Newton’s laws of motion are three statements describing the physical relations between the forces acting on a body and the motion of the body. Isaac Newton developed his three laws in order to explain why planetary orbits are ellipses rather than circles, but it turned out that he explained much more. Inertia is the natural tendency of objects to stay in motion or rest, unless a force acts on them. Learn about the origin and development of the concept of inertia, from Aristotle to Newton, and the different formulations of the first law of motion. Newton's first law says that a body at rest or in uniform motion will remain at rest or in uniform motion until and unless it is subjected to a net external force. The football remains stationary until a force is applied, which demonstrates the Law of Inertia, as shown in the image below: Newton’s First Law: Inertia An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by an unbalanced force. Newton’s first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. This tendency to resist changes in a state of motion is inertia. If all the external forces cancel each other out, then there is ...
