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Why does a moving object eventually stop when friction and air resistance act on it?

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Title page of Isaac Newton's Philosophiae Naturalis Principia Mathematica, 1687, featuring large Latin text and publication details in a bordered layout. — Newton’s laws of motion The title page of Isaac Newton's *Philosophiae Naturalis Principia Mathematica* (1687; *Mathematical Principles of Natural Philosophy*), the work in which the physicist introduced his three laws of motion.

According to Newton’s first law of motion, also known as the law of inertia, an object will remain at rest or continue to move at a constant speed in a straight line unless it is acted upon by an external force.

While it may appear that objects naturally come to a stop on their own, this observation is actually the result of unbalanced forces acting on the object. In the context of classical mechanics, when a moving object slows down and eventually stops, it is because forces such as friction and air resistance are exerting an opposing influence.123

These forces act in the direction opposite to the object's motion, effectively removing the kinetic energy that sustains its movement. Because these forces are present in our everyday environment, they provide the necessary "push" or "pull" required to change an object's state of motion, consistent with the principles established by Isaac Newton.2413