1. TOPIC 1: PHYSICS AND MEASUREMENT
IB SL PHYSICS
GARCIA
GOHS

2. TOPIC 1.1: The Realm of Physics
Magnitude:
Estimations of size, often using powers of ten.
Useful when dealing with very large/small amounts
Make comparisons to known amounts

3. Magnitude exercises How high is a two-story house in meters? Solution:
How high is the ceiling compared to you?
How tall are you?
Approx. height of room then multiply by two.

4. 1.2 Measurement and Uncertainties
S.I. system of measurement
“Systeme International”
Fundamental: base units
Derived: two or more base units combined

5. 1.2 Measurement and Uncertanties
Units
Metric system
Accuracy vs. Precision
Significant Figures in calculations

6. Fundamental SI units

7. Derived SI units Name Symbol Concept Broken down to base units Newton
Force or weight
Kgms-2
Hertz Hz
Frequency
1/s or s-1
Joule J
Energy or work
Kgm2s-2

8. 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

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

10. Metric Prefixes

11. 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

12. 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.

14. 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

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

16. 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

17. 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

18. Graphing
Practice to come later.