Question

What is energy? What is its unit?

Answer 1

In order to answer this question, first we will explain the definition of energy or we will go through the whole concept of energy and then we will write the unit of energy. And then we will also discuss how energy is converted into one form to another.

Complete step-by-step solution:
In physics, energy is the ability to perform work. It can take many many forms, including potential, kinetic, thermal, electrical, chemical, radioactive, and others. Furthermore, there is heat and work—that is, energy in the transmission of energy from one body to another. Energy is always identified according to its type once it has been transmitted.
Motion is linked to all sources of energy. When a body is in motion, for example, it has kinetic energy. Even while at rest, a tensioned device like a bow or spring has the capacity to create motion; its arrangement includes potential energy. Nuclear energy is also potential energy because it arises from the arrangement of subatomic particles in an atom's nucleus.
Energy cannot be generated or destroyed; it can only be transformed from one state to another. The conservation of energy, or the first law of thermodynamics, is the name given to this principle. When a box slides down a hill, for example, the potential energy it has from being high up on the slope is converted to kinetic energy, or motion energy. The kinetic energy from the box's motion is transferred to thermal energy, which heats the box and the slope as it comes to a halt due to friction.
In the International System of Units (SI), energy is measured in joules. One joule is equal to the work done by a one-newton force acting over a one-metre distance.

Note: Other methods of converting energy from one form to another exist. Many types of technologies, such as fuel-burning heat engines, generators, batteries, fuel cells, and magnetohydrodynamic systems, produce usable mechanical or electrical energy.