1. All waves carry energy Waves

2. A wave can be drawn as a squiggly line:

3. Wave Components  • Wavelength () • This is the distance from the crest of one wave to the crest of the next wave (or trough to trough)

4. Wave Components Amplitude This is the height of a wave from the mid-point to a crest (or from the mid-point to a trough)

5. Wave Components Frequency (f) • This is the number of complete waves per second. It is measured in Hertz (Hz)

6. Examples of Frequency What is the frequency of the second hand of a clock? Frequency = 1cycle/60 sec What is the frequency of US Presidential elections? Frequency = 1 election/4 yrs

7. Frequency & Pitch high frequency = high pitch low frequency = low pitch

8. Transverse vs. Longitudinal Waves • Transverse waves (water waves, light waves) move perpendicular (at a 90o angle) to the direction of the wave and the direction its energy is traveling

9. Transverse vs. Longitudinal Waves • Sound is a longitudinal wave, meaning that the vibrations move the same direction the wave is traveling in

10. Example of what a speaker does to air molecules to produce sound A longitudinal wave!