1. Doing Physics

2. Observations Qualitative - Observe characteristics of an object.
Useful for categorizing objects.
Quantitative - Assign a numerical value to an observation.
Useful for applying mathematics to make predictions.
Concepts - Try to explain why it happens
Rutherford – “All science is either physics or stamp collecting.”

3. Base Units 7 independent base units based on fundamental quantities.
All other units are combinations of these units.
Time
Mass
second (s)
kilogram (kg)
Length
meter (m)
Current
Luminosity
Amount
Temperature
mole (mol)
kelvin (K)
ampere (A)
candela (cd)

4. Metric Prefixes Common powers of 10 are given special names.
Learn and be able to use the following.
Examples
1012 tera T
109 giga G
106 mega M
103 kilo k
10-2 centi c
10-3 milli m
10-6 micro m
10-9 nano n
10-12 pico p
16,000,000 bytes = 16 × 106 bytes = 16 Mbytes
700 nm = 700 × 10-9 m = m

5. Conversion Factors
From a known relationship you can make two different conversion factors
How many inches are in 100 cm?

6. Atoms in Graphite
Knowing that 1 u = 1.66 × kg and 1 carbon atom has a mass of u, how many carbon atoms are in 1 kg of graphite?

7. Dimensional Analysis
Dimensions for a particular physical quantity will always be the same.
[Mass] = M [Time] = T [Length] = L
All equations should be dimensionally correct.
How is centripetal acceleration, ac, related to velocity and radius?

8. Scientific Notation
Move the decimal point until it is to the right of the first non-zero digit.
Multiply by a power of 10 to offset the change in the decimal point’s position.
Shift left use positive power of 10
290 m = 2.9 × 100 m = 2.9 × 102 m
Shift right use negative power of 10

9. Sig. Figs. and derived values
When multiplying and dividing, keep the # of sig. figs. of the least precise number.
When adding or subtracting keep the number of digits consistent with the least number of digits to the right of the decimal point.
Ex. What are the perimeter and area of a rectangle which is 3.82 m by 4.35 mm?

10. Estimation Making an educated guess.
Will help you catch order of magnitude errors.
Always ask yourself if your answer makes sense.

11. IDEA Strategy Interpret Develop Evaluate Assess
Identify applicable concepts and players in the problem.
Develop
Draw diagrams and determine appropriate formulas to develop a plan towards a solution.
Evaluate
Execute your plan using algebra, trig, calculus, etc. to reach your solution.
Assess
Ask whether your answer makes sense.

12. Benjamin Franklin regarding George Whitefield
He had a loud and clear voice, and articulated his words and sentences so perfectly, that he might be heard and understood at a great distance,…
...I had the curiosity to learn how far he could be heard, by retiring backwards down the street towards the river; and I found his voice distinct till I came near Front-street, when some noise in that street obscur'd it. Imagining then a semi-circle, of which my distance should be the radius, and that it were fill'd with auditors, to each of whom I allow'd two square feet, I computed that he might well be heard by more than thirty thousand.
Excerpt from The Autobiography of Benjamin Franklin