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Dimensional Analysis. Dimensional Analysis. Dimensional analysis : a method of solving problems that involves using equivalence statements and conversion factors; the units (dimensions) guide you through the problem. Dimensional Analysis.
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Dimensional Analysis Dimensional analysis: a method of solving problems that involves using equivalence statements and conversion factors; the units (dimensions) guide you through the problem
Dimensional Analysis Equivalence statement: an accepted relationship between two units Example: 12 inches = I foot
Dimensional Analysis Conversion factors: two possible ratios from an equivalence statement Equivalence statement: 12 inches = I foot Conversion factors: 12 inches and I foot I foot 12 inches
Dimensional Analysis Look at the equivalence statements on page 163. Write down the the two possible conversion factors for each equivalence statement.
How to use dimensional analysis • Steps: 1. Identify starting & ending units. 2. Line up conversion factors so units cancel. 3. Multiply all top numbers & divide by each bottom number. 4. Check units & answer.
Dimensional Analysis Example problems using the equivalence statements on page 163. Be sure to copy the work done on the board. Example #1: 62 cm = ____ in Example #2: _____ yd = 2.45 m
Dimensional Analysis You will need to match the metric prefixes you memorized to units and construct your own equivalence statements. Example: kilo is 103 Which is true for the prefix kilo matched to the unit meter (m)? 1 m = 103 km or 103 m = 1 km
Dimensional Analysis Which is true for the prefix kilo? 1 m = 103 km or 103 m = 1 km Remember: the “1” always goes with the prefix; the “meaning” you memorized always goes with the unit (without the prefix). Which one above is correct?
Dimensional Analysis Write an equivalence statement by matching the unit g (gram) to these prefixes: M, d, c, µ.
Dimensional Analysis Use dimensional analysis to solve these problems. Be sure to show all work. a. 3.45 cm = ___ m • 2.4 X 10-3 g = ___ng • 6.8 X 105ms = ___ s
Dimensional Analysis Use the equivalence statements on page 163 to do problems 39 and 40 on page 166. One equivalence statement needed that is not listed on page 163: 16 oz = 1 lb