All objects, regardless of their state of motion.
Explanation
The 'Law of Inertia' is synonymous with Newton's First Law of Motion. It states that an object will remain in its state of rest or of uniform motion in a straight line unless compelled to change that state by an applied external force. Inertia is the inherent property of a body to resist changes to its state of motion.
Analysis of Applicability:
- Inertia of Rest: This aspect applies to objects that are stationary. They resist being set into motion.
- Inertia of Motion: This aspect applies to objects that are already moving. They resist changes to their speed or direction.
- Universal Nature: Inertia is a fundamental property of matter directly related to mass. Since all material objects possess mass, the Law of Inertia applies to all objects regardless of their current state (rest or motion) or their environment (vacuum or atmosphere).
Therefore, the law is not limited to objects at rest or in uniform motion exclusively; it governs the behavior of all objects in both states.
Key Takeaway:
The Law of Inertia is a universal principle applicable to all objects with mass, governing their resistance to changes in velocity, whether they are at rest or in motion.