1. sound waves

2. Sound waves Sound waves are caused by vibrations
Vibrations cause contraction and expansion of an object, which creates regions of high and low pressure in the air (or medium that sound is traveling through)
High pressure regions are called COMPRESSIONS
Low pressure regions are called RAREFACTIONS

3. SOUND WAVES Sound waves are longitudinal
The vibrations of particles in a sound wave move parallel to the direction of the wave
We only hear sound waves because our ear drums interact with them

4. Sound waves
Sound travels at a constant speed through different mediums
The speed of sound in air (at STP) is 343 m/s
High pitch= high frequency= short wavelength
Low pitch= low frequency= long wavelength
Wave amplitude is associated with energy
Higher amplitude = more energy
In sound waves, a higher amplitude means a louder sound