Relationship Between Work, Energy And Force!

The terms work, energy and force are so common that they get used even in daily life. Also, people knowingly or unknowingly relate the three terms to one another. It is essential to understand how work, energy, and force are related. But, before that, one must understand the three physical quantities completely. Understanding their definition, formulas and different types aids a person to understand the relationship between them.

What is work? 

The work done on an object is defined as the measured energy transfer that takes place when the object is moved over a distance by an external force applied in the direction of the displacement. If the applied force on an object remains constant, the work can be calculated by multiplying the length of the path by the force component that is acting along the path. Hence, the work done W is equal to F (force) times the distance. 

W=Fd

Also, if the force is exerted at an angle θ to the displacement, then

W=Fd cos θ

It is also crucial to understand that work is not only done with the displacement of a body. It can also be done by an external magnetic force, compressing a gas, or rotating a shaft. Work done can also be described as the increase in energy of the object because work transfers energy to it. The physical quantity has its SI unit specially named as Joule (Newton-meter). 

What is energy?

The ability or the capacity to do work is known as energy. The conservation of energy law suggests that energy can neither be made nor destroyed as it can only change its forms. It means energy can only transform from one form to another. The SI unit for energy is also Joule. 

Energy can either be kinetic or potential energy, which are two forms of it. The energy possessed by an object due to its motion is known as kinetic energy, and the energy formula for the kinetic energy of an object is-

KE= ½ mv²

In this formula of energy for kinetic energy, m= mass of the object

                v= speed of the object

The potential energy is defined as the energy possessed by an object by virtue of its position. The formula of energy for potential energy is

Ep or PE= mgh

In this energy formula, m= mass of the object

                                                        g= acceleration due to gravity

                                           h= height of the object

Now, the energy formula for calculating total energy is 

TE= KE + PE

What is force?

Force is defined as a push or pull on an object whenever it comes in contact with another object. To be precise, when two objects interact with one another, a force is applied to each one of them. It can also be described as an external agent that is capable of changing the state of rest or motion of an object. 

Force is a vector quantity. Hence, both magnitude and direction are required to define it. Its SI unit is given a unique name- Newton (N). Force can be found out by using the following formula

F= ma

Here, m= mass of the object

                       a= acceleration of the object

Understanding the relationship between work, energy and force

Understanding the relationship between force, work, and energy is essential to understanding physics’s different concepts. Although each term has its unique properties, they are all interdependent. Hence, none of these three physical quantities can exist without the existence of the other two. Understanding their definitions solely can give you a brief idea of their interdependency. 

To move an object, energy is transferred to it. Transferring energy can be in the form of force, and this amount of energy transferred by the force to move an object is nothing but the work done. Hence, the three quantities are related. 

W= Fd

= ma vf²- v²i/ 2a

= ½ mvf²- ½ mvi²

=KEf – KEi

= ΔKE
If the applied force on an object or body is opposite to its motion, then the work done is negative, implying that the energy is taken from the object.

Conclusion

Although mostly all are aware of the physical quantities of work, force and energy and their formulas, it is crucial to understand how these three are related. It helps to understand the concepts of Physics that incorporate the use of their relation. Also, at times, understanding their definitions can be enough to understand the relationship between these three terms. The formulas of these physical quantities can also be used to understand the relationship.