How Do You Calculate Reactions at Supports in Equilibrium Problems?

In summary, the conversation involves drawing a free-body diagram of a structure and determining the reactions at points A and E. The equations used in the solution are M = (Fy)*x and M = (Fx)*y, where x represents horizontal distance, y represents vertical distance, and M represents the moment. The attempt at a solution involves finding Ax and using the equation -200 ft-lb = (2 ft)*Ax to solve for it. However, this method is incorrect and the correct approach is to balance the applied force. To find Ay and Ey, the moments are summed about E and A, respectively. Finally, the solution is checked by ensuring that the net force in the y-direction is equal to 0.
  • #1
Cursed
39
0

Homework Statement



Draw the free-body diagram of the structure by isolating it from its supports at A and E. Determine the reactions at A and E.

[PLAIN]http://img715.imageshack.us/img715/7161/physics.png

Homework Equations



M = (Fy)*x, or M = (Fx)*y
where "x" represents horizontal distance and "y" represents vertical distance. "M" is the moment.

The Attempt at a Solution



I found Ax.

When I convert the moment (curved, pink arrow) to a force, I find that the moment and force at A must be equal and opposite to the 200 ft-lb moment.

-200 ft-lb = (2 ft)*Ax

Ax = -100 ft-lb

I have no idea how to find Ay or E.
The book says Ay = -225 lb; E = 625 lb

Can anyone help me get started? I'm not sure how to go about finding those two values!
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
60 views and no answers?

can someone help me with this?
 
  • #3
Have some patience, please. :rolleyes: Well, the supports aren't showm very clearly; I had to work the problem backwards and it appears that the frame is roller supported at E and pinned at A. Your method for the calculation of Ax is not correct...Ax must balance the applied force. Sum moments about E to solve for Ay; sum moments about A to solve for Ey; check your work by ensuring that F_net_y =0
 

Related to How Do You Calculate Reactions at Supports in Equilibrium Problems?

What is an object in equilibrium?

An object in equilibrium is one that is not moving or changing its state of motion. This means that all forces acting on the object are balanced, resulting in a net force of zero.

What is the difference between static and dynamic equilibrium?

Static equilibrium occurs when an object is at rest, while dynamic equilibrium occurs when an object is moving at a constant velocity. In both cases, the net force on the object is zero.

How do you determine if an object is in equilibrium?

An object is in equilibrium when the sum of all forces acting on the object is zero. This can be determined by using Newton's First Law of Motion, which states that an object will remain at rest or in motion with a constant velocity unless acted upon by an unbalanced force.

What happens to an object in equilibrium when an external force is applied?

If an external force is applied to an object in equilibrium, the object will no longer be in equilibrium and will begin to accelerate. This is because the balance of forces is disrupted, resulting in a net force acting on the object.

How do you calculate the forces acting on an object in equilibrium?

To calculate the forces acting on an object in equilibrium, you must first identify all the forces acting on the object and their direction. Then, use the principle of vector addition to determine the net force. If the net force is zero, the object is in equilibrium.

Similar threads

  • Introductory Physics Homework Help
Replies
12
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
8K
  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
11
Views
776
  • Introductory Physics Homework Help
Replies
1
Views
799
  • Engineering and Comp Sci Homework Help
Replies
9
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
2K
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
2
Views
6K
Back
Top