1. Waves

2. A. What are Waves? - Rhythmic disturbances that carry energy through matter and space. B. Medium - Type of material that waves can pass through. -gas, liquids, solids

3. C. Two Types of Waves 1. Transverse Wave: a. The medium moves at a right angle to the direction the wave travels. -examples: Ocean Waves & Jump Ropes

4. b. Transverse waves can be described using characteristics called Crests and Troughs. -Crest: the high point in a wave. -Trough: the lowest points in a wave.

5. Rest Position Crest Trough

6. c. Waves are measured using wavelengths. -Wavelength: the distance from one point on one wave to the identical point on another wave. (crest to crest)

7. Rest Position Crest Wavelength Trough

8. d. Amplitude: -the distance from the crest or trough of one wave to the rest position of the medium. - Waves with large amounts of energy have greater amplitudes.

9. Rest Position Crest Wavelength Amplitude Amplitude Trough

10. e. Wave Frequency - The # of wave crests that pass one place per second. - Expressed as Hertz (Hz) - As frequency increases, wavelength decreases.

11. Velocity = Wavelength x Frequency Velocity = Wavelength x Frequency v = λ x f v = λ x f - Wave Velocity Formula f. Wave Velocity: - How fast a wave moves.

12. 2. Compressional Waves -Matter vibrates in the same direction the wave is traveling. - “Slinky”

13. compression wavelength rarefaction Compressional Wave

14. D. Sound Waves - Sound can be transmitted through any type of matter. - Compressional Waves -The wave that carries sound energy.

15. - Speed of Sound depends on: 1. The Type of Medium - solids & liquids are better than gases because of the particles being closer together. 2. The Temperature of the Medium -The warmer the temperature, the faster the sound will travel.

16. - Which travels faster, sound or light? - Light travels almost 1 million times faster!!!!! - Fireworks - No Air = No Sound

17. E. Key Concepts for Sound - Pitch: highness or lowness of sound. -Higher frequency = Higher Pitch -Human ears hear between 20 Hz and 20,000 Hz. - Intensity: depends on the amount of energy each wave. - Loudness: human perception of sound

18. -Doppler Effect: -Change in wave frequency due to a moving sound source. -Louder the closer it gets to you, fades as it goes away. -Example: Police Car or Ambulance

19. http://www.colorado.edu/physics/2000/applets/doppler2.htmlwww.colorado.edu/physics/2000/applets/doppler2.html http://www.colorado.edu/physics/2000/applets/doppler.html Examples of the Doppler Effect (The Police Car!!!!)