09/24/07 DIMENSIONAL ANALYSIS

Objectives To learn how dimensional ______________ can be used to solve problems To learn to ___________ from one metric unit to another To learn to convert between _______ units and standard _____ units To practice using problem solving techniques

A. Tools for Problem Solving Be systematic Ask yourself these questions

A. Tools for Problem Solving Converting Units of Measurement We can convert from one ___________ of units to another by a method called _____________________ using conversion factors. Unit1  _______________________ = Unit2

A. Tools for Problem Solving Converting Units of Money Conversion factors are built from an ________________________which shows the ______________ between the units in different systems. Conversion factors are ____________ of the two parts of the equivalence statement that relate the two units.

Using Simple Dimensional Analysis Example 1: You have 12 nickels and to save pocket space you want to trade them to your friend for dimes. How many dimes would you have?

Using Simple Dimensional Analysis Example 2: It takes you 2.6 days to travel to a remote get away in California. How many seconds will it take you?

Using Dimensional Analysis Use the same method to convert metric to metric. How many centimeters are in 2.5 meters?

A. Tools for Problem Solving Converting Units of Measure 2.85 cm = ? in. 2.85 cm  conversion factor = ? in. Equivalence statement _______ cm = 1 in. Possible conversion factors Does this answer make sense?

***THINGS TO REMEMBER when doing Conversions Take what you are given -i.e. What is/are my ____________? Determine what units want to convert to -i.e. What is/are the unit(s) I want in my final answer (what are the _________________)? Find the ___________________________. -To convert between any units you must have _____________________ What is/are the possible _____________ factors?

***THINGS TO REMEMBER when doing Conversions cont… Choose the conversion factor that fits your __________. Conversion factor should be a __________. The unit you want to get rid of should be on the ______ (i.e. in the denominator) to cancel out (or on the top depending on your conversion) The ending unit should be on the ________ (i.e. in the numerator) -The answer should make sense if you got to the right unit(s) Check you Sig. Figs. -Remember the EXACT NUMBERS Sig. Figs. Rule???

A. Tools for Problem Solving Tools for Converting from One Unit to Another Step 1 Find an equivalence statement that relates the 2 units. Step 2 Choose the conversion factor by looking at the direction of the required change (cancel the unwanted units). Step 3 Multiply the original quantity by the conversion factor. Step 4 Make sure you have the correct number of significant figures.