Why is force P not included for body CD in this statics problem?

[yecko]

Homework Statement

Homework Equations

Sum of force = 0 / Sum of moment = 0

The Attempt at a Solution

Why don't the solution consider force P at join C for body CD?
And it considered both force P and reaction force C at join C for body AC... So force C doesn't seems to be the net force at point C...
The written one is my attempt, just for reference.
Thanks for any reply!

 

[Orodruin]

You need to choose which body the force at joint C acts on. It does not matter what you choose, the answer will be the same. The only thing that will change is the force between CD and AC. In fact, you could distribute the force P at C in any way you would like between the bodies. The final answer will not depend on this - only the force between CD and AC.

Note that you cannot include a force P for both CD and AC. This would make the total force on AC+CD be equal to 2P at that point and that is not what the problem asks you for.