1. Converting and Sig Figs
Mr. Garcia
IB Physics SL
GOHS

2. Conversion Factors
Conversion Factor: ratio of equal units to convert from one unit to the other.
4 quarters/1 dollar = 1; etc…
Factor Label Method: units used for mathematical conversion of measurements
12 dollars (4 quarters/1 dollar) = ?
Answer = 48 quarters

3. Converting Units To convert units:
Measured Amount (Conversion Factor) = New Unit

4. Metric Prefixes

5. Using Metric Conversion Factors
When using the metric table for conversion factor remember:
The base unit gets the exponent (base unit is the unit without a prefix)
The prefix gets the number 1
Example:
9 m  ? mm
Chart says 10-3  milli-
Convert: 9 m (1 mm/10-3 m) = 9000 mm

6. Uncertainty and Error
Accuracy: how close a measurement is to the accepted value.
Precision: is the degree of exactness of a measurement; consistency in measurement.
Uncertainty: the measure of confidence in a measurement. A lower uncertainty indicates greater confidence.

8. Significant Figures (Sig Figs)
Determining Sig Figs: Garcia paraphrase
All nonzero digits are significant
Zero is significant IF:
Between nonzero digits
Right of nonzero digits AND there’s a decimal in the number

9. Sig Figs cont. Addition & Subtraction:
Keep the least accurate decimal place.
Example:
= = 27.1
= = 5766

10. Sig Figs cont. Multiplication and Division
Keep the least significant figures
Example:
3.05 g/8.470 mL = g/mL = g/mL
Conversion factors are not included for sig figs

11. Scientific Notation Used to represent large or small numbers
General form: M x 10n
1 < M < 10
n is an integer (+ or - whole number)
Example:
= 6.02 x 1023
= 6.02 x 10-9