新编文档-DimensionalAnalysis-MrsLarson27sClasses空间分析-拉尔森夫人的类-精品文档

1、Dimensional AnalysisDimensional Analysis What happens when you divide a number by itself? What happens when you divide a unit by itself? In both cases, you get the numbers Dimensional analysis involves multiplication and division口 Focus on cancelation of UNITSJust another method of unit conversionFi

2、rst- learn the metric prefixes essexi/pGople/spGer/larqe.htinl You should memorize：口 Kilo i x io3 base units or 1000 base units So 1 km = 1000 mQ Centi ix io-2 base units or o.oi base units Soicm = o.oi m OR 100 cm = 1 mQ Midi ix io-3 base units or q,ooi base units Soi mm = o.ooi m OR 1000 mm = lm B

3、e able to use a chart for the others!On the chart, use 1 with the prefix Use the other number with the base unit (Lz mz g)Conversion factors To con vert betwee n un its： Figure out what CONVERSION FACTOR you need to perform your calculation口 Conversion factors-take a definition and turn it into a fr

4、action equal to one-for example： There are 12 inches in 1 foot 12 inches or lfootlfoot12 inchesExamples of dimensional analysisMultiply across the top. Divide by whatever on the bottomScientific Notation Why do we need to know this?口 It's hard to work with numbers like this：口 6,000,000,000,000,0

5、00,000,000口 Orthis 0.00000000000000000000876 What is scientific notation?D Simplifying large or small numbers by converting them to a number between 1 and 10 multiplied by powers of 10Scientific Notation Powers of 10?口 io x io x io = looo or io3口二 l/10n So 1O = 1/10 = 1/1000 = 0.001Converting regula

6、r notation to Scientific Notation Always move the decimal so there is onenumber LEFT of the decimal口 If the original number is LARGER than 1 and the decimal is moved to the LEFT, use a positive exponent 1,567 =1.567x10口 If the original number is SMALLER than 1 and the decimal is moved to the RIGHT, use a negative exponent0.0000045 = 45 x io-6Converting from scientific notation to regular notation Move the decimal the number of places in dicated by the exp orient.口 If the exponent is positive, yourfinal number should be largerthan