Math Problem Statement

A survey team is trying to estimate the height of a mountain above a level plain. From one point on the plain, they observe that the angle of elevation to the top of the mountain is 31 . From a point 1000 feet closer to the mountain along the plain, they find that the angle of elevation is 33 . How high (in feet) is the mountain?

Solution

To determine the height of the mountain, we can solve this using trigonometry. Here is the step-by-step solution:

Define Variables:

  1. Let the height of the mountain be hh.
  2. Let the distance from the first observation point to the base of the mountain be dd.

From the problem, two angles of elevation are provided:

  • At dd, the angle of elevation is 3131^\circ.
  • At d1000d - 1000, the angle of elevation is 3333^\circ.

Using the tangent function: tan(θ)=oppositeadjacent\tan(\theta) = \frac{\text{opposite}}{\text{adjacent}}

We can write two equations for the two observations:

  1. From the first point: tan(31)=hd\tan(31^\circ) = \frac{h}{d} h=dtan(31)h = d \cdot \tan(31^\circ)

  2. From the second point: tan(33)=hd1000\tan(33^\circ) = \frac{h}{d - 1000} h=(d1000)tan(33)h = (d - 1000) \cdot \tan(33^\circ)

Solve for hh:

Set the two expressions for hh equal: dtan(31)=(d1000)tan(33)d \cdot \tan(31^\circ) = (d - 1000) \cdot \tan(33^\circ)

Expand and simplify: dtan(31)=dtan(33)1000tan(33)d \cdot \tan(31^\circ) = d \cdot \tan(33^\circ) - 1000 \cdot \tan(33^\circ)

Group terms with dd: d(tan(31)tan(33))=1000tan(33)d (\tan(31^\circ) - \tan(33^\circ)) = -1000 \cdot \tan(33^\circ)

Solve for dd: d=1000tan(33)tan(31)tan(33)d = \frac{-1000 \cdot \tan(33^\circ)}{\tan(31^\circ) - \tan(33^\circ)}

Calculate dd:

Using approximate values: tan(31)0.6009,tan(33)0.6494\tan(31^\circ) \approx 0.6009, \quad \tan(33^\circ) \approx 0.6494 d=10000.64940.60090.6494d = \frac{-1000 \cdot 0.6494}{0.6009 - 0.6494} d=649.40.048513396.9feetd = \frac{-649.4}{-0.0485} \approx 13396.9 \, \text{feet}

Calculate hh:

Using h=dtan(31)h = d \cdot \tan(31^\circ): h=13396.90.60098052.1feeth = 13396.9 \cdot 0.6009 \approx 8052.1 \, \text{feet}

Final Answer:

The height of the mountain is approximately 8052 feet.


Would you like a detailed explanation of any step or related visualizations?

Related Questions:

  1. How is the tangent function used in real-life surveying problems?
  2. What other methods could be used to estimate the height of a mountain?
  3. How would the calculation change if the second observation point was farther away instead of closer?
  4. How accurate is this estimation if the angles are measured with a small error?
  5. What are the implications of atmospheric refraction on angle measurements?

Tip: Always double-check the precision of your angle measurements to ensure accurate results in trigonometric calculations!

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Math Problem Analysis

Mathematical Concepts

Trigonometry
Angle of Elevation
Tangent Function

Formulas

tan(θ) = opposite / adjacent
h = d * tan(θ)
d = -1000 * tan(θ2) / (tan(θ1) - tan(θ2))

Theorems

Basic Trigonometric Ratios

Suitable Grade Level

Grades 9-12