Energy: meaning, definition and types

Everything around us retains some or the other kind of energy. Life was impossible if energy wouldn’t have been there. The largest energy source for our Earth and its beings is the Sun which emits light and provides us with energy. Some other energy sources other than the Sun include nuclei of atoms, tides and the interior of the Earth. 

Interestingly, an object which retains the capacity to work necessarily has energy in it.

You can understand this better with an example of the inflated balloon, when pressed, transforming its position from the part where it is pressed. Another instance can be of a cricket ball, if tossed into the wickets, hit the wickets off. Thus, energy gives the capacity to a person to do work. So, how does this work? When the ball hits the stump, the energy present in the ball gets transferred to the wickets, thus hitting it off and giving it the capacity of doing work. That’s how the concept of conservation of energy also works. 

Definition of Energy 

Energy refers to the property which has to be present in the object to make it work. In other words, Energy refers to the ability of a being to do work. It can also be interpreted as the resilience to complete any category of physical activity. According to the Law of conservation of energy, energy can be transferred in a different form, but it cannot be created or destroyed. 

The SI unit of measurement with which energy is measured in Joule. One joule is defined as the energy that is transmitted to an object by moving it from a distance of about 1 m against a one newton force exerted from the object. There are various forms of energy namely, kinetic energy, potential energy, elastic energy, chemical energy, and radiant energy.

Types of Energy 

There are various distinct forms of energy present on our planet. They are categorised under two different heads namely, Kinetic and potential energy. 

Kinetic energy 

Kinetic energy refers to the energy that is associated with the movement of an object. This pertains to the energy that is existing in a moving object. Let’s understand this better with an example of a wrecking ball that is capable of destroying things when in motion, even a light one has the capacity of doing so. However, if the wrecking ball is kept at rest, it doesn’t hold any ability for work. 

Another example can be of continually moving atoms and molecules in an object. Kinetic energy has numerous categorizations namely, Radiant energy, Electric energy, sound energy, thermal energy, and mechanical energy. The Kinetic energy can also be interpreted with the help of a formula.

          Kinetic energy = ½ mv²

Potential energy

Potential energy refers to the energy that is stored in the object if it is not made to do any kind of work. It is the type of energy that exists in an item by its arrangement and configuration. 

There are several types of potential energy namely, elastic potential energy, gravitational potential energy, electric potential energy and chemical potential energy.  Instances of potential energy can be a radio tower that isn’t working, a book at the lowermost shelf and a light when turned off have potential energy. 

         Potential energy = mgh

If we combine both these energies, we get Mechanical energy. 

   Mechanical energy = ½ mv² + mgh

Law of Conservation of Energy 

According to the Law of conservation of energy, energy can be transferred in a different form, but it cannot be created or destroyed. A form of energy can be changed to the other forms of energy, but the total energy in the object remains the same throughout the process. Thus, the total energy that is present in the object before and after the transformation remains unchanged. 

Conservation of Energy is one of the most basic concepts of energy and is valid on all kinds of transformation. Consider a simple example for getting clarity about the Law of conservation of energy. A ball is thrown from a height. At the starting point, the ball has zero kinetic energy and potential energy mgh. As soon as it is thrown, the potential energy of an object gets converted into kinetic energy. So, while the ball is in motion, the potential energy remains zero and the kinetic energy is ½ mv². Notably, the total energy of the object remains the same, it’s just that one form of energy gets changed into another form of energy. 

Conclusion 

Thus, energy refers to the ability of a being to do work. In general words, it can also be interpreted as the resilience to complete any category of physical activity. Man has been utilising energy for various chores it does in daily life. So, it becomes necessary that the energy is utilised in the most efficient way. Indeed, the man is slowly moving towards an energy-efficient planet, with its main focus on sustainability. Mankind is trying to figure out all possible ways of how energy can be conserved. Conservation of energy will give us long term results in ways of a healthier and a comfortable life, which goes with nature.