1. Unit Conversion
“Hard work has made it easy. That is my secret. That is why I win”
Nadia Comaneci
Olympic gymnast

2. Unit Conversion Learning Target ‘GUESS’ procedure
Students learn how to:
1) Convert between metric and non-metric units
e.g. meters and yards
2) Convert between metric units
e.g. meters and kilometers
3) Do multi-step conversion problems
e.g. seconds to years

3. Challenge Question
How many seconds are there in 1 year? * reminder: bring your calculator to class every day this semester

4. Unit Conversion
Why important? Youtube: When NASA Lost a Spacecraft Because It Didn't Use Metric - It Happened in Space #21 Re-Read sec 1.2 p Units of measurement and intro to unit conversion.

5. 1.2 Unit Conversion: non-metric  metric
How many centimeters is 5 feet? (1 foot = 30 centimeters)
ANS = 150 centimeters

6. Unit Conversion Notes:
The unit you are converting from goes in the bottom (top/bottom?) of the conversion factor
The unit you are converting to goes in the top (top/bottom?) of the conversion factor
See ‘Skills Toolkit’ p. 13
Youtube: Tyler DeWitt - Converting Units with Conversion Factors

7. GUESS Procedure
Given
Unknown
Equation
Substitute
Solve

8. Unit Conversion: metric  non-metric
A bicycle has its frame size given as 62 cm. What is the frame size in inches? (1 inch = 2.54 cm) *Note: metric to non-metric conversion factors will always be given to you ANS = 24 inches

9. Significant Figures
Significant figures tell you the accuracy with which a measurement was made e.g. 62 cm OR cm Suggested reading Sec 2.3 Measurements and Calculations p

10. Significant Figures – multiplication & division
Notes: The number of sig figs in your answer….. is the same as the number of sig figs in the ‘given’

11. Significant Figures – multiplication & division
Notes: * If there is more than one given….. the number of sig figs in your answer….. is the same as the number of sig figs in the ‘given’ …. which has the least (least/most) number of sig figs e.g. 2.2 x = ? ANS = 11 (2 sig figs) (rounding)

12. Significant Figures – Exact Values*
Conversion factors have an infinite number of significant figures e.g. 1 m = 100 cm m = cm

13. Practice: scratch paper
The distance between Los Angeles and San Diego is about 124 miles. How many kilometers is the distance between the two cities (1 mile = 1.6 km) ANS = 198 kilometers

14. 1.2 Prefixes Think about it…....
How many grams are there in 1 kilogram?

15. Notes: Prefixes (see Table 3 p. 13)
Meaning
Sci Notn
Example
Mega (M)
Million
106
1 MByte =
Bytes
Kilo (k)
Thousand
103
1 kg =
1000 g
Centi (c)
Hundredth
10-2
1 m =
100 cm
Milli (m)
Thousandth
10-3
1000 mm
Micro (µ)
Millionth
10-6 µm
Nano (n)
Billionth
10-9 nm

16. Dimensional Analysis Scratch paper work
1) Convert 1258 cm to meters
ANS = m
2) Convert 234g to kg

17. 1.2 Dimensional Analysis Practice
2) Convert 234g to kg
ANS = kg
3) Convert 123 km to m

18. 1.2 Dimensional Analysis 3) Convert 123 km to meters. ANS = 123 000 m
4) How many milligrams are there in 4.3 kg?

20. 1.2 Dimensional Analysis 4) How many milligrams are there in 4.3 kg?
First convert kg to g
Then convert g to mg
ANS = mg
Convert to scientific notation
ANS = 4.3 x 106 mg

21. Scientific Notation When to use it? 16 = 1.6 x 101
When a number is greater than 10000
34000 = 3.4 x 104
When a number is smaller than 1/1000th
= 3.4 x 10-4

22. 1.2 Dimensional Analysis: Practice Scratch paper work
(* HONS: 1 cm3 = 1 mL)
To check your answers, show work to teacher when complete

23. 1.2 Dimensional Analysis: Practice Scratch paper work
More practice:
p. 32 # 22 a,b, & 23a,b,c,d*, e*, f*
To check your answers, show work to teacher when complete
Work sheet: One-Step Dimensional Analysis Problems

24. Challenge Question
How many seconds are there in 1 year? ANS = seconds ANS = x 107 seconds

25. Practice*
Superman can run continuously at 62 miles per hour. How many miles can Superman run in one week? Write your final answer in scientific notation to 2 sig figs. ANS = miles/week

26. Dimensional Analysis* Scratch paper
If the average heart rate is 72 beats per minute, approximately how many times will a heart beat in a year?
Given: average heart beat is 72 beats/min
Unknown: heartbeats per year (unit is beats/year)

27. Dimensional Analysis
72 beats/min X 60 min/hour X 24 hours/day X 365 days/year ANS = beats/year Convert to sci notn (2 sig figs) 3.8 X 107 beats/year