Final Answer:
The water depth in the harbor reaches its maximum at 5, 11, 17, and 23 hours during the first 24 hours.
Step-by-step explanation:
The water depth reaches its maximum when the sine function in the model reaches its peak value of 1. In the given function, f(t) = 4.1 sin(π/6 t - π/3) + 19.7, the sine function reaches its peak every time the argument (π/6 t - π/3) is an odd multiple of π/2.
Within the first 24 hours (t = 0 to 24):
At t = 5, π/6 t - π/3 = π/2, making sin(π/6 t - π/3) = 1 and f(t) reaches its maximum.
Similarly, at t = 11, 17, and 23, the argument of the sine function becomes 3π/2, 5π/2, and 7π/2, respectively, each leading to a peak value of sin(π/6 t - π/3) and a maximum for f(t).
Therefore, the water depth in the harbor reaches its maximum at 5, 11, 17, and 23 hours during the first 24 hours.