Sound

Sound

1. Speed equation

   • Speed = Distance/Time
   • Measured meters per second (m/s)
   • Speed of sound
     • 340 m/s

2. Finding the speed of sound with data loggers

   • 1) Two mircophones are set up 1 metre apart
   • 2) A large sound is made
   • 3) The noise travelled to the microphone A and then to microphone B
   • 4) The computer measured the amount of time it took the sound to travel between A+B

3. The decibel scale

   • The loudness of a sound is linked to the size of the vibrations.
   • Large vibrations produce louder sounds
   • Quiet sounds are caused by small vibrations
   • The number of vibrations made in one second is called the frequency
     • It is measured in hertz.
   • The pitch of a sound is linked to the frequency of the vibrations
     • High pitch sounds have a high frequency.
     • Low pitched sound have a low frequency

4. Ultrasound

   • Pre-natal screening
     • Used for medical use
     • Pre-natal screening is used to image the foetus
   • Removal of kidney stones
     • Used for medical use
     • The ultrasound is used to shatter the stones allowing them to be passed out in urine
   • Removal of tartar
     • Used for medical use
     • Break up tartar deposits on teeth
   • Quality control
     • For industrial use
     • Used for checking cracks in metal casting
   • Sonar
     • Used for military and scientific
     • Measure distances to objects or maps the sea bed
   • Cleaning
     • For industrial use
     • Cleaning delicate mechanisms without dismantling them