Science

How are plastic bags made?

Sep 23rd, 2008 | By

Plastics bags are made up of polyethylene in its low density form (LDPE). This polythene is derived from natural gas, crude oil and non-renewable sources. Blown film extrusion or “tubular film extrusion” is one of the most common ways to make a plastic bag. The plastic resin pellets of different types are taken from storage
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What are the affects of global warming?

Sep 20th, 2008 | By

Global warming is the trapping of heat on the earth surface due to the rise in temperature caused by transportation, burning of fossil feul, emission of gases from the factories etc. It affects in many ways to all the living beings on the earth. Natural disaster Global warming can cause more serious, frequent and strong
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What is protein synthesis?

Sep 18th, 2008 | By

Protein is a group of complex organic molecules which consist of carbon, oxygen, hydrogen, nitrogen, sulfur and also have the one or number of amino acids chain. The word synthesis means that when smaller molecules come together to form a larger molecules. Similarly protein synthesis is a process in which small amino acids molecules put
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Why does ice float?

Sep 18th, 2008 | By

Density of an object is increased with the cooling, but this is not completely applicable in the case of fresh water. It is densest at four degree Celsius and if water is further cooled its density keeps on decreasing. So a substance having less density or less mass per unit volume than other substances in
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Why does lightning strike?

Sep 14th, 2008 | By

When there is a great difference among the positive electrons of cloud in upper part and negative electrons of cloud in the lower. Then an energy discharge takes place causing the lightening to strike within the cloud and when there is enough difference of charge between one cloud and another lightening takes place to maintain
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How does a solar cell work?

Sep 13th, 2008 | By

The solar cells can be used as the alternative source of electricity. As all know the fossil fuels and other sources of energy such as coal which we have been utilizing so far for making electricity is decreasing day by day. The solar power can be used to solve this problem. Since the energy provided
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Why do we have leap year?

Sep 12th, 2008 | By

We know that leap year occurs after every four years. Earth revolves around the sun in 365 days, five hours, 48 minutes and 46 seconds but we take one year of 365 days. There is still five hours left for the earth to complete its revolution around earth which is approximately ¼ of a day.
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Why does metal rust?

Sep 9th, 2008 | By

Many times we have seen reddish brown flakes on the metal. This is known as rust. When iron reacts with oxygen it forms a new substance called iron oxide. This can happens only if the oxygen level is enough for reaction. Chemical reaction takes place in this process. Iron never reacts with the oxygen present
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Why is the sky dark at night?

Sep 6th, 2008 | By

This seems to be a very easy question and almost everybody thinks that the answer for this question is very simple that the sky appears dark in night because earth’s rotating around the sun. The part of earth which moves away from the sun will not receive the sunlight and hence sky appears dark. But
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Why do we have shorter days in winter?

Sep 6th, 2008 | By

We know that earth is tilted at a particular angle and also revolves around the sun. Different parts on the earth get more or less amount of the sunrays which cause the seasons and length of days and nights. This can be easily understood by performing an experiment. Take an apple and pass a stick
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