Difference Between Work and Power

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Work vs Power

In our day to today life, we use these terms work and energy as randomly as possible. Though people who are not familiar with the scientific meaning of these but most often used for terms related to energy. In this article, we will learn about the major difference between work and power, and we will compare and contrast work and power. To understand the difference between work and power we must first understand the concept of energy in detail. One of the important differences between work and energy is the meaning of these two. We know that work is the energy required to displace an object from its position whereas power is the rate of doing work.


Differences Between Power and Work

Physics has many technical and practical theories, which can be witnessed in day-to-day life, the movements of anybody, or objects. Physics elaborates all the relevant points of movements with respect to nature, force, etc... Science has been considered to be the most practical subject of all time, as it trusts in what is present in the universe and not the hypothetical thought. Science is the oldest concept in the world, it always persisted since the times of early human life to now 21st century, and the only difference could be the acknowledgment of it.

The difference between work and power or the difference between power and work is the amount and rate of energy used. Work and power might appear similar to each other as both involve energy but they have differences, in scientific terms. There are mainly 5 differences between work and power that one should always remember while discussing the terms work and power or if we want to differentiate between work and power.

Before we explain the difference between work and power, let us have a look at what do we mean by the terms work and power individually.


What is Work?

Now, what is work? Work and Energy are the two terms frequently used in everyday life. We know that both work and energy are two interrelated topics that play an important role in the world. Before understanding the scientific meaning of Work in the context of physics, in general, we can say Work is just Energy transferred by force.

Whenever we exert force on an object or a body, it is evident that there will always be some changes, if you push a box placed on the floor it will move, which can be put forward by saying, a force was applied resulting in work. To lift a box or open a closed-door, all we are doing is spending some energy which is depending on the amount of force applied, in other words, the amount of energy required to push the box or lift the box from the ground.


Work Done

Work done is defined as, when an external force is exerted on a body in steady motion (or at rest), it will experience some displacement, this action is termed as the work is done.


Work is said to be done when:

i) There is an external force acting on the object under consideration.

ii) The force must result in displacement, the object should be displaced from its actual position i.e., net displacement should not be zero.


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Work done can be mathematically expressed as follows,

W = Force × displacement

W = F. ds = Fds Cos θ

Where,

F - External force applied

ds - Small displacement

θ - Angle between Force applied and the displacement


What is Power?

Now let us see what is power? So, the power of a source is the rate of doing work. It can be defined as the rate at which energy is consumed. The definition of power in physics is different from how it is used in the context of regular life.

The SI unit of power is Watt (W). In the case of mechanical machines or motor vehicles, the SI unit is different and is measured in horsepower (hp). Watt can be observed in daily life as a unit of electricity as well. This implies that electricity is a form of power. The main benefit of understanding power is, the power of a body decides how quickly work could be done, it is interrelated with work. But power is more used in regular life when compared to work. Power refers to the rate at which work can be done, it can be either slow or fast.


The factors that affect the power of an object is:

  1. The total work is done by the object.

  2. Time consumed in doing that work.

Power is defined as the rate of energy consumed, so when power is calculated it is dependent on the work and how much time has taken to accomplish it.

There is an average power which signifies the energy spent divided by the total time taken. The average amount of work done or energy consumed per unit of time. Therefore, the power can be calculated by using the formula given below:

P = W/t

Where,

W - The total work done

t - Time consumed by the object


After understanding what are work and power individually it is easy to differentiate work from power. Now, let us have look at major work and power difference:


Distinguish Between Work and Power

Sl.No

Work

Power

1. 

Work refers to the amount of energy required to displace an object from one place to another.

Power of the body refers to the energy consumed by the object to displace from one position to another.

2.

Work is defined as the work done by an object is equal to the scalar product of force and displacement.  Mathematically we write:

⇒ W = F•S

Where,

F - The external force exerted on the object.

S - The displacement of the body.

The power of a source is defined as the rate of doing work.  Mathematically, we write:

⇒ P = W/t

Where,

W - The total work done

t - Time consumed by the object

3.

The SI unit of work is given by Joules and it is denoted by J.

The SI unit of power is the watt and it is denoted by W.

4.

Work is the most frequently used concept in our regular living.

Power is a comparatively less used concept but is of the same importance.

5.

Work is independent of time. 

Power is a time-dependent quantity.

6.

The factors that affect the work done by an object is:

  1. Force exerted on the body.

  2. Displacement of the body.

The factors that affect the power of an object is:

  1. The total work is done by the object.

  2. Time consumed in doing that work.


Did You Know:

Power can be altered so to measure the standard power it is either calculated at a given instant of time or by estimating the average power. Some illustrations of power are: 100 Watt power bulbs spend 100 Joules of energy or a car speeding which does work and consumes large amounts of fuel, etc…

FAQs (Frequently Asked Questions)

1. What is the Difference Between Momentum and Inertia?

Ans: The major difference between inertia and momentum is inertia is a term referred to as the state of rest and momentum term refers to the state of motion.

2. What is the Definition of Power and Work?

Ans: Work is defined as the work done by an object is equal to the scalar product of force and displacement and The power of a source is defined as the rate of doing work.

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