Energy:
Energy is a fundamental concept in the realm of science, acting as a connection between various natural occurrences. In physics, energy is defined as the capacity of a body to perform work. It is an extensive property that can transfer between bodies or physical systems. The standard unit of energy in the International System of Units (SI) is the Joule (J), with one joule representing the amount of energy required to perform one joule of work. The dimensional analysis of energy is [ML2T-2].
Forms of Energy:
Naturally, energy exists in several forms. Some of these forms are as follow:
1. Kinetic Energy:
In physical sciences, the form of energy which is possessed by a body due to its motion is termed as kinetic energy (K.E.). The kinetic energy of a body is directly proportional to its mass and square of speed. The formula of K.E. is 1/2mv2.
2. Potential Energy:
The form of energy which a body possesses due to its height is called potential energy (P.E.). Potential energy is directly proportional to the applied force and height. The mathematical expression of potential energy is mgh or F x h. An object can have potential energy even if it is at rest. The sub-forms of potential energy are elastic potential energy, gravitational potential energy, absolute potential energy, etc.
3. Mechanical Energy:
The energy due to both motion and height is mechanical energy. In other words, mechanical energy is the sum of kinetic energy and potential energy.
4. Electrical Energy:
Electrical energy is a form of Kinetic energy. This energy is formed from the movement of charged particles like electrons and protons. The faster the charge carriers move, the more energy they carry. Lightning and electrical eels exhibit this phenomenon in nature. Nowadays, human beings use this energy for various purposes.
5. Heat Energy:
Hotter bodies emit heat energy. It occurs only when there is a temperature difference between two or more objects or by friction. Sun is the biggest and main source of this energy.
6. Chemical Energy:
This energy is present in chemical substances such as molecules, compounds, batteries, food, gasoline, etc. This energy releases or absorbs only during chemical reaction (bond formation and bond breakage).
7. Light Energy:
Light energy is a form of kinetic energy. It is an electromagnetic radiation that travels in the form of waves and is visible to human eye. Tiny packets of energy called photons make up light.
8. Sound Energy:
This energy is a form of energy which produces due to vibration of bodies. Sound travels in the form of mechanical waves. They require some medium for their propagation.
9. Nuclear Energy:
This form of energy is related to the nucleus of an atom. Nuclear energy produces during nuclear fission and fusion reactions.
Law of Conversion of Energy:
According to this law, “Energy can neither be created nor be destroyed, but it is transferred from one form to another.”
