What do you mean by equilibrium of a body?

State the condition when a body is in

(i) static equilibrium.

(ii) dynamic equilibrium.

Give one example each of static and dynamic equilibrium.

State the principle of moments. Name one device based on it.

A, B and C are the three forces each of magnitude 4N acting in the plane of paper as shown in figure. The point O lies in the same plane.

(i) Which force has the least moment about O? Give reason.

(ii) Which force has the greatest moment about O? Give reason.

(iii) Name the forces producing (a) clockwise, (b) anticlockwise moments.

(iv) What is the resultant torque about the point O?