Question

Can a moment be negative?

Answer 1

Hint: We know that the moment of a force is the effect on an unopposed force which is applied along the direction different from its line of action on an object that is pivoted about an axis. Moment which is also known as the moment of a force is usually defined as the tendency of a force to cause a body to rotate about a specific axis or a specific point.

Complete answer:
A moment can be defined with a directional sense. The direction of the moment of force is similar to that of the tendency of the body to turn in some direction. A clockwise rotation about the pivot will be considered as a positive moment and the anticlockwise rotation about the pivot will be treated as a negative moment.

This will lead us to a principle of moments which says that when a system is balanced the overall sum of the anti-clockwise moments will be same as the sum of clockwise moment which means when a system is in balance or is stable, it is said to be in a state of equilibrium since all the forces acting on the system cancel each other out and rotational motion will not occur. So, we can say that moments can be negative also.

Therefore, a moment can be negative.

Note: The direction of the moment may depend on the axis of rotation with respect to which we are measuring the turning effect. The clockwise and counterclockwise qualifications are usually dependent on the viewpoint of the observer.