00:01
This one, we need to find the force acting on the crane at point a and also in point b.
00:07
And we need to know the order of magnitude sense that making to determine the reasonableness of the answer from part a and b.
00:17
So for part a, at a, pivot over pin, which is the joint will be a, y, that is will be increased at b, the crane is at rest, pressed against b.
00:50
So only bn.
00:54
Now take the moment at a is equals to zero.
00:59
For clockwise your tve and for anticlockwise for anticlockwise for your ve.
01:07
So clockwise for your positive ve and anti -clockwise for minus ve.
01:19
So we have 1 times bn is equals to 3 ,000 times 9 .8 times 2 plus 1 -0000 times 9 .81 times 2 plus 1 -0 -0 -0 -0 -0 times 9 .81 times 6.
01:40
So we have 647 .46 times 10 raised to the power of 3 newton or 647 .46 kn.
01:57
Now we have another one...