Pole Elevation 2C85Ee
1. **Problem statement:**
A man stands 50 m from the foot of a pole. His eye level is 1.5 m above the ground. The angle of elevation to the top of the pole is 30º.
(1) Let the height of the pole be $x$ m. Find the length $AB$ in terms of $x$.
(2) Find the height of the pole.
(3) Find how much higher the pole is than the man's eye level.
(4) If the man moves 33.34 m closer to the pole, find the new angle of elevation. Given $\tan 60^\circ = 1.732$.
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2. **Step 1: Define variables and setup**
- Let $AB$ be the vertical segment from the man's eye level to the top of the pole.
- The total height of the pole is $x$ m.
- The man's eye level is 1.5 m, so $AB = x - 1.5$.
- The horizontal distance from the man to the pole is 50 m.
3. **Step 2: Use the tangent formula for angle of elevation**
The tangent of the angle of elevation is the ratio of the opposite side to the adjacent side:
$$\tan 30^\circ = \frac{AB}{50}$$
4. **Step 3: Substitute $AB = x - 1.5$ and solve for $x$**
$$\tan 30^\circ = \frac{x - 1.5}{50}$$
We know $\tan 30^\circ = \frac{1}{\sqrt{3}} \approx 0.577$.
So,
$$0.577 = \frac{x - 1.5}{50}$$
Multiply both sides by 50:
$$x - 1.5 = 50 \times 0.577 = 28.85$$
Add 1.5 to both sides:
$$x = 28.85 + 1.5 = 30.35$$
5. **Step 4: Calculate how much higher the pole is than the man**
Height difference:
$$x - 1.5 = 30.35 - 1.5 = 28.85 \text{ m}$$
6. **Step 5: New position and angle of elevation**
The man moves 33.34 m forward, so new distance:
$$50 - 33.34 = 16.66 \text{ m}$$
Using tangent again:
$$\tan \theta = \frac{AB}{16.66} = \frac{28.85}{16.66} \approx 1.732$$
Given $\tan 60^\circ = 1.732$, so
$$\theta = 60^\circ$$
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**Final answers:**
1. $AB = x - 1.5$
2. Height of pole $x = 30.35$ m
3. Pole is $28.85$ m higher than the man's eye level
4. New angle of elevation is $60^\circ$