00:01
In this problem, you're looking at adding vectors with components and also graphical procedure.
00:10
I've transferred what you wrote into the question just to have it in front of us.
00:19
Everything looks good.
00:23
I'd always suggest draw a nice picture, label everything.
00:28
Remember, cosine is with the adjacent, signs with the opposite.
00:32
It.
00:33
Nothing really there.
00:34
One other comment i'll make, you know, it's fine either way.
00:40
Using the full angle from the positive xx all the time, certainly anything works, but i sometimes think it may be more understandable, less error prone if you always just deal with the right triangles and put in the quadrant signs yourself, like the second quadrant, so x is negative, y is positive, and just using the angles, you know, there are between zero and 90, instead of having to worry about, there's some external axis to the line.
01:11
It's whatever you're comfortable with, just to give you a tidbit.
01:14
If you use 45, then you have sign for x, opposite, and cosine for y.
01:23
So it shows you the switch there.
01:27
Now, then you add up as components to get cx and ey, the sum.
01:36
Everything's fine here.
01:38
One couple more comments.
01:40
When you put this minus sign for cx, you're very careful.
01:45
If you're going to put it in, make sure you use parentheses.
01:47
If you don't, you're going to get, this is going to be a negative number.
01:50
Minus 195 square button on your calculator is a minus.
01:54
It's a negative number because it's not squaring the minus.
01:57
Minus not included.
01:59
It's only the 1 .95.
02:00
So be careful.
02:01
Either use parentheses or just drop it anyway.
02:04
Because it's going to be squared.
02:05
It's going to go away.
02:06
So whatever you're comfortable with.
02:09
Next thing is that you did the inverse tangent on cy over cx and reported a negative number for the angle.
02:18
Well, just by that alone, that's a fourth quadrant angle.
02:22
This is not a fourth quadrant vector, the second quadrant vector.
02:26
So you've got to be careful.
02:28
Absolute value will give you an angle between 0 and 90, and then you have your picture and you can adjust, depending on what's asked of you or how you want to say it.
02:37
Everything can follow from that single value between 0 and 90 angle.
02:42
You could say it's clockwise from the negative x -axis.
02:49
You could talk about it being counterclockwise from the positive x -axis where you do 180 minus 5 .90 minus to talk about the angle from the positive y.
03:03
Get an angle, have the diagram, get an angle, and then that.
03:07
But the negative one is the wrong quadrant.
03:10
So you've got to be very careful.
03:13
Now, the next part of this wants the graphical.
03:17
This is where you use your scale, your 10 units, 10 centimeter scale.
03:23
So obviously you take out your ruler, you'll be measuring everything in your protractor, doing everything as precise as possible.
03:29
I'm just going to crew that give you the procedure.
03:31
Now, the procedure we use is called the triangle rule.
03:35
You put the tail of the second vector at the tip of the first, and then draw from the tail of the first to the tip of the second.
03:41
So here is vector b.
03:47
So tail of the second, tip of the first...