Energy is the ability to do work
We humans have harnessed the ability to transform the energy from one form to another and doing this we are able to do all our daily work like walking, bicycling, watching Tv, Playing Games, in each of these actions we are using some form of energy.
Thus energy exists in different forms but mainly two types of energy are most popular.
Kinetic Energy – The energy generated by motion or mass
Potential Energy – The energy that is stored and can be used in future.
Energy can be converted from one form to another. For example we eat food that contains chemical energy and then we use this energy to play or work in the form of kinetic energy.
Water stored at hill top is the best example of potential energy as well as gravitational energy. When that water falls it runs into motion and changes into kinetic energy.
Energy sources can be broadly classified into renewable and non renewable energy.
Example of renewable energy is sunlight, hydro power, wind power etc. These types of energy can be used over and over again and they do not harm the nature.
Example of non renewable energy includes fossil fuels like coal, Petrol, Diesel etc. These sources of energy are not indefinite. They will be vanished in future after their use and also they pollute the environment when they are burned.
There are many other different forms of energy.
In short mechanical energy is the sum of kinetic and potential energy. If you are sitting on a chair without moving then you have the potential energy. If you are running then you have the kinetic energy plus potential energy. Now if you want to cross hole by jumping over it then you will run and jump. Here both kinetic and potential energy will be used to do the work and this is called Mechanical energy.
Another good example of mechanical energy is to drive a nail into the piece of wood you would need both kinetic and potential energy. Hammer already has a potential energy ( because of it’s weight ), when you lift the hammer it’s increases it’s potential energy because of more height, now when you move it at a great speed downwards it will have kinetic energy due to it’s motion. When you hit the nail into wood then the both kinetic energy and potential energy has been used to do the work. And the energy that hammer acquired to do that work is called Mechanical Energy.
Electrical energy is the energy that is carried by a moving electron in a conducting wire or an electric conductor. Those materials that can carry the electrons are called conductors while those materials that can not carry electrons are called insulators. Electrical Energy is the most common form of energy that we use everyday e.g for watching TV, running fan, AC, Fridge, Cooler etc.
Thermal power plants produce electrical energy from thermal energy.
Thermal Energy also know as heat energy comes by heating a substance. When the temperature rises the particles inside a substance starts vibrating. More heat means more vibration means more thermal energy. For e.g using solar lights to cook food. During winters we need room heaters that is an example of thermal energy. Thermal energy is related to the temperature of the substance. Thermal energy is measured in Joules (J).
Chemical energy is released when chemical reaction occurs. e.g burning of Wood is a chemical reaction that releases heat. Chemical energy is stored in the bonds of the chemical compound. Since it is stored, it is the form of potentials energy. Whenever any chemical reaction occurs this stored energy is released.
When an atom splits e.g uranium it releases tremendous amount of energy and this is called Nuclear energy. This nuclear energy is used to heat the water into steam and produce electricity through turbine in this process. There are no carbon emissions in Nuclear energy because it uses atoms of Uranium and not fossil fuels. The atoms of uranium are split in a controlled chain reaction which releases heat energy and that is used to boil the water.
There are two types of Nuclear Energy
- Fusion – Combining of atoms
- Fission – Splitting of atoms
Nuclear energy is the clean and reliable source of electricity. It helps us to fight the climate change.
Electromagnetic energy is released in the form of electrical and magnetic waves. This energy is radiated in the form of radio waves, microwaves, X-rays and gamma rays.
E.g Microwave oven emits microwaves that heat our food. If you are listening a radio , using X ray machine then you are using electromagnetic energy.
Our human eyes can only detect a very small portion of this electromagnetic spectrum called visible light.
Sonic energy also known as sound energy that is generated when an object vibrates. Sound energy is transferred in waves through medium such as air and water. Sound energy needs a medium to travel like it can travel through metals, wood, water, air etc but it can not travel through vacuum.
Gravitational energy is the energy that is possessed by any object that lies in a gravitational field.
Gravitational energy also known as gravitational potential energy
What is gravity? Gravity is the force that tries to pull two objects towards each other.
Pendulum is a simple example of a gravitational potential energy. The pendulum transfers the gravitational potential energy to kinetic energy.