Energy is a term that we come across every day. For instance, the energy required to push a 10-kilogram box is too much. Or we need the energy to do day-to-day activities such as working, talking, writing, etc. So, what is the exact definition of energy, and how was this term derived? In this article, we shall try to answer a few commonly asked questions on energy.
History of Energy
The term energy is derived from the Greek word “energeia” which means activity. Back in the 4th century BC, the term energy was first used in the work of Aristotle. However, according to the modern definition, energeia is a qualitative philosophical concept and includes broader ideas such as pleasure and happiness.
However, in the 19th and 20th centuries, the theory of conservation of energy was developed by famous scientists such as William Rankine, Gustave-Gaspard Coriolis, and James Prescott Joule.
What is Energy?
According to Physics, energy is a quantitative property and is defined as the ability to do work. Also, based on the law of conservation of energy, the energy can neither be created nor be destroyed but can be converted from one form to another.
Unit of Energy
Joule is the SI unit of energy. This unit is named after James Prescott Joule. Joule is defined as the one-newton force applied through a distance of one meter. Joule is a derived unit. The other units of energy are calories, ergs, kilowatt-hours, kilocalories, and British Thermal Units.
Types of Energy
There are different types of energy. However, most of these energy types are classified as kinetic energy and potential energy. Here is the list of types of energy:
- Chemical energy
- Electromagnetic energy
- Gravitational energy
- Ionization energy
- Kinetic energy
- Mechanical energy
- Nuclear energy
- Potential energy
- Sonic energy
- Thermal energy
The energy stored in the bonds of chemical compounds such as atoms and molecules is known as chemical energy. To release the chemical energy, the chemical reaction takes place. Chemical energy can be considered as one of the widely used energy types as it is the reason for the existence of the natural world.
Photosynthesis and electrochemical reactions are examples of chemical energy.
Thermal energy is also known as heat energy. Thermal energy is defined as the energy that comes from the rise in temperature. As there is an increase in the temperature of a substance, the atoms start to vibrate faster resulting in the continuous collision of them.
The change in the state of a substance from solid to liquid and from liquid to gas is an example of thermal energy.
Sources of Energy
There are different sources of energy however, these sources of energy can be classified into two:
- Renewable energy sources
- Non-renewable energy sources
The following is the list of sources of energy:
- Nuclear energy
- Natural gas
- Solar energy
- Tidal energy
- Wind energy
Renewable Energy Source
An energy source that is sustainable, naturally replenished, abundant in nature, and eco-friendly is known as a renewable source of energy. Solar energy and tidal energy are examples of renewable energy sources.
Non-Renewable Energy Source
An energy source that is limited in supply and cannot be replenished naturally is known as a non-renewable energy source. Fossil fuels are an example of non-renewable energy.
Stay tuned to learn more about other concepts of energy such as kinetic energy, potential energy, and conservation of energy.