Explain the different forms of energy .

Explanation

(1) Heat Energy :
The frictional force is not a conservatitional force and work is associated with the force of friction .
A block of mass m sliding on a rough horizontal surface with speed `v_(0)` comes to a halt over a distance `x_(0)`. The work done by the force of kinetic friction f over `x_(0)` is `-fx_(0)` .
By the work energy theorem `(mv_(0)^(2))/2 = fx_(0)` .
Of one think in mechanics , the nietic energy of the block is lost due of the frictional force. When the block is sliding on a table , the slight temperature of block increase and hence internal energy of block and table increases .
In winter , in order to feel warm , we gnerate heat by vigorously rubbing our pulms together .
A quantative idea of the transfer of heat energy is obtained nothing that 1 kg of water releases about releases about 42000 J of energy when it cools by `10^(@)C`.
Chemical energy arises form the molecules participating in the chemical reaction have different binding energies .
A stable chemical compound has less energy than the separated parts .
A chemical reaction is basically a rearrangment of atoms
Hence , in fact chemical energy is a electromagnetic energy .
If the total energy of the reactants is more than the products of the reaction , heat is released and the reaction is said to be an exothermic reaction.
If the total energy of the reactants is less than the is less than the products of the reaction , heat is absorded and the reaction is endothermic .
Coal consists of carbon and a kilogram of it when burnt releses about `3xx10^(7)` J of energy .
Chemical energy is associated with th forces that give rise to the stability of substances . These forces bind atoms into molecules into polymeric chains .
The chemical energy arising from the combusion of coal , cooking gas , wood and petroleum is indispensable to our daily existence.
(3) Electrical Energy :
Electric energy is consumed due to the flow of electric circuit .
Electric energy = Electric potential `xx` Electric charge .
Energy is associated with an electric current .
An urban Indian household consumes about 200 J of energy per second on an average .
The Equivalence of Mass and Energy :
Till the end of the nineteeth century , physicists believed that in every physical and chemical process, the mass of an isolated sustem is conserved matter is neither created nor destroyed .
Albert Einstein (1879 -1955) showed that mass energy are equivalent and are related by the relation .
` :. E = mc^(2)`
where E = energy , m = mass and c = speed of light in vacuum is approximately `3xx10^(8) "ms"^(-1)`
According to this equation , the energy associated with 1 kg of mass, energy
`E = 1xx (3 xx10^(8))^(2)`
`= 9 xx10^(16)` J
This is equivalent to the annual electric output of a larger (3000 MW) power generating stations .
(5) Nuclear Energy :
The energy released during nuclear fission or fusion is called nuclear energy .
In a nuclear fusion , four light hydrogen nuclei fuse to form a helim nucleus whose mass is less than the sum of the masses of the reactants .
This mass difference is called the mass defect `Deltam` is the source of energy `E= Deltamc^(2)` . It is the principle of hydrogen bomb .
In a fission , a heavy nucleus like uranium nucleus . In this process mass defect `Deltam` is also obtained and it will be the source of energy `._(92)U^(235)` is split by a neutron into two lighter nucleus . In this process mass defect `Deltam ` is also obtained and it will be the source of energy `E = Deltamc^(2)` . It is the principle of atom bomb .
The energy released due to nuclear fission is uncontrolled and can be used in making nuclear weapons . If this released energy is controlled then it is use in nuclear power plants and in pruducing electric energy .
For a chemical reaction , a mass defect obtained is much smaller than for a nuclear reaction .
(6) The principle of Consrvation of Energy :
The total mechanical energy of the system is conserved if the forces doing work on it are conservative .
If some of the forces involved are non- conservative , part of the mechanical energy may get transformed into forms such as heat , light and sound .
The total energy of an isolated system does not change that remains constant .
Energy may be transformed from one form to another but the total energy of an isolated sustem remains constant . Energy can neither be created nor destroyed .
The universe as whole may be viewed as isolated system , the total energy of the universe is constant . Total energy = sum of all energy .
The principle of conservation and transformation of energy into various forms links together various bracnches of physics , chemistry and life sciences .
From enegineering point of view all electrons , communication and mechanical devices depends on some forms of energy transformation .