Which law states that an object at rest will remain at rest?

The statement that an object at rest will remain at rest is a direct expression of Newton's First Law of Motion. This law, often referred to as the law of inertia, indicates that an object will maintain its state of motion unless acted upon by a net external force. Therefore, if there are no unbalanced forces acting on a stationary object, it will not change its state and will remain at rest.

This principle is foundational in physics as it helps understand how forces interact with objects. In contrast, Newton's Second Law deals with the relationship between force, mass, and acceleration, while Newton's Third Law focuses on the interactions between two objects, stating that for every action, there is an equal and opposite reaction. The law of gravitation, on the other hand, describes the attractive force between two masses but does not relate specifically to the state of motion of an object.