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.
Gravimetry
Gravity is usually measured in units of acceleration. In the SI system of units, the standard unit of acceleration is 1 metre per second squared (abbreviated as m/s). Other units include the gal (sometimes known as a "galileo", in either case with symbol Gal), which equals 1 centimetre per second squared, and the "g" ("g"), equal to 9.80665 m/s. The value of the "g" approximately equals the acceleration due to gravity at the Earth's surface (although the value of "g" varies by location).