Answer:
The frequency is 0.25Hz and the period is 4s
Step-by-step explanation:
To solve this we can use the formula:
, where f=frequency, v=velocity and lambda = wavelength.
In the question, we are given the information that the velocity of the wave is 6.5m/s and the wavelength is 26 meters long. By putting these values into the formula, we can find the frequency:

Period is the inverse of frequency:

Therefore the period is:

Hope this helped!