Angle problem

1. Dec 13, 2015

OmniNewton

1. The problem statement, all variables and given/known data
A 500-kg concrete slab is supported by a chain and sling attached to the bucket of the front-end loader shown. The action of the bucket is controlled by two identical mechanisms, only one of which is shown. Knowing that the mechanism shown supports half of the 500-kg slab, determine the force
(a) In cylinder CD,
(b) In cylinder FH.

2. Relevant equations

3. The attempt at a solution
Using the summation of Fy

FDCsin26 - 2452.5 = 0
FDC = 5594.5
The correct answer for FDC is 7680 N compression

2. Dec 13, 2015

SteamKing

Staff Emeritus
This is a complicated mechanism. You can't just split the weight in two and say that's the force on Pin D.

You've got to start making FBDs at the bucket and work your way back until you reach the pins connecting the cylinders to the arm.

3. Dec 13, 2015

OmniNewton

Is it not possible to dismantle the bucket leaving the 2 two force members and the weight of the slab. Now one knows the external forces of the bucket and can now calculate. Therefore the only forces in the y-direction are the weight of the slab and the component of FDC.

4. Dec 14, 2015

haruspex

Not so. You can quickly deduce the tension in AB, for example.

5. Dec 14, 2015

OmniNewton

It would seem I am missing a force coming from Pin D. Sorry guys! Thanks for your help I determined my error!