit you want to cancel on the denominator: 3kg x ___ 1 kg

6. 4. place unit you want to go to on the numerator: 3kg x _g_ 1 kg

7. 5. place the quantitative equivalents on both the numerator and denominator: 3kg x 1,000g 1 1 kg

8. 6. cancel units which are the same on the numerator and denominator: 3kg x 1,000g 1 1 kg

9. 7. multiply the numerator and denominator out, then divide (remember: no fractions): 3 x 1,000g = 3,000g 1

10. 8. circle all answers: 3,000g

11. 9. when converting units, you must ALWAYS show the conversion of these prefixes: kilo base centi milli If your conversion does not go through some of these, that is fine, don’t do them: Kilogram to centigram does not go through milligram, so do not use milli

12. 3. examples: Convert 5 ft to inches: what is the first thing to do? 5 feet 1 5 feet x __ 1 1 Feet 5 feet x inches 1 feet

13. 5 feet x 12 inches 11 feet 5 feet x 12 inches 11 feet 5 x 12 inches = 60 inches1

14. Convert 5 meters to millimeters: 5m 1 5m x __ 1 1m1m 5m x cm 1 m 5m x 100cm 1 1m 5m x 100cm 1 1m

15. 5 x 100cm x ___ 1 5 x 100cm x ___ 1 1 cm 5 x 100cm x mm 1 1 cm 5 x 100cm x 10mm 1 1 1cm 5 x 100cm x 10mm 1 1 1cm 5 x 100 x 10mm = 5,000mm 1 1 1

16. Convert 25cL to kL: 25cL 1 25cL x ___ 1 1 cL 25cL x L(notice you can skip prefix deci) 1 cL 25cL x 1L 1 100cL 25cL x 1L 1 100cL

17. 25 x 1L x ___ 1 100 25 x 1L x ___ 1 100 L 25 x 1L x kL 1 100 L 25 x 1L x 1kL 1 100 1,000L 25 x 1L x 1kL 1 100 1,000L 25 x 1 x 1kL = 0.0000025kL 1 100 1,000

18. convert: 1.6 feet to meters (remember: 2.54cm = 1inch) 2.Convert the average age of a human (75 years) to how many seconds. 3.Give me a number and a unit give me a unit to convert into let’s convert it!