The Light List indicates that a light has a...

Question 1 of 29218fork_18862776a11a45ba8ff

The Light List indicates that a light has a nominal range of 10 miles and is 11 feet high. If the visibility is 5 miles and your height of eye is 20 feet, at what approximate distance will you sight the light?

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Question 1 of 29218

🔍 Key Concepts

• Nominal range vs. geographic range of a light • Effect of meteorological visibility (5 miles) on luminous range • How to find geographic range using height of eye and height of light

💭 Think About

• Think about whether a light with a nominal range of 10 miles can actually be seen that far when visibility is only 5 miles. How does that limit the luminous range? • First, estimate the geographic range based on your height of eye and the light’s height. Is that value greater or less than the visibility-limited range? • Which range ultimately controls the maximum distance you can see the light: the geographic range or the range limited by visibility?

✅ Before You Answer

• Be sure you understand that nominal range assumes a standard visibility of 10 nautical miles, not the actual 5-mile visibility in this problem. • Confirm that you are combining geographic range (distance to the horizon for both observer and light) and luminous/visibility limits, and then choosing the smaller of the two. • Check that your final answer is not greater than both the nominal range and the distance allowed by 5-mile visibility conditions.