Rotation vs Revolution
Revolution and rotation are very important concepts in the study of circular motion in physics. Ask a kid in junior classes and he will come up with the example of his spinning BeyBlade as something showing rotation while the motion of a car in a circular track on road is an example of revolution. He is right, but do you understand the differences between these two different types of circular motions?
Rotation and revolution are perhaps vital for us as human beings if we were to look at the rotation and revolution of earth around the sun. These are the reasons of night and day and change of seasons on our planet. Revolution is that has made possible development of all sorts of automobiles that have helped us in faster and simpler transport. Though both these circular motions are perhaps equally important, there are differences that need to be highlighted.
Rotation is the motion of a body in which the body moves in a circular motion around itself along a perpendicular axis. If we evaluate the example of our own planet, earth we see that the earth rotates or moves around its own axis. But if we see the motion of the earth around the sun, the earth moves forward while rotating on its axis, it is an example of revolution. In rotation the body does not actually move but stays in its original position while turning on its axis. In rotation the position of the body actually changes and the body moves along a circular path either clockwise or anticlockwise. The effects of both the type of motions are also different like if we see the example of earth, when the earth turns around on its axis the change in day and night is observed. When the earth rotates, half the portion of the earth which receives the light of the sun is illuminated while the portion of the earth which does not face the sun experiences darkness.
When the earth revolves or moves around the sun along an elliptical path, due to its various positions in different periods of time different seasons are observed on the earth. As the imaginary axis of the earth is inclined at an angle of 23 ½ degrees from the centre of the earth, the portion of the earth bend towards the sun experiences summer season for half the year while the portion of the earth bend away from the sun experiences winter season for half the year. As the earth continuously changes its position with respect to the sun due to its revolutionary motion, difference in seasons is observed.
Difference Between Rotation and Revolution
• Thus rotation is the motion of a body in which the body turns around its own axis without any change in its position while revolution is the movement of a body along a circular path with continuous change in its position.
• Both rotation and revolution are important for our planet and also find many applications in daily life.