Given Moment about a Pin and a Roller

Click For Summary

Homework Help Overview

The discussion revolves around a statics problem involving a beam supported by a pin and a roller. Participants are tasked with drawing a free body diagram and applying equilibrium equations to find support reactions, specifically focusing on problem 4.10.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss the clarity of the problem diagram and the necessity of identifying support reactions at points A and B. There is exploration of the correct moment equations and how they relate to the support reactions. Questions arise regarding the validity of moment equations and the implications of pin connections on moment support.

Discussion Status

Several participants have offered guidance on writing correct moment equations and understanding the relationship between the support reactions. There is an ongoing exploration of how to mathematically determine the directions of the support reactions and the implications of equilibrium equations.

Contextual Notes

Participants note that the reactions must sum to zero, leading to discussions about the directions of the forces and the role of distances in determining moments. There is mention of potential confusion regarding the representation of equations and their intended purpose in solving for reactions.

  • #31
oh, alright. Well thank you so much, I really appreciate it!
 
Physics news on Phys.org
  • #32
hdp12 said:
no there were not, simply the moment is acting on that point at the rigid body between the roller, A, and the pin, B. It's then necessary to find the support reactions at A and B, which are RAY, RBY, and RBX
I'm glad SteamKing seems to understand it because I still don't. If A is a roller, how is it going to supply the downward force necessary to oppose the applied moment? I see no mention of mass or gravity.
I note that the bases of the supports are drawn differently, but not according to any diagrammatic convention I know.
 
  • #33
haruspex said:
I note that the bases of the supports are drawn differently, but not according to any diagrammatic convention I know.

It's possible the support at A was drawn slightly differently to permit the x-axis to be drawn on the diagram w/o interference.

To me, it looked like both supports were pinned connections with no indication of any rollers present.
 
  • #34
SteamKing said:
It's possible the support at A was drawn slightly differently to permit the x-axis to be drawn on the diagram w/o interference.

To me, it looked like both supports were pinned connections with no indication of any rollers present.
The text says A is a roller.
 
  • #35
haruspex said:
The text says A is a roller.
What text? The OP simply posted a pitcher out of his textbook. He put the word "roller" in the thread title, but ... :rolleyes:
 
  • #36
SteamKing said:
What text? The OP simply posted a pitcher out of his textbook. He put the word "roller" in the thread title, but ... :rolleyes:
Post #3
 

Similar threads

When are reactive forces enough to support this body?
  • · Replies 14 ·
Replies
14
Views
1K
How Do Support Reactions Affect 2D Static Equilibrium in a Shopping Cart?
  • · Replies 6 ·
Replies
6
Views
2K
Reaction Forces on a Frame With Roller Joint and Pin Joint
  • · Replies 7 ·
Replies
7
Views
9K
Mechanics question: Roller passing over a step
  • · Replies 9 ·
Replies
9
Views
3K
Static equilibrium -- interpretation of forces
  • · Replies 10 ·
Replies
10
Views
3K
Statics problem (moment and equilibrium)
  • · Replies 6 ·
Replies
6
Views
3K
Identifying Pin Joints & Rollers - Structural Analysis Homework Help
  • · Replies 20 ·
Replies
20
Views
4K
What mistake did I make in finding the reaction at hinge A?
  • · Replies 3 ·
Replies
3
Views
2K
Statically Indeterminate Truck - Finding reaction forces at supports
  • · Replies 8 ·
Replies
8
Views
3K
Yet another statics problem involving several forces
  • · Replies 6 ·
Replies
6
Views
2K