sound waves

• how do sound waves travel through a solid

  the particles in the solid vibrate and transfer kinetic energy through the material
• how does the human ear work

  the outer ear collects sound which travels into the ear , the sound waves cause the eardrum to vibrate at the same frequency , this is amplified by 3 ossicles , this causes the hair in the cochlea to vibrate , the cochlea converts the vibrations into electrical signals , the signals are passed to the brain through the auditory nerve , the brain converts electrical signals into sound
• what is the frequency range of human hearing

  20hz-20khz
• what is an ultrasound wave

  a sound wave with a greater frequency that 20,000 hz
• what is the sound of frequencies less than 20hz called

  infrasound
• what natural evemt causes seismic waves to be produced , what are the types produced

  earthquakes , they produce both p waves and s waves
• are p waves transverse or longitudinal 


  longitudinal
• are s waves transverse or longitudinal

  transverse
• state a difference between the mediums that p waves and s waves can travel through

  p waves travel through both solids and liquids , s waves only travel through solids( not liquids)
• what is the significance of p and s waves

  they provide evidence that the earth has a liquid core , only p waves produced by an earthquake can be detected on the other side of the globe
• how does foetal scanning work

  an ultrasound wave is sent into the patients body , it passes through the body and reflects off the organs and tissue , the device then uses the reflected ultrasound waves to produce an image of the foetus , ultrasound is safe and therefore does not damage cells
• why cant the ear detect some frequencies

  brain cannot interpret high/low frequencies

  eardrum not sensitive enough to detect high low frequencies