00:01
In this problem, we have a kind of a complicated mechanism, which i haven't drawn, but you can see in the book.
00:06
And we're given all the dimensions that we need.
00:10
And so it's kind of going through the same procedure as we've done in lots of previous problems, is writing all the position vectors.
00:18
So i used a as my origin, and so then i have positioned to b, c, d, e, g, and f.
00:25
So there are three members in this mechanism.
00:28
So we're going to have actually lots of equations.
00:30
And lots of unknowns.
00:32
What we can see from generally speaking is that the fg, which is the, i defined as a point on the body where load p acts, and i used, let's see here, g is where the 360 pound load x and q is the 240 pound load.
01:01
Pound load.
01:02
So i define two new points here to where the external loads at.
01:08
And then we also know that because point e is on a roller, that the force is, there's only a force component in the x direction and the force component in the y direction is zero.
01:23
And that's good because we have, they have lots of unknowns here.
01:29
And we have two forces, force, force, the force, force at a, force it b, force at c, and force it d.
01:36
And so two components each, that's eight.
01:39
And then the force of e gives us nine unknown force components.
01:44
And so we need nine equations.
01:47
So we need to draw, do force and moment balances on three different, three different sections or subsections of this, of this mechanism.
01:57
And so what i did is i did just some of the forces and moment all over the entire body.
02:06
So we have just the external, external forces acting from the, where it's connected to the wall, connected to the ground.
02:15
So those are at e and e, and then we have our applied loads at f and g.
02:21
And then i looked at just the horizontal bar, remember, with loads that act on it are loads at a, b, and d...