Question

The SI unit of work or energy is joule. Explain why the work and energy have the same SI unit?

Answer 1

Hint: Work is a process done on an object or by an object when we transfer energy to the object or from the object. Define how work is done by an object using energy. One is used to perform the other i.e. energy is used to perform work.

Complete step-by-step answer:
When a force is applied to an object in motion, work is done on the object by the force. The work done is mathematically expressed as the product of the force applied on the object and the distance covered by the object. Work can also be defined as the process of energy transfer to the motion of an object via a force.
Energy can be defined as a physical quantity which must be transferred to an object in order to do work. We cannot create or destroy energy; we only can transform energy from one form to another.
Energy is the quantity required to perform work on or by an object. Energy is transferred to an object and work is done on the object or by the object. They are not the same but energy is added to the object and then work is done by the object or on the object using the energy transferred to the object. So, we can say that their units must be the same as the energy is what is lost or gained by doing work on an object or by the object.

Note: The SI unit of both the work and energy is Joule. The dimension of both quantities is also the same because their units are the same. The dimension of work and energy is $[ML^2T^{-2}]$. We have different forms of energy and we can only transform them from the form to another.