1. WAVES

2. What is a wave?
Any disturbance that transmits energy through matter or space.

3. What is a medium?
A substance through which a wave can travel. A medium can be a solid, liquid, or gas.
Sound waves and ocean waves require a medium (these are mechanical waves)

4. Waves that don’t need a medium
Visible light, microwaves, tv and radio waves are electromagnetic waves. They CAN travel through substances but move faster through empty space.

5. Types of Waves
Transverse waves: particles move perpendicular to the direction the wave is traveling. (ex. Electromagnetic waves)
crest
trough

6. Longitudinal waves: the particles move back and forth along the path the wave travels. (sound waves)
compressions
rarefactions

7. Combination of Waves
Surface waves are a combination of transverse and longitudinal.

8. Properties of Waves

9. Amplitude
The maximum distance the wave vibrates from its rest position.
(large amplitude= more energy)

10. Loudness of sound is related to amplitude.
Amplitude of Sound
Loudness of sound is related to amplitude.

11. Wavelength
The distance between any two adjacent crests or compressions in a series of waves.

12. Frequency The number of waves produced in a certain amount of time.
(the higher the frequency, the shorter the wavelength)
Higher frequency means more energy
Frequency is measured in Hertz (Hz) waves per second.

13. Frequency of Sound
Frequency of sound is called pitch. This determines how high or low a sound is.

14. Wave Interactions

15. Reflection When a wave bounces back after striking a barrier.
Reflected sound waves are called echoes.

16. Refraction
The bending of light waves as they pass at an angle into a new medium.

17. Diffraction
The bending of waves around a barrier or through an opening.

18. Interference
Two or more waves overlapping.