>[!abstract] >Newton's laws of motion are three physical laws (first stated by Isaac Newton in his *Philosophiæ Naturalis Principia Mathematica* in 1687) that describe the relationship between the motion of an object and the forces acting on it. These laws, which provide the basis for Newtonian mechanics, can be paraphrased as follows: > >1. A body remains at rest, or in motion at a constant speed in a straight line, unless it is acted upon by a force. >2. At any instant of time, the net force on a body is equal to the body's acceleration multiplied by its mass or, equivalently, the rate at which the body's momentum is changing with time. >3. If two bodies exert forces on each other, these forces have the same magnitude but opposite directions. > >Limitations to Newton's laws have also been discovered; new theories are necessary when objects move at very high speeds (special relativity), are very massive (general relativity), or are very small (quantum mechanics) (Wikipedia, 2025). >[!related] >- **North** (upstream): [[Classical mechanics]] >- **West** (similar): [[Kepler's laws of planetary motion]] >- **East** (different): [[Relativity]] (special and general relativity, which supersede Newton's laws at high speeds and strong gravity) >- **South** (downstream): [[Laws of inertia, force, and action–reaction]] (the three individual Newtonian laws)