1. Sound

2. Review
A wave can be described as a disturbance that travels through a medium, transporting energy from one location to another location.
The medium is simply the material through which the disturbance is moving

3. Wave Categories
An electromagnetic wave is a wave which is capable of transmitting its energy through a vacuum
A mechanical wave is a wave which is not capable of transmitting its energy through a vacuum.
Sound is a mechanical wave

4. Sound Sound is a Longitudinal Wave
Waves in which the motion of the individual particles of the medium is in a direction which is parallel to the direction of energy transport.

5. Sound
The compressions are regions of high air pressure while the rarefactions are regions of low air pressure.

6. Sound
Since a sound wave consists of a repeating pattern of high pressure and low pressure regions moving through a medium, it is sometimes referred to as a pressure wave

7. Speed of Sound
The speed of sound depends on the elasticity, density, and temperature of the medium.

8. Speed of Sound
Elasticity is the ability of a material to bounce back after being disturbed.
Sound travels more quickly that have a high degree of elasticity
Best solids gasses Worst

9. Speed of Sound
Density of a medium is how much matter there is in a given amount of space.
Sound travels slower in dense materials
lead vs steel

10. Speed of Sound Temperature
Sound travels slower at lower temperature within a given medium.

11. Music In sound, frequencies are commonly referred to as pitch.
When two sounds with a frequency difference of greater than 7 Hz are played simultaneously, most people are capable of detecting the presence of a complex wave pattern resulting from the interference and superposition of the two sound waves.

12. Music
Any two sounds whose frequencies make a 2:1 ratio are said to be separated by an octave.