Question

The frequency of a sound wave is 4000hz and its wavelength is 17.5cm. How much time wiil it take to cover a distance of 3.5km?

Answer 1

The speed of a sound wave

$$v=f\lambda=4000\:\rm Hz\times 0.175\: m=700\: m/s$$

So, the time needed for wave to cover a distance 3.5 km

$$t=\frac{d}{v}=\frac{3500\:\rm m}{700\:\rm m/s}=5\: \rm s$$