Work, energy and power are the most used terms in Physics. They are probably the first thing you learn in your Physics class. Work and energy can be considered as two sides of the same coin. In this article, we will learn all about the concept of work, power and energy.
Work done is generally referred in relation to the force applied while energy is used in reference to other factors such as heat. Power is defined as work done per unit time.
Work is said to be done when a body or object moves with the application of external force. We can define work as an activity involving a movement and force in the direction of the force. For example, a force of 30 newtons (N) pushing an object 3 meters in the same direction of the force will do 90 joules (J) of work.
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
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.
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.
The SI unit of energy is joules (J), which is named in honour of James Prescott Joule.
Power is a physical concept that has several different meanings, depending on the context and the information that is available. We can define power is the rate of doing work. It is the amount of energy consumed per unit time.
As discussed power is the rate of doing work. Therefore it can be calculated by dividing work done by time. The formula for power is given below. P = W/t
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. Watt can be defined as the power taken to do one joule of work in one second. The unit Watt is dedicated in honour of So James Watt, the developer of the steam engine.