Newton's laws of motion are three laws that describe the relationship between the motion of an object and the forces acting on it. These laws create the foundation of Newtonian mechanics. Newton's laws of motion break down when objects move at very high speeds (special relativity), are very massive (general relativity), or are very small (quantum mechanics), and in these situations, we require a different set of physical laws ## Newton's 1st Law *(Also known as the **law of inertia**)* ![[newtonLaw1.jpeg]] *A body remains at rest, or in motion at a constant velocity, unless acted upon by a force.* ## Newton's 2nd Law ![[newtonLaw2.jpeg|align:center|360]] $ \vec{F} = m \vec{a} = m \left(\frac{\mathrm{d}^{2} \vec{r}}{\mathrm{d} t^{2}} \right) = \frac{\mathrm{d} \vec{p}}{\mathrm{d} t} \hspace{1cm} \text{where} \hspace{1cm} m \equiv {\rm constant} $ *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 changes with time.* ## Newton's 3rd Law ![[newtonLaw3.jpeg|align:center|540]] *Every action has an equal and opposite reaction. Meaning, if two bodies exert forces on each other, these forces have the same magnitude but opposite directions.*