Phase : An angle that tells us how much a wave has shifted

        θ = phase difference


90 degrees out of phase

180 degrees out of phase

velocity : speed and direction

        Ex. Movement up :         + 5 m/s

               Movement down : - 5 m/s

Position vs. Time of a spring

take the derivative and get:

Velocity vs. Time of a spring

        90 out of phase

Sound Waves : longitudinal pressure waves


  1. Transverse : Oscillations perpendicular to the direction of motion
  2. Longitudinal: Oscillations parallel to motion
  1. ex. compressing and uncompressing waves in a slinkey

Pressure : Force/ Area (F/A)

Amplitude of Sound Waves

 - Amplitude is largely responsible for volume

Frequency : Determines pitch

        higher f ⇒higher pitch

Timbre : Determined by wave shape

        Ex, sine wave, square wave, triangle wave, ...etc