How to determine which point to take the moment about?

  • Thread starter Thread starter CCenturion
  • Start date Start date
  • Tags Tags
    Moment Point
Click For Summary
SUMMARY

The discussion focuses on determining the reactions at points C, D, and E of a T-shaped bracket supported by a wheel and pegs, specifically when the angle is 30 degrees. The user initially calculated moments about point E but was advised to take moments about point D for simplification. It is established that while moments can be summed about any point in equilibrium, choosing the right point can minimize steps and reduce errors in calculations.

PREREQUISITES
  • Understanding of static equilibrium principles
  • Knowledge of moment calculations in mechanics
  • Familiarity with T-shaped bracket structures
  • Basic proficiency in resolving forces and reactions
NEXT STEPS
  • Study the method of summing moments about different points in static systems
  • Learn how to analyze T-shaped structures in mechanical engineering
  • Explore the effects of friction in reaction calculations
  • Practice solving equilibrium problems using various pivot points
USEFUL FOR

Mechanical engineering students, structural analysts, and anyone involved in static equilibrium problems will benefit from this discussion.

CCenturion
Messages
3
Reaction score
0
Problem -
  1. The T-shaped bracket shown is supported by a small wheel at E and pegs at C and D. Neglecting the effect of friction, determine the reactions at C, D, and E when the angle is 30 degrees.

    I have taken the moment about E, and gotten a result for all the reactions. However, in the solutions it says that i should be taking the moment about D.
    I don't understand what the difference is between picking one point or the other.
    Please refer to the two attached pictures. Thank you
 

Attachments

  • 4.41.png
    4.41.png
    7.4 KB · Views: 579
  • 4.41 work.jpg
    4.41 work.jpg
    27.3 KB · Views: 532
Last edited:
Physics news on Phys.org
See template for homework section.
You did not show neither the problem nor your solution.
 
CCenturion said:
Problem -
  1. The T-shaped bracket shown is supported by a small wheel at E and pegs at C and D. Neglecting the effect of friction, determine the reactions at C, D, and E when the angle is 30 degrees.

    I have taken the moment about E, and gotten a result for all the reactions. However, in the solutions it says that i should be taking the moment about D.
    I don't understand what the difference is between picking one point or the other.
    Please refer to the two attached pictures. Thank you
For a system in equilibrium, you can sum moments about any point = 0, but you can simplify the number of steps and reduce chances for errors when summing moments about a selectively chosen point. You might want to first solve for Ex and Ey, then sum moments about D (or C) to see how this works.
 
Got it Phantom, Thanks a lot !
 

Similar threads

How is the moment at A using the Force 1200N calculated?
  • · Replies 22 ·
Replies
22
Views
3K
To find the modulus of elasticity of a light elastic string
  • · Replies 7 ·
Replies
7
Views
3K
Moment about a point of a hammer
  • · Replies 9 ·
Replies
9
Views
4K
Momentum in a Head-on collision
  • · Replies 2 ·
Replies
2
Views
1K
Engineering Solving for the Reaction Force by taking Moment about a Point
  • · Replies 1 ·
Replies
1
Views
3K
To locate the centre of gravity of a rod
  • · Replies 5 ·
Replies
5
Views
2K
To find the reaction in a system at a ring
  • · Replies 2 ·
Replies
2
Views
1K
How Do Support Reactions Affect 2D Static Equilibrium in a Shopping Cart?
  • · Replies 6 ·
Replies
6
Views
2K
Moment about a point of a crane
  • · Replies 18 ·
Replies
18
Views
6K
Moments of Inertia: Hi, Need Help Understanding?
  • · Replies 1 ·
Replies
1
Views
2K