00:02
All right.
00:04
We've hit the century mark kind of on our problems here.
00:10
For 100, notice that the answer is not in the back of the book.
00:14
And we need to find the resultant force.
00:17
Oh, my goodness.
00:19
So how do i want to do this? i think that what i'm going to do is i'm going to try to do it the way that seems to be a little easier.
00:38
A little less technical though.
00:45
I'm going to draw it, but i'm going to put some things on the drawing that aren't there on the book's drawing.
00:58
So we've got a point c over here, but the distance out to point c is four.
01:17
It's just four meters.
01:24
So this distance is four meters here.
01:28
This distance is 3 meters, and that is shown.
01:37
All right, and that's the distance to point c.
01:40
The distance to point a is also 3 meters, and then we've also got a point b way out here, and it's showing that this is 2, and this is 4.
02:11
All right, so i think this will work out.
02:16
Got a force here, and i've got a force there.
02:23
Fab is 200.
02:26
Newton's, fac is 150 newton's.
02:34
We've got to figure out the resultant.
02:37
So, first of all, uab, or rather, let's just go to fab, is going to be fab times the vector form of uab.
03:15
Well, in the x direction, it's going to, in the y, direction it's going four and in the z direction it's going three two squared plus four squared plus three squared okay f ac is just going to be f ac times oh wait a minute there should be a negative here positive positive negative okay f ac is going in the negative negative direction and in the negative y direction and in the negative z direction.
04:26
Everything's negative on that one.
04:28
So it's going to go negative 3 in the x direction, negative 4 in the j direction, and negative 3 in the k direction.
05:00
That's it.
05:01
Well, that's not it because now i've got to add them all together.
05:06
What is the square root? you know, these are not going to work out nicely.
05:12
Trying to think of what's the best way to do this now.
05:17
Well, i'm just going to write it down.
05:27
All right.
05:29
200 times 2 over the square root of 2 squared plus 4 squared plus 3 squared.
05:51
That gives me 74 .3.
06:03
4 is the next one.
06:06
4 in the numerator...