Physics » Sound and the Physics of Hearing » Doppler Effect and Sonic Booms

Summarizing Doppler Effect and Sonic Booms

Summary

  • The Doppler effect is an alteration in the observed frequency of a sound due to motion of either the source or the observer.
  • The actual change in frequency is called the Doppler shift.
  • A sonic boom is constructive interference of sound created by an object moving faster than sound.
  • A sonic boom is a type of bow wake created when any wave source moves faster than the wave propagation speed.
  • For a stationary observer and a moving source, the observed frequency \({f}_{\text{obs}}\) is:

    \({f}_{\text{obs}}={f}_{s}\left(\cfrac{{v}_{w}}{{v}_{w}±{v}_{s}}\right),\)

    where \({f}_{s}\) is the frequency of the source, \({v}_{s}\) is the speed of the source, and \({v}_{w}\) is the speed of sound. The minus sign is used for motion toward the observer and the plus sign for motion away.

  • For a stationary source and moving observer, the observed frequency is:

    \({f}_{\text{obs}}={f}_{s}\left(\cfrac{{v}_{w}±{v}_{\text{obs}}}{{v}_{w}}\right),\)

    where \({v}_{\text{obs}}\) is the speed of the observer.

Glossary

Doppler effect

an alteration in the observed frequency of a sound due to motion of either the source or the observer

Doppler shift

the actual change in frequency due to relative motion of source and observer

sonic boom

a constructive interference of sound created by an object moving faster than sound

bow wake

V-shaped disturbance created when the wave source moves faster than the wave propagation speed

Do you want to suggest a correction or an addition to this content? Leave Contribution

[Attributions and Licenses]


This is a lesson from the tutorial, Sound and the Physics of Hearing and you are encouraged to log in or register, so that you can track your progress.

Log In

Share Thoughts


Do NOT follow this link or you will be banned from the site!