# Hydrostatics Problem

1. Nov 27, 2003

### AngelofMusic

Hello,

I'm currently trying to solve a problem involving hydrostatics, but I'm getting stuck when it comes to drawing the forces in the FBD.

The original problem is here:

Diagram & Problem Info

This is my attempt at drawing the FBD:

My FBD

My calculations:

R(water) = 187.3 kN
R(mud) = 644.7 kN

I think that should be correct.

However, once I isolated the joint at the intersection of A,B, and C, there is no way I can get the joint to be in equilibrium. (See the bottom right corner of my FBD).

The same problem occurs at D, where the compression force in member D only goes up vertically, but I also have a horizontal component to the reaction force at D.

What am I doing wrong? Does anyone have any hints/suggestions on how to solve this?

Thanks a lot!

2. Nov 27, 2003

### HallsofIvy

You will need to assume that A and D are set in at their base (not hinged) so that they can support sideways forces.

3. Nov 27, 2003

### AngelofMusic

Okay, so would the FBDs look something like this, then?

Second Attempt at FBD

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