Angle Depression Distance
1. **Problem 1: Angle of Depression from Hot Air Balloon**
We are given a hot air balloon 40 ft above the ground and 70 ft away horizontally from a farm. We need to find the angle of depression from the balloon to the farm.
2. **Formula and Explanation:**
The angle of depression corresponds to the angle between the horizontal line from the balloon and the line of sight to the farm. We can model this as a right triangle where:
- Opposite side = height difference = 40 ft
- Adjacent side = horizontal distance = 70 ft
We use the tangent function:
$$\tan(\theta) = \frac{\text{opposite}}{\text{adjacent}} = \frac{40}{70}$$
3. **Calculation:**
Calculate the angle $\theta$:
$$\theta = \tan^{-1}\left(\frac{40}{70}\right) = \tan^{-1}(0.5714)$$
Using a calculator:
$$\theta \approx 29.74^\circ$$
4. **Answer:**
The angle of depression is approximately **29.74 degrees**.
5. **Problem 2: Distance Between Airports A and B**
An airplane travels 50 miles North 35° West (N35°W), then 70 miles South 20° West (S20°W). We want to find the straight-line distance between airports A and B.
6. **Understanding Directions and Components:**
- N35°W means 35° west of north.
- S20°W means 20° west of south.
We break each leg into components using trigonometry, assuming north is positive y-axis and east is positive x-axis.
For the first leg (50 miles N35°W):
- $x_1 = -50 \times \sin(35^\circ)$ (west is negative x)
- $y_1 = 50 \times \cos(35^\circ)$
For the second leg (70 miles S20°W):
- $x_2 = -70 \times \sin(20^\circ)$
- $y_2 = -70 \times \cos(20^\circ)$ (south is negative y)
7. **Calculate components:**
$$x_1 = -50 \times 0.574 = -28.7$$
$$y_1 = 50 \times 0.819 = 40.95$$
$$x_2 = -70 \times 0.342 = -23.94$$
$$y_2 = -70 \times 0.940 = -65.8$$
8. **Total displacement components:**
$$x = x_1 + x_2 = -28.7 - 23.94 = -52.64$$
$$y = y_1 + y_2 = 40.95 - 65.8 = -24.85$$
9. **Distance between airports:**
Use Pythagorean theorem:
$$d = \sqrt{x^2 + y^2} = \sqrt{(-52.64)^2 + (-24.85)^2}$$
Calculate:
$$d = \sqrt{2771.5 + 617.6} = \sqrt{3389.1} \approx 58.23$$
10. **Answer:**
The distance between airports A and B is approximately **58.23 miles**.