In physics, force is an influence that which tends to change the motion of an object.Force causes objects to accelerate, add to the object's overall pressure, or change direction.Whenever there is an interaction between two objects, there is a force upon each of the objects.
In the universe are four fundamental forces , the gravity force , the electromagnetic force, the nuclear weak force, and the nuclear strong force.
Force was first mentioned by Archimedes in the 3rd century BC but only mathematically defined by Isaac Newton in the 17th century.
The SI unit for force is the Newton (named after Isaac Newton (1642-1727), British mathematician, physicist, and natural philosopher), which is defined by Newton's second law of motion:
F = ma
where F is the force,
m is the mass of an object,
and a is the acceleration of the object.
The newton (symbol N), is equivalent to kg·m·s-2.The earlier CGS unit is the dyne.
A force of one newton will accelerate a mass of one kilogram at the rate of one meter per second per second.
In traditional English terms, one newton is about 0.224 809 pounds of force (lbf) or 7.233 01 poundals . The newton is also equal to about 0.101 972 kilograms of force (kgf) or kiloponds (kp).
A common unit of force is Kilogram force (kgf). KGF is a unit of force equal to the gravitational force on a mass of one kilogram. One kilogram of force
equals 9.806 65 newtons, or 2.204 622 6 pounds of force in the traditional English system.
The kilogram-force is not a part of the modern SI system, but is still used in applications such as: jet and rocket engines,Draw weight of bowsSpoke tension of bicycles,pressure gauges,Torque wrenches.