Rotation and Revolution - Definition, Advantages, FAQs
Rotation and revolution are two fundamental concepts in physics and geography that help students understand the motion of the Earth and other planets. Rotation refers to the spinning of the Earth on its own axis, which causes day and night, while revolution is the movement of the Earth around the Sun along a fixed path called an orbit, responsible for seasons and changes in day length. These motions also explain important phenomena such as leap years, equinoxes, and solstices. Understanding rotation and revolution is essential for Class 11 and 12 students as it forms the base for topics like planetary motion, time calculation, and Earth–Sun relationships. This topic is frequently asked in exams and is important for building strong conceptual clarity in physics and astronomy.
This Story also Contains
- What is Rotation?
- What is Revolution?
- Rotation of the Earth
- Revolution of the Earth
- Rotation and Revolution of Planets
- Difference Between Rotation and Revolution
What is Rotation?
Rotation means when an object spins or turns around a fixed line (called an axis) without moving from one place to another.
For example, a ceiling fan spinning, a wheel turning on its axle, or the Earth spinning on its own axis are all examples of rotation.
In simple words, rotation is spinning in the same place, not moving forward or backward.
What is Revolution?
Revolution means when an object moves around another object along a fixed path.
In simple words, it is going around something, not spinning in one place.
For example, the Earth moves around the Sun—this motion is called revolution. Similarly, the Moon moves around the Earth, and a satellite moves around a planet.
NCERT Physics Notes:
Rotation of the Earth
Rotation of the Earth means that the Earth spins on its own axis, an imaginary line passing through the North and South Poles. The Earth rotates from west to east and takes about 24 hours to complete one full rotation. This spinning motion is the main reason for the occurrence of day and night. When a part of the Earth faces the Sun, it experiences day, and when it turns away from the Sun, it experiences night.
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- NCERT Solutions for Class 11 Physics
- NCERT Solutions for Class 12 Physics
- NCERT Solutions for All Subjects
The Advantages of Earth rotation:
The following are some of the advantages of Earth rotation's rotation:
- The diurnal cycle of light and darkness, temperature, and humidity variations are caused by the earth rotation's rotation.
- The tides in the oceans and seas are caused by the earth rotation's rotation.
Revolution of the Earth
Revolution of the Earth means the movement of the Earth around the Sun along a fixed path called an orbit. The Earth takes about 365¼ days to complete one revolution around the Sun. This motion is responsible for the change of seasons and the difference in the length of days and nights throughout the year. To adjust the extra ¼ day each year, one extra day is added every four years, known as a leap year.
Importance of Revolution
The revolution of the Earth is important because it brings many changes on our planet. Due to revolution, we get different seasons like summer and winter. While moving around the Sun, the Earth sometimes comes closer to the Sun, called perihelion, and sometimes goes farther away, called aphelion. Revolution also changes the length of day and night. At the equator, day and night are almost equal, which is called an equinox. But in the Northern and Southern hemispheres, days and nights become longer or shorter at different times of the year.
Rotation and Revolution of Planets
| Planet | Mean Distance from Sun (million km) | Period of Revolution | Period of Rotation |
| Mercury | 58 | 88 days | 59 days |
| Venus | 108 | 224.7 days | 243 days |
| Earth | 150 | 365.2 days | 23 hr 56 min 4 sec |
| Mars | 228 | 687 days | 24 hr 37 min |
| Jupiter | 778 | 11.86 years | 9 hr 55 min 30 sec |
| Saturn | 1,427 | 29.46 years | 10 hr 40 min 24 sec |
| Uranus | 2,870 | 84 years | 16.8 hours |
| Neptune | 4,497 | 165 years | 16 hr 11 min |
Difference Between Rotation and Revolution
| Rotation | Revolution |
| Earth spins on its own axis | Earth moves around the Sun |
| Takes about 24 hours | Takes about 365¼ days |
| Causes day and night | Causes seasons |
| Spinning in one place | Moving in an orbit |
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Frequently Asked Questions (FAQs)
The fragmental material composing part of surface of globe especially cultivable soil is called as earth.
Earth spins on its axis, and it takes one day to make one rotation.
Rotation is the phenomenon which causes day and night on earth.
When the day is over, Night starts.
Rotation causes deflection of ocean and air currents.
