00:01
Okay, so this problem asks us to find the internal forces at point of the structure, which is given in problem 676.
00:08
I'll let you scroll up and find that problem.
00:11
But we know from problem 676 that cx equals 720 pounds, and cy equals 140 pounds.
00:26
If you didn't get that, then go ahead and go back and rework with the problem.
00:31
But, so what we want to do is draw the free body diagram from j to c because that's where we have calculated the reaction forces.
00:45
So if have the bar, say this is j to c.
00:56
That means this is 8 inches.
01:00
This is c, and this is j.
01:17
Okay, and then we know that we have cy here, and cx here.
01:35
And then because we have made a cut, we know that we know that imagine that there was a cut on this end right here at j.
01:47
We know that there's some reaction force here b...