00:01
All right, so there's actually three problems listed here.
00:04
So what i'll do is i'll answer the first one, and hopefully you can resubmit the other two and get answers for those as well.
00:13
So for this first problem, we have four different coordinate systems, and we need to divide this force into its x and y components.
00:21
So this first one here, letter a, we have the force at an angle alpha with respect to the y axis.
00:28
And so we need to divide this into its coordinate parts.
00:33
And the opposite side, so we're going to draw the legs of a right triangle around this force.
00:39
And the angle here is going to give us the x component, which is the opposite side to it, and the y component, which is the adjacent side.
00:48
So the x component here will be in the negative x direction.
00:52
So we'll write f subx is equal to negative.
00:56
And then it's the magnitude of the force, which is our hypotenuse here, times the sign of this angle.
01:03
So f sign of alpha is that.
01:07
And again, this is in the negative direction, so that's why i've drawn the negative sign there.
01:12
And the y component here will be with the cosine.
01:16
So again, f cosine of theta, or cosine of alpha, i should say.
01:24
And in this case, we're in the positive y direction.
01:27
Stays positive.
01:30
For letter b, we can do much the same where now we have the positive x direction is pointed down on our axis here.
01:39
But again, we're just dividing this into its x and my components.
01:44
And so right here we have the positive x direction is down.
01:47
Positive y direction is to the left.
01:50
And so this alpha angle here, if we look at this opposite side, that's going to give us the positive of x direction.
01:58
So f sub x is going to be f sine of alpha and f some y is going to be the adjacent side.
02:09
So that gives us f cosine of alpha like so.
02:16
Okay...