Question

In a ripple tank, $10$ full ripples/s are produced. The distance between peaks of consecutive trough and crest is $15cm$. Calculate the velocity of the ripples.

• A. $2m/s$
• B. $3m/s$
• C. $4m/s$
• D. $6m/s$

Answer 1

The correct option is B $3m/s$

The relationship between frequency, speed of sound and wavelength of a sound wave is given as $Frequency=\frac{Speedofsound\left(m/s\right)}{Wavelength\left(m\right)}$.

In the question, it is given that the frequency is $10Hz$ and the total wavelength (twice the distance between peaks of consecutive trough and crest) is $2\times 15cm=30cm=0.03meters$.

The speed of the wave can be derived as follows.
$Speedofwave\left(v\right)=Frequency\left(f\right)\times Wavelength\left(\lambda \right)$

That is, $v=f\times \lambda =10Hz\times 0.030m=3m/s$.

Hence, the wavelength of the wave is 3 m/s