00:01
In this problem we are going to compute the moment or torque of some temperature force in a system.
00:10
So with respect to some point.
00:12
So this is our system.
00:15
But first let me draw my x, y and z axis.
00:22
So x here, y here, z here.
00:28
Now we have this object, some bent shaped object.
00:33
That stands on the ground so it starts from the origin it goes up to some height along the positive z direction then it goes in the negative extraction and goes in the positive y direction okay let's throw it better like that so this is our band object and we see that there is a cable connect to to a at this end point and it goes to the ground.
01:14
Like that, so we have our cable here.
01:19
And this cable or along this cable there is a tension.
01:24
There is some tension developing on this cable.
01:28
So let's label it like cd here.
01:34
And along this, we have this tension vector t.
01:40
With a magnitude 600 pounds.
01:43
With, okay, about this point, the origin, we are going to compute the torque or the moment of this tension force.
02:00
So this will be, this vector here from o to point c here will be our moment arm.
02:11
So when we write moment or torque equal to our cross.
02:20
Cross force or this tension we are going to use this our this moment arm so basically we are done with the problem the rest is just determining the these vectors explicitly okay let's do it in a very systematic fashion first we need to identify the lengths so from o to d we have eight feet here we have 16 feet and this short arm is 6 feet and this side is 7 feet now we have the following coordinates for these points see is given by okay i'm going to use this notation the tappell notation so i will list my coordinates in parentheses separated by commas the first component will be the x component second y and the third component will be z so this is my notation and it's a short -time notation to express the vectors okay so c is given by the following it its x component is minus six feet and its y component is seven feet and it is at a height given by 16 feet.
04:07
So this are the coordinates of my point c.
04:12
Let's do the second one, point d.
04:16
It is on the y axis, so it only has a non -zero -y component and it is 8 feet from the origin...