00:01
So i would like to draw this, but it's so complicated.
00:05
And on this whiteboard, it doesn't appear very good.
00:08
So it's really not helpful.
00:11
You really should draw it in your notes, though.
00:16
So we're given a force, and we need the direction bc.
00:23
So i'm going to start with rbc.
00:28
And so, trying to figure this out from b to c, okay, it looks like in the x direction, we're going four.
01:12
In the y direction, we're going two feet, four feet, two feet.
01:26
And in the z direction, it's going negative.
01:35
4.
01:42
I think the y direction.
01:48
No, that was good.
01:49
It's going out to positive, positive, and negative.
01:58
Okay.
02:00
So then we've got, well, then i can get ubc, is just 4i plus 2j minus 4k over the square root.
02:18
Of 4 squared plus 2 squared plus 4 squared, plus 4 squared, which is square root of 36.
02:29
So i can just replace all of this with 6.
02:37
F is given to us as 30i minus 45j plus 50k pounds...