According to the principle of moments, what is true for a system in equilibrium?

In a system in equilibrium, the principle of moments states that the sum of the clockwise moments about any pivot point must equal the sum of the anti-clockwise moments around that same point. This balance is essential for maintaining equilibrium, ensuring that there is no net rotational force acting on the system.

For instance, if a seesaw is perfectly balanced, the torque created by the weights on either side must be equal, which aligns with the principle of moments. This principle accounts for the distances from the pivot and the magnitudes of the forces involved, confirming that as long as these conditions are met, the object will remain stationary or in uniform motion.

The other options, while related to the broader topic of equilibrium, do not specifically address the principle of moments. The sum of forces being equal to zero is a separate requirement for translational equilibrium and does not capture the concept of rotational balance. The idea that one type of force must be greater than another contradicts the definition of equilibrium. Lastly, while objects in equilibrium can be stationary, they can also be in uniform motion; therefore, stating that the system must be stationary is not accurate.