What is energy and how does it work?

Question

What is energy? Put it in your own descriptive words
how does it work = Optional.

Answer 1

Best Answer - Chosen by Voters

Nobody knows what energy is, and we resolve to define it by its effect: " The ability to do work ".
We do not appreciate energy until it is manifested in producing work or generating heat.

Answer 2

Energy (in joules) is usually meant as the ability to do work. Work means a force that acts through a distance, as in moving a mass against gravity. Energy pushes or pulls a force of nature along some path. This could involve gravity, mass, friction, magnetic or electric forces for example. Energy is the amount of work done. The unit of energy is a joule, which is defined as a force of one newton acting through one meter, or a power of one watt for one second, and in other ways. Look up joule for more info. Power (watts) is the rate of doing work, so watts = joules/seconds and joules = power * seconds.

The usefulness of energy and even our understanding of it is often related to the ability to convert it from one form to another, perhaps through several steps. The following are a few examples.

Electrical energy can be used to heat or light or power a machine by conversion to these other forms of energy.

Mechanical energy can be used to generate electrical energy or move a mass.

Electromagnetic energy is radiated and can be used to carry information, illuminate our way, or produce x-rays, as well as be converted to electrical energy, heat energy.

Chemical energy can be used to convert molecules from one kind to another, involving other forms of energy such as heat and light and electricity and mechanical energy. This is important to life forms too.

Nuclear energy involves processes that change atoms from one element to another, and can involve large amounts of energy as in the sun.

Source(s):

http://en.wikipedia.org/wiki/Energy
http://en.wikipedia.org/wiki/Joule

Answer 3

Energy is measure of how fast you can complete a work. In physical world, it is measured as E= W/t,
work over time.

It doesn't work by itself, its helps to measure the magnitude of efficiency.