changes in earth and sky

Force of Gravitation - What do you observe when you drop a stone from a height? The stone which was initially at rest starts moving towards the ground and attains a maximum speed just before it touches the ground. Is the stone moving with a constant speed? No, it is not moving with uniform speed. I..

Introduction - In the second century AD a Greek writer named Lucian wrote a story about a trip to the moon. He did not even know how far the moon was but his story revealed that the idea of space travel was certainly not new. Much later in 1865, the French novelist Jules Verne wrote a story in whic..

Excessive production of CO 2 leads to an increase in the concentration of CO in the Earth's atmosphere. This leads to what is known as 'the green house effect'. Simply stated green house effect creates ozone layer depletion or displaces ozone protection from certain areas (or holes) in ..

The main constituents of coal are- carbon, hydrogen, oxygen and small amounts of sulphur and nitrogen. Coal is obtained by mining and occurs deep inside the Earth. It is now believed that the changes in the Earth's crust might have buried the prehistoric forests under..

Calculating Kinetic energy using the formula E=(1/2)mv 2 Calculating changes in gravitational potential energy near the Earth Problems involving conservation of energy in simple systems Calculating momentum as the product mv Momentum as a separately conserved quantity, differ..

Calculating Kinetic energy using the formula E=(1/2)mv 2 Calculating changes in gravitational potential energy near the Earth Problems involving conservation of energy in simple systems Calculating momentum as the product mv Momentum as a separately conserved quantity, differ..

. Scientists in the early periods considered water to be an element. In 1784, Henry Cavendish burnt a mixture of hydrogen and oxygen and prepared water in his laboratory. By doing so, he proved that water is not an element, but a compound. Do you know how much water is there on the earth?..

Air pollution can cause number of health hazards to human beings, animals, birds, in addition to causing number of deleterious effects on earth's atmosphere as well as vegetation and even on some buildings. It is a global malady causing innumerable irreversible changes to ..

The natural 'Green-house Effect' is essential for life on earth. Various gases in the atmosphere like water vapour and carbon dioxide trap some of the outgoing radiation from the earth, retain the heat and keep the earth's temperature at levels where living things, i..

. These developments indicate a gradual change in the life style of mankind. Today metals are so vital to the modern man that it is unthinkable to live without them. They are essential for the construction of houses, transportation, communication, electricity, household articles, scientif..