Difference Between Kinetics and Kinematics

Kinetics and kinematics are two interrelated topics that are integral parts of deriving the motion of a body or object working in separate spaces. Even so, these factors work hand-in-hand; they have some stark differences that students need to learn to get a firm grip on mechanics.

Often students confuse these two terms and use them as synonyms, which is incorrect. Thus, it is imperative for them to find the difference between kinetics and kinematics at various points. They can start with knowing the definition of these two terms to get the basics right.

The study of physics begins with Kinetics and Kinematics. Kinetics deals with the absolute motion of an object i.e with respect to that object. It is further divided into Dynamics and Statics. And Kinematics deals with the relative motion of an object. For instance, the Sun moves around the earth. It is Kinematically correct but kinetically wrong. Because, relative to the Earth, the Sun moves around it.

The word “Kinematics” comes from the Greek word “kinesis”, which means motion. It is also related to other English words such as “cinema” and “kinesiology”.The study of kinematics can be used to calculate various aspects of motion such as acceleration, velocity, displacement, time, trajectory, etc. 

Kinetic = the action of forces in producing or changing motion.

Kinematic = the mechanics of motion without reference to the forces causing that motion – so only from a geometrical point of view.  This is the displacement and velocity of your body’s segments and joints.

For better clarification, keep on reading!

What is Kinetics?

Kinetics, also called dynamics, is a vital part of mechanics that deals with the function of different forces and torques on an object in motion. As a matter of fact, an object moves only when these forces create movement.

For instance, when you spin a top, it rotates in a circular motion. In this case, you apply energy on the top, and that converts the top’s stored potential energy into kinetic energy. Besides, they also have some parameters that are seen in real life as well. 

Along with that, you also need to learn about kinematics as well to find a difference between kinetics and kinematics. 

What is Kinematics?

Kinematics refers to the study of how motion is working, instead of explaining the reasons for this motion. More specifically, kinematics describes the motion of an object, considering the factors like position, acceleration and velocity. It gives an answer to the different positions of a body in a particular space. It also has some significant parameters that are associated with the position, speed and other factors. 

Thus, before knowing about kinetics and kinematics differences, students need to learn the definitions of them. 

What is The Difference Between Kinematics and Kinetics?

The table mentioned below elucidates the kinetics and kinematics difference clearly. 

This difference between kinetics and kinematics in tabular form allows students to learn this concept quickly and remember easily. However, besides these fundamental differences, some others are there that students need to know. 

Difference Between Kinetics and Kinematics with Example

Following are some of the factors that differentiate between kinematics and kinetics further. 

1. Causes of Motion 

A major kinetic and kinematic difference is that kinetics explains concepts like

• Different forces

• Torques

Where kinematics explains 

• Speed 

• Accelerations

• Final position of an object in motion. 

For instance, when you throw a ball in the air, kinetics explains the friction that causes the throw. Kinematics explains the acceleration, speed and final position of the ball when it falls in the ground. 

2. Particle Mass Inclusion 

Kinematics includes influences of different forces like gravitational forces that work between two systems. Kinetics consists of the masses of particulars while explaining a phenomenon. 

3. Mathematics or Physics 

While kinematics is applicable to physics and other streams of study, kinematics is restricted to mechanics only. However, some scientists also connect kinematics to mathematics as it only deals with physics. Thus, it is also called “geometry of motion” which is not applicable for kinetics. 

Students can also note down other kinematics and kinetics differences as well from their understanding of these concepts. However, they need to get it checked by the subject teacher for accuracy. 

Thus, kinetics deals with the causes of motion that is force, gravitation, torque, etc. On the other hand, kinematics deals with the position of a moving object in terms of its acceleration, velocity and other aspects. Moreover, after learning the difference between kinetics and kinematics, you can also solve moderate to difficult mathematical problems with much ease.

Furthermore, with assistance from e-learning platforms like Vedantu, you can improve your preparations. The availability of notes, model question papers, and online doubt clearing sessions help you to iron out your doubts and better your understanding of the topic.

Why Kinetics and Kinematics Matters

Both kinetics and kinematics are important branches of classical mechanics. They allow us to understand the nature of motion in different ways and to calculate different values depending on what they are studying.

Kinematics might answer more of the "what" questions that specifically describe the motion of an object: its velocity, acceleration, position, time and the like. But without kinetics, physicists wouldn't also be able to answer the "why" questions, such as what caused the object to begin moving in the first place, and why doesn't that motion continue forever? Where does the acceleration pulling a thrown ball back to the Earth come from?

There are four kinematic equations when the initial starting position is the origin, and the acceleration is constant:

§  v = \[v_{0}\] + at.  v = \[v_{0}\] + at.

§  d = \[\frac{1}{2}\] (\[v_{0}\] + v)t.  d = \[\frac{1}{2}\] (\[v_{0}\] + v)t or alternatively average=dt. v average = d t.

§  d= \[v_{0}t + (\frac{at^{2}}{2})\]

§  \[v^{2} = v_{0}^{2} + 2ad\].

Key Differences Between Kinetics and Kinematics

• Kinetics considers the mass of the body as it deals with force and we know F = ma, thus mass is a major considerable factor in the case of kinetics. However, the study of kinematics never considers the mass of the body.

• Kinetics is mainly defined as the branch of physics as it is concerned with how the motion is occurring. While kinematics is somewhat regarded as the branch of mathematics as it deals with the geometry of motion that calculates a variation in different variables with different functions.

• Kinetics is the branch of physics that studies the cause that results in motion thus majorly considers force or torque. While kinematics is concerned with the parameters like position, acceleration, speed, etc. of the body while in motion.

• The branch of science including physics, chemistry, and biology majorly uses the principle of kinetics like in chemistry it is associated with the rate of chemical reaction while in the field of biology it deals with the effect of enzymes on biochemical reactions. On the contrary, kinematics is the branch of physics and mechanics concerning the amount of change that occurred rather than how the change occurred.

• When we deal with kinetics then force plays a crucial role as the different forces acting on the body are studied in kinetics. As against, though the motion of the body is the result of some applied force still kinematics is not concerned with the applied force.

Summary

• Kinetics and kinematics are used in the field of biomechanics

• Kinetics studies motion as well as forces that are involved, whereas kinematics studies motion without taking into account forces that cause it.

• The study of kinetics has practical applications in designing automobiles whereas kinematics finds applications in the study of the movement of celestial bodies