Nothing Special   »   [go: up one dir, main page]
Scribd Logo
Upload

Welcome to Scribd!

  • 95 views

    Doppler Effect

    Uploaded by

    Theo Moloto
    The Doppler effect describes how the frequency of a wave (such as sound or light) is altered by the relative motion between the source of the wave and the observer. When the source is moving towards the observer, the observed frequency increases. When the source is moving away, the frequency decreases. This change in observed frequency results in changes to properties like pitch for sound waves. The Doppler effect has applications in areas like ultrasound, radar, and astronomy for determining if stars are moving towards or away from Earth.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd

    Doppler Effect

    Uploaded by

    Theo Moloto
    95 views4 pages
    The Doppler effect describes how the frequency of a wave (such as sound or light) is altered by the relative motion between the source of the wave and the observer. When the source is moving towards the observer, the observed frequency increases. When the source is moving away, the frequency decreases. This change in observed frequency results in changes to properties like pitch for sound waves. The Doppler effect has applications in areas like ultrasound, radar, and astronomy for determining if stars are moving towards or away from Earth.

    Original Title

    DOPPLER EFFECT

    Copyright

    © © All Rights Reserved

    Available Formats

    DOCX, PDF, TXT or read online from Scribd

    Did you find this document useful?

    Is this content inappropriate?

    The Doppler effect describes how the frequency of a wave (such as sound or light) is altered by the relative motion between the source of the wave and the observer. When the source is moving towards the observer, the observed frequency increases. When the source is moving away, the frequency decreases. This change in observed frequency results in changes to properties like pitch for sound waves. The Doppler effect has applications in areas like ultrasound, radar, and astronomy for determining if stars are moving towards or away from Earth.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    95 views4 pages

    Doppler Effect

    Uploaded by

    Theo Moloto
    The Doppler effect describes how the frequency of a wave (such as sound or light) is altered by the relative motion between the source of the wave and the observer. When the source is moving towards the observer, the observed frequency increases. When the source is moving away, the frequency decreases. This change in observed frequency results in changes to properties like pitch for sound waves. The Doppler effect has applications in areas like ultrasound, radar, and astronomy for determining if stars are moving towards or away from Earth.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    You are on page 1of 4

    DOPPLER EFFECT

    Doppler effect: The change in frequency/pitch of the sound detected by a listener due
    to relative motion between the sound source and the listener.
    Frequency: The number of vibrations per second
    Wavelength: The distance between two successive points in phase
    Wave equation: Speed = frequency x wavelength ( v = f x λ )

    Explaining the doppler effect with sound


    The pitch of a sound wave is related to the wave’s frequency.
    The frequency of a sound wave is the number of wavefronts that pass a given point in
    one second.
    The higher the frequency, the higher the pitch of the sound produced. The pitch of a
    sound is how high or deep it sounds.

    (a) sound waves emitted from a stationary truck.


    When its whistle is sounding, a sound wave is emitted in all directions.

    The sound travels at the same speed in all directions, and so the distance
    between any two successive compressions is the same in all directions.

    An Observer on the left and an Observer on the right, therefore, observes the
    same frequency, and hears the same pitch, from the whistle, no matter where
    they are standing.
    (a) Sound waves emitted from a moving source.

    In front of the truck

    The compressions in front of the truck will be closer together than when the train was at
    rest.

    This is because the truck is moving towards the previously emitted wavefront when the
    next wavefront is sent.

    A stationary observer in front of the truck will experience more wavefronts arriving per
    second than when the truck was stationary.

    This increased frequency of the wave results in this observer hearing a higher pitched
    sound.

    Behind the truck

    The compressions behind the truck will be further apart than when it was at rest.

    This is because the truck is moving away from the previously emitted wavefront when
    the next wave front is sent.

    An observer behind the truck will experience fewer wavefronts arriving per second than
    when the truck was stationary.

    This decreased frequency of the wave results in this observer hearing a deeper pitched
    sound.

    Using the plus (+) or minus (-) sings depends on the relative motions of the
    source and observer.
    If the relative motion of the source and observer is towards one another, use the
    equation.
    If the relative motion of the source and observer is away from one another, use the
    equation.

    Application of the doppler effect (ultrasound) in medicine

    Doppler flow meter; Measuring foetal heartbeat; Ultrasound/Sonar; Radar (for speeding)
    or
    Blood flow meter; Measuring the heartbeat of a foetus; Radar; Sonar; Used to
    determine whether stars are receding or approaching earth.

    Explaining the doppler effect with light


    Red shift: Observed when light from an object increased in wavelength (decrease in
    frequency). A red shift occurs when a light source moves away from an observer.

    You might also like