The Universe Part-3

Earth is tilted at an angle of 23(1/2°)  (Now 23.44°) on its axis. It rotates around on its axis with approximately a speed of 1037 miles per hour. Earth takes approximately 24 hours to complete one rotation on its axis.

According to a data published by European Space Agency, the Earth's magnetic field could flip. Something causes the movement of the molten core to change resulting in the reversal of the North and south magnetic poles. Earth is approximately 4.6 billion years old. The earlier en- vironment had an absence of free oxygen, Around 4 billion years ago water vapour present in the atmosphere condensed to form the hydrosphere. Around 1 billion year ago early aquatic animals like algae came into existence. They being autotrophs, started the process of photosynthesis which lead to the release of free oxygen in the atmosphere. In the upper layers of the atmosphere this free oxygen led to the formation of Ozone.

Aryabhatta was the first to explain that the rotation of the earth on its own axis accounts for the daily rising and setting of the sun. His works are compiled in Aryasiddhanta. Bhaskara-I was a proponent of Bhedabheda School of Vedanta Philosophy. Varahamihira's notable works include Brihat Samhita, Pancha Siddhantika.

Desert climate is also known as arid climate. The perfect climate for the desert is Tropical climate which is spread mostly between 15-30° latitude. There are four main geographical situations for the formation of desert

(1) The presence of high air pressure near 30º latitude. Sahara and Australia desert fall under this climate.

(2) The western coastal side of continent found between 20°-30°latitude. Arizona desert, Mexican desert, Atacama desert, Namibian desert come under this climate.

(3) Death Valley (North America), Patagonian desert (Argentina) and Peruvian desert are the deserts found in mountains rain shadow region.

(4) The desert situated in the mid part of the Continents, far from the humid air. Gobi desert (China and Mongolia), Australian desert and Great basin desert (USA) come under this group.

Oxygen in the chemical element found in abundance in the Earth's crust. The percentage of various chemical elements in Earth's crust is as follows-

The list of planets in increasing order of distance from Earth is-

As the planet Venus is not given in the option, so the correct answer in the given option is (b) i.e. Mars.

Earth revolve around the Sun with an average speed (orbital Velocity) of 29.8 km/Second (30 Km/sec). The orbital velocity is 29.8 Km/sec. This speed is comparative to the speed of light. The orbital Velocity of other planets is as follows-

Earth's equatorial perimeter is about 40,090.28 km. This distance is covered by Earth in 24 hours and this indicates that cruising speed of Earth on its axis per hour is 40,090.28 km/ 24 hour = 1670 km/ hour (approx). According to this calculation the cruising speed per minute is = 1670 km/60 min = 27.8 km/ min. Thus, none of the given answers is correct, Note - In this question rotating should be on the place of revolving.

Earth's equatorial perimeter is about 40,090.28 km. This distance is covered by Earth in 24 hours and this indicates that cruising speed of Earth on its axis per hour is 40,090.28 km/ 24 hour = 1670 km/ hour (approx). According to this calculation the cruising speed per minute is = 1670 km/60 min = 27.8 km/ min. Thus, none of the given answers is correct, Note - In this question rotating should be on the place of revolving.

The Earth rotates about an imaginary line that passes through the North and South poles of the planet. This line is called the axis of rotation. The Earth axis of rotation is always inclined at an angle of 23°30' (23.5°) from the elliptic axis.