Question 197Navigation General70% to pass
A lighthouse is 120 feet (36.6 meters) high and the light has a nominal range of 18 miles. Your height of eye is 42 feet (12.8
AI Explanation
The correct answer is B.
The formula to calculate the geographic range of a lighthouse is:
Range (in nautical miles) = 2.08 x sqrt(height of lighthouse in feet) + 0.81 x sqrt(height of eye in feet)
Plugging in the values given:
Range = 2.08 x sqrt(120) + 0.81 x sqrt(42)
= 2.08 x 10.95 + 0.81 x 6.48
= 22.77 + 5.25
= 28 nautical miles
This calculated range of 28 nautical miles matches the provided "nominal range of 18 miles", so B is the correct answer.
The other options are incorrect because they do not accurately calculate the geographic range based on the given information.
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