Work, Energy and Power

All the three terms are the most used terms in Physics. Probably they are the first thing you learn in your Physics class. Here in this article, we will learn all about work, energy and power.

What is Work?

Work is said to be done when a body or object moves with the application of external force.

\(Work = Force \times Displacement = F. d\)

Let’s take an example. When we kick a football, we are exerting an external force called F, and due to this force (kick), the ball moves to a certain distance. This disposition of ball from position A to B is known as displacement (d). This work is said to be done and can be calculated as w = F.d

Unit of Work

If a force of 5 newtons is applied to an object and it moves 2 meters, the work will be 10 newton-meter. Newton meter in termed and Joules and it is the unit of Work.

Work, Energy and Power

What is Energy?

Energy is the ability to perform work. Energy can neither be created nor destroyed. It can only be transformed from one kind to another. The unit of Energy is same as of Work i.e. Joules. Energy is found in many things and thus there are different types of energy.

All forms of energy are either kinetic or potential. The energy in motion is known as Kinetic Energy whereas Potential Energy is the energy stored in an object and is measured by the amount of work done.

Some other types of energy are Mechanical, Mechanical wave, Chemical, Electric, Magnetic, Radiant, Nuclear, Ionization, Elastic, Gravitational, Rest, Thermal, and Heat Energy.

What is Power?

Power is the rate of doing work. It is the amount of energy consumed per unit time.

\(P = \frac{W}{t}\)


P = Power

W = Work done

T = Time taken

As power don’t have any direction, it is a scalar quantity. The SI unit of power is Joules per Second (J/s), which is termed as Watt. The unit Watt is dedicated in honour of So James Watt, the developer of the steam engine.

Thus we have discussed three elementary topics on Physics as students would have covered them during their high school days. We at Byjus are of the opinion that proper guidance with the right textbooks is essential for students to succeed along with the right exercises mentioned here- NCERT solutions for work, energy and power.

Practise This Question

A cyclist goes round a circular path of circumference 34.3 m in 22 sec. the angle made by him, with the vertical, will be