sound

• sound is a longitudinal & mechanical wave
• speed of the sound:

  • in air = 330 m/s
  • in water = 1500 m/s
  • in steel = 5000 m/s
• as the amplitude increases the sound gets louder & as the amplitude decreases the sound gets quiter
• as the frequency increases the pitch increases and as the frequency decreases pitch decreases
• 20 - 20,000 Hz = human range
• uses of ultrasound:

  1. imaging
  2. treatment of joints
  3. measuring depth of water (sonar)
  4. material testing
• echo = depth = distance / 2