What is energy?

Energy is the result of two objects interacting with each other. When 2 or more objects inter-act with one another, the reaction between 2 solid, liquid, or gas produce a reaction called energy.

An energy is produced between physical , chemical, or temperature reaction. 

What makes energy?

There are several different forms of energy, and one kind can be changed into another kind. But although it can be changed from one form into another it can never be lost. The total amount of energy in the universe remains constant.

If you strike a match on the side of a match-box, mechanical and chemical energy is changed into heat energy. If you use a saw, the blade gets hot because the energy of movement or mechanical energy becomes heat energy. The end of a bicycle pump becomes warm after several minutes of pumping, because heat is generated when air is compressed.

In a simple electric circuit there are several changes. The battery has chemical energy, which passes along the wire as electrical energy, which lights the bulb as light and heat energy.

We depend for a large part of our power on steam, diesel and petrol engines in which chemical energy stored in a fuel is converted first into heat energy, which is then turned into work.