ETYM French énergie, Late Lat. energia, from Greek energeia; en in + ergon work. Related to In, and Work.
Capacity for doing work. Potential energy (PE) is energy deriving from position; thus a stretched spring has elastic PE, and an object raised to a height above the Earth's surface, or the water in an elevated reservoir, has gravitational PE. A lump of coal and a tank of gasoline, together with the oxygen needed for their combustion, have chemical energy. Other sorts of energy include electrical and nuclear energy, and light and sound. Moving bodies possess kinetic energy (KE). Energy can be converted from one form to another, but the total quantity stays the same (in accordance with the conservation of energy principle). For example, as an apple falls, it loses gravitational PE but gains KE.
Although energy is never lost, after a number of conversions it tends to finish up as the kinetic energy of random motion of molecules (of the air, for example) at relatively low temperatures. This is “degraded” energy that is difficult to convert back to other forms.
Resources.
So-called energy resources are stores of convertible energy. Nonrenewable resources include the fossil fuels (coal, oil, and gas) and nuclear-fission “fuels”— for example, uranium-235. Renewable resources, such as wind, tidal, and geothermal power, have so far been less exploited. Hydroelectric projects are well established, and wind turbines and tidal systems are being developed.
E=mc2 Einstein’s special theory of relativity 1905 correlates any gain, E, in energy with a gain, m, in mass, by the equation E = mc2, in which c is the speed of light. The conversion of mass into energy in accordance with this equation is the basis of nuclear power. The equation applies universally, not just to nuclear reactions, although it is only for these that the percentage change in mass is large enough to detect.
1. (Physics) The capacity of a physical system to do work; the units of energy are joules or ergs.
2. Any form of power, such as electrical energy, nuclear energy.
3. A healthy capacity for vigorous activity; SYN. vim, vitality.
4. An exertion of force; SYN. vigor, vigour.
5. An imaginative lively style (especially style of writing); SYN. vigor, vigour, vim.
6. Enterprising or ambitious drive; SYN. push, get-up-and-go. + prikaži više

Any influence that tends to change the state of rest or the uniform motion in a straight line of a body. The action of an unbalanced or resultant force results in the acceleration of a body in the direction of action of the force, or it may, if the body is unable to move freely, result in its deformation (see Hooke's law). Force is a vector quantity, possessing both magnitude and direction; its si unit is the newton.
According to Newton’s second law of motion the magnitude of a resultant force is equal to the rate of change of momentum of the body on which it acts; the force F producing an acceleration a m s-2 on a body of mass m kilograms is therefore given by: F = ma See also Newton’s laws of motion.
1. Physical energy or intensity:; SYN. forcefulness, strength.
2. The physical influence that produces a change in a physical quantity
3. A powerful effect or influence:
4. Group of people willing to obey orders; SYN. personnel.
5. A group of people having the power of effective action + prikaži više

ETYM Old Eng. gom, gome, attention; akin to AS. geómian, gyman, to regard, observe, gyme care, OS. gomean to heed, Goth. gaumjan to see, notice.
Courage; audacity.

ETYM Old Eng. pouer, poer, Old Fren. poeir, pooir, French pouvoir, n and v , from Late Lat. potere, for Latin posse, potesse, to be able, to have power. Related to Possible, Potent, Posse comitatus.
1. Possession of controlling influence; SYN. powerfulness, potency.
2. One possessing or exercising power or influence or authority; SYN. force.
3. (Physics) The rate of doing work; measured in watts (joules/second). + prikaži više