# Problem with caclulatin forces in structure

1. Oct 18, 2008

### louike

Hallo all, I have been working on a little problem.
I have to calculate the forces on a certain structure, but I can not seem to find the solution.

I have given a picture, drawing with my attempt and the drawing of how I try to solve it.

The first drawing is to find the first forces, those are easy.
Then I split the structure in 2 structures to find the other forces, however when I do this I get 2 structures with 3 equations, in total 6 equations. But when you try to work those 6 calculaitions, you will see they are the same (meaning those 6 equations are only 3 equations).

Any one who can help me out here?

The forces 450N and 300N are given.

http://img375.imageshack.us/my.php?image=teck0.jpg
http://img375.imageshack.us/my.php?image=teck0.jpg
The distances are in metres (drawing is not really accurate in scale:rofl:)

As you can so I start of with calculating the force on A , then I find the forces in C.

But then I get stuck.

2. Oct 18, 2008

### Redbelly98

Staff Emeritus
You're obviously aware that all the forces must balance each other, i.e. they sum to zero.

What else should sum to zero here?

p.s. Welcome to PF!

3. Oct 18, 2008

### louike

I do not know.

I just wrote down 3 equations for each drawing (1+2) meaning 6 in total, but they are the same.

1.

X forces: 450N + Dx + Bx = 0
Y: By - Ay - Dy = 0
M around B makes: +Ay. 0,15 -450. 0,25 - Dy.0,45 + Dx.0,1

for 2 its the same: they are the same then for 1.

so what can I do then?