Table of Contents

**Introduction:**

Conservative or non-conservative forces exist. Working for a non – conservative force is reliant on the path taken. A nice example of a non-conservative force is friction. The amount of work performed against friction is determined by the distance between the beginning and terminating positions. There really is no potential energy attributed to non-conservative forces because of this dependence on the route. The work performed by a non-conservative force adds or subtracts mechanical energy from a system, which is an important property. Friction, for example, generates thermal energy that fades, depleting the system’s energy. Moreover, even if the thermal energy is captured or kept, it cannot be fully transformed back to work, so it is also lost or unrecoverable in that sense.

**A brief outline:**

- A force is an important determinant in motion. Some forces modify the speed or direction of motion in a visible way.
- Macroscopic motion is converted to microscopic motion by other forces. Any force whose work is contingent on the path traveled since microscopic impacts are based on macroscopic processes is classified as a non-conservative force.
- A non-conservative force, in other words, transforms macroscopic motion into tiny motion. A non-conservative force performs work by taking into account the route traced with the object’s initial and final positions.
- This journey can be in a linear fashion or along a non-straight path. So, if an object does not travel in a straight line, the amount of effort done is determined by the overall path travelled by the object.
- The force used for such operations is referred to as non-conservative force. Friction, air resistance, viscosity, non-elastic material stress, and water drag on a moving boat are all examples of non-conservative forces.

**Important concepts:**

**Mechanical Energy and Non-conservative Forces:**

When non-conservative forces are present, mechanical energy may not have been conserved. When a car comes to a halt on level ground, for example, it loses kinetic energy, which would be wasted as thermal energy, lowering its mechanical energy. A system characterized by non-conservative forces. Non-conservative forces stop a boulder from falling to the ground, dissipating its mechanical energy as thermal energy, sound, and surface distortion. Mechanical energy has been wasted by the rock.

**The Work-Energy Theorem in Action:**

If we look at what the work-energy theorem looks like when both conservative and non-conservative factors are in action. We’ll show that the work done by non-conservative forces is equivalent to the change in a system’s mechanical energy. The work-energy theorem says that the network on a system corresponds to the change in its kinetic energy, or **W _{net} = K E**, as mentioned in Kinetic Energy and the Work-Energy Theorem. The network is the total of non-conservative forces’ work plus conservative forces’ work. That is to say,

**W **_{net}* = ***N _{ c}**

*+***W**

_{c }

*,***W **_{n c}_{ }+ **W **_{c}* = ΔK E *

W _{n c} reflects the amount of work done by all non – conservatives.

The amount of work performed by non-conservative forces adds to a system’s mechanical energy. Mechanical energy is enhanced if W _{n c} is positive. Mechanical energy is reduced when W_{ n c} is negative. It is conserved and non-conservative forces are balanced if W _{n c} is zero. When you push a lawnmower at a constant speed on level ground, for example, the effort you do is eliminated by friction work, and the mower has constant energy.

**Using Non-conservative Forces to Apply Energy Conservation:**

Since there is no alteration in potential energy, utilizing K E i + P E i + W n c = K E f + P E f is similar to trying to apply the work-energy theorem by placing the change in kinetic energy to really be equal to network performed on the system, which involves both conservative and non-conservative forces in the most general case. When looking for a change in total mechanical energy in situations involving both potential and kinetic energy changes, the previous equation,

** K E i+ P E i + W n c = K E f + P E f**

asserts that you might start by monitoring the difference in mechanical energy which would have ultimately resulted from just the conservative forces, including potential energy changes, and then add the work done, with the proper sign, by multiplying by the number of conservative forces.

In a baseball game, here’s a presence of non-conservative forces:

**Normal force**:

When a baseball and a bat collide (macroscopic motion), a sound is produced (microscopic motion)

**Air drag**:

The ball will travel through the air when a baseball player hits it (macroscopic motion). The ball will give air molecules kinetic energy, causing them to vibrate faster. This produces heat (microscopic motion). This is the mechanical equivalent of heat, which turns a fluid’s motion into heat. The sooner the ball dissipates kinetic energy into thermal energy, the more air drag there is.

**Significance of Non – conservative forces in NEET exam:**

Physics is concerned with conservative and non-conservative forces. These topics are covered in the **NEET** test. They are discussed in length in the NCERT textbook for Physics, which is written specifically for the NEET test. From the infinity learn website, students can learn about such concepts as well as the derivation of numerous formulas linked with them. There are also several problems in the chapter’s exercises to help you practice and comprehend the topic’s application. Students can also consult physics textbooks from other publishers.

Infinity learn provides a variety of materials to help people learn each subject in a systematic manner. Students can also use the study materials offered for self-study to learn more about the subject. There are indeed sample question sets that can be used to practice more questions and better prepare for the tests. By enrolling on the website, which is completely free, any student can gain access to these resources. The rest of the study materials are also available for free download.

Also read: **Conservative forces**

**Frequently Asked Questions:**

**Question 1: What would it mean to be a non-conservative force?**

**Answer: **Work for a non-conservative force is dependent on the path. As a result, knowing where the object begins and ends is critical.

**Question 2: Give some non-conservative forces examples.**

**Answer: **Air drag, friction, and rope tension are examples of non-conservative forces.

**Question 3: Give two instances to illustrate the law of energy conservation.**

**Answer: **The following are some examples of energy conservation:

- Mechanical energy is transformed into electric power in a generator.
- Electrical energy is transformed into acoustic energy in a speaker.