# Appendices

- Page ID
- 2042

- Useful Constants, Units, and Approximations
- These constants are provided for your convenience. You should know the SI unit conversions and SI prefixes, as well as be familiar with approximate values of common units. Do not memorize anything else; physics is not rote memorization (important values of constants will be given to you for quizzes and tests).

- Vectors
- A vector is a quantity with a magnitude and direction. In these notes, a vector quantity will be denoted by a bold letter (such as the electric field vector E ). Graphically, vectors are represented as straight arrows. The length of the arrow typically represents the vector's magnitude, and the arrow points in the same direction as the vector.