kinematics
The branch of mechanics concerned with objects in motion, but not with the forces involved.
Examples of kinematics in the following topics:

Defining Kinematics
 Kinematics is the study of the motion of points, objects, and groups of objects without considering the causes of its motion.
 The study of kinematics is often referred to as the "geometry of motion."
 A formal study of physics begins with kinematics.
 Kinematic analysis is the process of measuring the kinematic quantities used to describe motion.
 Kinematic equations can be used to calculate the trajectory of particles or objects.

Constant Angular Acceleration
 Kinematics is the description of motion.
 We have already studied kinematic equations governing linear motion under constant acceleration:
 Similarly, the kinematics of rotational motion describes the relationships among rotation angle, angular velocity, angular acceleration, and time.
 By using the relationships a=rα, v=rω, and x=rθ, we derive all the other kinematic equations for rotational motion under constant acceleration:
 Relate angle of rotation, angular velocity, and angular acceleration to their equivalents in linear kinematics

Applications
 There are four kinematic equations that describe the motion of objects without consideration of its causes.
 Kinematics is the branch of classical mechanics that describes the motion of points, bodies (objects), and systems of bodies (groups of objects) without consideration of the causes of motion.
 There are four kinematic equations when the initial starting position is the origin, and the acceleration is constant:
 Notice that the four kinematic equations involve five kinematic variables: $d$, $v$, $v_0$, $a$, and $t$.
 Choose which kinematics equation to use in problems in which the initial starting position is equal to zero

ProblemSolving Techniques
 Examine the situation to determine that rotational kinematics (rotational motion) is involved.

Kinematics of UCM

Motion with Constant Acceleration
 Acceleration can be derived easily from basic kinematic principles.
 Due to the algebraic properties of constant acceleration, there are kinematic equations that relate displacement, initial velocity, final velocity, acceleration, and time.

Relationship Between Linear and Rotational Quantitues
 With the relationship of the linear and angular speed/acceleration, we can derive the following four rotational kinematic equations for constant $a$ and $\alpha$:

The Kinematics of Photon Scattering

Centripetial Acceleration
 As mentioned in previous sections on kinematics, any change in velocity is given by an acceleration.

Average Velocity: A Graphical Interpretation
 The kinematic formula for calculating average velocity is the change in position over the time of travel.