A siren on a police car that is moving produces sound waves of frequency $440\,\text{Hz}$. A fixed observer detects a sound frequency of $494\,\text{Hz}$. The speed of sound in air is $340\,\text{m s}^{-1}$. What are the possible speed and direction of travel of the car?
- A$37\,\text{m s}^{-1}$ directly away from the observer
- B$37\,\text{m s}^{-1}$ directly towards the observer
- C$42\,\text{m s}^{-1}$ directly away from the observer
- D$42\,\text{m s}^{-1}$ directly towards the observer