Question: TRY THIS!!!
Adding Displacement Using the Component Method
Solve the problem below. Follow the steps in computing for vectors using
component method.
1. A hiker walks 80 m East and then 60 m at 30° North of East.
Determine the hiker's resultant displacement.
1. **State the problem:** A hiker walks $80$ m East and then $60$ m at $30^\circ$ North of East. We need to find the resultant displacement vector.
2. **Formula and rules:** To find the resultant displacement using the component method, we break each vector into its $x$ (East-West) and $y$ (North-South) components and then add these components.
3. **Step 1: Components of the first vector** (80 m East):
- $x_1 = 80$ m (since it is directly East)
- $y_1 = 0$ m
4. **Step 2: Components of the second vector** (60 m at $30^\circ$ North of East):
- $x_2 = 60 \cos 30^\circ = 60 \times \frac{\sqrt{3}}{2} = 30\sqrt{3}$ m
- $y_2 = 60 \sin 30^\circ = 60 \times \frac{1}{2} = 30$ m
5. **Step 3: Sum the components:**
- $x_R = x_1 + x_2 = 80 + 30\sqrt{3}$ m
- $y_R = y_1 + y_2 = 0 + 30 = 30$ m
6. **Step 4: Calculate the magnitude of the resultant displacement:**
$$
R = \sqrt{x_R^2 + y_R^2} = \sqrt{(80 + 30\sqrt{3})^2 + 30^2}
$$
7. **Step 5: Calculate the direction (angle) of the resultant displacement relative to East:**
$$
\theta = \tan^{-1}\left(\frac{y_R}{x_R}\right) = \tan^{-1}\left(\frac{30}{80 + 30\sqrt{3}}\right)
$$
8. **Step 6: Numerical evaluation:**
- Approximate $30\sqrt{3} \approx 30 \times 1.732 = 51.96$
- So, $x_R \approx 80 + 51.96 = 131.96$ m
- $y_R = 30$ m
- Magnitude:
$$
R = \sqrt{131.96^2 + 30^2} = \sqrt{17411.5 + 900} = \sqrt{18311.5} \approx 135.4 \text{ m}
$$
- Direction:
$$
\theta = \tan^{-1}\left(\frac{30}{131.96}\right) = \tan^{-1}(0.2274) \approx 12.9^\circ
$$
**Final answer:** The hiker's resultant displacement is approximately $135.4$ m at $12.9^\circ$ North of East.