sound

sound

1. the speed of sound is roughly 740 MPH

   • in air its 330 M/S

2. sound is a logitudinal pressure which travel through elastic medias

3. frequencys

   • quite sound, low frequency
   • quite sound, high frequency
   • loud sound, loud frequency
   • loud sound, high frequency

4. echoes are a reflection of sound waves. harder surfaces reflect sound. E.G. a wall.

5. examples of using echoes

   • to measure; distance between 2 walls
   • to measure; depth of ocean
   • radar to know how far a star/planet is

6. calculations

   • speed = distance/time
   • echoe time = distance/speed of sound

7. ultra sound

   • used for...
     • cancer
     • check up on feotus
     • looking at heart problems
     • liver problems
     • braking down kidney stones
       • and other stone in body
     • measuring blood flow
   • ultra sound in medicine
     • advantages
       • quick to use
       • doesn't require needles/injections
       • not expensive
     • disadvantages
       • not in much detail
       • can't pass through bones
       • can't be used in areas with gas

8. hearing through the ear

   • middle ear bones
     • carrys vibrations from ear drum to cochlea
   • auditory nerve
     • carrys impulses from cochlea to brain
   • ear drum
     • vibrates when sound waves reach it
   • semi-circular canals
     • three tubes containing a liquid which moves when your head moves
   • cochlea
     • contains cells, which are sensitive to sound vibrations