Question

What is energy? Name different forms of energy. Give the unit of energy.

Answer 1

Hint: The following question is divided into three parts. Firstly, we have to understand the meaning of energy. Then we have to discuss the various types of energy or the various forms that energy has. Lastly, we will understand the unit of energy in the SI system.

Complete answer:
We have to find the definition of energy. In physics, energy is defined as the ability to do work. Or in other words we can say that, it is the way by which we are able to live in our daily life. Energy is also proportional to power. From the First Law of Thermodynamics, we get to know that energy can neither be created nor be destroyed. Energy of the Universe always remains conserved. We can transform energy from one form to another, but we can neither destroy it or try to create it through external agency.

There are two different forms of energy mainly-
Kinetic Energy: Energy associated with the motion of a body.
Potential Energy: Energy associated with the shape, size deformation of a body. In other words, energy that is stored within a body.
There are various other energies like heat energy, chemical energy, mechanical energy, electrical energy, wave energy and much more.

Unit of Energy:The SI unit of energy is Joule. In the CGS unit it is calorie.

Note:It must be noted that even kinetic energy and potential energy are classified in various ways. Like, when kinetic energy is associated with rotation then it is known as rotational kinetic energy. Kinetic energy does not depend upon altitude of a body whereas potential energy depends upon the height at which the body is positioned.