Solve this :
8. (a) How are the wavelength and frequency of a sound wave related to its speed? 
b) A laboratory uses an ultrasonic scanner to trace tumour in tissue. The operation scanner is 4.2*10⁶   Hz. Calculate the wavelength of sound in the tissue if the speed of the sound is 1700 m/s. 

Dear Student,
       
(a). The wavelength and frequency of a sound wave are related to its velocity (v),
                                         $V=\nu \lambda$
(b). Here given $\nu = 4.2 \times {10}^{6}Hz$ and $velocity, v = 1700 m/s$.
              So, we have to find out the wavelength,
                                           $$\begin{gathered} \lambda =\frac{V}{\nu }= \frac{1700}{4.2\times {10}^6} \\ = 4.04 \times {10}^{-4} m \end{gathered}$$

Regards