Everything in this universe is moving; from the blood cells in our body to the earth that revolves around its axis.
What will happen if it stops moving? The consequences are unimaginable.
In physics, motion means a change in the position of an object with the reference to time. In simpler words, if a body changes its position with time it is said to be in motion.
When the body does not change its position with time, we can say the body is at rest but is it really at rest. Let’s understand this further with an example. A man sitting on the railway station observes a moving train, for him, the train and the passengers both are in motion, but can the passenger sitting inside the train say the same for the other passenger sitting in the train. Thus the motion of any object is relative to the observer.
Types of Motion in physics
Different type of motion is seen in different objects therefore it is divided into different types. Each of these types is achieved with different mechanical means. The three main types are as follow:
- Translational Motion – is a motion by which the body shifts from one point in space to another. Rectilinear and Curvilinear motions fall under the category of Translational Motion.
- Rectilinear Motion– Position, Velocity, Acceleration of particle moves in a straight line.
- Curvilinear Motion– Position, Velocity, Acceleration of particles move in a curved path.
- Rotational Motion-when an object moves along a circular path about a fixed axis.
- Oscillatory Motion – when an object repeats the same movement over and over. It is defined as the to and fro motion of an object from its mean position.
Types of Motion and its examples
- Rectilinear Motion- the motion of an object in a straight path for example. Light from sun or bulb light. Elevators and trains travel in a straight line.
- Curvilinear Motion- a stone thrown in the air or throwing of paper airplanes
- Circular motion- the motion of an object in a circular path for example. the orbit of planets
- Rotational Motion- when an object turns about a fixed axis for example the motion of a spinning top, turning of the blades of a fan, the spinning of the earth on its axis.
- Oscillatory Motion- the motion of a body on its mean position. For example, when a child on a swing is pushed, the swing moves to and fro about its mean position.
- Periodic Motion- a motion that repeats itself after regular intervals of time. For example the movement of seconds hands of a clock.
1. Circular Motion
To understand circular motion better, let us take an example of a Ferris wheel. As the wheel turns, the cars exhibit circular motion because they revolve around a single axis of rotation which runs to the center of the wheel, perpendicular to the plane that contains it. The cars move around this with a constant radius so they trace a circle as they move therefore the body is said to be moving in a circular motion.
2. Rotatory Motion
Rotatory motion is anything that moves in circles. This motion was first discovered in ancient times. Think of a spinning wheel on which people spun wool.
3. Random Motion
In this type of Motion, the movement is unpredictable. Hence it can be in any directions, in which a body does not follow any single path. Common examples of Random motion can be seen in our day to day activities.
The Brownian motion is the random motion of particles suspended in a liquid of gas.
More examples are of kites flying in the air, helium balloons in the sky.
Concept of Physics
Physic is the study of the fundamental nature of all things. All motion is relative to some frame of reference. If a body is not it motion it is being described with respect to a frame of reference that is moving with the body. For example, a body on the surface of the earth may appear to be at rest, but that is only because the observer is also on the surface of the earth. The earth with itself, the body, and the observer is rotating on it axis. The motion of the body obeys Newton’s law of Motion.