Math Problem Statement

Calculate the reaction forces at Point A and Point B if x = 9.4 meters. Report your magnitude in the box, then select the appropriate units and direction.

beam16.8 kN2.9 m

Ax = 0

Correct: Your answer is correct.

kN Correct: Your answer is correct.

no direction Correct: Your answer is correct.

Ay = 5.18

Incorrect: Your answer is incorrect.

kN Correct: Your answer is correct.

down Correct: Your answer is correct.

By= 11.62

Incorrect: Your answer is incorrect.

kN Correct: Your answer is correct.

up Correct: Your answer is correct.

Solution

To calculate the reaction forces at Points A and B, we need to apply the principles of static equilibrium, specifically the sum of forces and moments.

Given information:

  • The length of the beam is 16.8 meters.
  • The total applied load is 2.9 kN.
  • The applied load is 9.4 meters from point A.
  • The force at Point A is divided into horizontal (Ax) and vertical (Ay) components.
  • The force at Point B is vertical (By), since there is no horizontal force given at B.

Step-by-Step Solution:

  1. Sum of Forces in the Vertical Direction (ΣFy = 0): Ay+By=2.9kN\text{Ay} + \text{By} = 2.9 \, \text{kN} This is because the beam is in equilibrium and the total vertical forces must sum to zero. The applied load (2.9 kN) is vertical.

  2. Sum of Moments about Point A (ΣMA = 0): To find Ay and By, we can use the sum of moments about Point A. The moment arm for Ay is 0 meters (since it acts at point A), and the moment arm for By is the full length of the beam (16.8 meters). The applied load creates a moment around point A at a distance of 9.4 meters.

    The moment equilibrium equation is: 2.9×9.4=By×16.82.9 \times 9.4 = \text{By} \times 16.8 By=2.9×9.416.8=1.62kN\text{By} = \frac{2.9 \times 9.4}{16.8} = 1.62 \, \text{kN} So, the reaction at B is 1.62 kN upwards.

  3. Substitute the Value of By into the Force Equation: Now, substitute By = 1.62 kN into the vertical force equilibrium equation: Ay+1.62=2.9\text{Ay} + 1.62 = 2.9 Ay=2.91.62=1.28kN\text{Ay} = 2.9 - 1.62 = 1.28 \, \text{kN} So, the reaction at A in the vertical direction is 1.28 kN downward.

Summary of Reaction Forces:

  • Ax = 0 kN (no horizontal forces).
  • Ay = 1.28 kN (downward).
  • By = 1.62 kN (upward).

Answer Box:

  • Ax = 0 kN (no direction).
  • Ay = 1.28 kN (down).
  • By = 1.62 kN (up).

Would you like me to walk you through any further details of this solution? Also, here are 5 related questions:

  1. How would the reaction forces change if the applied load was placed at a different distance along the beam?
  2. What would happen if Point B was fixed instead of a roller?
  3. How can we calculate the moment at Point A for different load types (point loads vs distributed loads)?
  4. How do you handle horizontal forces in static equilibrium when Ax is non-zero?
  5. What are the conditions for a beam to be in static equilibrium?

Tip: Always ensure that your moment arms are correctly identified based on the chosen pivot point when calculating moments in static equilibrium.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Statics
Static Equilibrium
Forces and Moments
Beam Analysis

Formulas

Sum of forces in vertical direction (ΣFy = 0)
Sum of moments about a point (ΣM = 0)
Moment equation M = F × d

Theorems

Static equilibrium conditions
Principle of moments

Suitable Grade Level

Grades 11-12