1. **Problem Statement:**
Determine the forces in cables AB, AC, and AD that support a 28-kg flowerpot in equilibrium.
2. **Given Data:**
- Mass of flowerpot $m = 28$ kg
- Coordinates of points relative to A (origin):
- $B = (0, 1.5, 0)$ m
- $C = (2, 0, 0)$ m
- $D = (0, 0, 1.5)$ m
3. **Step 1: Calculate the weight force acting downward at A.**
$$ W = mg = 28 \times 9.81 = 274.68 \text{ N} $$
4. **Step 2: Define unit vectors along cables AB, AC, and AD.**
- Vector $\vec{AB} = B - A = (0, 1.5, 0)$
- Vector $\vec{AC} = C - A = (2, 0, 0)$
- Vector $\vec{AD} = D - A = (0, 0, 1.5)$
Calculate magnitudes:
$$ |\vec{AB}| = 1.5, \quad |\vec{AC}| = 2, \quad |\vec{AD}| = 1.5 $$
Unit vectors:
$$ \hat{u}_{AB} = \frac{1}{1.5}(0, 1.5, 0) = (0, 1, 0) $$
$$ \hat{u}_{AC} = \frac{1}{2}(2, 0, 0) = (1, 0, 0) $$
$$ \hat{u}_{AD} = \frac{1}{1.5}(0, 0, 1.5) = (0, 0, 1) $$
5. **Step 3: Set up equilibrium equations.**
Since the flowerpot is in equilibrium, the sum of forces must be zero:
$$ \vec{F}_{AB} + \vec{F}_{AC} + \vec{F}_{AD} + \vec{W} = 0 $$
Express forces in cables as magnitudes times unit vectors:
$$ F_{AB} \hat{u}_{AB} + F_{AC} \hat{u}_{AC} + F_{AD} \hat{u}_{AD} = -\vec{W} $$
Weight vector points downward:
$$ \vec{W} = (0, 0, -274.68) $$
6. **Step 4: Write component equations:**
- $x$-component:
$$ F_{AB} \times 0 + F_{AC} \times 1 + F_{AD} \times 0 = 0 \implies F_{AC} = 0 $$
- $y$-component:
$$ F_{AB} \times 1 + F_{AC} \times 0 + F_{AD} \times 0 = 0 \implies F_{AB} = 0 $$
- $z$-component:
$$ F_{AB} \times 0 + F_{AC} \times 0 + F_{AD} \times 1 = 274.68 $$
7. **Step 5: Solve for forces:**
$$ F_{AB} = 0 \text{ N} $$
$$ F_{AC} = 0 \text{ N} $$
$$ F_{AD} = 274.68 \text{ N} $$
8. **Interpretation:**
Only cable AD supports the flowerpot's weight vertically. Cables AB and AC carry no load in this configuration.
**Final answers:**
- $F_{AB} = 0$ N
- $F_{AC} = 0$ N
- $F_{AD} = 274.68$ N
Rounded to three significant figures:
- $F_{AB} = 0.00$ N
- $F_{AC} = 0.00$ N
- $F_{AD} = 275$ N
Cable Forces 0Bf55B
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