1. Essential Question: How does data collected provide evidence that the amount of energy a wave carries determines the properties of a wave?

2. Waves Any disturbance that transmits energy through matter or empty space

3. Wave Energy  Waves transfer energy through vibrations of particles in a medium.  Medium- a substance through which a wave can travel.  As a particle vibrates, it passes energy to the next particle.

4. Waves and Media  Waves that need a medium to travel (mechanical): Sound Sound Ocean Ocean Seismic (earthquakes) Seismic (earthquakes)  Waves that do not need a medium to travel (electro- magnetic) Light X-rays Microwaves TV and Radio

5. Types of Waves  Waves can be classified based on the direction in which the particles in the wave vibrate compared to the direction the wave moves.  3 main types: Transverse Longitudinal Longitudinal Surface Surface

6. Transverse Waves  The particles move perpendicular to the direction the wave is traveling.

7. Transverse Waves Continued.  Crest- The highest point  Trough- the lowest point

8. Longitudinal Waves  Particles in the medium vibrate parallel to the direction of the wave motion.

9. Longitudinal Waves Continued  Compression- particles are crowded  Rarefaction- particles are spread apart

10. Sound  Sound waves are a type of longitudinal wave that is the result of compressions and rarefactions of air particles.

11. Surface Waves  Surface waves are a combination of transverse and longitudinal waves.  Water Waves:

12. Properties of Waves

13. Properties of Waves: Amplitude  Amplitude: The maximum distance the particles of a medium travel from their rest position.

14.  Larger amplitude = More energy

15. Properties of Waves: Wavelength  The distance from any point of a wave to the identical point on the next wave.  Shorter wavelength = More energy

16. Properties of Waves: Frequency  The number of waves produced in a given amount of time.  Often measured in Cycles per Second or hertz  Higher frequency = More energy

17. Properties of a Wave: Wave Speed  The speed at which a wave travels. V= λ * f V= Wave speed λ = Wavelength f = frequency

18. REVIEW http://www.bbc.co.uk/schools/gcsebitesize/science/edexcel/waves/anintroductiontowavesact.shtml

19. Practice Question 1  How many waves are there if there are 7 nodes (places the wave touches the median line)

20. Practice Question 2  What is the wavelength of a wave with a frequency of 10 Hz and a wave speed of 300 m/s?

21. Practice Question 3  What is the wave speed of a wave with a wavelength of 10 meters, 5 nodes and takes 2 seconds to pass?