Conservative and Non Conservative Force

In this article, we will learn about the scientific term force and its effects. Then, we will discuss two types of forces - non-conservative and conservative forces with their examples and their important properties.

• Forces which don’t conserve energy are generally known as non-conservative or dissipative forces.

• Forces whose work depends only on the initial and final positions of the object are said to be conservative forces. Conservative forces do not depend upon the nature of the path drawn between the object’s initial and final positions.

Scientific Concept of Force

Force always plays an important role in Physics. The word force is used to express the push or pull in a particular direction which means the force is the external form of push and pull. Force has both magnitudes as well as directional properties. Following are the few effects of force:

• Force can cause an object to move.

• Force can make a moving object speed up.

• Force can affect the direction of an object.

• The shape of an object can also be changed due to force.

These are some important effects of force which can be felt in our daily life.

What is a Non-Conservative Force?

A non-conservative force is one where the work done on an object by the force depends on the path taken by that object. Mechanical energy may not be conserved during the work done by a non-conservative force.

What is a Conservative Force?

As the name suggests, this force conserves energy and it follows the law of conservation of energy. Conservative force is responsible for energy conservation and the stability of matter. Conservative force is a force wherein the work done by the force on an object only depends on the initial and final position of the object. So, the work done by this force on an object does not depend on the path taken by that object. The work done by this force on an object moving through any closed path equals zero. This is a very important property of conservative force. Another important property is that mechanical energy is conserved during the work done by a conservative force.

Examples of Non-Conservative and Conservative Force

Examples of Non-Conservative Forces

Tension force, rocket propulsion force, motor propulsion force, viscous force, air resistance and the force of friction are a few examples of non-conservative force.

Examples of Conservative Force

Consider that a ball is thrown vertically at height h from the ground. In this case, the gravitational force would become,

F_{g}=mg

Where, F_{g} is the gravitational force and m is the mass of the ball.

g is the acceleration due to gravity.

So, we can say that the work done on this ball is W=-mgh

Now, if the same ball falls down from that same height h , then we can say that the work done on this ball would be W'=mgh

So, total work done on the ball would be W_{Total}=W+W'

Substituting the values of W and W'

W_{Total}=-mgh+mgh=0

From this calculation, we can say that the total work done for the ball travelling from the ground to a height and then falling back to the ground is equal to zero. So, the work done is conserved. Hence, we can say that the gravitational force is a conservative force.

Other good examples of conservative force are magnetic force, elastic force and electrostatic force.

Properties of Non-Conservative and Conservative Force

The following are the properties of non-conservative force:

• Non-conservative force is path-dependent so we can say that it depends on the object’s path.

• The total work done by this non-conservative force is not zero in any closed path.

• The work done by this force is irreversible and there is no potential energy function of frictional force.

• The work done is not recoverable and this force dissipates energy as heat energy.

The following are the properties of conservative force:

• The work done by a conservative force will remain zero in any closed path.

• It is independent of the area covered by an object and depends upon the final and initial position of the object.

• Work done is completely recov