The most common circular motions that come to mind are rotation and revolution. The two types of circular movement may be perplexing. The purpose of this section is to describe the various ways in which the two motions can be distinguished. They are not the same thing. The use of the terms is best justified by the movements associated with the earth, specifically the rotation and revolution of the earth.
Rotation vs Revolution
The main difference between rotation and revolution is that the axis or path of movement differs. Rotation is the rotating of an object around its axis, whereas revolution is the revolving of an object around an object in a specified circular path. A body can rotate independently on its axis, whereas revolution considers an object circling another object where external forces act.
The natural movement of an object around its axis is known as rotation. An axis is a virtual line of reference around which rotating object pivots to complete its rotation. The rotation of the earth around its axis, which can be visualized as a spinning top, is the most common example used to illustrate the phenomenon.
On the other hand, revolution is the phenomenon of an object’s periphery around another object. The term “revolution” refers to an object that revolves around another object while remaining within a defined circular path. Consider the revolution of the earth around the sun or the revolution of the moon around the earth.
Comparison Table Between Rotation and Revolution
|Parameters of comparison||Rotation||Revolution|
|Definition||Rotation is the circular motion of an object around its axis||Revolution is the circular motion around another object’s axis|
|Does it involve an internal axis?||yes||no|
|Does it involve an external axis?||no||yes|
|Is there a change in position?||no||yes|
|Example||Rotation of earth causes the day and night||Revolution of the earth around the sun causes the change in seasons|
What is Rotation?
We are familiar with two circular motions: rotation and revolution, which will be discussed later. Rotation is a phenomenon in which an object rotates around its axis. What this means is that an object rotates in a circular path around an imaginary line of reference. It does not consider any external axes; instead, it considers its axis. The earth, for example, rotates around its axis, causing day and night to change. The earth takes twelve hours to rotate, and its axis is tilted by an angle that causes four seasons in the application of another phenomenon called revolution.
The position of the body does not change during rotation; instead, the body circles around its axis in a specific position. If we try to think of rotation in mathematical terms, we’ll see that the origin remains fixed while the coordination system is transferred to new axes with a specific angular displacement during rotation. It’s also possible to imagine it as a spinning top. Its axis is a sharp needle, and its spin is encircling that needle. During rotation, the radial distance remains constant and does not change. You can think of it as a continuous loop or a sequence with a constant variation.
What is Revolution?
The other circular movement is revolution. The circular motion of an object around another object is known as revolution. The main difference between rotation and revolution is that rotation uses an internal axis for circular motion, whereas revolution uses an external axis. The earth revolving around the sun, as well as the moon revolving around the earth, are the most common examples of the phenomenon. The earth revolves around the orbit, which is the axis of the sun, and it takes 365 days for the earth to complete one revolution around the sun.
External forces such as centrifugal and centripetal forces operate during the revolution. That is why the earth does not come out of its axis during the revolution. Both forces are fairly balanced, keeping the earth in its orbit. Because centrifugal and centripetal forces are opposed, they balance each other. Revolution, unlike rotation, includes an external axis. This phenomenon is caused by the change in seasons, as well as the earth’s tilt at an angle. The object rotating in a circular path must change its direction during the revolution, even though the circular path is confined and the radius remains constant. However, because the path of the earth as it revolves around the sun is elliptical, it has two radial points.
Main Differences Between Rotation and Revolution
- Rotation is rotating around its axis whereas revolution is revolving around another object.
- Rotation uses the object’s internal axis whereas revolution uses an external axis.
- Rotation does not require changing position whereas revolution requires a change in position.
- Rotation of earth around its axis causes day and night whereas revolution of the earth around the sun changes the seasons.
- Rotation is independent without any external force whereas revolution acts on external forces as well.
The most common example used to illustrate the phenomenon is the rotation of the earth around its axis, which can be visualized as a spinning top. During rotation, the body’s position does not change; instead, it circles its axis in the same position.
An object that revolves around another object while remaining within a defined circular path is referred to as a “revolution.” Consider the earth’s revolution around the sun or the moon’s revolution around the earth. During a revolution, external forces such as centrifugal and centripetal forces are at work. They balance each other because centrifugal and centripetal forces are opposed. The earth’s path as it revolves around the sun, however, is elliptical, and it has two radial points.
The main distinction between rotation and revolution is the circular movement’s axis or path. A rotation is when an object rotates around its axis, whereas a revolution is when an object rotates around another object in a circular path. A body can rotate on its axis, whereas revolution refers to an object circling another object under the influence of external forces.