# Phy 125 - Book Pages 1 - 28

Published on: Mon Jan 25 2010

1. Read chapter, learn vocab and notation
2. Go to class
3. Read again, follow details, Answer exerciseâ€™s and questions
4. Solve problems at chapter end

Quantities are italicized, units are not, and bold with arrow is vector
**Symbol & Color Guide** - Pg 19
**Significant figures:** The final result of multiplication or division should have only as many digits as the number with the least number of significant figures used in calculation
Precision - Repeatability
Accuracy - nearness to true value
The meter is the length of path traveled by light in vacuum during a time interval of 1/299,792,458 of a second
1 inch = 2.54 centimeters
mass of atoms and molecules = unified atomic mass unit (u)
1u = 1.6605 x 10^-27 kg
Speed of light = 299,792,458 m/s
5280 feet in mile
length = meter (m)
time = second (s)
mass = kilogram (kg)
Electric Current = ampere (A)
Temperature = kelvin (K)
amount of substance = mole (mol)
Luminous intensity = candela (cd)
*Stopped Page 26*
299 792 458 Two ninety-nine, seven ninety-two, four fifty-eight meters per second.
Meter: length light vacuum two ninety-nine, seven ninety-two, four fifty-eight
Make sure understand changing units on page 28. Practice multiplication of scientific numbers
**To Check when solving**
Is unit correct? Is dimension correct? Is Decimal correct? Any exponents?
**Dimensional Analysis**
breaking down the unit into the underlying base units
Planck length
Uncertainty
Order of Magnitude
Notion of Symmetry?