🔍 Key Concepts

• Nominal range vs. geographic range of a light • Using the distance to the horizon formula based on height of eye and height of light • How visibility affects luminous range compared to geographic range

💭 Think About

• Think about whether you are limited first by how far you can see over the curvature of the earth, or by the brightness/nominal range of the light. • Use the height of eye and the height of the light to estimate each horizon distance, then combine them appropriately. • Compare that combined geographic distance with the light’s nominal range and the given visibility to decide what actually limits when you first see the light.

✅ Before You Answer

• Be sure you convert heights to the correct units required by the horizon-distance formula you’re using (feet vs. meters). • Double‑check whether you should add or subtract the observer’s and light’s horizon distances. • Confirm whether 27.0 miles of visibility is greater or less than the light’s nominal range, and what that implies.