How Far is the Ship from the Rocks When Sighting a Lighthouse?

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Homework Help Overview

The problem involves a lighthouse situated on a rocky cliff, with a sailor on a ship sighting the top of the lighthouse at a specific angle. The context includes determining the distance from the ship to the rocks based on given heights and angles.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • The original poster attempts to use trigonometric relationships to find the distance, but expresses uncertainty about the correctness of their approach. Some participants question the clarity of the problem's wording, particularly regarding the horizontal distance of the cliff.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the problem's wording. Some guidance has been offered regarding the original poster's method, but there is no explicit consensus on the correct interpretation of the cliff's distance.

Contextual Notes

Participants note potential ambiguity in the problem statement, particularly about the horizontal distance of the rocks from the lighthouse, which may affect the interpretation of the solution.

cphill29
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Homework Statement



A lighthouse that rises 49 ft above the surface of the water sits on a rocky cliff that extends 19 feet from its base. A sailor on the deck of a ship sights the top of the lighthouse at an angle of 30 degrees above the horizontal. If the sailor's eye level is 14 ft above the surface of the water, how far is the ship from the rocks?

Homework Equations



tanx=opp/adj

The Attempt at a Solution



tan30=35/x
xtan30=35
x=35/(tan30)
x=60.6 ft

Since the lighthouse is 49 feet above the surface and the sailor is 14 feet above the surface, the opposite side of the triangle is 35 feet, but I can't get the right answer doing this.
 
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The wording of the problem is not that clear. I believe when saying that ' the rock cliff extends 19 feet from its base ' , that it means that the rocks start 19 feet horizontally away the lighthouse. So your method is correct, just make the necessary adjustment to your answer.
 
PhanthomJay said:
The wording of the problem is not that clear. I believe when saying that ' the rock cliff extends 19 feet from its base ' , that it means that the rocks start 19 feet horizontally away the lighthouse. So your method is correct, just make the necessary adjustment to your answer.

That's what I thought, too, but it gives me a picture and it's clear that is not the case. I did try it though and still got the answer wrong.
 

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