PHY 317K 1st Edition Lecture 1 Outline of Current LectureI. Measurements and UnitsII. Significant Figures(a) Rules(b) Adding/Subtracting(c) Multiplying/DividingCurrent LectureMeasurements and Units:Measurement Unit SI UnitLength Meter mTime Second sMass Kilogram kgElectric Current Ampere ATemperature Kelvin KAmount of a Substance Mole molLuminosity Candela cdSignificant Figures:1. Non-zero digits are always significant - Example: 26.34 has four significant figures2. Any zeros between two significant digits are significant- Example: 406 has three significant figures3. Zeros at the end are significant ONLY if there is a decimal point- Example: 5.640 has four significant figures4. Zeros to the left of the first nonzero digit are NOT significant- Example: 0.000456 has three significant figuresAdding/Subtracting with Significant Figures:When adding or subtracting two numbers, the final value will have the same number of digits tothe right of the decimal point as that of the least precise quantityExample: 7.939 + 6.26 + 11.1 = 25.299- 11.1 has the least amount of digits after the decimal place (it is the least precise quantity)- So the final value is limited to one significant figure after the decimal point because 11.1 only has one number after the decimal point- Therefore the final value is 25.3Multiplying/Dividing with Significant Figures:When multiplying or dividing two numbers, the final value will have the same amount of significant figures as the number with the least amount of significant figuresExample: (27.2 x 15.63) ÷ 1.846 = 230.3011918- 27.2 has the least amount of significant figures (it is the least precise quantity)- So the final value is limited to three significant figures because 27.2 only has three significant figures- Therefore the final value is
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