00:01
We've drawn all the dimensions and forces and stuff, and we want to draw a shear force and bending moment diagram.
00:08
So to start off with, we need to figure out what these reactions are.
00:11
So we know that by summing up the upward forces, they have to equal the sum of the downwards forces, which is 180.
00:20
This is all in kilonewtons, by the way.
00:24
Then if we take moments about b, we find that we get 6 .33 times re plus 2 times 50, that's the anticlockwise moment, has to equal the clockwise moment, which is 2 times 50 plus 4 .33 times 40 plus 8 .33 times 40.
01:02
And we can solve to find that re is equal to 80 kn and therefore rb, using this equation up here, is equal to 100 kn.
01:16
So the shear force diagram, initially we're going to start at minus 50 and that stays until b when we get a boost of 100 kn upwards, that's going to take us up to minus 50...