Newtons first law of motion, also known as the law of inertia, states that every object will remain at rest or in uniform motion in a straight line unless acted upon by an unbalanced force. In other words, an object at rest will remain at rest, and an object in motion will continue to move at a constant velocity in a straight line unless acted upon by an external force. This tendency to resist changes in a state of motion is called inertia. If all the external forces cancel each other out, then there is no net force acting on the object, and it will maintain a constant velocity.

Newtons first law is the foundation of classical mechanics and explains why objects move or dont move as they do. It is also important to note that Newtons laws are valid only in inertial frames of reference. There are many applications of Newtons first law of motion in daily life. For example, wearing a seat belt in a car while driving is an example of Newtons first law of motion.