** Energy vs Force **

Force and energy are two fundamental concepts in both classical and relativistic mechanics. It is important to have a clear interpretation of these terms in order to excel in such fields. This article we will discuss the basics of the two concepts, force and energy, their similarities and finally their differences.

**Energy**

Energy is a non-intuitive concept. The term “energy” is derived from the Greek word “energeia” which means operation or activity. In this sense, energy is the mechanism behind an activity. Energy is not a directly observable quantity. But it can be calculated by measuring external properties. Energy can be found in many forms. Kinetic energy, thermal energy and potential energy are to name a few. Energy was thought to be a conserved property in the universe up until the special theory of relativity was developed. The theory of relativity along with quantum mechanics showed that energy and mass are the interchangeable. This gives rise to the energy – mass conservation of the universe. Both of these quantities are two forms of matter. The famous equation E = mc^{2} gives us the amount of energy that can be obtained from m amount of mass. However, when nuclear fusion or nuclear fission is not presented, it can be considered that the energy of a system is conserved. The kinetic energy is the energy that causes the movements of the object; the potential energy arises due to the place where the object is placed, and the thermal energy arises due to temperature.

**Force**

Force is a fundamental concept in all forms of physics. In the most basic sense, there are four fundamental forces. These are gravitational force, electromagnetic force, weak force and strong force. These are also known as interactions and are non-contacting forces. The day to day force we use when pushing an object or doing any work is contact force. It must be noted that forces always act in pairs. The force from object A on object B is equal and opposite to the force from object B on object A. This is known as Newton’s third law of motion. The common interpretation of force is the “ability to do work”. It must be noted that to do work a force is required, but every force does not necessarily do work. To apply a force, an amount of energy is required. This energy is then transferred to the object which the force is acted upon. This force does work on the second object. In this sense, force is a method to transfer energy. The classical mechanics was developed mainly by Sir. Isaac Newton. His three laws of motion are the foundation of all classical mechanics. In the second law, the net force acting upon an object is defined as the rate of change of the momentum of the object.

• Energy is an ability to operate or activate things while force is a method of transferring energy. • Energy and mass of a closed system is conserved, but there is no such conservation for force. • Force is a vector quantity while energy is a scalar. |