# Terminology/Kinematics

## Kinematics

In classical mechanics "kinematics" generally refers to the study of properties of motion-- position, velocity, acceleration, etc.-- without any consideration of why those quantities have the values they do.

### Defining Kinematics

Kinematics is the branch of classical mechanics that study and describes the motion of points, objects and systems of groups of objects, without reference to the causes of motion (i.e., forces ). The study of kinematics is often referred to as the “geometry of motion.”

A formal study of physics begins with kinematics. The word “kinematics” comes from a Greek word “kinesis” meaning motion, and is related to other English words such as “cinema” (movies) and “kinesiology” (the study of human motion). Kinematic analysis is the process of measuring the kinematic quantities used to describe motion. The study of kinematics can be abstracted into purely mathematical expressions, which can be used to calculate various aspects of motion such as velocity, acceleration, displacement, time, and trajectory.

To describe motion, kinematics studies the trajectories of points, lines and other geometric objects, as well as their differential properties (such as velocity and acceleration). Kinematics is used in astrophysics to describe the motion of celestial bodies and systems; and in mechanical engineering, robotics and biomechanics to describe the motion of systems composed of joined parts (such as an engine, a robotic arm, or the skeleton of the human body).

#### Professor Shankar's introduction

Professor Shankar describes the Newtonian procedure for predicting the future, given the present, has two parts: Kinematics and Dynamics.

Kinematics is a complete description of the present. It's a list of what you have to know about a system right now. For example, if you're talking about a piece of chalk, you'll want to know where it is and how fast it's moving.

Shankar has a course at Yale where he gives an overview of Newtonian mechanics and explains its two components: kinematics and dynamics. He then reviews basic concepts in calculus through two key equations:

...tracing the fate of a particle in one dimension along the x-axis. ^{[1]}