Math Problem Statement

T 1 ​ =5,000lb with a slope of 4:3. The slope of 𝑇 2 T 2 ​ is 3:4. The slope of 𝑇 3 T 3 ​ is 5:12. The resultant force is 10 , 000   lb 10,000lb acting vertically downward.

Three forces are concurrent at point O, and the tension in cable T1 is 5,000 lb with the slope as shown. Determine the magnitudes necessary for T2 and T3 such that the resultant force of 10,000 lb acts vertically down the axis of the pole.

Solution

The problem involves determining the magnitudes of tensions T2T_2 and T3T_3 such that the resultant force of 10,000 lb10,000 \, \text{lb} acts vertically downward. Here’s how we can approach the solution step by step:

Step 1: Break forces into components

The system is in equilibrium, so the sum of the forces in both the horizontal (xx) and vertical (yy) directions must equal zero. We will decompose the tensions T1T_1, T2T_2, and T3T_3 into their respective horizontal and vertical components using the given slopes.

Tension T1T_1:

  • Given slope: 4:34:3, the ratio of vertical to horizontal components.
    • Vertical component: 45T1=45Γ—5000=4000 lb\frac{4}{5} T_1 = \frac{4}{5} \times 5000 = 4000 \, \text{lb}
    • Horizontal component: 35T1=35Γ—5000=3000 lb\frac{3}{5} T_1 = \frac{3}{5} \times 5000 = 3000 \, \text{lb}

Tension T2T_2:

  • Given slope: 3:43:4 (horizontal:vertical).
    • Vertical component: 35T2\frac{3}{5} T_2
    • Horizontal component: 45T2\frac{4}{5} T_2

Tension T3T_3:

  • Given slope: 5:125:12 (horizontal:vertical).
    • Vertical component: 1213T3\frac{12}{13} T_3
    • Horizontal component: 513T3\frac{5}{13} T_3

Step 2: Apply equilibrium conditions

Since the system is in equilibrium, we have two main conditions:

  1. Sum of horizontal components equals zero: T1(horizontal)+T2(horizontal)=T3(horizontal)T_1 \text{(horizontal)} + T_2 \text{(horizontal)} = T_3 \text{(horizontal)} Substituting the components: 3000 + \frac{4}{5} T_2 = \frac{5}{13} T_3 \tag{1}

  2. Sum of vertical components equals the downward resultant: T1(vertical)+T2(vertical)+T3(vertical)=10,000 lbT_1 \text{(vertical)} + T_2 \text{(vertical)} + T_3 \text{(vertical)} = 10,000 \, \text{lb} Substituting the components: 4000 + \frac{3}{5} T_2 + \frac{12}{13} T_3 = 10,000 \tag{2}

Step 3: Solve the system of equations

Now we solve the system of equations (1) and (2) to find the values of T2T_2 and T3T_3.

Let me calculate these values.The solution to the system of equations is:

  • T2=βˆ’476.19 lbT_2 = -476.19 \, \text{lb} (This negative value indicates that the assumed direction for T2T_2 may be incorrect. It likely points in the opposite direction).
  • T3=6809.52 lbT_3 = 6809.52 \, \text{lb}

Thus, the tension T3T_3 is approximately 6809.52 lb6809.52 \, \text{lb}, while the tension T2T_2, considering its negative value, should be re-evaluated for its direction, suggesting the cable could be in compression rather than tension.

Would you like a detailed breakdown of the interpretation of these results or have any further questions?

Here are 5 related questions to deepen understanding:

  1. Why does a negative value for T2T_2 indicate a change in direction for the force?
  2. How would the problem change if the resultant force was not vertical?
  3. What would happen if the slopes of the cables were different?
  4. How can we visualize the forces in terms of vector components?
  5. How does the equilibrium condition affect structures in real-world engineering?

Tip: Always check the direction of forces when solving equilibrium problems, as the sign can provide important insights into the physical behavior of the system.

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Math Problem Analysis

Mathematical Concepts

Statics
Force Resolution
Vector Components

Formulas

Vertical component = (vertical ratio/total ratio) * Tension
Horizontal component = (horizontal ratio/total ratio) * Tension
Sum of horizontal forces = 0
Sum of vertical forces = resultant force

Theorems

Equilibrium of forces

Suitable Grade Level

Undergraduate Engineering or Advanced High School Physics