Answer:
Speed of the wave is 1.406 m/s.
Explanation:
Crest is define as the maximum displacement of particle in a wave. A single wave is form between two successive crest.
As shown in the figure, there are 4 crest, so 3 waves are formed.
According to the problem, 5 wave crest are form in time 8.1 s. Hence the number of waves formed is 4.
Frequency of wave, f = [tex]\frac{number\ of\ waves}{time}[/tex] = [tex]\frac{3}{8.1}[/tex] = 0.37 Hz
Wavelength of wave, λ = 3.8 m
Speed of the wave = λ x f = 3.8 x 0.37 = 1.406 m/s