A firework is fired straight up from the ground. At a height of $360\,\text{m}$, it bursts and gives off coloured light. A student standing on the ground beneath the firework wrongly times the interval between seeing the coloured light and hearing the explosion. The student records a value of $1.8\,\text{s}$. What speed of sound does the student's result imply?
- A$200\,\text{m s}^{-1}$
- B$360\,\text{m s}^{-1}$
- C$400\,\text{m s}^{-1}$
- D$650\,\text{m s}^{-1}$