In our day-to-day life, we notice the movement of various objects passing in front of our eyes. For example, a moving train, animals running, a ball falling downwards, people climbing on mountains, rivers flowing, etc.
All of them are in motion and will keep moving. And would come to rest as per their wish.
Physics deals with such type of motion of objects, and the study of these objects in simple terms is called Mechanics.
Here, we are going to learn about the following:
- Kinetics and kinematics
- Difference between kinetics and kinematics
- Difference between kinetics and kinematics in tabular form
- Difference between kinetics and kinematics with example
It is that branch of science which deals with the effects of forces upon the motions of material bodies or with the changes that takes place in a physical or chemical system.
Real-life examples of kinetics
How the enzyme has an effect on the rate of biochemical reactions, torque, friction.
When a person pushes the ground in backward motion, a reaction takes place on the rough surface of the road and it gives a forward force as a result of the friction which caused the motion. Had there been no friction, then the person would have slipped and would not have been able to move.
In this example, kinetics comes into play. It handles the why of motion by taking into account the static frictional force.
Let us take the example of a little boy who switches on the button of a toy. The toy then starts to rotate around the bar. This type of force which makes the body to rotate around the fixed axis is torque.
When a jar which has gas is put on fire, then there is elastic collision between the molecules. This happens because of the production of kinetic energy during collision called the Brownian motion. Kinetics is also used to study thermodynamics.
- Nano particles production
- Process of conversion of synthesis gas to hydrocarbons
Kinematics is that branch of science which deals with the motion of any object in the world, beginning from the smallest particles to the largest particles in the universe and even includes the fastest ones, photons. Without kinematics, man would not have known about the motion of the earth around the Sun. Also, there would not have been the use of cannonballs in wars or any kind of games like football or cricket.
The meaning of the word Kinema means motion.
Suppose there is a wooden block of weight 8kg. If one wants to see if the block moves, its position, what time and speed it will take to move a particular distance, and the path through which it will travel. It will be either parabolic, circular or straight. But why it travelled that path, or who made the block move?
All these phenomena are explained by kinematics. Kinematics tells us how the motion is occurring and it does not consider why the body is moving, or what is causing that body to move.
Parameters in kinematics
- Displacement- Movement in a given direction
- Velocity- Change in displacement: how fast an object can move in a particular direction
- Acceleration: Change in velocity per second
- Time- Reference for change through which the above three will be calculated.
Let us study a few examples by different types of motions:
Suppose a person throws a stone and that person wants to know its velocity, whether there is any change in velocity or the how much change is there in velocity, and also the time it will take for the stone to hit the ground.
Suppose there is a moving car and we want to know how much the car travelled in meters per second, does the velocity change or how much change is there in the velocity.
Examples of projectile motion are:
- Firing a cannonball
- Shooting a basketball
Suppose a cannonball is being fired or when a basketball is thrown upwards at some angle. It will travel some distance up in the air before it reaches the ground. A parabola can be used to represent the locus of these objects.
The fundamental difference between kinetics and kinematics
Kinetics: It is the study of motion taking into account the mass and external forces.
Kinematics: It is not dependent on the mass of the object.
Kinetics: It establishes the relationship between the motion of bodies caused due to the inertial force and the mass of a body.
Kinematics: It only describes motion such as velocity, displacement, time, and acceleration.