Using Waves

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Created by
PassthebiscuitsGCSE

Cards (11)

  • How does the human ear work?
    The outer ear collects the sound waves which travel into the ear causing the eardrum to vibrate at the same frequency, this is amplified by three ossicles (small bones), causing the hair in the cochlea to vibrate, the cochlea converts the vibration into electrical signals, which are passed to the brain through the auditory nerve and converted into sound.
  • What is the frequency range of human hearing?
    20 Hz - 20 kHz
  • What is an ultrasound wave?
    A sound wave with a frequency greater than 20,000 Hz.
  • What causes seismic waves and what types are produced?
    Earthquakes, they produce 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
  • What is the significance of P and S waves?
    They provide evidence that the Earth has a liquid core; only P waves predicted by an earthquake can be detected in the other side of the globe.
  • What technique is used to detect objects in deep water and measure water depth?
    Echo sounding, high frequency sound waves are emitted, reflected and detected. Time difference between emission and detection, alongside wave speed, are used to calculate distances.
  • How does sonar work?
    When ultrasound waves are emitted they reflect off boundaries and their echoes are detected, the speed of the ultrasound is known and also the time it takes to detect the echoes, the equation speed = distance/time is used to find the distance travelled. This value is halved as the wave had to travel to the boundary and back from the emitter.
  • How does foetal scanning work?
    An ultrasound wave is sent into the patient’s 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, it is safe and does not damage cells.