Force is a fundamental concept in physics that describes the interaction between two objects. It is defined as a push or pull on an object that can cause it to accelerate, change direction, or deform . The SI unit of force is the newton (N), which is defined as the amount of force required to accelerate a mass of one kilogram at a rate of one meter per second squared .

There are several types of forces that can act on an object, including gravitational, electromagnetic, normal, frictional, and tension forces . Gravitational force is the force that attracts two objects with mass towards each other . Electromagnetic force is the force that arises between electrically charged particles and is responsible for the behavior of electric and magnetic fields . Normal force is the force that acts perpendicular to the surface of an object and prevents it from falling through the surface . Frictional force is the force that opposes the motion of an object when it is in contact with another object . Tension force is the force that is transmitted through a string, rope, or wire when it is pulled tight by forces acting from opposite ends .

The concept of force is central to classical mechanics and is described by Newton’s three laws of motion . The first law states that an object at rest will remain at rest, and an object in motion will remain in motion with a constant velocity unless acted upon by an external force . The second law states that the acceleration of an object is directly proportional to the force applied to it and inversely proportional to its mass . The third law states that for every action, there is an equal and opposite reaction .

In addition to classical mechanics, the concept of force is also important in other areas of physics, such as electromagnetism, thermodynamics, and quantum mechanics . For example, in electromagnetism, the force between two charged particles is described by Coulomb’s law . In thermodynamics, the force that drives heat transfer is described by the temperature gradient . In quantum mechanics, the force between two particles is described by the exchange of virtual particles .

## Force Diagram Physics image