Non-conservative Forces

Introduction

Non-conservative Forces

The forces that influence motion are important. Certain forces manifest themselves visibly by altering the speed or direction of motion. Macroscopic motion is converted to microscopic motion by other forces. The law of conservation of energy states that the total energy of a closed system, that is, a system without any external influences, will be conserved. A force can either be conservative or non-conservative. Conservation of energy governs conservative forces. For instance, gravitational force. In contrast, non-conservative forces cause the system to lose mechanical energy. Examples of Non-conservative forces are tension, air resistance, etc. It is possible to calculate motion when conservative and non-conservative forces act based on their potential energies and work performed by the non-conservative forces if energy conservation is used.

Energy conservation 

The definition of conservation in physics refers to something which does not change. When an equation contains a conserved quantity, its variable remains constant. If we have to state the law of conservation of energy, then the law of conservation of energy states that energy cannot be created nor destroyed. However, it can be transformed. Energy conservation governs many electrical and mechanical devices. For instance, the sound energy in a microphone is converted into electric energy.

Whenever a particle is moved from one point to another, a conservative force is used, which does not depend on the particle’s path. Conservation forces rely solely on the particle’s initial and final positions. Gravitational force is one of its examples. Conservative forces conserve energy. Conservative forces follow energy’s Law of Conservation. Nature is full of conservative forces, such as magnetic, gravitational, etc. 

Conservative forces exhibit the following characteristics: 

• The force is independent of the path taken and depends on the starting and ending positions
• Any closed path is subject to a conservative force that does zero work
• A conservative force’s work can be reversed

Object position determines the conservative force. Defining scalar potentials is difficult if the force isn’t conservative since taking different paths would result in conflicting potential differences between the start and endpoints. Conserving mechanical energy is an informal definition of a conservative force. Consider a particle that starts at point A and is acted upon by force F. The particle is redirected by other forces and eventually reaches A again. When the particle passes point A again, it has traveled a closed path again, even if it is still moving. The closed path test passes for F if its net work is zero for this point. A conservative force passes all possible closed path tests. Due to energy conservation, mechanical energy lost by non-conservative forces must be channeled somewhere else. Heat is usually generated when energy is converted, for example, by friction. Besides heat, friction can also produce sound energy.

Knowing what conservative force is, you should also determine what non-conservative force is. Forces like friction are non-conservative. Forces that are non-conservative result in a change in mechanical energy, consisting of potential and kinetic energy. By adding or removing mechanical energy, non-conservative forces accomplish work. For example, friction leads to thermal energy loss, which can never recover fully. In contrast to conservative forces, non-conservative forces have the following properties:

• In addition to being path-dependent, it is also determined by initial and final velocity.
• Any closed path does not have a zero total work from a non-conservative force.
• The work of a non-conservative cannot be reversed.

For instance, a boulder experiencing air resistance force when falling from a cliff. Heat and sound are produced by air resistance, both of which are forms of thermal energy that are released into the air. This is why dissipative forces are sometimes called non-conservative forces. A boulder’s impact creates a deep crater in the ground and more heat and sound due to friction. There is no way the boulder can reclaim heat or sound, nor can the ground heal back to its original form.

When non-conservative forces are acting, mechanical energy might not be conserved. For instance, whenever a car stops due to friction, it loses kinetic energy, which is dispersed as thermal energy, resulting in a loss of mechanical energy. We now turn our attention to how the work-energy theorem behaves when conservative and non-conservative forces are involved. The change in mechanical energy of a system is equal to the amount of work performed by non-conservative forces. According to the Work-energy theorem, the change in kinetic energy equals the net work done on a system. The work done by conservative forces plus non-conservative forces is the net work.

With friction everywhere, converting potential and kinetic energy is not always convenient. Furthermore, any moving object will always generate heat due to non-conservative friction forces. As a result, heat constantly increases, so there will eventually be no more useful energy in the universe.

Conclusion

The law of conservation of energy states that all the energy in a closed system is conserved, that is, a closed system isolated from its surroundings. During a transition between potential and kinetic energy, the total energy of the system is conserved. We examined two types of forces in this article: conservative and non-conservative forces. It’s important to distinguish between conservative and nonconservative forces in physics. Conservative force abides by the law of conservation of energy and does zero work in a closed path. The non-conservative forces, on the other hand, cause the system to lose mechanical energy.