1. SOUND WAVES are the result of VIBRATIONS

2. A SOUND WAVE is a LONGITUDINAL WAVE but it is drawn as a transverse wave
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

3. Sound is a MECHANICAL WAVE
Sound requires a medium
Sound can travel in a solid, liquid, or gas

4. The Speed of SOUND in AIR
The speed of sound 331 m/s at 00C
The speed of sound increases about 0.6 m/s for each 0C rise in temperature
Sound travels faster in liquids and fastest in solids than in air (a gas) because the molecules are closer together
vT = v T

5. The Frequency of a SOUND WAVE
Represents the PITCH or a NOTE on a MUSICAL SCALE

6. Frequencies of Sound
The human ear is capable of detecting sound waves between 20 Hz to Hz.
Any sound with a frequency below the audible range of hearing is an infrasound and any sound with a frequency above the audible range of hearing is known as an ultrasound.
Dogs can detect frequencies between 50 Hz and Hz.
Bats, who must rely on sound echolocation for navigation and hunting, can detect frequencies as high as Hz.
Dolphins can detect frequencies as high as Hz.
An elephant possesses the unusual ability to detect infrasound, having an audible range from approximately 5 Hz to approximately Hz.

7. The AMPLITUDE of a SOUND WAVE
Represents the LOUDNESS of the sound

8. LOUDNESS in Decibels Silence 10 Heartbeat 20 Whisper 30 Soft piano 50
Silence 10
Heartbeat 20
Whisper 30
Soft piano 50
Soft talking 60
Conversation 80
Street traffic 90
Food blender
110
Thunder
120
Painful sounds
170
Jet engine

9. Resonance
Resonance occurs when two interconnected objects share the same frequency.
Resonance occurs when one object vibrating at the same natural frequency of a second object forces that second object to vibrate.

10. The Doppler Effect

11. The Doppler Effect