Given Moment about a Pin and a Roller

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SUMMARY

This discussion focuses on solving a statics problem involving a beam supported by a pin and a roller. The key equations used are the equilibrium equations: ΣFx=0, ΣFy=0, and ΣM=0. Participants clarify that the moments at the supports MA and MB are zero due to the nature of pin connections, which do not resist moments. The correct moment equation is established as 0=M2-(a+b)RBY, leading to the determination of support reactions RAY and RBY through proper application of static equilibrium principles.

PREREQUISITES
  • Understanding of static equilibrium principles
  • Familiarity with free body diagrams
  • Knowledge of moment equations in mechanics
  • Ability to apply force and moment equilibrium equations
NEXT STEPS
  • Study the concept of couples in mechanics
  • Learn how to construct and analyze free body diagrams
  • Explore advanced static equilibrium problems involving multiple supports
  • Review the effects of different types of supports on reaction forces
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Students studying statics, mechanical engineers, and anyone involved in structural analysis or mechanics of materials.

  • #31
oh, alright. Well thank you so much, I really appreciate it!
 
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  • #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
 

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