1. What is Dimensional Analysis? A fancy term for converting from one unit to another Examples … Going from dollars to cents Going from miles to kilometers Going from meters to cm to inches Going from seconds to years Going from mph to m/s

2. What is Dimensional Analysis? I will teach you a systematic way of doing these problems The method uses conversion factors

3. Some Typical Conversion Factors 60 s = 1 min as 60 s or 1 min 1 min 60 s 1.6 km = 1 mile as 1.6 km or 1 mile 1 mile 1.6 km 13.38 US dollars = 0.075 Mexican pesos as 13.38 USD or 0.075 pesos 0.075 pesos 13.38 USD

4. How Does Dimensional Analysis Work? A conversion factor is used, along with what you’re given, to determine what the new unit will be. Enough talk lets do one or two on the board!!!

5. Examples of Conversions Again, just be careful how you write the fraction. The fraction must be written so that like units cancel.

6. Steps 1. Start with the given value. 2. Write the multiplication symbol. 3. Choose the appropriate conversion factor. 4. The problem is solved by multiplying the given data & their units by the appropriate unit factors so that the desired units remain. 5. Remember, cancel like units.

7. Let’s try some examples together… 1. Suppose there are 12 slices of pizza in one pizza. How many slices are in 7 pizzas? Given: 7 pizzas Want: # of slices Conversion: 12 slices = one pizza

8. 7 pizzas 1 Solution Check your work… X 12 slices 1 pizza = 84 slices

9. Let’s try some examples together… 2. How old are you in days? Given: 17 years Want: # of days Conversion: 365 days = one year

10. Solution Check your work… 17 years 1 X 365 days 1 year = 6052 days

11. Multiple-Step Problems Most problems are not simple one-step solutions. Sometimes, you will have to perform multiple conversions. Example: How old are you in hours? Given: 17 years Want: # of days Conversion #1: 365 days = one year Conversion #2: 24 hours = one day

12. Solution Check your work… 17 years 1 X 365 days 1 year X 24 hours 1 day = 148,920 hours