As shown in the figure,the tension in the horizontal cord is $30 \, N$. The weight $W$ and the tension in the string $OA$ in Newton are:

When a body is stationary,which of the following statements is true?

$A$ body is in equilibrium under the influence of a number of forces. Each force has a different line of action. The minimum number of forces required is:

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?

$A$ small sphere is hung by a string fixed to a wall as shown in the figure. The sphere is pushed from the wall by a stick. The forces acting on the sphere are as shown. Then,identify the incorrect expression.