Bending diagram, answers don't match book

Click For Summary

Discussion Overview

The discussion revolves around a homework problem related to calculating moments in a bending diagram. Participants are examining discrepancies between their calculations and the values provided in a textbook, focusing on the application of moment equations and the interpretation of distributed loads.

Discussion Character

  • Homework-related, Technical explanation, Debate/contested

Main Points Raised

  • One participant states that the maximum moment calculated was 5.6 kN at a distance of 2.4 m from point A, questioning the accuracy of this calculation after considering an upward force at point A.
  • Another participant points out that the moment of the distributed load was incorrectly calculated, noting that the moment arm for the resultant of the distributed load should be based on its center of gravity rather than the full distance of 4 m.
  • A request is made for the original question to clarify the context of the problem, indicating uncertainty about the distributed load's value.
  • A participant confirms that the value of the distributed load is 2 kN per meter.
  • A later reply acknowledges a basic error in the moment calculation, suggesting a realization of the mistake made in the initial assessment.

Areas of Agreement / Disagreement

Participants do not reach a consensus, as there are competing views regarding the calculation of moments and the interpretation of the distributed load's effect.

Contextual Notes

Limitations include potential misunderstandings about the moment arm and the distribution of loads, as well as the need for clarity on the original problem statement.

togo
Messages
106
Reaction score
0

Homework Statement


x1gm10.jpg

Homework Equations


moment = force x distance

The Attempt at a Solution


on sheet.

According to the book, the max moment is 5.6 kN (at a distance of 2.4 m from point A), which was my calculation before adding the force at A (.8 kN upward)

whats wrong?
 
Physics news on Phys.org
When you summed moments about point A = 0, you calculated the moment of the distributed load as (8 kN)(4m) = 32 kN-m, but the moment arm (perpendicular distance) of the resultant of the distributed load is not 4m (the resultant of the distributed load acts at its center of gravity).
 
Could you post the original question? The general shape of your graph looks right, but I'm not certain what the value of that distributed load is suppose to be.
 
the value of the distributed load is 2 kN per meter
 
wow. You're right phantom, was a basic error on that one.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 10 ·
Replies
10
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 22 ·
Replies
22
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 9 ·
Replies
9
Views
10K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 16 ·
Replies
16
Views
4K