2. Ch. 15 What are waves? -A wave is a traveling disturbance that carries energy from one place to another.

3. Waves and Energy -Mechanical waves require a medium to travel through -A medium is a solid, liquid, or gas -Mechanical waves require a medium to travel through -A medium is a solid, liquid, or gas

4. Waves and Energy Waves (energy) travel through the medium but do not carry the medium with it. Notice how the duck stays put as the waves pass under it Waves (energy) travel through the medium but do not carry the medium with it. Notice how the duck stays put as the waves pass under it

5. Waves and Energy Energy is transferred from particle to particle in the medium. The energy travels along but the particles (medium) does not. Do you think sound travels faster through a solid, liquid, or a gas? Energy is transferred from particle to particle in the medium. The energy travels along but the particles (medium) does not. Do you think sound travels faster through a solid, liquid, or a gas?

6. Types of Waves

7. Transverse waves -A transverse wave moves the medium up and down, but the wave moves left and right

8. Longitudinal/Compression Waves

9. A longitudinal wave move the medium in the same direction as the wave

10. Properties(characteristics)of Waves Frequency- the number of waves that pass a given point in a given amount of time Measured in Hertz(Hz) The higher the frequency, the more energy the wave has. Frequency- the number of waves that pass a given point in a given amount of time Measured in Hertz(Hz) The higher the frequency, the more energy the wave has.

11. Draw a wave with a high frequency: Draw a wave with a low frequency:

12. Wavelength Wavelength is the distance between two crests or two troughs.

13. Amplitude Amplitude is the height of the wave. It is the maximum distance moved from the rest position.

14. Amplitude The higher the amplitude, the more energy the wave has.

15. Interactions of Waves Reflection- when a wave hits a surface through which it can’t pass, it bounces back. Examples: Reflection- when a wave hits a surface through which it can’t pass, it bounces back. Examples:

16. The angle of incidence is the incoming wave The angle of reflection is the reflected wave The angle of incidence is the incoming wave The angle of reflection is the reflected wave

18. Refractions When a wave moves from one medium to another at an angle, it changes speed, causing it to bend.

19. Visible light can be refracted using a prism, or water, to create a rainbow

21. Diffraction When a wave passes a barrier or moves through a hole in a barrier, it bends and spreads out.

23. Interference When two or more waves meet, they have an effect on each other. This is called an interference.

24. Constructive Interference Occurs when two waves combine to form a wave with a larger amplitude

25. Destructive Interference When the amplitudes of two waves combine and produce a smaller amplitude

26. Resonance Most objects have a natural frequency of vibration Resonance occurs when vibrations traveling through object match the objects natural frequency If vibrations of same frequency are added, the amplitude will increase Most objects have a natural frequency of vibration Resonance occurs when vibrations traveling through object match the objects natural frequency If vibrations of same frequency are added, the amplitude will increase

27. Resonance Objects absorb the energy of objects with the same frequency If object is not very flexible, it could shatter http://video.mit.edu/watch/breaking-glass- with-sound-3947/ http://video.mit.edu/watch/breaking-glass- with-sound-3947/ Objects absorb the energy of objects with the same frequency If object is not very flexible, it could shatter http://video.mit.edu/watch/breaking-glass- with-sound-3947/ http://video.mit.edu/watch/breaking-glass- with-sound-3947/

28. Speed, Frequency, Wavelength Waves travel at different speeds The speed of a wave is how far it travels in one unit of time (distance/time) Waves travel at different speeds The speed of a wave is how far it travels in one unit of time (distance/time)