Different Types Of Motion

Linear Motion

The most basic form of motion is called linear motion. Any motion involves changes in specific physical quantities. A body that is moving in a fashion such that the direction of its movement does not change abruptly is called linear motion. 

A body in linear motion will cover a certain amount of distance and will move at a certain velocity, but the direction of the body will not change too frequently. It means that the direction of the body changes in such intervals such that the motion in each interval can be modelled as a linear motion.

Linear motion can be uniform or non-uniform. In a uniform linear motion, the body covers equal distances in equal time intervals. Nevertheless, in non-uniform linear motion, the body covers unequal distances as time moves. Essentially, the body moves with a constant velocity in linear motion, whereas in non-uniform motion, the body moves with varying velocity with time. 

A body in linear motion covers a certain distance from its initial position, and the rate at which it covers this distance is called the velocity of the body. The force on a body in linear motion  can be given by Newton’s law of motion. This force also accelerates the body, increasing or decreasing its velocity.

The equation of force that is acting on a body in linear motion is given as 

F = ma, where m is the mass of the body and a is the acceleration of the body.

Circular Motion

The distance covered by a body can be traced to form a shape. When the path followed by a body is in the form of a circle, then the body is said to be in a circular motion. A circular motion is different from linear motion because the direction of motion of the body is constantly changing. The force acting on the body is also not in the direction of the body’s motion. Instead, the force acts towards the centre of the circle, that is, the body’s path in a circular motion. This force is called centripetal force.

A particle in circular motion is constantly accelerated, and this is because there is a constant force applied to keep the particle in a circular motion. Circular motion can also be divided into uniform and non-uniform circular motion. In a uniform circular motion, the body covers an equal distance on the circle’s circumference in equal time and is equally accelerated. When a body is not equally accelerated and is covering an unequal distance across the circumference of a circle in equal intervals of time, it is called non-uniform circular motion.

The force that is acting on the body when it is in circular motion is given as 

F = mv²/r

Where m is the mass of the body, v is the body’s velocity, and r is the radius of the circular path followed by the body.

Rotational Motion

All bodies are made up of particles. When a rigid body moves in a fashion such that all the particles in the body are moving in a circular motion around a fixed axis or a fixed point at an angular velocity equal to each other, then the body is said to be rotational motion.

A body in rotational motion will have angular displacement, which measures in radians as the angle separating the body’s current and initial position. The rate at which the body changes its angular displacement is its angular velocity. However, what is rotational motion? A rigid body’s particles follow a circular path around the rotational axis in rotational motion. The rotational axis can be fixed or unfixed.

Torque or the moment of force is the ability to rotate an object rotating at a fixed axis. The application of torque on a body can increase its angular acceleration or maintain the body’s angular velocity. When torque is applied such that it does not change the body’s angular velocity, it is called static torque. When the torque applied to the body causes angular acceleration, it is called dynamic torque.

In rotational motion, torque or a moment of force acts on the body. The formula for torque is given as 

= F r

Where F is the force acting on the body and r is the distance between the line of force and the body’s axis of rotation.

Oscillatory motion

The movement that occurs in this type of motion is the front and back movement or rather oscillation that takes place. It is described as the movement of an object around its mean position. If the object is repeating its cycle of motion after a particular period, then it is called oscillating motion.

A pendulum clock can be considered to be a very good example of an oscillating motion. As it can be seen that it repeats its motion at intervals. A few other examples of oscillatory motion are a child swinging in a to and fro motion on a swing, a table fan spinning, also the cords of a guitar.

Conclusion

Motion is a fundamental observation in the physical world. All types of motion can be classified into three basic types: linear, rotational and circular motion. In linear motion, the body is covering distance but without frequent changes in its direction. The force is acting on the body in the direction of the motion. In a circular motion, the body follows a circular path and changes its direction constantly. The force acting on the body is directed towards the centre of the circular path. In rotational motion, all the particles in a body are moving in a circular motion around a given axis. The body is in rotational motion due to the torque or the moment of the force acting on the body.