Tunnel pressure waves – A smartphone inquiry on rail travel

• Andreas Müller ^[1] ; Michael Hirth ^[2] ; Jochen Kuhn ^[2]
  1. [1] Université de Genève

     Université de Genève

     Genève, Suiza

     
  2. [2] University of Kaiserslautern

     University of Kaiserslautern

     Kreisfreie Stadt Kaiserslautern, Alemania

     
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 54, Nº. 2, 2016, págs. 118-119
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • When traveling by rail, you might have experienced the following phenomenon: The train enters a tunnel, and after some seconds a noticeable pressure change occurs, as perceived by your ears or even by a rapid wobbling of the train windows. The basic physics is that pressure waves created by the train travel down the tunnel, are reflected at its other end, and travel back until they meet the train again. Here we will show (i) how this effect can be well understood as a kind of large-scale outdoor case of a textbook paradigm, and (ii) how, e.g., a prediction of the tunnel length from the inside of a moving train on the basis of this model can be validated by means of a mobile phone measurement.