The words work and power might seem similar to each other as they both involve energy but they are not the same. Work is the amount of energy required to move an object from one point to the other or work is said to be done when a force displaces an object in the direction of the force. Power is defined as the rate of doing work or it is also defined as the amount of energy transferred in unit time. The SI unit of work is joule (J) while the SI unit of power is Watt (W). Let’s see the exact difference between work and power.
Difference between Work and Power in tabular form
Let’s look at the differences between work and power with the help of a table.
| Work | Power |
| It is the amount of energy required to move an object from one point to the other or work is said to be done when a force displaces an object in the direction of the force. | Power is defined as the rate of doing work or it can also be defined as the rate at which energy is spent. |
| The SI unit of work is joules (J). | The SI unit of power is Watt (W) or Horsepower (hp). |
| The formula used to calculate work is Work = Force × Displacement. | The formula used to calculate power is $Power=\frac{Work}{Time\; taken}$ |
| The factors affecting the work done are force and displacement. | The factors affecting power are work and time. |
| The work done does not depend on the time. | Power spent depends on the time. |
Now since we have discussed the differences between work and power let’s discuss what power and work are?
What is work?
Work is defined as the amount of energy required to move an object from one point to another. Work is quite different in science from what we see in our daily life. For work to be done there should be a displacement in the direction of the force.
For example a coolie carrying a load on his head and moving on a frictionless horizontal surface is doing some work according to us but according to science, he is not doing any work because the angle between the force applied (vertically upwards) and the displacement (along the horizontal) of the load is 90°.
The SI unit of work is joule (J). It can also be defined as the product of the component of force in the direction of displacement and the magnitude of displacement.
Work done by a force is calculated with the help of a formula which is as follows:
W = f × d
Where W is the work done, f is the force applied and d is the displacement caused by the force.
One joule of work is said to be done when a force of 1 newton produces a displacement of 1 meter in the object in the direction of the force. The two factors which affect the work done are:
1. Force – Force is defined as the pull or push upon an object resulting from the object’s interaction with another object. For the work to be done a force should act on the object. If the force acting on the object is zero then the work done by the force is zero irrespective of the state of the object.
2. Displacement – It is defined as the shortest distance between the initial and final position of the object. It is a vector quantity. If the displacement of an object due to the force acting on it is zero then the work done will also be zero.
A few examples of work are: shooting a bullet, pushing the car horizontally from rest, walking upstairs, the book falling from the table, sawing the log, etc.
What is Power?
Power is defined as the rate of doing work. It can also be defined as the rate at which energy is spent. The SI unit of power is Watt (W). The SI unit of power is different for machines and motor vehicles which are given the term horsepower (hp). Watt is used as the unit of electricity in our daily life.
Power determines how quickly work can be done. Power refers to the rate at which work can be done, so it can be fast or slow. Both power and work are interlinked with each other but the term power is used more often in regular work as compared to the work.
We can calculate the power by using the below formula:
$Power=\frac{Work}{Time\; taken}$
Watt is the measuring unit of power so we can say that 1 watt is the power that does a work of 1 joule in 1 second.
Conclusion
From the above discussion, we have concluded that both work and power are important in terms of science. Both are necessary for daily life. Their meaning and definition are somewhat different in science than what is used in daily life. The term power is used more often than the work.
Author
Deepak Yadav
Aligarh Muslim University, Aligarh
