Equilibrium equation for a frame

[princejan7]

Homework Statement

http://postimg.org/image/scm11r483/




So when considering the free body diagram for member BE, why is the force P not included?

Does the Ex account for the bit of the P=210 that would act on member BE?

 

[Chestermiller]

Homework Statement

http://postimg.org/image/scm11r483/




So when considering the free body diagram for member BE, why is the force P not included?

Does the Ex account for the bit of the P=210 that would act on member BE?

The problem statement seems to imply that the force is acting on the pin. The pin is then assumed to exert a force E_x on member BE. In the problem solution, moments are taken about the pin, so the force at E doesn't matter in this moment balance. However, the solution implicitly assumes that the moment at the pin is zero (i.e., BE rotates freely at the pin).

 

[PhanthomJay]

Does the Ex account for the bit of the P=210 that would act on member BE?

Did you solve for Ex? It's quite a bit of P.
In the FBD of the member, the internal cut is made an infinitesimal distance away from the joint, so it does not include P in your FBD of the member, just internal forces Ex, Ey, CD, and the external roller vertical reaction.