A dam consists of continuous flat$-$plat barriers whose masses are negligible. Supporting struts $A,B,C$ and $D$ are placed every $3$ metres along the dam structure. A mud sample drawn up to the surface has a density of $1\mathrm{.}6M\frac{g}{m^3}.$ Determine the force in struts $C$ and $D.$ All joints can be assumed to be hinged.

Answers: C $=474$ kN $($C$)$ and D $=88\mathrm{.}3$ kn $($C$)$

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