Resultant Force 225E5F
1. **Problem Statement:**
We have three forces acting on an object at its center of mass. We need to find:
a) The resultant horizontal force.
b) The resultant vertical force.
c) The magnitude and orientation of the resultant total force.
2. **Given Data:**
- Force 1 (purple): 500 N, directed up and left at 65° from the horizontal right line.
- Force 2 (blue): 300 N, directed up and right at 35° from the vertical line.
- Force 3 (red): 400 N, directed right at 25° from the horizontal right line.
3. **Approach:**
- Resolve each force into horizontal ($F_x$) and vertical ($F_y$) components.
- Sum all horizontal components to get resultant horizontal force $R_x$.
- Sum all vertical components to get resultant vertical force $R_y$.
- Use Pythagoras theorem to find magnitude $R = \sqrt{R_x^2 + R_y^2}$.
- Find orientation angle $\theta = \tan^{-1}(\frac{R_y}{R_x})$ relative to horizontal.
4. **Resolving Forces:**
- Force 1 (500 N, 65° from horizontal left/up):
- Horizontal component: $F_{1x} = -500 \cos(65^\circ)$ (left is negative)
- Vertical component: $F_{1y} = 500 \sin(65^\circ)$ (up is positive)
- Force 2 (300 N, 35° from vertical up/right):
- Since angle is from vertical, horizontal component: $F_{2x} = 300 \sin(35^\circ)$ (right positive)
- Vertical component: $F_{2y} = 300 \cos(35^\circ)$ (up positive)
- Force 3 (400 N, 25° from horizontal right):
- Horizontal component: $F_{3x} = 400 \cos(25^\circ)$ (right positive)
- Vertical component: $F_{3y} = 400 \sin(25^\circ)$ (up positive)
5. **Calculate components:**
- $F_{1x} = -500 \times \cos(65^\circ) = -500 \times 0.4226 = -211.3$
- $F_{1y} = 500 \times \sin(65^\circ) = 500 \times 0.9063 = 453.1$
- $F_{2x} = 300 \times \sin(35^\circ) = 300 \times 0.574 = 172.2$
- $F_{2y} = 300 \times \cos(35^\circ) = 300 \times 0.8192 = 245.8$
- $F_{3x} = 400 \times \cos(25^\circ) = 400 \times 0.9063 = 362.5$
- $F_{3y} = 400 \times \sin(25^\circ) = 400 \times 0.4226 = 169.0$
6. **Sum components:**
- Resultant horizontal force:
$$R_x = F_{1x} + F_{2x} + F_{3x} = -211.3 + 172.2 + 362.5 = 323.4$$
- Resultant vertical force:
$$R_y = F_{1y} + F_{2y} + F_{3y} = 453.1 + 245.8 + 169.0 = 867.9$$
7. **Magnitude of resultant force:**
$$R = \sqrt{R_x^2 + R_y^2} = \sqrt{323.4^2 + 867.9^2} = \sqrt{104588 + 753243} = \sqrt{857831} = 926.1$$
8. **Orientation angle relative to horizontal:**
$$\theta = \tan^{-1}\left(\frac{R_y}{R_x}\right) = \tan^{-1}\left(\frac{867.9}{323.4}\right) = \tan^{-1}(2.684) = 69.5^\circ$$
**Final answers:**
a) Resultant horizontal force = 323.4 N (right)
b) Resultant vertical force = 867.9 N (up)
c) Magnitude of resultant force = 926.1 N
Orientation = 69.5° above the horizontal to the right