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Dimensional Analysis. NEVER use inches in science Each small Space between division is millimeters large numbers (or mm) is centimeters (or cm) NEVER write a measurement in a fraction form! 6 ½ mm 6.5 mm. Dimensional Analysis.
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NEVER use inches in science Each small Space between division is millimeters large numbers (or mm) is centimeters (or cm) NEVER write a measurement in a fraction form! 6 ½ mm 6.5 mm
Dimensional Analysis • Dimensional analysis- finding the proper units to measure in • Science measures in the metric system! • Meters measure _______________ • Liters measure_________________ • Grams measure________________ Base Units
Prefixes go BEFORE the unit Size Examples Nano: 1/1,000,000,000 Nano Technology (1 billionth) Micro: 1/1,000,000 Compound Microscopes (1 millionth) Milli: 1/1,000 Small divisions on ruler (1 thousandth) Centi: 1/100 Large divisions on ruler (1 hundredth) Deci: 1/10 Measure watch size (1 tenth) UNIT (meters, liters, grams) Deca: 10 Measure rooms (ten) Hecto: 100 Measure plots of land (hundred) Kilo: 1,000 Long drivable distances (thousand) Mega: 1,000,000 Larger than the circumference (million) of the earth Giga: 1,000,000,000 Larger than the circumference (billion) of earth
Challenge! What unit would 1,000 grams be measured in? 1 ________________________ What unit would 10,000 liters be measured in? 1 ___________________________ What unit would 1/100,000 meters be measured in? 1 _____________________________
Conversions Step 1: Determine if move decimal point left or right Step 2: Determine how many spaces move the decimal point giga mega kilo hectodeca Unit decicentimilli micro nano G M k h da d c m µ n 9 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 8 9 As units get BIGGER, move the decimal point to the LEFT As units get SMALLER, move the decimal point to the RIGHT Examples: 1000 mg = _____ g 1 L = __________ mL
Another Situation • What does 5.2 x 106 mean? • What does 104.2 x 10-2 mean?
English to Metric Conversions Conversion Table 1 inch = 2.54 cm 1 gallon = 3.79 L 1 oz = 29.57 mL 1 yard = 0.91 m 1 lb = 0.45 kg 1 ft = 0.30 m 1 oz = 28.35 g • Find units in conversion table similar to in the problem & write the conversion • Cross multiply fractions • 1st fraction: Left side of original equation in numerator, right side (x) in denominator • 2nd fraction: Set up so units are diagonal from original fraction • Multiply when in numerator, divide when in denominator • 50 gallons = ________ mL
You Try! • 20 oz = ____________ kg
Challenge: Convert Among Different Types of Units (Apples to Oranges) • You will be given a conversion example • Set up fractions so that the units cancel out • Multiply! • Example: 12 gallons = ______ miles (25 miles per gallon)