Sound from an object moving toward you sounds higher in pitch than the same sound coming from that same object moving away from you. This phenomenon is called the Doppler effect. While more noticeable from fast and loud vehicles like speeding cars and trains, the doppler effect can even be observed from an electric skateboard. The Doppler effect occurs because the sound waves emanating from the moving object are closer together in front of it than they are behind it. The speed of sound through air is constant, so when Owen yells while as he rides, the sound always travels from his mouth to the microphone at the same speed. The difference is that when Owen rides toward the microphone, he moves forward slightly between each individual peak of the sound wave he makes. This means that the sound reaching the microphone effectively has a higher frequency and therefore a higher pitch than if Owen was stationary. The opposite is also true as he rides away. Owen travels a slight distance away from the microphone in between each sound wave crest that he generates, making the frequency and pitch lower. While Owen could have easily lowered his voice while passing the microphone to fake this experiment, a camera and microphone on the board itself proves otherwise. Because the board-mounted camera always maintains the same distance from Owen the pitch remains constant.
0 Comments
|
Zach Pabisis a high school junior writing about his adventures in physics. Archives
April 2019
Categories |