According to the principle of moments, when is an object in equilibrium?

An object is in equilibrium according to the principle of moments when the clockwise moments equal the counterclockwise moments. This condition signifies that the sum of the moments acting about any pivot point is zero, resulting in no net torque acting on the object. When the moments are balanced in this way, the object will not rotate.

In mechanical contexts, moments are calculated as the product of the force applied and the distance from the pivot point, with careful attention paid to the direction of the forces (clockwise or counterclockwise). If these moments are equal, the net torque is zero, and thus, the object remains in a state of rotational equilibrium.

The other options do not establish this specific condition for equilibrium: having equal clockwise and counterclockwise forces alone (such as in translational equilibrium) does not address moments, while having no mass or being in motion does not contribute to a concept of equilibrium as defined by moments.