Energy is the basic requirement for doing any kind of work. To the economist, energy is a synonym for fuel, but for a scientist, it is one of the fundamental modes of existence relating to inter convertible of matter.
It is energy that moves trains or cars, produces light from a bulb, makes rivers flow, etc. energy exists in eight forms- (i) Mechanical Energy (ii) Heat Energy (iii) Light Energy (iv) Electrical Energy (v) Sound Energy (vi) Magnetic Energy (vii) Chemical Energy and (viii) Atomic or Nuclear Energy.
The law of conservation of energy states that energy can neither be created nor be destroyed. The total energy content of the universe is constant. It means that the total amount of mass energy in the universe or in isolated system forming part of the universe cannot be changed. It can be simply transformed form one form to another.
Now the question arises- what are the different transformations of energy?
The motion of trains, buses, cars and scooters involves the change of heat energy into mechanical energy. The chemical energy associated with petrol, diesel or coal changes into heat energy on burning. In an electric bulb, the electrical energy is converted into heat and light energy. When we speak on a telephone, the sound energy changes into electrical energy and at the receiving in to electrical energy and energy transformed into sound energy again. Atomic energy is coveted into electrical energy in a nuclear power plant. Chemical reaction in our body produces heat energy to keep it warm. These are all examples of energy transformation that take place in daily life.