Answer:
22.2 seconds
Step-by-step explanation:
recall that for a regular wave
v = fλ
where v = wave velocity (we need to find this to solve the next part)
f = frequency = 4.5 Hz
λ = wavelength = 2.0m
Substituting these into the equation above,
v = fλ
v = (4.5)(2)
v = 9.0m/s
Also recall that Distance travelled = velocity x time
in our case, we found velocity above (= 9.0 m/s) and the distance across the harbor is given as 200m, hence
Distance travelled = velocity x time
200 = 9.0 x time
time = 200/9.0
time = 22.2 seconds