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

2. Equivalence Statements, & Conversion Factors
Dimensional Analysis
Equivalence Statements, & Conversion Factors

3. I) Equivalence Statements
An equivalence statement shows two quantities with different units that are equal to each other.

4. Equivalence Statements
A) equivalence statements can be counted numbers:
Examples:
1 dozen eggs = 12 eggs
1 pair of shoes = 2 shoes

5. Equivalence Statements
B) equivalence statements can be numbers with in the same measurement system:
Examples:
1 km = 1000m
5280 feet = 1 mile

6. Equivalence Statements
C) equivalence statements can be numbers in different measurement systems:
Examples:
1 lb = 2.21 kg
1 in = cm

7. Equivalence Statements
D) equivalence statements can be numbers that are specific to a situation:
Examples:
1 in = 50 km such as on a map 1m = 3.45cm such as in a photograph
3 students = 1 lab group such as during a particular lab

8. Practice: Design four equivalence statements and write them on your paper:

9. II) Conversion Factors
A) Conversion factors are a set of fractions that ALWAYS equal one. The numerator and the denominator have equal value.

10. II) Conversion Factors
B) Every equivalence statement can be used to construct 2 conversion factors.

11. Practice:
Write the two conversion factors for the equivalent statement below:
equivalence statements
13 steps = 1 flight of stairs

12. II) Conversion Factors
Use background information sheet (equivalent statements) to write base conversion factors.

13. III) Using Conversion Factors for Dimensional Analysis
A) What happens to the value of a number when you multiply it by one?

14. III) Using Conversion Factors for Dimensional Analysis
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.

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

16. III) Using Conversion Factors for Dimensional Analysis
D) To decide which of the two conversion factors to use make sure the units from the known value will cancel leaving units for the unknown value.

17. DO IT!! Convert 3.5 hours to minutes:
Write down the given information and put it over 1.

18. DO IT!!
Get up a conversion factor such that the information in the numerator and denominator equal each other.
3.5 hrs 1

19. DO IT!!
Cancel the units
3.5 hrs X 60 min
hrs

20. DO IT!!
Multiply the numerators.
3.5 hrs X 60 min = 210 min hr

21. DO IT!!
Multiply the denominators
3.5 hrs X 60 min = 210 min
hr 1

22. DO IT!! Divide your final answer and include the new units.
3.5 hrs X 60 min = 210 min = 210min
hr 1

23. Practice:
convert 27.5 L to mL

24. Convert 67.9dam to m

25. Convert 950g to kg