(a) The frequency of water wave is 2 Hz.
(b) The wave speed of the water wave is 3.6 m/s.
Explanation:
(a) It is known that completion of one complete wave in 1 second is defined as frequency of 1 HZ. So here there are 120 waves crossing the boat in 1 minute. So the frequency of the water wave will be
[tex]Frequency =\frac{\text { Number of waves }}{\text { Time in seconds }}[/tex]
As the time is 1 minute which is equal to 60 seconds and the number of waves is given as 120 then the frequency of the water wave is
[tex]\text { Frequency }=\frac{120}{60}=2 \mathrm{Hz}[/tex]
So the frequency of water wave is 2 Hz.
(b) Then if the wavelength of the water wave is 1.8 m with a frequency of 2 Hz, then speed of the wave can be determined as the product of wavelength with frequency.
So Speed = Frequency × Wavelength
Speed = 2 × 1.8 = 3.6 m/s.
So the speed of the water wave is 3.6 m/s.
