What is Energy?
ability to do work is the classic answer to the the question "What is
Energy?", but how is energy measured.
Who does more work, a man who walks across a level field or a man who walks up a
flight of stairs? How many kinds of energy are there?
Energy is derived from the Greek word energeia and it means activity . E = mc2 is the nuclear relation between energy and matter in which E (energy) is equal to mass times the velocity of light times the velocity of light. The physical and chemical relationships between energy and matter involve other forms of energy.
Kinetic Energy is the measure of activity or motion. K.E. = 1/2mv2
Potential Energy measures the possibility to produce motion. P.E. = md
Work is the amount of energy transferred by a force acting through a distance W = fd
Force is an influence that causes a mass to change speed and direction F = ma
Temperature is the average Kinetic Energy of molecules. T = temperature
Heat Energy is the product of mass and temperature. It takes 1 BTU to raise 1lb of water 1*F
Solar Energy is the amount of radiant energy available to a given area per hour. On a clear day there may be as much as 300 BTUs of solar energy available per square ft.
universe is driven by a constant expanding motion called entropy. It has been spreading out and cooling down ever since time began 13.7 billion years
ago. About 5 billion years ago our sun condensed out of a cloud of hydrogen and debris
left over from a nearby supernova star that exploded in the distant past..
The supernova debris mixed with a cloud of hydrogen gas to form our solar system. Solar
energy from the condensing cloud of hydrogen was only released when the
temperatures and pressures needed
to bring hydrogen atoms together was sufficient.
The TOTAL ENERGY of the Universe never changes and the TOTAL MASS of the universe never changes. As a matter of fact energy and mater are part of the same equation... E=mc2 We just give them different names according to the forms that they take. When we think of mater we think of protons and neutrons and electrons and atoms and molecules. When we think of energy we think of sunlight and other forms of electromagnetic radiation, but remember even sunlight is made of matter. During the process of photosynthesis matter from sunlight is transferred through an endothermic process to water and carbon dioxide during the formation of sugar. Without energy transfer compounds like chlorophyll or hemoglobin life as we know it would be impossible on our tiny planet. After high energy molecules like sugar are assembled by a plants and assimilated by animals they may be joined with oxygen to produce the energy needed for life. This chemical energy transfer is illustrated by clicking on the atom to the left. As long as you understand how energy from sunlight may is transferred into living tissue you will understand "What is energy?" The millions of organic chemical reactions that take place within liquid water would not be possible without the electromagnetic and thermal energy transfers from the sun so let's take a trip to the sun and see how this energy works on a nuclear level..
Here is a nuclear power plant at a safe distance of 93 million mile from population centers. It's a self sustaining, power plant that can satisfy all the energy requirement of Earthlings and it's expected to last another 4 billion years without producing toxic waste products to worry about. Every second this ideal nuclear fusion power plant converts 700 billion tons of Hydrogen into 695, billion tons of of Helium and 5 billion tons of pure energy in the form of gamma rays. As this energy travels out toward the Earth's surface, the energy is absorbed and re-emitted at lower and lower temperatures so that by the time it reaches our planet's surface it is primarily in the form of visible light at a power level of about 1 Kilowatt per square meter under ideal conditions.
Sooo... now that you understand what energy is and where it comes from all you have to do now is figure out how to get your fair share.
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Connecting with Sunshine
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Strawberry Fields Solar Book
How to Build a Solar Hot Water System
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Our Sun and Our Future
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When the Lights go Out
Sun Dancing With Robert Redford Earth Bound Leonardo Bonnie Raitt, the Sunshine Lady
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