Answer:
13 Hz
Step-by-step explanation:
The frequency of a wave is given by the equation:
![f=(v)/(\lambda)](https://img.qammunity.org/2020/formulas/physics/high-school/ywa4ck2lanc1vlixqqoq0pn8qcavsocqho.png)
where
f is the frequency
v is the speed of the wave
is the wavelength
In this problem, we have:
v = 5.2 m/s is the speed of the wave
is the wavelength (distance between two adjacent crests)
Substituting into the formula, we find the frequency of the wave:
![f=(5.2 m/s)/(0.40 m)=13 Hz](https://img.qammunity.org/2020/formulas/physics/high-school/fdbp6rlxy7v9gkn8zgagnp656wsmxdcc1e.png)