ドップラー効こう果か

noun

Doppler effect

Physics term for the change in frequency of a wave in relation to an observer moving relative to the source.

• 救きゅう急きゅう車しゃのサイレンはドップラー効こう果かで音おとが変かわる。

  The siren of an ambulance changes pitch due to the Doppler effect.