:PROPERTIES:
:ID: 80ae7654-34d0-449e-a305-2e5b7512410e
:mtime: 20231007011821
:ctime: 20231007011528
:END:
#+title: Kinematics
#+filetags: :public:project:
* Definition
Kinematics is the mathematics of describing the motion of physical objects
using Newtonian mechanics.
* Common Notations in kinematics
Here is some common notation used in kinematics:
$\vec{r}(t)$ is a position [[id:5864974d-0edf-4757-9b1f-31b159c9aa7a][vector]] of our object $P$, parametrized by
some time $t$.
The velocity of $P$ is
$\vec{u}(t) = \lim_{\delta t \to 0} \frac{\vec{r}(t+\delta t) - \vec{r}(t)}{\delta t} = \frac{d\vec{r}}{dt}$.
$\vec{u}$ is also a [[id:5864974d-0edf-4757-9b1f-31b159c9aa7a][vector]], and has units of distance/time
The acceleration of $P$ is
$\vec{a}(t) = \frac{d\vec{u}}{dt} = \frac{d^{2}\vec{r}}{dt^2}
* Common Misconceptions
$\vec{u}$ and $\vec{a}$ are not necessarily parallel.