Three spheres $A,B,$ and $C$ having

their diameters $500mm,500mm,$ and

$800$ mm respectively, are placed in a

trench with smooth side walls and

floor as shown in the figure. The

center$-$to$-$center distance of spheres

A and $B$ is $600$ mm $.$ The weights of

the cylinders A$,$ B and C are $4kN,4$

kN $,$ and $8$ kN respectively. Determine

the reactions at $P,Q,R,$ and $S.$