Moment Calculation Dae966
1. **Problem Statement:**
Find the moment about point M for the rectangle ABCD inscribed in a circle of diameter 10 cm.
2. **Given Data:**
- Diameter of circle = 10 cm, so radius $r = \frac{10}{2} = 5$ cm.
- Rectangle ABCD with side AB = 8 cm.
- Forces and angles are indicated but not fully specified in the problem statement, so we assume the moment calculation involves the force of 8 N at 20° acting at a distance related to the rectangle.
3. **Formula for Moment:**
The moment $M$ about a point is given by:
$$M = F \times d \times \sin(\theta)$$
where:
- $F$ is the force magnitude,
- $d$ is the perpendicular distance from the point to the line of action of the force,
- $\theta$ is the angle between the force and the lever arm.
4. **Calculate the lever arm $d$:**
Since the rectangle is inscribed in the circle, the diagonal of the rectangle equals the diameter of the circle.
Using Pythagoras theorem for rectangle ABCD:
$$d = \text{diagonal} = 10 \text{ cm}$$
5. **Calculate the moment:**
Given force $F = 8$ N, angle $\theta = 20^\circ$, and lever arm $d = 10$ cm,
$$M = 8 \times 10 \times \sin(20^\circ)$$
Calculate $\sin(20^\circ)$:
$$\sin(20^\circ) \approx 0.3420$$
So,
$$M = 8 \times 10 \times 0.3420 = 27.36 \text{ N.cm}$$
6. **Compare with options:**
The calculated moment 27.36 N.cm does not match any given options (88, 152, 58, 122 N.cm). Possibly, the force or distance values or the angle need clarification.
**Final answer:** Based on the given data and assumptions, the moment about M is approximately **27.36 N.cm**.
If more precise force or distance data is provided, the calculation can be adjusted accordingly.