Question

If the wavelength of a sound wave is 40 cm and the time period is 0.0005 s, how many seconds will it take to travel 4 km?

• A. 5
• B. 11 seconds
• C. 7 seconds
• D. 16 seconds

Answer 1

The correct option is A 5

We know that, velocity = wavelength $\times$ frequency
And, frequency = $\frac{1}{T}$
Speed of the sound wave, v = $\frac{wavelength}{time}=800m/s$
Hence, time taken to cover 4 km = $\frac{distance}{speed}=\frac{4000}{800}=5s$