A siren on a police car that is moving produces a sound wave with frequency of $440\,\text{Hz}$. An observer who is not moving detects sound with frequency of $494\,\text{Hz}$. The speed of sound in air is $340\,\text{m s}^{-1}$. What might be the car’s speed and direction of travel?
- A$37\,\text{m s}^{-1}$ directly towards the observer
- B$37\,\text{m s}^{-1}$ directly away from the observer
- C$42\,\text{m s}^{-1}$ directly towards the observer
- D$42\,\text{m s}^{-1}$ directly away from the observer