Find Reactions of 4000lb Crate in Truss Figure 1

AI Thread Summary
To determine the reactions at points A and E of a truss supporting a 4000lb crate, the moment arm equation M = F*Distance is utilized. The discussion clarifies that there are no reactions at joints B, D, and C, as they do not serve as supports. The user expresses initial confusion about calculating the forces at these joints but gains clarity on how to approach the problem. It is emphasized that each joint's forces must sum to zero, aiding in the understanding of the system's dynamics. The user concludes that they now have the necessary information to complete their assignment effectively.
kennyvs
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Homework Statement


A 4000lb uniformly weighted crate is attached by light inextensible cables to the trus show below. Simply determine the reaction at A and E of the truss show below

Figure 1 attachment

Homework Equations


I used the Moment arm equation of M = F*Distance

The Attempt at a Solution



I know how to find out the Fx and Fy force of A and E, but I am having trouble determine the Fx and Fy force of B D C
 

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Hi, kennyvs, welcome to PF!
The problem asks you to determine the reactions at A and E, which you know how to find. There are no supports at B, D, and E, therefore, there are no reactions at those joints. Are you trying to take this problem one step further by determining the member forces? Each of the joint forces must sum to 0. For example, at joint D, the cable exerts a 2000 pound downward pull on the joint, so the member BD must exert an upward pull of 2000 pounds on that joint. But I'm not sure what you are trying to do.
 
I think i got what i need to complete the assignment. Initially I don't know what the force at B D C are, but knowthnx to your reply ^^ now i can find moment A with the force from joint B, D, C. Thnx
 
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