Force
In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. It is measured in the SI unit of newtons and represented by the symbol F.
International Practical Shooting Confederation
The official unit used for the power factor is the imperial unit "kilo grain feet per second" (kgr·ft/s). "Grain feet per second" (gr·ft/s) can be obtained by measuring the "mass" in grain (gr) (equal to pound), and "velocity" in feet per second (ft/s), but since their product yields a very large number it is common to multiply by a factor of , obtaining the power factor in ""kilo" grain feet per second" instead.