Sound Waves

Sound Waves

PROPERTIES
1. loudness (amp) - loud and quiet
2. pitch(frequency) - high and low
3. quality (wave form/shape) - simple and complex
4. ALWAYS LONGITUDINAL
  1. made of
    1. compressions
      1. Constructive
      2. high pressure
      3. speakers= pushed out
    2. rarefractions
      1. depression
      2. destructive
      3. low pressure
      4. speakers= pushed in
FUNTIONS
1. transmit energy through a medium
2. go thru, around, and reflect off of things
3. hav constructive and destructive interference
4. similar to mechanical waves
TUNING FORKS
1. always vibrate at a specific frequency
OSILISCOPE
PRESSURE/TIME GRAPH
1. shows how pressure changes over a period of time
Definition
1. sound made by changes in pressure
SOUND INTENSITY
1. measure of the amount of sound reaching an area (1m2) in 1 s
2. exact measurement verses perception(loudness)
3. pW/m2
4. sound intensity level - to the power of 10
  1. measured in the Bel (B)
    1. or the decibel (dB)
  2. intensity increases by factor of 10 = increases by 1B
5. conversions
  2. 1B = 10pW/m2
VELOCITY OF SOUND IN AIR
HUMAN HEARING
1. 20 - 20 000 Hz range
2. dogs - 50 - 50 000 Hz range
3. infrasonic
4. ultrasonic
5. supersonic
6. subsonic

Resource summary

	Created by Danielle McCulloch almost 11 years ago