1. Dimensional Analysis

2. Imagine This! You’re driving along a highway in Mexico when you notice this sign What should your speed be in miles per hour?

3. Using Conversion Factors for Dimensional Analysis Dimensional analysis is the process by which a conversion factor is used to convert a value from one unit to another.

4. Conversion Factors A)Conversion factors are a set of fractions that ALWAYS equal one. The numerator and the denominator have equal value. B) Because a conversion factor is a fraction that equals one, when it is used in a calculation it does not effect the value of the number, however, it does change the units.

5. Steps to Problem Solving Read problem Identify data Write down a unit plan from the initial unit to the desired unit Select conversion factors Change initial unit to desired unit Cancel units and check Do math on calculator LecturePLUS Timberlake5

6. How many minutes are in 2.5 hours ? Conversion factor 2.5 hr x 60 min = 150 min 1 1 hr cancel By using dimensional analysis / factor-label method, the UNITS ensure that you have the conversion right side up, and the UNITS are calculated as well as the numbers!

7. Learning Check How many seconds are in 1.4 days? Unit plan: days hr min seconds 1.4 days x 24 hr x ?? 1 1 day LecturePLUS Timberlake7

8. Learning Check What is wrong with the following setup? 1.4 day x 1 day x 60 min x 60 sec 24 hr 1 hr 1 min LecturePLUS Timberlake8

9. John Isner serves 140 miles per hour. What is that in feet per second?

10. 80 Km per hour equals ___________ miles per day?