Written by: Eshita Shrestha - 2027024, Grade V
Posted on: 09 February, 2021
We need the energy to do most of our daily work. As an example, we need the energy to cook food, boil water, milk, tea, etc. Energy is the capacity to do work. The required energy obtained by the sun, kerosene, coal, petrol, firewood, etc are called "sources of energy".
The substance from which energy is obtained is called the sources of energy. The sources of energy can be used directly or indirectly in our everyday life. They can be classified into two groups;
a. Non-renewable sources of energy
b. Renewable sources of energy
Non-renewable sources of energy
The sources of energy which cannot be replaced immediately after they are used up from their original place are called non-renewable sources of energy. Coal, petrol, diesel, etc are some examples of this type of energy. Coal and petroleum are collectively called fossil fuels. They are formed from the dead bodies of plants and animals in a period of millions of years. These sources of energy are limited in an amount in nature.
Renewable sources of energy
The sources of energy which can be replaced immediately after they are used are called renewable sources of energy. Solar energy, hydroelectricity, biomass, biogas, etc are some of the examples of this type of energy. They are continuously obtained from nature. These sources of energy will never finish and can be used again and again.
Forms of energy
We use different forms of energy in our daily life. Different forms of energy are as follows:
a. Mechanical energy
b. Heat energy
c. Light energy
d. Sound energy
e. Electrical energy
f. Magnetic energy
1. Mechanical energy
The energy possessed due to the virtue of its motion or it's position in rest is called mechanical energy. There are two types of mechanical energy: Kinetic energy and potential energy.
a. Kinetic energy
The energy possessed due to the motion of a body is called kinetic energy. A bullet fired from a gun, a speeding car, and a rolling stone possesses kinetic energy.
b. Potential energy
The energy possessed by a body by virtue of its position and condition is called potential energy. Potential energy is found in a stone lifted up in a compressed spring, in the water stored in a tank, the water of a lake, etc.
2. Heat energy
The total kinetic energy of molecules contained in a body is called heat energy. Heat energy can be found in electric heater, sun, fire, etc
3. Light energy
The energy which makes bodies visible is light energy. We can obtain heat and light energy simultaneously from the sources of light. Sun, candle, bulb, etc are some of the sources of energy.
4. Sound energy
Sound is a type of energy that is possessed by the vibration of bodies.Sound travels outwards to all directions from a vibrating body. Musical instruments are an example of sound energy.
5. Electrical energy
Batteries, cells, and dynamos are the main sources of electrical energy. The electricity which we use in our house is hydroelectricity. Cells and batteries change chemical energy into electrical energy. Electric bulb, torchlight, television are some of the examples of electrical energy
6. Magnetic energy
The property of attracting magnetic material like iron and nickel by a magnet is called magnetic energy.
