1. Ch. 14 Waves and Energy Transfer Milbank High School

2. Sec. 14.1 Wave Properties Objectives  Identify how waves transfer energy without transferring matter.  Contrast transverse and longitudinal waves.  Relate wave speed, wave-length, and frequency.

3. Waves Waves are everywhere!  Sound, light, radio, microwave, water, sine, cosine, telephone, earthquake, stadium, slinky… Wave—rhythmic disturbance that carries energy through matter or space

4. Mechanical Waves Require a medium  Water, air, ropes Will not occur in a vacuum Non-mechanical waves  Electromagnetic  light

5. Waves Con’t Wave Pulse Continuous Wave Transverse Wave Longitudinal Wave  Compressions and rarefactions

6. Surface Waves Combination of both…(water)

7. Wavelengths Crests Troughs Wavelength (λ) Frequency f = 1/T  Hertz Speed of wave v = λf Ex: Pg. 333

8. Sec. 14.2 Wave Behavior Objectives  Relate a wave’s speed to the medium in which the wave travels  Describe how waves are reflected and refracted at boundaries between media, and explain how waves diffract  Apply the principles of superposition to the phenomenon of interference

9. Wave Behavior Waves can be reflected Incident wave Reflected wave  Sometimes passed on, sometimes reflected back, sometimes both

10. Superposition of Waves Principle of superposition  A wave meets a reflected wave Interference

11. Destructive Interference Superposition of waves with equal but opposite amplitudes

12. Constructive Interference Amplitudes are in the same direction Creates a larger wave Antinode Node

13. Waves and Boundaries Boundaries change speed and wavelength Frequency stays the same Type of barrier determines amount of change

14. Waves in two dimensions Water waves Reflection  Law of reflection  Angle of incidence = angle of reflection

15. Refraction of waves in two dimensions Change in direction of waves at the boundary between two different media

16. Diffraction Spreading of waves around a barrier Water waves around a coral reef Or more than one object  Interference would occur Long wavelengths diffract the least  AM vs FM radio