semester -3 session 2022 rotation and revolution
Rotation Revolution1. The Earth takes 24 hours to complete one rotation.The Earth takes around 365 days and 6 hours to complete one revolution around the Sun.2. The Earth rotates on its axis. The Earth revolves around the Sun in an elliptical orbit.3. The rotation of the Earth causes day and night.The revolution of the Earth causes the occurrence of seasons.
Vertical RaysSlanting Rays1. These are concentrated rays and carry more heat.These are not concentrated and carry less heat.2. These rays spread over a very small area on the EarthThese rays spread over a large area on the Earth.3. The part of the Earth tilted towards the Sun receives vertical rays.The part of the Earth tilted away from the Sun receives slanting rays.
This is because the Earth rotates on its axis and completes one rotation in 24 hours. During this rotation, sunrays fall on half of the spinning Earth and this half of the Earth experiences day. The other darker side of the Earth experiences night during this time. With each spin, the Earth moves from darkness to light and vice versa.
The variation in the lengths of days and nights occurs because the Earth revolves around the Sun, with its axis always inclined at an angle of 66.5°. This causes longer days and shorter
nights in summer in the southern hemisphere. This variation between the lengths of days and nights increases with increasing distance from the Equator to the poles.
On 21 June, the Northern Hemisphere is inclined towards the Sun. The rays of the Sun fall directly on the Tropic of Cancer, causing summer in the Northern Hemisphere and winter in the Southern Hemisphere. Because of this, we experience the longest day and the shortest night of the year on 21 June.
On 21 March and 23 September, the Sun shines
vertically on the Equator; therefore, all places on the Earth experience equal days and equal nights. On 21 March, the Northern Hemisphere has spring, while the Southern Hemisphere has autumn. On 23 September, the Northern Hemisphere has autumn, while the Southern Hemisphere has spring.
Explanation: The Earth's axis is an imaginary line joining the North Pole and the South Pole. This axis is tilted at an angle of 23½° with respect to the plane of the Earth's orbit. This tilt is also known as the inclination of the Earth's axis.
29 окт 2022
