The tides at Cape Capstan, New Brunswick, cause the depth of the water in the harbour to change. The tidal chart indicates that the tides have a high point of approximately 10 m at 2.00 pm and a low point of 1.2 m at 8.15 pm. A sailboat has a draft of 2m. The water needs to be at least 2 m deep in order to the sailboat to safely pass. At what times on that day can the sailboat safely travel in the harbour?

Question

The tides at Cape Capstan, New  Brunswick, cause the depth of the water in the harbour to change. The tidal chart indicates that the tides have a high point of approximately 10 m at 2.00 pm and a low point of 1.2 m at 8.15 pm. A sailboat has a draft of 2m. The water needs to be at least 2 m deep in order to the sailboat to safely pass. At what times on that day can the sailboat safely travel in the harbour?

Student · Answer

Oh another thing I forgot to add, the problem I have with this question is I don't know where to start, I know I need a graph and equation, but I don't know exactly where to start

drwls · Answer

The boat can sail the harbor when the water is 2 or more feet deep. You need a tidal graph to estimate that time interval. It would be anytime except, roughly, 7 to 9:30 PM

drwls · Answer

Without a graph, you might try fitting 1/4 of a sine or cosine wave between the high and low tide times of day. (Maximum at 2 PM and minimum at 8:15 PM)

Mean depth = 5.6 m
Amplitude = 4.4 m
quarter-period = 6.25 hours