This can also be written in summation notation, The net force on an object is the sum of the forces that act on it (as written above), The first of these laws relates to the superposition of forces. Sir Isaac Newton (1643 - 1727) wrote a set of laws of motion that describe how objects are affected by forces. This is called the superposition of forces. This means that the effect on the motion of the object is the same as if a single force is acting on it.
If forces, , and so on all act on the object, then the total force (the net force) on the object is, When a number of forces act on an object, the overall effect on the object is equal to the vector sum of the forces. Examples of forces that act at a distance are gravity, and electromagnetism. There are also long-range forces that act on objects that are separated. Many forces are the result of direct contact, for example, a person pushing a rock, or pulling a rope that is attached to an object. In SI units, the unit of force is the Newton (N), which is defined as, The unit of force is defined in terms of the units of mass and acceleration. force is a vector quantity, and so it has both magnitude and direction. A force is a measure of the interactions between objects.
In physics, it has a more specific definition. In simple terms, a force is a push or pull.