Write the condition of equilibrium when three forces act on a particle.

$A$ flexible chain of weight $W$ hangs between two fixed points $A$ and $B$ which are at the same horizontal level. The inclination of the chain with the horizontal at both the points of support is $\theta$. What is the tension of the chain at the mid point?

One end of a horizontal uniform beam of weight $W$ and length $L$ is hinged on a vertical wall at point $O$ and its other end is supported by a light inextensible rope. The other end of the rope is fixed at point $Q$,at a height $L$ above the hinge at point $O$. $A$ block of weight $\alpha W$ is attached at the point $P$ of the beam,as shown in the figure. The rope can sustain a maximum tension of $(2 \sqrt{2}) W$. Which of the following statement$(s)$ is(are) correct?

There are four forces acting at a point $P$ produced by strings as shown in the figure. The system is at rest. Find the forces $F_1$ and $F_2$.

$A$ uniform sphere of weight $W$ and radius $5\, cm$ is held by a string of length $8\, cm$ attached to a smooth vertical wall as shown in the figure. The tension in the string is:

Describe the different types of common forces.