MP Board · Class 9 · Science · SoundA sound wave has a frequency of $2\text{ kHz}$ and a wavelength of $35\text{ cm}$. How long will it take to travel a distance of $1.5\text{ km}$?

Given Data:

• Frequency of sound wave ($f$) = $2\text{ kHz} = 2000\text{ Hz}$
• Wavelength ($\lambda$) = $35\text{ cm} = 0.35\text{ m}$
• Distance ($d$) = $1.5\text{ km} = 1500\text{ m}$

Step 1: Calculate the speed of the sound wave ($v$) $$\text{Speed } (v) = \text{Frequency } (f) \times \text{Wavelength } (\lambda)$$ $$v = 2000 \times 0.35$$ $$v = 700\text{ m/s}$$

Step 2: Calculate the time taken ($t$) to travel $1500\text{ m}$ $$\text{Time } (t) = \frac{\text{Distance } (d)}{\text{Speed } (v)}$$ $$t = \frac{1500}{700} = \frac{15}{7} \approx 2.14\text{ seconds}$$

Answer:\nThe sound wave will take approximately $2.14\text{ seconds}$ to travel a distance of $1.5\text{ km}$.