From the study of subatomic particles to the laws of motion, Physics Topics offer insights into the workings of the world around us.
What are the Different Types of Energy Manifest?
A body can do work by the transfer of some amount of energy
Definition: Energy is the capacity of doing work.
The total amount of work that a body can do is the same as its total amount of energy. Hence, energy and work are equivalent physical quantities, having the same units and dimensions. Both are scalar quantities.
Energy is manifested in nature in different forms:
- mechanical energy
- heat energy
- light energy
- sound energy
- magnetic energy
- electrical energy
- chemical energy
- atomic energy
In all natural events, energy changes from one form to another. In fact, every natural phenomenon can be interpreted as a sequence of energy transformations.
Examples:
- In an electric bulb, electrical energy is converted into heat energy at first, and then into light energy
- In an electric fan, electrical energy changes into mechanical energy.
- In a telephone, sound energy is converted into electrical energy (during speaking), and electrical energy into sound energy (during listening).
- In hydroelectric plants, water stored in a high reservoir flows downwards and its potential energy changes into kinetic energy This kinetic energy rotates the turbines which generate electrical energy.
- Water from sea, river and other water bodies evaporates and forms clouds. This water eventually returns to the earth in the form of rain. Potential energy of the clouds converts into the kinetic energy of the rain drops.
- On burning coal, chemical energy is converted into heat and light energy.
We observe such numerous incidents of energy transformations in daily life. But neither energy is created nor destroyed in such incidents. Energy can only get transferred from one body to another or can change its form. As soon as a body loses energy another body gains it in equal amount. Hence the total energy in the universe remains the same. This is the law of conservation of energy.
Law of conservation of energy: Energy cannot be created or destroyed. It can only be converted from one form to another.
It means that the total energy in the universe remains constant.
After the introduction of Einsteins theory of relativity, the law of conservation of energy was corrected and the law of conservation of mass-energy was established. This means that mass and energy in the universe are not conserved individually.