In one of the earliest experiments used to show the Doppler effect, a train was packed with trumpeters, each of whom played a note of frequency $440\,\text{Hz}$. When the train moved directly towards a stationary observer, the change in the observed frequency of the note was $22\,\text{Hz}$. The speed of sound was $340\,\text{m s}^{-1}$. At which speed was the train moving?
- A$15.4\,\text{m s}^{-1}$
- B$16.2\,\text{m s}^{-1}$
- C$17.0\,\text{m s}^{-1}$
- D$17.9\,\text{m s}^{-1}$