ANSWER:
6.8 m/s
STEP-BY-STEP EXPLANATION:
We must calculate the frequency, knowing that per minute (60 seconds) there are 34 crests, therefore:
[tex]f=\frac{34}{60}=0.57\text{ Hz}[/tex]Therefore, the speed of the wave would be:
[tex]\begin{gathered} s=f\cdot w \\ s\text{ =speed} \\ f=\text{ frequency = 0.57 Hz} \\ w\text{ = wavelength = 12 m} \end{gathered}[/tex]Replacing:
[tex]\begin{gathered} s=0.57\cdot12 \\ s=6.8\text{ m/s} \end{gathered}[/tex]The speed of the wave is 6.8 m/s