What does the First Law of Newton state?

The First Law of Newton, often referred to as the Law of Inertia, states that an object at rest stays at rest unless acted upon by an external force. This principle highlights the tendency of objects to maintain their state of motion—whether that means remaining stationary or moving at a constant velocity—unless influenced by an external force.

This concept is fundamental in understanding how forces interact with matter. For example, consider a book lying on a table; it will not move until something (like a hand) exerts a force on it. Similarly, a moving vehicle would continue to roll indefinitely at a constant speed in a straight line if there were no forces—such as friction from the road or air resistance—acting upon it.

Understanding this law is crucial for grasping the concepts of motion and force, which are foundational in physics and are applicable in fitness contexts, such as understanding the mechanics of human movement and ensuring safe practices during physical activities.