An object at rest tends to stay at rest unless acted upon by a net external force. This describes which of Newton's laws?

An object at rest tends to stay at rest unless acted upon by a net external force. This describes which of Newton's laws?

• A. Newton's First Law of Motion
• B. Newton's Second Law of Motion
• C. Newton's Third Law of Motion
• D. Law of Conservation of Energy

Answer: (A)

This statement captures inertia—the tendency of an object to resist changes in its motion. An object at rest will remain at rest unless a net external force acts on it, and if the net force is zero, its velocity stays constant (zero here), so it remains at rest. This is Newton's First Law of Motion, also called the Law of Inertia. In contrast, the Second Law describes how a net force produces acceleration (F = ma), the Third Law describes action-reaction force pairs, and the Law of Conservation of Energy concerns how energy is preserved in interactions, not the tendency of motion to persist without a force.

This statement captures inertia—the tendency of an object to resist changes in its motion. An object at rest will remain at rest unless a net external force acts on it, and if the net force is zero, its velocity stays constant (zero here), so it remains at rest. This is Newton's First Law of Motion, also called the Law of Inertia.

In contrast, the Second Law describes how a net force produces acceleration (F = ma), the Third Law describes action-reaction force pairs, and the Law of Conservation of Energy concerns how energy is preserved in interactions, not the tendency of motion to persist without a force.