1. **Problem statement:** Find the algebraic measure of the moment of the force $20\sqrt{2}$ newton with respect to point A.
2. **Given:** Force magnitude $F = 20\sqrt{2}$ N, angle $\theta = 45^\circ$ from vertical, vertical segment length $1.2$ m, horizontal segment length $0.2$ m from A to vertical segment.
3. **Formula for moment:**
$$ M = F \times d \times \sin(\alpha) $$
where $d$ is the perpendicular distance from point A to the line of action of the force, and $\alpha$ is the angle between the force and the lever arm.
4. **Calculate components:**
- Horizontal distance from A to force line: $0.2$ m
- Vertical distance: $1.2$ m
- The force acts at $45^\circ$ from vertical, so the force components are:
$$ F_x = F \sin 45^\circ = 20\sqrt{2} \times \frac{\sqrt{2}}{2} = 20 $$
$$ F_y = F \cos 45^\circ = 20\sqrt{2} \times \frac{\sqrt{2}}{2} = 20 $$
5. **Calculate moment about A:**
Moment due to horizontal component $F_x$ acting at vertical distance $1.2$ m:
$$ M_x = F_x \times 1.2 = 20 \times 1.2 = 24 $$
Moment due to vertical component $F_y$ acting at horizontal distance $0.2$ m:
$$ M_y = F_y \times 0.2 = 20 \times 0.2 = 4 $$
6. **Determine sign of moments:**
- $F_x$ tends to rotate counterclockwise (positive moment)
- $F_y$ tends to rotate clockwise (negative moment)
7. **Algebraic sum of moments:**
$$ M = M_x - M_y = 24 - 4 = 20 $$
8. **Final answer:**
The algebraic measure of the moment of the force about point A is $20$ newton.meter.
**Answer: a) 20**
Moment Force 768C32
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