Statics Questions: Help with Finding Correct Answers

  • Thread starter Thread starter qpzm77gg
  • Start date Start date
  • Tags Tags
    Statics
Click For Summary

Discussion Overview

The discussion revolves around solving statics problems, specifically focusing on calculating forces and tensions in a system under static equilibrium. Participants are examining the methods and assumptions necessary to arrive at correct answers for given scenarios.

Discussion Character

  • Technical explanation, Debate/contested, Homework-related

Main Points Raised

  • One participant expresses difficulty in finding the correct answer to a statics problem and seeks assistance.
  • Another participant suggests that the original poster may be incorrectly applying maximum forces simultaneously, indicating that only one element can reach its maximum force at a time.
  • A suggestion is made to start by assuming the maximum force in one element (the jib) is reached first and to set up static equilibrium equations to solve for the tension in the tie.
  • There is a question about the necessity of using the moment method to solve the problems, with a later reply stating that it may not be necessary if the sum of forces at a specific point is zero.

Areas of Agreement / Disagreement

Participants do not appear to reach a consensus on the best approach to solve the problems, with differing opinions on the application of maximum forces and the necessity of the moment method.

Contextual Notes

There are unresolved assumptions regarding the conditions under which maximum forces occur and the specific methods required for solving the problems. The discussion also reflects uncertainty about the sufficiency of different analytical approaches.

qpzm77gg
Messages
19
Reaction score
0
The first picture is the question picture.
The second picture is my calculation for this questions.
I can't find the correct answer, everybody know why?

Thanks
 

Attachments

  • 20120926_statics 2.jpg
    20120926_statics 2.jpg
    30.6 KB · Views: 440
  • 20120926_statics 2_1.jpeg
    20120926_statics 2_1.jpeg
    36.2 KB · Views: 485
Physics news on Phys.org
You seem to be applying both maximum forces at the same time. It won't be the case that for a given load the maximum force occurs in both elements simultaneously; one will reach its maximum before other (but you can't tell which yet).

So, start by assuming that the maximum in the jib element is reached first. Set up static equilibrium equations and solve for the tension in the tie. Does it exceed its maximum? If not, find the load and this will be your maximum load. If it does, then clearly the tie maxes out first so redo the calculations beginning with the tie tension set to maximum.
 
supplementary one of my problems.
Is't necessary the moment method to solve this questions?

Thanks
 
qpzm77gg said:
supplementary one of my problems.
Is't necessary the moment method to solve this questions?

Thanks

It should be sufficient to realize that for stasis to hold, the sum of the forces acting at point C should be zero.
 

Similar threads

Spiral scissor lift statics
  • · Replies 4 ·
Replies
4
Views
3K
Engineering Statics of Rigid Bodies - Why is the normal force not considered?
  • · Replies 4 ·
Replies
4
Views
2K
Engineering Statics problem (Simple first year): Calculate the internal forces for this structure
  • · Replies 11 ·
Replies
11
Views
4K
Engineering Static Vs Dynamic Force Analysis in Mechanism
  • · Replies 3 ·
Replies
3
Views
2K
Engineering How do I find the transition matrix of this dynamic system?
  • · Replies 18 ·
Replies
18
Views
4K
Engineering Maximal effect in an AC circuit
  • · Replies 4 ·
Replies
4
Views
1K
Engineering Instantaneous Center of Rotation (Polplan in german) and STATICS
  • · Replies 1 ·
Replies
1
Views
2K
Static B.C & first moment of area of connecting rod
  • · Replies 4 ·
Replies
4
Views
2K
Engineering Question on Opamp homework problem: Find Iout between these two Opamps
  • · Replies 5 ·
Replies
5
Views
2K
Engineering Please help me make sense of this question in plumbing textbook
  • · Replies 10 ·
Replies
10
Views
3K