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

θ = phase difference

Example:

90 degrees out of phase

180 degrees out of phase

velocity : speed and direction

• speed = distance / time
• direction is given by sign (+ or -)

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

• wave passing through a medium (usually air)

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

• Smallest audiable amplitude = 0.00002 pa {}
• Threshold of pain : 20 pa
• Average atmospheric Pressure : 100000 pa

Frequency : Determines pitch

higher f ⇒higher pitch

• Human audible range : 20 Hz -20 kHz

Timbre : Determined by wave shape

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