A submarine A travelling at 17 m / s is being chased along the line...

\therefore$Given, velocity of submarine$A, v_A=17 \mathrm{~m} / \mathrm{s}$Velocity of submarine$B, v_B=34 \mathrm{~m} / \mathrm{s}$Signal sent by submarine$B$is detected by submarine$A$can be shown as <img src="/api/proxy-image?url=httpsFreqency of the signal,$f_0=600 \mathrm{~Hz}$Speed of sound in water$v_s=1500 \mathrm{~ms}^{-1}$Frequency received by submarine$A$is f_1=$\left(\frac{v_{\mathrm{S}}-v_A}{v_{\mathrm{S}}-v_B}\right)$f_0=\left[\frac{1500-17}{1500-34}\right] \times$600 $\mathrm{~Hz}$f_1=$\frac{1483}{1466} \times$600 Frequency received by submarine $B$ is f_2=$\left(\frac{v_{\mathrm{S}}+v_B}{v_s+v_A}\right)$f_1 Substituting given values and $f_1$ value from Eq. (i), we get $$\begin{aligned}f_2 & =\left(\frac{1500+34}{1500+17}\right) \times\left[\frac{1483}{1466} \times600\right] \\ f_2 & =1.0112 \times1.0115 \times600 \\ f_2 & =613.7 \mathrm{~Hz} \end{aligned}$$