According to Newton's First Law, what will happen to an object in motion?

According to Newton's First Law of Motion, an object in motion tends to remain in motion with the same speed and in the same direction unless acted upon by an external force. This principle is often summarized by the term "inertia," which is the tendency of an object to resist changes to its state of motion. Therefore, if no external force—such as friction, gravity, or a collision—interrupts the motion, the object will continue to move indefinitely in a straight line at a constant speed. This understanding is foundational in mechanics, illustrating the inherent characteristics of objects in motion and their interactions with forces in their environment.