3.3 Conversion Problems Conversion Factor - A conversion factor is a ratio of equivalent measurements. Examples: 1 dollar = 4 quarters = 10 dimes 100 cm = 1m or 100cm/1m or 1m/100cm *Conversion factors have an unlimited # of sig.figs.

3.3 Conversion Problems Dimensional Analysis -A way to analyze and solve problems using the units, or dimensions, of the measurements. Example: How many seconds are in a workday that lasts exactly eight hours? KnownsUnknown Time worked = 8 h seconds worked = ? s 1 hour = 60 min. 1 minute = 60 sec. = 8 h60 min 1 h 60 sec. 1 min 28,800 sec.

3.3 Conversion Problems Dimensional Analysis Example: The directions for an experiment ask each student to measure 1.84 g of copper (Cu) wire. The only copper wire available is a spool with a mass of 50.0 g. How many students can do the experiment before the copper runs out? KnownsUnknown 50.0g of wire # of students 1.84 g per student = 50.0 g1 student 1.84 g students

3.3 Conversion Problems Converting Between Units -Problems in which a measurement with one unit is converted to an equivalent measurement with another unit are easily solved using dimensional analysis. Example: How many grams are in kilograms? KnownsUnknown kilograms grams 1 kg = 1000 g = kg1000 g 1 kg 575 g

Base Unit: Gram (g) Meter (m) Liter (l) x x x10 -3 “deci”-“centi”- “milli” x10 1 1x10 2 1x10 3 “deka”- “hecto”- “kilo”- Question: If Ms. Nadeau is 1.4 meters tall. How tall is she in millimeters? Answer :_________________ 1 4 meters mm

Base Unit: x x x10 -3 “deci”-“centi”- “milli” x10 1 1x10 2 1x10 3 “deka”- “hecto”- “kilo”- Using the scale above, perform the following metric conversions: cm to hm. ________________4. 75 mm to cm. ________________ km to dm. ________________5. 25 dam to hm. ________________ cm to dam. ______________6. 10 dm to km. _________________ 0.01 hm 25,000 dm 2 dam 7.5 cm 2.5 hm km