What is Newton's first law of motion, often called the law of inertia?

Newton's first law of motion, known as the law of inertia, states that an object at rest will remain at rest, and an object in motion will continue to move at a constant velocity, unless acted upon by a net external force. This principle highlights the inherent tendency of objects to resist changes to their state of motion.

In practical terms, this means that if no external force is applied, a stationary object will not start moving by itself, and a moving object will not alter its speed or direction without any interference. This concept is foundational in physics, laying the groundwork for understanding motion and forces.

The idea of inertia is crucial in various applications, such as in aviation where understanding how an aircraft will behave under different forces is essential for control and stability. By recognizing that external forces are needed to change an object's motion, pilots can make informed decisions about control inputs during flight.