The first records of the word air come from the later 1100s. It ultimately comes from the Greek word aēr, meaning “the lower atmosphere.” Generally speaking, the lower part of the atmosphere is the part that we live in and contains the gaseous mixture of air that we breathe and feel as wind.
Air is the invisible mixture of gases that surrounds the Earth. Air contains important substances, such as oxygen and nitrogen, that most species need to survive. 5 – 12+ Earth Science, Meteorology, Physics.
When the less favoured names had been eliminated, the final count showed 72 votes for Air-India and 58 for Indian Air Lines. “Thus, the name of the new company comes to be ‘AIR-INDIA’,” the bulletin said.
Energy levels are usually higher near a river’s source, when its course is steep and its valley narrow.
At the plant level, water flows through a pipe—also known as a penstock—and then spins the blades in a turbine, which, in turn, spins a generator that ultimately produces electricity. Most conventional hydroelectric facilities operate this way, including run-of-the-river systems and pumped storage systems.
Water is a vital resource that has fuelled human progress. It transports solids, dissolves minerals, chemicals and nutrients, and stores thermal energy. This ‘carrier characteristic’ allows for countless industrial, agricultural, and transport processes that enable our society to thrive.
Kallanai Dam built across the Kaveri river of Tamil Nadu is the oldest dam (first dam) in India. It is also known as the Grand Anicut.
There are 8 major river systems in India, with more than 400 rivers in total. Rivers play an important role in the lives of the Indian people due to their crucial importance in sustenance and their place in Indian religions.
A watershed is the area of land from which water drains into a river, stream, or other waterbody. Water flows from the land into a waterbody by way of rivers and streams, and underground through groundwater aquifers. The rivers and streams that flow into a larger waterbody are called tributaries.
A tributary is a freshwater stream that feeds into a larger stream, river or other body of water. The larger, or parent, river is called the mainstem. 6 – 12+
