Kinetics (physics)

In <a href="/facts/Physics/a7aH2y08">physics</a> and <a href="/facts/Engineering/RFVg8H3I">engineering</a>, kinetics is the branch of <a href="/facts/Classical_mechanics/ykG8upsN">classical mechanics</a> that is concerned with the relationship between the <a href="/facts/Motion/dCnP7MlB">motion</a> and its causes, specifically, <a href="/facts/Force/533Q1uzq">forces</a> and <a href="/facts/Torque/KcrcvNtV">torques</a>. Since the mid-20th century, the term "<a href="/facts/Dynamics_(mechanics)/JLk81H71">dynamics</a>" (or "<a href="/facts/Analytical_dynamics/3yqJfP8l">analytical dynamics</a>") has largely superseded "kinetics" in physics textbooks, though the term is still used in engineering.
In <a href="/facts/Plasma_(physics)/1d3btMVU">plasma physics</a>, kinetics refers to the study of <a href="/facts/Continuum_mechanics/vI7LpFDk">continua</a> in <a href="/facts/Velocity/Q3o1LVDe">velocity</a> space. This is usually in the context of non-thermal (<a href="/facts/Maxwell%E2%80%93Boltzmann_distribution/KAuVfdKJ">non-Maxwellian</a>) velocity distributions, or processes that <a href="/facts/Perturbation_theory_(quantum_mechanics)/lYGgk9Ph">perturb</a> thermal distributions. These "<a href="/facts/Plasma_(physics)/1d3btMVU">kinetic plasmas</a>" cannot be adequately described with <a href="/facts/Magnetohydrodynamics/7mQbJPPD">fluid equations</a>.
The term kinetics is also used to refer to <a href="/facts/Chemical_kinetics/D8vyX4aE">chemical kinetics</a>, particularly in <a href="/facts/Chemical_physics/VEqp9VrK">chemical physics</a> and <a href="/facts/Physical_chemistry/WqwnJjRM">physical chemistry</a>. In such uses, a qualifier is often used or implied, for example: "physical kinetics", "crystal growth kinetics", and so on.

Kinetics (physics) open-in-new

Kinetics (physics)