Coupon Accepted Successfully!



In general, the concept of energy refers to "the potential for causing changes". The word is used in several different contexts. The scientific use has a precise, well-defined meaning, whilst the many non-scientific uses often do not.

In physics, the energy of a system in a certain state is defined as the work needed to bring the system to that state from some reference state. Because work is defined through force involved, forms of energy are usually classified according to that force (elastic, gravitational, nuclear, electric, etc). Energy is a conserved quantity: it is neither created nor destroyed, but only transferred from place to place or from one form to another. Ultimately, this is because the laws of nature do not change with time.

In nature, Sun is the biggest source of energy which is stored in the food. We indirectly use up this energy to do work. 

What is this energy that we are talking about?

Let us take for example of a woodcutter. He raises his axe to cut the wood. In doing so he does work on it. When he lets the axe fall on the log, it splits the wood. The axe had acquired the capability to do work when it was raised. It possessed energy to do work when it was raised. An object which possesses energy is able to apply force on another object and in doing so energy gets transferred from one to the other. The axe loses the energy gained when it splits the wood. It has to be raised again and again for it to do more work. 

‘Energy is defined as the capacity of a body to do work.’ The energy possessed by a body is measured by its capacity to do work. So energy also has the same unit as work. It is measured in 'joule'. 1J is the amount of energy required to do 1 joule of work.

There are different forms of energy, for example – heat, light, sound, magnetic, electrical, mechanical (potential or kinetic), solar and atomic (nuclear) energies. They can be converted from one form into another. Energy can be stored in many ways.


Test Your Skills Now!
Take a Quiz now
Reviewer Name