Extra Sound Flashcards
What can sound not travel through?
A vacuum
What is the speed of sound in air?
About 320-350m/s
What are sound waves called?
Longitudinal waves
How are longitudinal waves caused?
When a vibrating object disturbs the air or other medium around it
What ‘c’ and ‘r’ are in a sound wave?
Compressions and rerefactions
Sound waves reflect off _____ surfaces causing _____?
Hard, echoes
What do we measure sound in?
Hertz (Hz)
What is the equation for echoes?
Speed=distance travelled/time taken
Time taken= distance travelled/speed of sound
What is the range of frequencies that the human ear can hear?
20Hz-20kHz
What is the equation for echo-sounding?
Distance to reflecting surface= 1/2 echo time X speed of sound in material
What controls how loud a sound wave is?
The Amplitude
What controls the pitch of a sound wave?
The Frequency
What controls the quality of the note?
The Shape or Waveform
3 applications of ultrasound:
Scanning metal castings for faults or cracks eg. Railway tracks
Scanning a woman’s womb to check on the development of a foetus
Scanning soft tissues to diagnose cancer
