00:01
We are on the xy plane and there is a structure here and we have this origin here and we have three forces acting on this structure.
00:27
The first one is in the upward direction t1.
00:38
Then we have f in this direction and the grade is three here.
00:48
4 here, 5 here, and we have this t2 in this direction such that this angle is theta.
01:04
Okay, given that t1 is equal to 5 .5 kilo -newtons and theta is 90 degrees, we are going to find the magnitude f and t2 such that this structure is in equilibrium.
01:22
Okay, now since this is 90 degrees, the grade of this vector will be such that, okay, we have three in the vertical here, so three will be in the horizontal, and we have four here in the horizontal, so four will be in the vertical.
01:47
Okay, with that, let us express t1, t2, and f as vectors.
01:53
T1 is magnitude times the direction.
01:58
It is in the y direction, so we have 0, x component, 1, y component, kiloons.
02:07
T2 is, we have the magnitude times the x component is 3 over 5, and the y component is negative 4 over 5.
02:20
It is negative because it's in the downward direction.
02:25
And f is the magnitude times the unit vector in this direction...