1. **State the problem:**
A body of mass 8 kg is suspended by two strings Mx and Nx attached to the ceiling. The strings make angles of 55° and 65° with the downward vertical. We need to find the tension in each string.
2. **Known values:**
- Mass, $m = 8$ kg
- Gravitational acceleration, $g = 10$ m/s$^2$
- Angles with downward vertical: $\theta_M = 55^\circ$, $\theta_N = 65^\circ$
3. **Calculate the weight of the body:**
$$ W = mg = 8 \times 10 = 80 \text{ N} $$
4. **Set up the equilibrium equations:**
Since the body is at rest, the sum of forces in both horizontal and vertical directions must be zero.
- Let tensions be $T_M$ and $T_N$ in strings Mx and Nx respectively.
- Resolve tensions into vertical and horizontal components:
- Vertical components: $T_M \cos 55^\circ$ and $T_N \cos 65^\circ$
- Horizontal components: $T_M \sin 55^\circ$ and $T_N \sin 65^\circ$
5. **Vertical equilibrium:**
$$ T_M \cos 55^\circ + T_N \cos 65^\circ = 80 $$
6. **Horizontal equilibrium:**
The horizontal components must balance each other:
$$ T_M \sin 55^\circ = T_N \sin 65^\circ $$
7. **Express $T_N$ in terms of $T_M$ from horizontal equilibrium:**
$$ T_N = T_M \frac{\sin 55^\circ}{\sin 65^\circ} $$
8. **Substitute $T_N$ into vertical equilibrium:**
$$ T_M \cos 55^\circ + T_M \frac{\sin 55^\circ}{\sin 65^\circ} \cos 65^\circ = 80 $$
9. **Simplify:**
Calculate the trigonometric values:
- $\cos 55^\circ \approx 0.5736$
- $\sin 55^\circ \approx 0.8192$
- $\cos 65^\circ \approx 0.4226$
- $\sin 65^\circ \approx 0.9063$
Substitute:
$$ T_M (0.5736) + T_M \times \frac{0.8192}{0.9063} \times 0.4226 = 80 $$
Calculate the fraction:
$$ \frac{0.8192}{0.9063} \times 0.4226 \approx 0.3819 $$
So:
$$ T_M (0.5736 + 0.3819) = 80 $$
$$ T_M (0.9555) = 80 $$
10. **Solve for $T_M$:**
$$ T_M = \frac{80}{0.9555} \approx 83.7 $$
11. **Find $T_N$:**
$$ T_N = 83.7 \times \frac{0.8192}{0.9063} \approx 83.7 \times 0.9045 = 75.7 $$
12. **Final answer:**
- Tension in string Mx, $T_M \approx 84$ N
- Tension in string Nx, $T_N \approx 76$ N
Tension Strings 1160E4
Step-by-step solutions with LaTeX - clean, fast, and student-friendly.